/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* e-vcard.c
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 * Copyright (C) 2013 Collabora Ltd.
 *
 * This library is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library. If not, see <http://www.gnu.org/licenses/>.
 *
 * Authors: Chris Toshok (toshok@ximian.com)
 *          Philip Withnall <philip.withnall@collabora.co.uk>
 */

/**
 * SECTION:e-vcard
 * @short_description: vCard parsing and interpretation
 * @stability: Stable
 * @include: libebook-contacts/libebook-contacts.h
 *
 * #EVCard is a low-level representation of a vCard, as specified in RFCs
 * 2425 and 2426 (for vCard version 3.0); this class only supports versions 2.1
 * and 3.0 of the vCard standard.
 *
 * A vCard is an unordered set of attributes (otherwise known as properties),
 * each with one or more values. The number of values an attribute has is
 * determined by its type, and is given in the specification. Each attribute may
 * also have zero or more named parameters, which provide metadata about its
 * value.
 *
 * For example, the following line from a vCard:
 * |[
 * ADR;TYPE=WORK:;;100 Waters Edge;Baytown;LA;30314;United States of America
 * ]|
 * is an <code>ADR</code> attribute with 6 values giving the different
 * components of the postal address. It has one parameter, <code>TYPE</code>,
 * which specifies that it’s a work address rather than a home address.
 *
 * Using the #EVCard API, this data is accessible as follows:
 * <example>
 * <title>Accessing a Multi-Valued Attribute</title>
 * <programlisting>
 * EVCard *vcard;
 * EVCardAttribute *attr;
 * GList *param_values, *values;
 *
 * vcard = e_vcard_new_from_string (
 *    "BEGIN:VCARD\n"
 *    "VERSION:3.0\n"
 *    "ADR;TYPE=WORK:;;100 Waters Edge;Baytown;LA;30314;United States of America\n"
 *    "END:VCARD\n");
 * attr = e_vcard_get_attribute (vcard, "ADR");
 *
 * g_assert_cmpstr (e_vcard_attribute_get_name (attr), ==, "ADR");
 * g_assert_true (e_vcard_attribute_is_single_valued (attr) == FALSE);
 *
 * param_values = e_vcard_attribute_get_param (attr, "TYPE");
 * g_assert_cmpuint (g_list_length (param_values), ==, 1);
 * g_assert_cmpstr (param_values->data, ==, "WORK");
 *
 * values = e_vcard_attribute_get_values (attr);
 * g_assert_cmpuint (g_list_length (values), ==, 6);
 * g_assert_cmpstr (values->data, ==, "");
 * g_assert_cmpstr (values->next->data, ==, "100 Waters Edge");
 * g_assert_cmpstr (values->next->next->data, ==, "Baytown");
 * /<!-- -->* etc. *<!-- -->/
 *
 * g_object_unref (vcard);
 * </programlisting>
 * </example>
 *
 * If a second <code>ADR</code> attribute was present in the vCard, the above
 * example would only ever return the first attribute. To access the values of
 * other attributes of the same type, the entire attribute list must be iterated
 * over using e_vcard_get_attributes(), then matching on
 * e_vcard_attribute_get_name().
 *
 * vCard attribute values may be encoded in the vCard source, using base-64 or
 * quoted-printable encoding. Such encoded values are automatically decoded when
 * parsing the vCard, so the values returned by e_vcard_attribute_get_value()
 * do not need further decoding. The ‘decoded’ functions,
 * e_vcard_attribute_get_value_decoded() and
 * e_vcard_attribute_get_values_decoded() are only relevant when adding
 * attributes which use pre-encoded values and have their <code>ENCODING</code>
 * parameter set.
 *
 * String comparisons in #EVCard are almost universally case-insensitive.
 * Attribute names, parameter names and parameter values are all compared
 * case-insensitively. Only attribute values are case sensitive.
 *
 * #EVCard implements lazy parsing of its vCard data, so the first time its
 * attributes are accessed may take slightly longer than normal to allow for the
 * vCard to be parsed. This can be tested by calling e_vcard_is_parsed().
 */

/* This file implements the decoding of the v-card format
 * http://www.imc.org/pdi/vcard-21.txt
 */

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include "e-vcard.h"

#define d(x)

#define CRLF "\r\n"

static EVCardAttribute *e_vcard_attribute_ref (EVCardAttribute *attr);
static void e_vcard_attribute_unref (EVCardAttribute *attr);
static EVCardAttributeParam *e_vcard_attribute_param_ref (EVCardAttributeParam *param);
static void e_vcard_attribute_param_unref (EVCardAttributeParam *param);

/* Encoding used in v-card
 * Note: v-card spec defines additional 7BIT 8BIT and X- encoding
 */
typedef enum {
	EVC_ENCODING_RAW,    /* no encoding */
	EVC_ENCODING_BASE64, /* base64 */
	EVC_ENCODING_QP      /* quoted-printable */
} EVCardEncoding;

struct _EVCardPrivate {
	GList *attributes;
	gchar *vcard;
};

struct _EVCardAttribute {
	gint ref_count;
	gchar  *group;
	gchar  *name;
	GList *params; /* EVCardParam */
	GList *values;
	GList *decoded_values;
	EVCardEncoding encoding;
	gboolean encoding_set;
};

struct _EVCardAttributeParam {
	gint ref_count;
	gchar     *name;
	GList    *values;  /* GList of gchar *'s */
};

G_DEFINE_TYPE_WITH_PRIVATE (EVCard, e_vcard, G_TYPE_OBJECT)

G_DEFINE_BOXED_TYPE (EVCardAttribute, e_vcard_attribute, e_vcard_attribute_ref, e_vcard_attribute_unref)

G_DEFINE_BOXED_TYPE (EVCardAttributeParam, e_vcard_attribute_param, e_vcard_attribute_param_ref, e_vcard_attribute_param_unref)

static void
vcard_finalize (GObject *object)
{
	EVCardPrivate *priv;

	priv = E_VCARD (object)->priv;

	/* Directly access priv->attributes and don't call
	 * e_vcard_ensure_attributes(), since it is pointless
	 * to start vCard parsing that late. */
	g_list_free_full (
		priv->attributes, (GDestroyNotify) e_vcard_attribute_free);

	g_free (priv->vcard);

	/* Chain up to parent's finalize() method. */
	G_OBJECT_CLASS (e_vcard_parent_class)->finalize (object);
}

static void
e_vcard_class_init (EVCardClass *class)
{
	GObjectClass *object_class;

	object_class = G_OBJECT_CLASS (class);
	object_class->finalize = vcard_finalize;
}

static void
e_vcard_init (EVCard *evc)
{
	evc->priv = e_vcard_get_instance_private (evc);
}

static EVCardAttribute *
e_vcard_attribute_new_take (gchar *attr_group,
			    gchar *attr_name)
{
	EVCardAttribute *attr;

	attr = g_slice_new0 (EVCardAttribute);

	if (attr_group && !*attr_group) {
		g_free (attr_group);
		attr_group = NULL;
	}

	attr->ref_count = 1;
	attr->group = attr_group;
	attr->name = attr_name;

	return attr;
}

static gboolean
e_vcard_attribute_is_singlevalue_type (EVCardAttribute *attr)
{
	g_return_val_if_fail (attr != NULL, FALSE);

	return g_ascii_strcasecmp (attr->name, EVC_KEY) == 0 ||
		g_ascii_strcasecmp (attr->name, EVC_LOGO) == 0 ||
		g_ascii_strcasecmp (attr->name, EVC_PHOTO) == 0 ||
		g_ascii_strcasecmp (attr->name, "SOUND") == 0 ||
		g_ascii_strcasecmp (attr->name, "TZ") == 0;
}

/* Case insensitive version of strstr */
static gchar *
strstr_nocase (const gchar *haystack,
               const gchar *needle)
{
/* When _GNU_SOURCE is available, use the nonstandard extension of libc */
#ifdef _GNU_SOURCE
	g_return_val_if_fail (haystack, NULL);
	g_return_Val_if_fail (needle, NULL);

	return strcasestr (haystack, needle)
#else
/* Otherwise convert both, haystack and needle to lowercase and use good old strstr */
	gchar *l_haystack;
	gchar *l_needle;
	gchar *pos;

	g_return_val_if_fail (haystack, NULL);
	g_return_val_if_fail (needle, NULL);

	l_haystack = g_ascii_strdown (haystack, -1);
	l_needle = g_ascii_strdown (needle, -1);
	pos = strstr (l_haystack, l_needle);

	/* Get actual position of the needle in the haystack instead of l_haystack or
	 * leave it NULL */
	if (pos)
		pos = (gchar *)(haystack + (pos - l_haystack));

	g_free (l_haystack);
	g_free (l_needle);

	return pos;
#endif
}

/*  Skip newline characters and return the next character.
 *  This function takes care of folding lines, skipping
 *  newline characters if found, taking care of equal characters
 *  and other strange things.
 */
static gchar *
skip_newline (gchar *str,
              gboolean quoted_printable)
{
	gchar *p;
	gchar *next;
	gchar *next2;
	p = str;

	/* -- swallow equal signs at end of line for quoted printable */
	/* note: a quoted_printable linefolding is an equal sign followed by
	 * one or more newline characters and optional a whitespace */
	if (quoted_printable && *p == '=' ) {
		next = g_utf8_next_char (p);
		if (*next == '\r' || *next == '\n') {
			p = g_utf8_next_char (next); /* swallow equal and newline */

			if ((*p == '\r' || *p == '\n') && *p != *next ) {
				p = g_utf8_next_char (p); /* swallow second newline */

				if (*p == ' ' || *p == '\t') {
					p = g_utf8_next_char (p); /* swallow whitespace */
				}
			}

		}

	/* -- swallow newline and (if present) following whitespaces */
	} else if (*p == '\r' || *p == '\n') {

		next = g_utf8_next_char (p);
		if ((*next == '\n' || *next == '\r') && *p != *next) {

			next2 = g_utf8_next_char (next);
			if (*next2 == ' ' || *next2 == '\t') {
				p = g_utf8_next_char (next2); /* we found a line folding */
			}

		} else if (*next == ' ' || *next == '\t') {
			p = g_utf8_next_char (next);  /* we found a line folding */
		}
	}

	return p;
}

/* skip forward until we hit the CRLF, or \0 */
static void
skip_to_next_line (gchar **p)
{
	gchar *lp = *p;

	while (*lp != '\n' && *lp != '\r' && *lp != '\0')
		lp = g_utf8_next_char (lp);

	/* -- skip over the endline */
	while (*lp == '\r' || *lp == '\n') {
		lp = g_utf8_next_char (lp);
	}

	*p = lp;
}

/* skip forward until we hit a character in @s, CRLF, or \0.  leave *p
 * pointing at the character that causes us to stop */
static void
skip_until (gchar **p,
            const gchar *s)
{
	gchar *lp;

	lp = *p;

	while (*lp != '\r' && *lp != '\0') {
		gboolean s_matches = FALSE;
		const gchar *ls;
		for (ls = s; *ls; ls = g_utf8_next_char (ls)) {
			if (g_utf8_get_char (ls) == g_utf8_get_char (lp)) {
				s_matches = TRUE;
				break;
			}
		}

		if (s_matches)
			break;
		lp = g_utf8_next_char (lp);
	}

	*p = lp;
}

static void
read_attribute_value (EVCardAttribute *attr,
                      gchar **p,
                      gboolean quoted_printable,
                      const gchar *charset)
{
	gchar *lp = *p;
	const gchar *chunk_start = NULL;
	GString *str;

	#define WRITE_CHUNK() G_STMT_START { \
		if (chunk_start) { \
			g_string_append_len (str, chunk_start, lp - chunk_start); \
			chunk_start = NULL; \
		} } G_STMT_END

	/* read in the value */
	str = g_string_sized_new (16);
	for (lp = skip_newline ( *p, quoted_printable);
	     *lp != '\n' && *lp != '\r' && *lp != '\0';
	     lp = skip_newline ( lp, quoted_printable ) ) {

		if (*lp == '=' && quoted_printable) {
			gunichar a, b;

			WRITE_CHUNK ();

			/* it's for the '=' */
			lp++;
			lp = skip_newline (lp, quoted_printable);

			a = g_utf8_get_char (lp);
			lp = g_utf8_next_char (lp);
			if (a == '\0')
				break;

			lp = skip_newline (lp, quoted_printable);

			b = g_utf8_get_char (lp);
			if (b == '\0')
				break;
			lp = g_utf8_next_char (lp);

			if (g_unichar_isxdigit (a) && g_unichar_isxdigit (b)) {
				gchar c;

				gint a_bin = g_unichar_xdigit_value (a);
				gint b_bin = g_unichar_xdigit_value (b);

				c = (a_bin << 4) | b_bin;

				g_string_append_c (str, c); /* add decoded byte (this is not a unicode yet) */
			} else {
				g_string_append_c (str, '=');
				g_string_insert_unichar (str, -1, a);
				g_string_insert_unichar (str, -1, b);
			}
		} else if (*lp == '\\') {
			WRITE_CHUNK ();

			/* convert back to the non-escaped version of
			 * the characters */
			lp = g_utf8_next_char (lp);
			if (*lp == '\0') {
				g_string_append_c (str, '\\');
				break;
			}

			/* beware, there might be a line break due to folding,
			 * need next real character
			 */
			lp = skip_newline (lp, quoted_printable);

			switch (*lp) {
			case 'n': g_string_append_c (str, '\n'); break;
			case 'N': g_string_append_c (str, '\n'); break;
			case 'r': g_string_append_c (str, '\r'); break;
			case 'R': g_string_append_c (str, '\r'); break;
			case ';': g_string_append_c (str, ';'); break;
			case ',': g_string_append_c (str, ','); break;
			case '\\': g_string_append_c (str, '\\'); break;
			default:
				g_warning ("invalid escape, passing it through");
				g_string_append_c (str, '\\');
				chunk_start = lp;
				break;
			}
			lp = g_utf8_next_char (lp);
		}
		else if ((*lp == ';' && !e_vcard_attribute_is_singlevalue_type (attr)) ||
			 (*lp == ',' && !g_ascii_strcasecmp (attr->name, "CATEGORIES"))) {
			WRITE_CHUNK ();
			if (charset) {
				gchar *tmp;

				tmp = g_convert (str->str, str->len, "UTF-8", charset, NULL, NULL, NULL);
				if (tmp) {
					g_string_assign (str, tmp);
					g_free (tmp);
				}
			}

			e_vcard_attribute_add_value (attr, str->str);
			g_string_set_size (str, 0);
			lp = g_utf8_next_char (lp);
		}
		else {
			if (!chunk_start)
				chunk_start = lp;

			lp = g_utf8_next_char (lp);
		}

		if (*lp == '\n' || *lp == '\r')
			WRITE_CHUNK ();
	}

	WRITE_CHUNK ();

	#undef WRITE_CHUNK

	if (str) {
		if (charset) {
			gchar *tmp;

			tmp = g_convert (str->str, str->len, "UTF-8", charset, NULL, NULL, NULL);
			if (tmp) {
				g_string_assign (str, tmp);
				g_free (tmp);
			}
		}

		e_vcard_attribute_add_value (attr, str->str);
		g_string_free (str, TRUE);
	}

	skip_to_next_line ( &lp );

	*p = lp;
}

static void
read_attribute_params (EVCardAttribute *attr,
                       gchar **p,
                       gboolean *quoted_printable,
                       gchar **charset)
{
	gchar *lp;
	const gchar *chunk_start = NULL;
	GString *str;
	EVCardAttributeParam *param = NULL;
	gboolean in_quote = FALSE;

	#define WRITE_CHUNK() G_STMT_START { \
		if (chunk_start) { \
			g_string_append_len (str, chunk_start, lp - chunk_start); \
			chunk_start = NULL; \
		} } G_STMT_END

	str = g_string_sized_new (16);
	for (lp = skip_newline ( *p, *quoted_printable);
	     *lp != '\n' && *lp != '\r' && *lp != '\0';
	     lp = skip_newline ( lp, *quoted_printable ) ) {
		gunichar uc;

		if (*lp == '"') {
			WRITE_CHUNK ();

			in_quote = !in_quote;
			lp = g_utf8_next_char (lp);
		} else  if (uc = g_utf8_get_char (lp), in_quote || *lp == '-' || *lp == '_' || g_unichar_isalnum (uc)) {
			WRITE_CHUNK ();

			g_string_insert_unichar (str, -1, uc);
			lp = g_utf8_next_char (lp);
		}
		/* accumulate until we hit the '=' or ';'.  If we hit
		 * a '=' the string contains the parameter name.  if
		 * we hit a ';' the string contains the parameter
		 * value and the name is either ENCODING (if value ==
		 * QUOTED-PRINTABLE) or TYPE (in any other case.)
		 */
		else if (*lp == '=') {
			WRITE_CHUNK ();

			if (str->len > 0) {
				param = e_vcard_attribute_param_new (str->str);
				g_string_set_size (str, 0);
				lp = g_utf8_next_char (lp);
			}
			else {
				skip_until (&lp, ":;");
				if (*lp == ';') {
					lp = g_utf8_next_char (lp);

				} else if (*lp == ':') {
					/* do nothing */

				} else {
					skip_to_next_line ( &lp );
					break;
				}
			}
		}
		else if (*lp == ';' || *lp == ':' || *lp == ',') {
			gboolean colon = (*lp == ':');
			gboolean comma = (*lp == ',');

			WRITE_CHUNK ();

			if (param) {
				if (str->len > 0) {
					e_vcard_attribute_param_add_value (param, str->str);
					g_string_set_size (str, 0);
					if (!colon)
						lp = g_utf8_next_char (lp);
				}
				else {
					/* we've got a parameter of the form:
					 * PARAM=(.*,)?[:;]
					 * so what we do depends on if there are already values
					 * for the parameter.  If there are, we just finish
					 * this parameter and skip past the offending character
					 * (unless it's the ':'). If there aren't values, we free
					 * the parameter then skip past the character.
					 */
					if (!param->values) {
						e_vcard_attribute_param_free (param);
						param = NULL;
						if (!colon)
							lp = g_utf8_next_char (lp);
					} else if (!colon) {
						lp = g_utf8_next_char (lp);
					}
				}

				if (param
				    && !g_ascii_strcasecmp (param->name, "encoding")
				    && !g_ascii_strcasecmp (param->values->data, "quoted-printable")) {
					*quoted_printable = TRUE;
					e_vcard_attribute_param_free (param);
					param = NULL;
				} else if (param
				    && !g_ascii_strcasecmp (param->name, "charset")
				    && g_ascii_strcasecmp (param->values->data, "utf-8") != 0) {
					g_free (*charset);
					*charset = g_strdup (param->values->data);
					e_vcard_attribute_param_free (param);
					param = NULL;
				}
			}
			else {
				if (str->len > 0) {
					const gchar *param_name;
					if (!g_ascii_strcasecmp (str->str,
								 "quoted-printable")) {
						param_name = "ENCODING";
						*quoted_printable = TRUE;
					}
					/* apple's broken addressbook app outputs naked BASE64
					 * parameters, which aren't even vcard 3.0 compliant. */
					else if (!g_ascii_strcasecmp (str->str,
								      "base64")) {
						param_name = "ENCODING";
						g_string_assign (str, "b");
					}
					else {
						param_name = "TYPE";
					}

					param = e_vcard_attribute_param_new (param_name);
					e_vcard_attribute_param_add_value (param, str->str);
					g_string_set_size (str, 0);
					if (!colon)
						lp = g_utf8_next_char (lp);
				}
				else {
					/* we've got an attribute with a truly empty
					 * attribute parameter.  So it's of the form:
					 *
					 * ATTR;[PARAM=value;]*;[PARAM=value;]*:
					 *
					 * (note the extra ';')
					 *
					 * the only thing to do here is, well.. nothing.
					 * we skip over the character if it's not a colon,
					 * and the rest is handled for us: We'll either
					 * continue through the loop again if we hit a ';',
					 * or we'll break out correct below if it was a ':' */
					if (!colon)
						lp = g_utf8_next_char (lp);
				}
			}
			if (param && !comma) {
				e_vcard_attribute_add_param (attr, param);
				param = NULL;
			}
			if (colon)
				break;
		} else if (param) {
			/* reading param value, which is SAFE-CHAR, aka
			 * any character except CTLs, DQUOTE, ";", ":", "," */
			if (!chunk_start)
				chunk_start = lp;

			lp = g_utf8_next_char (lp);
		} else {
			g_warning ("invalid character (%c/0x%02x) found in parameter spec (%s)", *lp, *lp, lp);
			chunk_start = NULL;
			g_string_set_size (str, 0);
			/*			skip_until (&lp, ":;"); */

			skip_to_next_line ( &lp );
		}

		if (*lp == '\n' || *lp == '\r')
			WRITE_CHUNK ();
	}

	#undef WRITE_CHUNK

	if (str)
		g_string_free (str, TRUE);

	*p = lp;
}

/* reads an entire attribute from the input buffer, leaving p pointing
 * at the start of the next line (past the \r\n) */
static EVCardAttribute *
read_attribute (gchar **p)
{
	gchar *attr_group = NULL;
	gchar *attr_name = NULL;
	EVCardAttribute *attr = NULL;
	GString *str;
	gchar *lp;
	gboolean is_qp = FALSE;
	gchar *charset = NULL;

	/* first read in the group/name */
	str = g_string_sized_new (16);
	for (lp = skip_newline ( *p, is_qp);
	     *lp != '\n' && *lp != '\r' && *lp != '\0';
	     lp = skip_newline ( lp, is_qp ) ) {
		gunichar uc;

		if (*lp == ':' || *lp == ';') {
			if (str->len != 0) {
				/* we've got a name, break out to the value/attribute parsing */
				attr_name = g_string_free (str, FALSE);
				break;
			}
			else {
				/* a line of the form:
				 * (group.)?[:;]
				 *
				 * since we don't have an attribute
				 * name, skip to the end of the line
				 * and try again.
				 */
				g_string_free (str, TRUE);
				*p = lp;
				skip_to_next_line (p);
				goto lose;
			}
		}
		else if (*lp == '.') {
			if (attr_group) {
				g_warning (
					"extra `.' in attribute specification.  ignoring extra group `%s'",
					str->str);
				g_string_set_size (str, 0);
			}
			if (str->len != 0) {
				attr_group = g_string_free (str, FALSE);
				str = g_string_sized_new (16);
			}
		}
		else if (uc = g_utf8_get_char (lp), *lp == '-' || *lp == '_' || g_unichar_isalnum (uc)) {
			g_string_insert_unichar (str, -1, uc);
		}
		else {
			g_warning ("invalid character found in attribute group/name");
			g_string_free (str, TRUE);
			*p = lp;
			skip_to_next_line (p);
			goto lose;
		}

		lp = g_utf8_next_char (lp);
	}

	if (!attr_name) {
		skip_to_next_line (p);
		goto lose;
	}

	/* This consumes (takes) both strings */
	attr = e_vcard_attribute_new_take (attr_group, attr_name);

	if (*lp == ';') {
		/* skip past the ';' */
		lp = g_utf8_next_char (lp);
		read_attribute_params (attr, &lp, &is_qp, &charset);
		if (is_qp)
			attr->encoding = EVC_ENCODING_RAW;
	}
	if (*lp == ':') {
		/* skip past the ':' */
		lp = g_utf8_next_char (lp);
		read_attribute_value (attr, &lp, is_qp, charset);
	}

	g_free (charset);

	*p = lp;

	if (!attr->values)
		goto lose;

	return attr;
 lose:
	if (attr)
		e_vcard_attribute_free (attr);
	return NULL;
}

/* Stolen from glib/glib/gconvert.c */
static gchar *
make_valid_utf8 (const gchar *name)
{
	GString *string;
	const gchar *remainder, *invalid;
	gint remaining_bytes, valid_bytes;

	string = NULL;
	remainder = name;
	remaining_bytes = strlen (name);

	while (remaining_bytes != 0) {
		if (g_utf8_validate (remainder, remaining_bytes, &invalid))
			break;
	      valid_bytes = invalid - remainder;

		if (string == NULL)
			string = g_string_sized_new (remaining_bytes);

		g_string_append_len (string, remainder, valid_bytes);
		/* append U+FFFD REPLACEMENT CHARACTER */
		g_string_append (string, "\357\277\275");

		remaining_bytes -= valid_bytes + 1;
		remainder = invalid + 1;
	}

	if (string == NULL)
		return g_strdup (name);

	g_string_append (string, remainder);

	g_return_val_if_fail (g_utf8_validate (string->str, -1, NULL), g_string_free (string, TRUE));

	return g_string_free (string, FALSE);
}

/* we try to be as forgiving as we possibly can here - this isn't a
 * validator.  Almost nothing is considered a fatal error.  We always
 * try to return *something*.
 */
static void
parse (EVCard *evc,
       const gchar *str,
       gboolean ignore_uid)
{
	gchar *buf;
	gchar *p;
	EVCardAttribute *attr;

	buf = make_valid_utf8 (str);

	d (printf ("BEFORE FOLDING:\n"));
	d (printf (str));
	d (printf ("\n\nAFTER FOLDING:\n"));
	d (printf (buf));

	p = buf;

	attr = read_attribute (&p);
	if (!attr || attr->group || g_ascii_strcasecmp (attr->name, "begin")) {
		g_warning ("vcard began without a BEGIN:VCARD\n");
	}
	if (attr && !g_ascii_strcasecmp (attr->name, "begin")) {
		e_vcard_attribute_free (attr);
		attr = NULL;
	} else if (attr) {
		if ((!ignore_uid || g_ascii_strcasecmp (attr->name, EVC_UID) != 0) &&
		    g_ascii_strcasecmp (attr->name, "end") != 0)
			e_vcard_add_attribute (evc, attr);
	}
	while (*p) {
		EVCardAttribute *next_attr = read_attribute (&p);

		if (next_attr) {
			attr = next_attr;

			if (g_ascii_strcasecmp (next_attr->name, "end") == 0)
				break;

			if (ignore_uid && g_ascii_strcasecmp (attr->name, EVC_UID) == 0) {
				e_vcard_attribute_free (attr);
				attr = NULL;
				continue;
			}

			e_vcard_add_attribute (evc, next_attr);
		}
	}

	if (!attr || attr->group || g_ascii_strcasecmp (attr->name, "end")) {
		g_warning ("vcard ended without END:VCARD\n");
	}

	if (attr && !g_ascii_strcasecmp (attr->name, "end"))
		e_vcard_attribute_free (attr);

	g_free (buf);

	evc->priv->attributes = g_list_reverse (evc->priv->attributes);
}

static GList *
e_vcard_ensure_attributes (EVCard *evc)
{
	if (evc->priv->vcard) {
		gboolean have_uid = (evc->priv->attributes != NULL);
		gchar *vcs = evc->priv->vcard;

		/* detach vCard to avoid loops */
		evc->priv->vcard = NULL;

		/* Parse the vCard */
		parse (evc, vcs, have_uid);
		g_free (vcs);
	}

	return evc->priv->attributes;
}

static gchar *
e_vcard_escape_semicolons (const gchar *s)
{
	GString *str;
	const gchar *p;

	if (s)
		str = g_string_sized_new (strlen (s));
	else
		str = g_string_new ("");

	for (p = s; p && *p; p++) {
		if (*p == ';')
			g_string_append_c (str, '\\');

		g_string_append_c (str, *p);
	}

	return g_string_free (str, FALSE);
}

/**
 * e_vcard_escape_string:
 * @s: the string to escape
 *
 * Escapes a string according to RFC2426, section 5.
 *
 * Returns: (transfer full): A newly allocated, escaped string.
 **/
gchar *
e_vcard_escape_string (const gchar *s)
{
	GString *str;
	const gchar *p;

	if (s)
		str = g_string_sized_new (strlen (s));
	else
		str = g_string_new ("");

	/* Escape a string as described in RFC2426, section 5 */
	for (p = s; p && *p; p++) {
		switch (*p) {
		case '\n':
			g_string_append (str, "\\n");
			break;
		case '\r':
			if (*(p + 1) == '\n')
				p++;
			g_string_append (str, "\\n");
			break;
		case ';':
			g_string_append (str, "\\;");
			break;
		case ',':
			g_string_append (str, "\\,");
			break;
		case '\\':
			g_string_append (str, "\\\\");
			break;
		default:
			g_string_append_c (str, *p);
			break;
		}
	}

	return g_string_free (str, FALSE);
}

/**
 * e_vcard_unescape_string:
 * @s: the string to unescape
 *
 * Unescapes a string according to RFC2426, section 5.
 *
 * Returns: (transfer full): A newly allocated, unescaped string.
 **/
gchar *
e_vcard_unescape_string (const gchar *s)
{
	GString *str;
	const gchar *p;

	g_return_val_if_fail (s != NULL, NULL);

	str = g_string_sized_new (strlen (s));

	/* Unescape a string as described in RFC2426, section 5 */
	for (p = s; *p; p++) {
		if (*p == '\\') {
			p++;
			if (*p == '\0') {
				g_string_append_c (str, '\\');
				break;
			}
			switch (*p) {
			case 'n':  g_string_append_c (str, '\n'); break;
			case 'r':  g_string_append_c (str, '\r'); break;
			case ';':  g_string_append_c (str, ';'); break;
			case ',':  g_string_append_c (str, ','); break;
			case '\\': g_string_append_c (str, '\\'); break;
			default:
				g_warning ("invalid escape, passing it through");
				g_string_append_c (str, '\\');
				g_string_append_c (str, *p);
				break;
			}
		} else {
			g_string_append_c (str, *p);
		}
	}

	return g_string_free (str, FALSE);
}

/**
 * e_vcard_construct:
 * @evc: an existing #EVCard
 * @str: a vCard string
 *
 * Constructs the existing #EVCard, @evc, setting its vCard data to @str.
 *
 * This modifies @evc.
 */
void
e_vcard_construct (EVCard *evc,
                   const gchar *str)
{
	e_vcard_construct_with_uid (evc, str, NULL);
}

/**
 * e_vcard_construct_with_uid:
 * @evc: an existing #EVCard
 * @str: a vCard string
 * @uid: (nullable): a unique ID string
 *
 * Constructs the existing #EVCard, @evc, setting its vCard data to @str, and
 * adding a new UID attribute with the value given in @uid (if @uid is
 * non-%NULL).
 *
 * This modifies @evc.
 *
 * Since: 3.4
 **/
void
e_vcard_construct_with_uid (EVCard *evc,
                            const gchar *str,
                            const gchar *uid)
{
	e_vcard_construct_full (evc, str, -1, uid);
}

/**
 * e_vcard_construct_full:
 * @evc: an existing #EVCard
 * @str: a vCard string
 * @len: length of @str, or -1 if @str is %NULL terminated
 * @uid: (nullable): a unique ID string
 *
 * Similar to e_vcard_construct_with_uid(), but can also
 * be used with an @str that is not %NULL terminated.
 *
 * Since: 3.12
 **/
void
e_vcard_construct_full (EVCard *evc,
                        const gchar *str,
                        gssize len,
                        const gchar *uid)
{
	g_return_if_fail (E_IS_VCARD (evc));
	g_return_if_fail (str != NULL);
	g_return_if_fail (evc->priv->vcard == NULL);
	g_return_if_fail (evc->priv->attributes == NULL);

	/* Lazy construction */
	if (*str) {

		if (len < 0)
			evc->priv->vcard = g_strdup (str);
		else
			evc->priv->vcard = g_strndup (str, len);
	}

	/* Add UID attribute */
	if (uid) {
		EVCardAttribute *attr;

		attr = e_vcard_attribute_new (NULL, EVC_UID);
		e_vcard_attribute_add_value (attr, uid);

		evc->priv->attributes = g_list_prepend (evc->priv->attributes, attr);
	}
}

/**
 * e_vcard_new:
 *
 * Creates a new, blank #EVCard.
 *
 * Returns: (transfer full): A new, blank #EVCard.
 **/
EVCard *
e_vcard_new (void)
{
	return e_vcard_new_from_string ("");
}

/**
 * e_vcard_new_from_string:
 * @str: a string representation of the vcard to create
 *
 * Creates a new #EVCard from the passed-in string
 * representation.
 *
 * Returns: (transfer full): A new #EVCard.
 **/
EVCard *
e_vcard_new_from_string (const gchar *str)
{
	EVCard *evc;

	g_return_val_if_fail (str != NULL, NULL);

	evc = g_object_new (E_TYPE_VCARD, NULL);

	e_vcard_construct (evc, str);

	return evc;
}

static gchar *
e_vcard_qp_encode (const gchar *txt,
                   gboolean can_wrap)
{
	const gchar *p = txt;
	GString *escaped = g_string_sized_new (strlen (txt));
	gint count = 0;

	while (*p != '\0') {
		if ((*p >= 33 && *p <= 60) || (*p >= 62 && *p <= 126)) {
			if (can_wrap && count == 75) {
				g_string_append (escaped, "=" CRLF " ");
				count = 1; /* 1 for space needed for folding */
			}

			g_string_append_c (escaped, *p++);
			count++;

			continue;
		}

		if (count >= 73 && can_wrap) {
			g_string_append (escaped, "=" CRLF " ");
			count = 1; /* 1 for space needed for folding */
		}

		g_string_append_printf (escaped, "=%2.2X", (guchar) *p++);
		count += 3;
	}

	return g_string_free (escaped, FALSE);
}

static gchar *
e_vcard_qp_decode (const gchar *txt)
{
	const gchar *inptr;
	gchar *decoded, *outptr;

	if (!txt)
		return NULL;

	decoded = g_malloc (sizeof (gchar) * strlen (txt) + 1);

	outptr = decoded;

	for (inptr = txt; *inptr; inptr++) {
		gchar c = *inptr;

		if (c == '=' && (inptr[1] == '\r' || inptr[1] == '\n')) {
			/* soft line-break */
			if (inptr[2] == '\n')
				inptr++;
			inptr++;
			continue;
		}

		if (c == '=' && inptr[1] && inptr[2]) {
			guchar a = toupper (inptr[1]), b = toupper (inptr[2]);
			if (isxdigit (a) && isxdigit (b)) {
				*outptr++ = (((a >= 'A' ? a - 'A' + 10 : a - '0') & 0x0f) << 4)
					   | ((b >= 'A' ? b - 'A' + 10 : b - '0') & 0x0f);
			} else {
				*outptr++ = '=';
				*outptr++ = inptr[1];
				*outptr++ = inptr[2];
			}

			inptr += 2;
		} else {
			*outptr++ = *inptr;
		}
	}

	*outptr = '\0';

	return decoded;
}

static GHashTable *
generate_dict_validator (const gchar *words)
{
	GHashTable *dict = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
	gchar **list = g_strsplit (words, ",", 0);
	gint i;

	for (i = 0; list[i]; i++)
		g_hash_table_insert (dict, list[i], NULL);

	g_free (list);

	return dict;
}

static gchar *
e_vcard_to_string_vcard_21 (EVCard *evc)
{
	GList *l, *v;
	GString *str = g_string_new ("");
	GHashTable *evc_prop = generate_dict_validator (E_VCARD_21_VALID_PROPERTIES);
	GHashTable *evc_params = generate_dict_validator (E_VCARD_21_VALID_PARAMETERS);

	g_string_append (str, "BEGIN:VCARD" CRLF);
	g_string_append (str, "VERSION:2.1" CRLF);

	for (l = e_vcard_ensure_attributes (evc); l; l = l->next) {
		GList *list;
		EVCardAttribute *attr = l->data;
		GString *attr_str;
		gboolean empty, encode;
		gchar *upper_name;

		if (g_ascii_strcasecmp (attr->name, "VERSION") == 0)
			continue;

		upper_name = g_ascii_strup (attr->name, -1);
		/* Checking whether current property (attribute) is valid for vCard 2.1 */
		if (!g_hash_table_lookup_extended (evc_prop, upper_name, NULL, NULL)) {
			g_free (upper_name);

			continue;
		}
		g_free (upper_name);

		empty = TRUE; /* Empty fields should be omitted -- some headsets may choke on it */
		encode = FALSE; /* Generally only new line MUST be encoded (Quoted Printable) */

		for (v = attr->values; v; v = v->next) {
			gchar *value = v->data;

			if (value && *value)
				empty = FALSE;
			else
				continue;

			if (strstr (value, "\n") != NULL) {
				encode = TRUE;
				break;
			}
		}

		if (empty)
			continue;

		attr_str = g_string_sized_new (strlen (attr->name) + (attr->group ? strlen (attr->group) + 1 : 0));

		/* From vCard 2.1 spec page 27, 28
		 *
		 * contentline  = [group "."] name *(";" param) ":" value CRLF
		 */

		if (attr->group) {
			g_string_append (attr_str, attr->group);
			g_string_append_c (attr_str, '.');
		}
		g_string_append (attr_str, attr->name);

		/* handle the parameters */
		for (list = attr->params; list; list = list->next) {
			EVCardAttributeParam *param = list->data;

			/* Page 28
			 *
			 * param        = param-name "=" param-value
			 */

			upper_name = g_ascii_strup (param->name, -1);
			/* Checking whether current parameter is valid for vCard 2.1 */
			if (!g_hash_table_lookup_extended (evc_params, upper_name, NULL, NULL)) {
				g_free (upper_name);

				continue;
			}
			g_free (upper_name);

			g_string_append_c (attr_str, ';');
			g_string_append (attr_str, param->name);
			if (!param->values)
				continue;

			for (v = param->values; v; v = v->next) {
				gchar *value = v->data;
				gchar *escaped_value = e_vcard_escape_semicolons (value);

				g_string_append_printf (attr_str, "=%s", escaped_value);

				if (v->next)
					g_string_append_printf (attr_str, ";%s", param->name);

				g_free (escaped_value);
			}
		}

		if (encode)
			g_string_append (attr_str, ";ENCODING=QUOTED-PRINTABLE");

		g_string_append_c (attr_str, ':');

		for (v = attr->values; v; v = v->next) {
			gchar *value = v->data;

			if (encode) {
				gchar *escaped_value;

				escaped_value = e_vcard_qp_encode (value, TRUE);
				g_string_append (attr_str, escaped_value);

				g_free (escaped_value);
			} else
				g_string_append (attr_str, value);

			if (v->next)
				g_string_append_c (attr_str, ';');
		}

		g_string_append (attr_str, CRLF);

		g_string_append (str, attr_str->str);

		g_string_free (attr_str, TRUE);
	}

	g_string_append (str, "END:VCARD");

	g_hash_table_destroy (evc_params);
	g_hash_table_destroy (evc_prop);

	return g_string_free (str, FALSE);
}

static gchar *
e_vcard_to_string_vcard_30 (EVCard *evc)
{
	GList *l;
	GList *v;

	GString *str = g_string_new ("");

	g_string_append (str, "BEGIN:VCARD" CRLF);

	/* we hardcode the version (since we're outputting to a
	 * specific version) and ignore any version attributes the
	 * vcard might contain */
	g_string_append (str, "VERSION:3.0" CRLF);

	for (l = e_vcard_ensure_attributes (evc); l; l = l->next) {
		GList *list;
		EVCardAttribute *attr = l->data;
		GString *attr_str;
		glong len;
		EVCardAttributeParam *quoted_printable_param = NULL;

		if (!g_ascii_strcasecmp (attr->name, "VERSION"))
			continue;

		attr_str = g_string_sized_new (strlen (attr->name) + (attr->group ? strlen (attr->group) + 1 : 0));

		/* From rfc2425, 5.8.2
		 *
		 * contentline  = [group "."] name *(";" param) ":" value CRLF
		 */

		if (attr->group) {
			g_string_append (attr_str, attr->group);
			g_string_append_c (attr_str, '.');
		}
		g_string_append (attr_str, attr->name);

		/* handle the parameters */
		for (list = attr->params; list; list = list->next) {
			EVCardAttributeParam *param = list->data;

			/* quoted-printable encoding was eliminated in 3.0,
			 * thus decode the value before saving and remove the param later */
			if (!quoted_printable_param &&
			    param->values && param->values->data && !param->values->next &&
			    g_ascii_strcasecmp (param->name, "ENCODING") == 0 &&
			    g_ascii_strcasecmp (param->values->data, "quoted-printable") == 0) {
				quoted_printable_param = param;
				/* do not store it */
				continue;
			}

			/* 5.8.2:
			 * param        = param-name "=" param-value *("," param-value)
			 */
			g_string_append_c (attr_str, ';');
			g_string_append (attr_str, param->name);
			if (param->values) {
				g_string_append_c (attr_str, '=');

				for (v = param->values; v; v = v->next) {
					gchar *value = v->data;
					gchar *pval = value;
					gboolean quotes = FALSE;
					while (pval && *pval) {
						if (!g_unichar_isalnum (g_utf8_get_char (pval))) {
							quotes = TRUE;
							break;
						}
						pval = g_utf8_next_char (pval);
					}

					if (quotes) {
						gint i;

						g_string_append_c (attr_str, '"');

						for (i = 0; value[i]; i++) {
							/* skip quotes in quoted string; it is not allowed */
							if (value[i] == '\"')
								continue;

							g_string_append_c (attr_str, value[i]);
						}

						g_string_append_c (attr_str, '"');
					} else
						g_string_append (attr_str, value);

					if (v->next)
						g_string_append_c (attr_str, ',');
				}
			}
		}

		g_string_append_c (attr_str, ':');

		for (v = attr->values; v; v = v->next) {
			gchar *value = v->data;
			gchar *escaped_value = NULL;

			/* values are in quoted-printable encoding, but this cannot be used in vCard 3.0,
			 * thus it needs to be converted first */
			if (quoted_printable_param) {
				gchar *qp_decoded;

				qp_decoded = e_vcard_qp_decode (value);

				/* replace the actual value with the decoded */
				g_free (value);
				value = qp_decoded;
				v->data = value;
			}

			escaped_value = e_vcard_escape_string (value);

			g_string_append (attr_str, escaped_value);
			if (v->next) {
				/* XXX toshok - i hate you, rfc 2426.
				 * why doesn't CATEGORIES use a; like
				 * a normal list attribute? */
				if (!g_ascii_strcasecmp (attr->name, "CATEGORIES"))
					g_string_append_c (attr_str, ',');
				else
					g_string_append_c (attr_str, ';');
			}

			g_free (escaped_value);
		}

		/* 5.8.2:
		 * When generating a content line, lines longer than 75
		 * characters SHOULD be folded
		 */
		len = g_utf8_strlen (attr_str->str, -1);
		if (len > 75) {
			GString *fold_str = g_string_sized_new (attr_str->len + len / 74 * 3);
			gchar *pos1 = attr_str->str;
			gchar *pos2 = pos1;
			pos2 = g_utf8_offset_to_pointer (pos2, 75);
			len -= 75;

			while (1) {
				g_string_append_len (fold_str, pos1, pos2 - pos1);
				g_string_append (fold_str, CRLF " ");
				pos1 = pos2;
				if (len <= 74)
					break;
				pos2 = g_utf8_offset_to_pointer (pos2, 74);
				len -= 74;
			}
			g_string_append (fold_str, pos1);
			g_string_free (attr_str, TRUE);
			attr_str = fold_str;
		}
		g_string_append (attr_str, CRLF);

		g_string_append (str, attr_str->str);
		g_string_free (attr_str, TRUE);

		/* remove the encoding parameter, to not decode multiple times */
		if (quoted_printable_param)
			e_vcard_attribute_remove_param (attr, quoted_printable_param->name);
	}

	g_string_append (str, "END:VCARD");

	return g_string_free (str, FALSE);
}

/**
 * e_vcard_to_string:
 * @evc: the #EVCard to export
 * @format: the format to export to
 *
 * Exports @evc to a string representation, specified
 * by the @format argument.
 *
 * Returns: (transfer full): A newly allocated string representing the vcard.
 **/
gchar *
e_vcard_to_string (EVCard *evc,
                   EVCardFormat format)
{
	g_return_val_if_fail (E_IS_VCARD (evc), NULL);

	switch (format) {
	case EVC_FORMAT_VCARD_21:
		if (evc->priv->vcard && evc->priv->attributes == NULL &&
		    strstr_nocase (evc->priv->vcard, CRLF "VERSION:2.1" CRLF))
			return g_strdup (evc->priv->vcard);

		return e_vcard_to_string_vcard_21 (evc);
	case EVC_FORMAT_VCARD_30:
		if (evc->priv->vcard && evc->priv->attributes == NULL &&
		    strstr_nocase (evc->priv->vcard, CRLF "VERSION:3.0" CRLF))
			return g_strdup (evc->priv->vcard);

		return e_vcard_to_string_vcard_30 (evc);
	default:
		g_warning ("invalid format specifier passed to e_vcard_to_string");
		return g_strdup ("");
	}
}

/**
 * e_vcard_dump_structure:
 * @evc: the #EVCard to dump
 *
 * Prints a dump of @evc's structure to stdout. Used for
 * debugging.
 **/
void
e_vcard_dump_structure (EVCard *evc)
{
	GList *a;
	GList *v;
	gint i;

	g_return_if_fail (E_IS_VCARD (evc));

	printf ("vCard\n");
	for (a = e_vcard_ensure_attributes (evc); a; a = a->next) {
		GList *p;
		EVCardAttribute *attr = a->data;
		printf ("+-- %s\n", attr->name);
		if (attr->params) {
			printf ("    +- params=\n");

			for (p = attr->params, i = 0; p; p = p->next, i++) {
				EVCardAttributeParam *param = p->data;
				printf ("    |   [%d] = %s", i,param->name);
				printf ("(");
				for (v = param->values; v; v = v->next) {
					gchar *value = e_vcard_escape_string ((gchar *) v->data);
					printf ("%s", value);
					if (v->next)
						printf (",");
					g_free (value);
				}

				printf (")\n");
			}
		}
		printf ("    +- values=\n");
		for (v = attr->values, i = 0; v; v = v->next, i++) {
			printf ("        [%d] = `%s'\n", i, (gchar *) v->data);
		}
	}
}

/**
 * e_vcard_attribute_new:
 * @attr_group: (nullable): a group name
 * @attr_name: an attribute name
 *
 * Creates a new #EVCardAttribute with the specified group and
 * attribute names. The @attr_group may be %NULL or the empty string if no
 * group is needed.
 *
 * Returns: (transfer full): A new #EVCardAttribute.
 **/
EVCardAttribute *
e_vcard_attribute_new (const gchar *attr_group,
                       const gchar *attr_name)
{
	return e_vcard_attribute_new_take ((attr_group && *attr_group) ? g_strdup (attr_group) : NULL, g_strdup (attr_name));
}

/**
 * e_vcard_attribute_free:
 * @attr: (transfer full): attribute to free
 *
 * Frees an attribute, its values and its parameters.
 **/
void
e_vcard_attribute_free (EVCardAttribute *attr)
{
	g_return_if_fail (attr != NULL);

	e_vcard_attribute_unref (attr);
}

static EVCardAttribute *
e_vcard_attribute_ref (EVCardAttribute *attr)
{
	g_return_val_if_fail (attr != NULL, NULL);

	g_atomic_int_inc (&attr->ref_count);

	return attr;
}

static void
e_vcard_attribute_unref (EVCardAttribute *attr)
{
	g_return_if_fail (attr != NULL);

	if (g_atomic_int_dec_and_test (&attr->ref_count)) {
		g_free (attr->group);
		g_free (attr->name);

		e_vcard_attribute_remove_values (attr);

		e_vcard_attribute_remove_params (attr);

		g_slice_free (EVCardAttribute, attr);
	}
}

/**
 * e_vcard_attribute_copy:
 * @attr: attribute to copy
 *
 * Makes a copy of @attr.
 *
 * Returns: (transfer full): A new #EVCardAttribute identical to @attr.
 **/
EVCardAttribute *
e_vcard_attribute_copy (EVCardAttribute *attr)
{
	EVCardAttribute *a;
	GList *p;

	g_return_val_if_fail (attr != NULL, NULL);

	a = e_vcard_attribute_new (attr->group, attr->name);

	for (p = attr->values; p; p = p->next)
		e_vcard_attribute_add_value (a, p->data);

	for (p = attr->params; p; p = p->next)
		e_vcard_attribute_add_param (a, e_vcard_attribute_param_copy (p->data));

	return a;
}

/**
 * e_vcard_remove_attributes:
 * @evc: vcard object
 * @attr_group: (nullable): group name of attributes to be removed
 * @attr_name: name of the arributes to be removed
 *
 * Removes all the attributes with group name and attribute name equal to the
 * passed in values. If @attr_group is %NULL or an empty string,
 * it removes all the attributes with passed in name irrespective of
 * their group names.
 **/
void
e_vcard_remove_attributes (EVCard *evc,
                           const gchar *attr_group,
                           const gchar *attr_name)
{
	GList *attr;

	g_return_if_fail (E_IS_VCARD (evc));
	g_return_if_fail (attr_name != NULL);

	attr = e_vcard_ensure_attributes (evc);
	while (attr) {
		GList *next_attr;
		EVCardAttribute *a = attr->data;

		next_attr = attr->next;

		if (((!attr_group || *attr_group == '\0') ||
		     (attr_group && !g_ascii_strcasecmp (attr_group, a->group))) &&
		    ((!a->name) || !g_ascii_strcasecmp (attr_name, a->name))) {

			/* matches, remove/delete the attribute */
			evc->priv->attributes = g_list_delete_link (evc->priv->attributes, attr);

			e_vcard_attribute_free (a);
		}

		attr = next_attr;
	}
}

/**
 * e_vcard_remove_attribute:
 * @evc: an #EVCard
 * @attr: (transfer full): an #EVCardAttribute to remove
 *
 * Removes @attr from @evc and frees it. This takes ownership of @attr.
 **/
void
e_vcard_remove_attribute (EVCard *evc,
                          EVCardAttribute *attr)
{
	g_return_if_fail (E_IS_VCARD (evc));
	g_return_if_fail (attr != NULL);

	/* No need to call e_vcard_ensure_attributes() here. It has
	 * already been called if this is a valid call and attr is among
	 * our attributes. */
	evc->priv->attributes = g_list_remove (evc->priv->attributes, attr);
	e_vcard_attribute_free (attr);
}

/**
 * e_vcard_append_attribute:
 * @evc: an #EVCard
 * @attr: (transfer full): an #EVCardAttribute to append
 *
 * Appends @attr to @evc to the end of a list of attributes. This takes
 * ownership of @attr.
 *
 * Since: 2.32
 **/
void
e_vcard_append_attribute (EVCard *evc,
                          EVCardAttribute *attr)
{
	g_return_if_fail (E_IS_VCARD (evc));
	g_return_if_fail (attr != NULL);

	/* Handle UID special case:
	 * No need to parse the vcard to append an UID attribute */
	if (evc->priv->vcard != NULL && attr->name != NULL &&
	    g_ascii_strcasecmp (attr->name, EVC_UID) == 0) {
		evc->priv->attributes = g_list_append (evc->priv->attributes, attr);
	} else {
		evc->priv->attributes = g_list_append (e_vcard_ensure_attributes (evc), attr);
	}
}

/**
 * e_vcard_append_attribute_with_value:
 * @evcard: an #EVCard
 * @attr: (transfer full): an #EVCardAttribute to append
 * @value: a value to assign to the attribute
 *
 * Appends @attr to @evcard, setting it to @value. This takes ownership of
 * @attr.
 *
 * This is a convenience wrapper around e_vcard_attribute_add_value() and
 * e_vcard_append_attribute().
 *
 * Since: 2.32
 **/
void
e_vcard_append_attribute_with_value (EVCard *evcard,
                                     EVCardAttribute *attr,
                                     const gchar *value)
{
	g_return_if_fail (E_IS_VCARD (evcard));
	g_return_if_fail (attr != NULL);

	e_vcard_attribute_add_value (attr, value);

	e_vcard_append_attribute (evcard, attr);
}

/**
 * e_vcard_append_attribute_with_values:
 * @evcard: an @EVCard
 * @attr: (transfer full): an #EVCardAttribute to append
 * @...: a %NULL-terminated list of values to assign to the attribute
 *
 * Appends @attr to @evcard, assigning the list of values to it. This takes
 * ownership of @attr.
 *
 * This is a convenience wrapper around e_vcard_attribute_add_value() and
 * e_vcard_append_attribute().
 *
 * Since: 2.32
 **/
void
e_vcard_append_attribute_with_values (EVCard *evcard,
                                      EVCardAttribute *attr,
                                      ...)
{
	va_list ap;
	gchar *v;

	g_return_if_fail (E_IS_VCARD (evcard));
	g_return_if_fail (attr != NULL);

	va_start (ap, attr);

	while ((v = va_arg (ap, gchar *))) {
		e_vcard_attribute_add_value (attr, v);
	}

	va_end (ap);

	e_vcard_append_attribute (evcard, attr);
}

/**
 * e_vcard_add_attribute:
 * @evc: an #EVCard
 * @attr: (transfer full): an #EVCardAttribute to add
 *
 * Prepends @attr to @evc. This takes ownership of @attr.
 **/
void
e_vcard_add_attribute (EVCard *evc,
                       EVCardAttribute *attr)
{
	g_return_if_fail (E_IS_VCARD (evc));
	g_return_if_fail (attr != NULL);

	/* Handle UID special case:
	 * No need to parse the vcard to append an UID attribute */
	if (evc->priv->vcard != NULL && attr->name != NULL &&
	    g_ascii_strcasecmp (attr->name, EVC_UID) == 0) {
		evc->priv->attributes = g_list_prepend (evc->priv->attributes, attr);
	} else {
		evc->priv->attributes = g_list_prepend (e_vcard_ensure_attributes (evc), attr);
	}
}

/**
 * e_vcard_add_attribute_with_value:
 * @evcard: an #EVCard
 * @attr: (transfer full): an #EVCardAttribute to add
 * @value: a value to assign to the attribute
 *
 * Prepends @attr to @evcard, setting it to @value. This takes ownership of
 * @attr.
 *
 * This is a convenience wrapper around e_vcard_attribute_add_value() and
 * e_vcard_add_attribute().
 **/
void
e_vcard_add_attribute_with_value (EVCard *evcard,
                                  EVCardAttribute *attr,
                                  const gchar *value)
{
	g_return_if_fail (E_IS_VCARD (evcard));
	g_return_if_fail (attr != NULL);

	e_vcard_attribute_add_value (attr, value);

	e_vcard_add_attribute (evcard, attr);
}

/**
 * e_vcard_add_attribute_with_values:
 * @evcard: an @EVCard
 * @attr: (transfer full): an #EVCardAttribute to add
 * @...: a %NULL-terminated list of values to assign to the attribute
 *
 * Prepends @attr to @evcard, assigning the list of values to it. This takes
 * ownership of @attr.
 *
 * This is a convenience wrapper around e_vcard_attribute_add_value() and
 * e_vcard_add_attribute().
 **/
void
e_vcard_add_attribute_with_values (EVCard *evcard,
                                   EVCardAttribute *attr,
                                   ...)
{
	va_list ap;
	gchar *v;

	g_return_if_fail (E_IS_VCARD (evcard));
	g_return_if_fail (attr != NULL);

	va_start (ap, attr);

	while ((v = va_arg (ap, gchar *))) {
		e_vcard_attribute_add_value (attr, v);
	}

	va_end (ap);

	e_vcard_add_attribute (evcard, attr);
}

/**
 * e_vcard_attribute_add_value:
 * @attr: an #EVCardAttribute
 * @value: a string value
 *
 * Appends @value to @attr's list of values.
 **/
void
e_vcard_attribute_add_value (EVCardAttribute *attr,
                             const gchar *value)
{
	g_return_if_fail (attr != NULL);

	attr->values = g_list_append (attr->values, g_strdup (value));
}

/**
 * e_vcard_attribute_add_value_decoded:
 * @attr: an #EVCardAttribute
 * @value: an encoded value
 * @len: the length of the encoded value, in bytes
 *
 * Encodes @value according to the encoding used for @attr, and appends it to
 * @attr's list of values.
 *
 * This should only be used if the #EVCardAttribute has a non-raw encoding (i.e.
 * if it’s encoded in base-64 or quoted-printable encoding).
 **/
void
e_vcard_attribute_add_value_decoded (EVCardAttribute *attr,
                                     const gchar *value,
                                     gint len)
{
	g_return_if_fail (attr != NULL);

	switch (attr->encoding) {
	case EVC_ENCODING_RAW:
		g_warning ("can't add_value_decoded with an attribute using RAW encoding.  you must set the ENCODING parameter first");
		break;
	case EVC_ENCODING_BASE64: {
		gchar *b64_data = g_base64_encode ((guchar *) value, len);
		GString *decoded = g_string_new_len (value, len);

		/* make sure the decoded list is up to date */
		e_vcard_attribute_get_values_decoded (attr);

		d (printf ("base64 encoded value: %s\n", b64_data));
		d (printf ("original length: %d\n", len));

		attr->values = g_list_append (attr->values, b64_data);
		attr->decoded_values = g_list_append (attr->decoded_values, decoded);
		break;
	}
	case EVC_ENCODING_QP: {
		GString *decoded = g_string_new_len (value, len);
		gchar *qp_data = e_vcard_qp_encode (decoded->str, FALSE);

		/* make sure the decoded list is up to date */
		e_vcard_attribute_get_values_decoded (attr);

		d (printf ("qp encoded value: %s\n", qp_data));
		d (printf ("original length: %d\n", len));

		attr->values = g_list_append (attr->values, qp_data);
		attr->decoded_values = g_list_append (attr->decoded_values, decoded);
		break;
	}
	}
}

/**
 * e_vcard_attribute_add_values:
 * @attr: an #EVCardAttribute
 * @...: a %NULL-terminated list of strings
 *
 * Appends a list of values to @attr.
 **/
void
e_vcard_attribute_add_values (EVCardAttribute *attr,
                              ...)
{
	va_list ap;
	gchar *v;

	g_return_if_fail (attr != NULL);

	va_start (ap, attr);

	while ((v = va_arg (ap, gchar *))) {
		e_vcard_attribute_add_value (attr, v);
	}

	va_end (ap);
}

static void
free_gstring (GString *str)
{
	g_string_free (str, TRUE);
}

/**
 * e_vcard_attribute_remove_values:
 * @attr: an #EVCardAttribute
 *
 * Removes and frees all values from @attr.
 **/
void
e_vcard_attribute_remove_values (EVCardAttribute *attr)
{
	g_return_if_fail (attr != NULL);

	g_list_foreach (attr->values, (GFunc) g_free, NULL);
	g_list_free (attr->values);
	attr->values = NULL;

	g_list_foreach (attr->decoded_values, (GFunc) free_gstring, NULL);
	g_list_free (attr->decoded_values);
	attr->decoded_values = NULL;
}

/**
 * e_vcard_attribute_remove_value:
 * @attr: an #EVCardAttribute
 * @s: a value to remove
 *
 * Removes value @s from the value list in @attr. The value @s is not freed.
 **/
void
e_vcard_attribute_remove_value (EVCardAttribute *attr,
                                const gchar *s)
{
	GList *l;

	g_return_if_fail (attr != NULL);
	g_return_if_fail (s != NULL);

	l = g_list_find_custom (attr->values, s, (GCompareFunc) strcmp);
	if (l == NULL) {
		return;
	}

	attr->values = g_list_delete_link (attr->values, l);
}

/**
 * e_vcard_attribute_remove_param:
 * @attr: an #EVCardAttribute
 * @param_name: a parameter name
 *
 * Removes and frees parameter @param_name from the attribute @attr. Parameter
 * names are guaranteed to be unique, so @attr is guaranteed to have no
 * parameters named @param_name after this function returns.
 *
 * Since: 1.12
 */
void
e_vcard_attribute_remove_param (EVCardAttribute *attr,
                                const gchar *param_name)
{
	GList *l;
	EVCardAttributeParam *param;

	g_return_if_fail (attr != NULL);
	g_return_if_fail (param_name != NULL);

	for (l = attr->params; l; l = l->next) {
		param = l->data;
		if (g_ascii_strcasecmp (e_vcard_attribute_param_get_name (param),
					param_name) == 0) {
			if (g_ascii_strcasecmp (param_name, EVC_ENCODING) == 0) {
				attr->encoding_set = FALSE;
				attr->encoding = EVC_ENCODING_RAW;
			}

			attr->params = g_list_delete_link (attr->params, l);
			e_vcard_attribute_param_free (param);
			break;
		}
	}
}

/**
 * e_vcard_attribute_remove_params:
 * @attr: an #EVCardAttribute
 *
 * Removes and frees all parameters from @attr.
 *
 * This also resets the #EVCardAttribute's encoding back to raw.
 **/
void
e_vcard_attribute_remove_params (EVCardAttribute *attr)
{
	g_return_if_fail (attr != NULL);

	g_list_foreach (attr->params, (GFunc) e_vcard_attribute_param_free, NULL);
	g_list_free (attr->params);
	attr->params = NULL;

	/* also remove the cached encoding on this attribute */
	attr->encoding_set = FALSE;
	attr->encoding = EVC_ENCODING_RAW;
}

/**
 * e_vcard_attribute_param_new:
 * @name: the name of the new parameter
 *
 * Creates a new parameter named @name.
 *
 * Returns: (transfer full): A new #EVCardAttributeParam.
 **/
EVCardAttributeParam *
e_vcard_attribute_param_new (const gchar *name)
{
	EVCardAttributeParam *param = g_slice_new (EVCardAttributeParam);

	param->ref_count = 1;
	param->values = NULL;
	param->name = g_strdup (name);

	return param;
}

/**
 * e_vcard_attribute_param_free:
 * @param: (transfer full): an #EVCardAttributeParam
 *
 * Frees @param and its values.
 **/
void
e_vcard_attribute_param_free (EVCardAttributeParam *param)
{
	g_return_if_fail (param != NULL);

	e_vcard_attribute_param_unref (param);
}

static EVCardAttributeParam *
e_vcard_attribute_param_ref (EVCardAttributeParam *param)
{
	g_return_val_if_fail (param != NULL, NULL);

	g_atomic_int_inc (&param->ref_count);

	return param;
}

static void
e_vcard_attribute_param_unref (EVCardAttributeParam *param)
{
	g_return_if_fail (param != NULL);

	if (g_atomic_int_dec_and_test (&param->ref_count)) {
		g_free (param->name);

		e_vcard_attribute_param_remove_values (param);

		g_slice_free (EVCardAttributeParam, param);
	}
}

/**
 * e_vcard_attribute_param_copy:
 * @param: an #EVCardAttributeParam
 *
 * Makes a copy of @param and all its values.
 *
 * Returns: (transfer full): a new #EVCardAttributeParam identical to @param.
 **/
EVCardAttributeParam *
e_vcard_attribute_param_copy (EVCardAttributeParam *param)
{
	EVCardAttributeParam *p;
	GList *l;

	g_return_val_if_fail (param != NULL, NULL);

	p = e_vcard_attribute_param_new (e_vcard_attribute_param_get_name (param));

	for (l = param->values; l; l = l->next) {
		e_vcard_attribute_param_add_value (p, l->data);
	}

	return p;
}

/**
 * e_vcard_attribute_add_param:
 * @attr: an #EVCardAttribute
 * @param: (transfer full): an #EVCardAttributeParam to add
 *
 * Prepends @param to @attr's list of parameters. This takes ownership of
 * @param (and all its values).
 *
 * Duplicate parameters have their values merged, so that all parameter names
 * in @attr are unique. Values are also merged so that uniqueness is preserved.
 **/
void
e_vcard_attribute_add_param (EVCardAttribute *attr,
                             EVCardAttributeParam *param)
{
	gboolean contains;
	GList *params, *p;
	const gchar *par_name;

	g_return_if_fail (attr != NULL);
	g_return_if_fail (param != NULL);

	contains = FALSE;
	params = attr->params;
	par_name = param->name;

	for (p = params; p; p = p->next) {
		EVCardAttributeParam *param2 = p->data;
		if (g_ascii_strcasecmp (param2->name, par_name) == 0) {
			/* param2 has same name as our new param;
			 * better merge them than have more parameters
			 * with same name within one attribute.
			*/
			GList *vals,*v;

			vals = param->values;

			for (v = vals; v; v = v->next) {
				const gchar *my_value;
				GList *vals2,*v2;

				my_value = (const gchar *) v->data;
				vals2 = param2->values;

				for (v2 = vals2; v2; v2 = v2->next) {
					if (g_ascii_strcasecmp ((const gchar *) v2->data, my_value) == 0) {
						break;
					}
				}

				if (!v2) {
					/* we did loop through all values and none of them was my_value */
					e_vcard_attribute_param_add_value (param2, my_value);
				}
			}

			contains = TRUE;
			break;
		}
	}

	if (!contains) {
		attr->params = g_list_prepend (attr->params, param);
	}

	/* we handle our special encoding stuff here */

	if (!g_ascii_strcasecmp (param->name, EVC_ENCODING)) {
		if (attr->encoding_set) {
			g_warning ("ENCODING specified twice");
			if (contains) {
				e_vcard_attribute_param_free (param);
			}
			return;
		}

		if (param->values && param->values->data) {
			if (!g_ascii_strcasecmp ((gchar *) param->values->data, "b") ||
			    !g_ascii_strcasecmp ((gchar *) param->values->data, "BASE64"))
				attr->encoding = EVC_ENCODING_BASE64;
			else if (!g_ascii_strcasecmp ((gchar *) param->values->data, EVC_QUOTEDPRINTABLE))
				attr->encoding = EVC_ENCODING_QP;
			else {
				g_warning (
					"Unknown value `%s' for ENCODING parameter.  values will be treated as raw",
					(gchar *) param->values->data);
			}

			attr->encoding_set = TRUE;
		}
		else {
			g_warning ("ENCODING parameter added with no value");
		}
	}

	if (contains) {
		e_vcard_attribute_param_free (param);
	}
}

/**
 * e_vcard_attribute_param_add_value:
 * @param: an #EVCardAttributeParam
 * @value: a string value to add
 *
 * Appends @value to @param's list of values.
 **/
void
e_vcard_attribute_param_add_value (EVCardAttributeParam *param,
                                   const gchar *value)
{
	g_return_if_fail (param != NULL);

	param->values = g_list_append (param->values, g_strdup (value));
}

/**
 * e_vcard_attribute_param_add_values:
 * @param: an #EVCardAttributeParam
 * @...: a %NULL-terminated list of strings
 *
 * Appends a list of values to @param.
 **/
void
e_vcard_attribute_param_add_values (EVCardAttributeParam *param,
                                    ...)
{
	va_list ap;
	gchar *v;

	g_return_if_fail (param != NULL);

	va_start (ap, param);

	while ((v = va_arg (ap, gchar *))) {
		e_vcard_attribute_param_add_value (param, v);
	}

	va_end (ap);
}

/**
 * e_vcard_attribute_add_param_with_value:
 * @attr: an #EVCardAttribute
 * @param: (transfer full): an #EVCardAttributeParam
 * @value: a string value
 *
 * Appends @value to @param, then prepends @param to @attr. This takes ownership
 * of @param, but not of @value.
 *
 * This is a convenience method for e_vcard_attribute_param_add_value() and
 * e_vcard_attribute_add_param().
 **/
void
e_vcard_attribute_add_param_with_value (EVCardAttribute *attr,
                                        EVCardAttributeParam *param,
                                        const gchar *value)
{
	g_return_if_fail (attr != NULL);
	g_return_if_fail (param != NULL);

	e_vcard_attribute_param_add_value (param, value);

	e_vcard_attribute_add_param (attr, param);
}

/**
 * e_vcard_attribute_add_param_with_values:
 * @attr: an #EVCardAttribute
 * @param: (transfer full): an #EVCardAttributeParam
 * @...: a %NULL-terminated list of strings
 *
 * Appends the list of values to @param, then prepends @param to @attr. This
 * takes ownership of @param, but not of the list of values.
 *
 * This is a convenience method for e_vcard_attribute_param_add_value() and
 * e_vcard_attribute_add_param().
 **/
void
e_vcard_attribute_add_param_with_values (EVCardAttribute *attr,
                                         EVCardAttributeParam *param, ...)
{
	va_list ap;
	gchar *v;

	g_return_if_fail (attr != NULL);
	g_return_if_fail (param != NULL);

	va_start (ap, param);

	while ((v = va_arg (ap, gchar *))) {
		e_vcard_attribute_param_add_value (param, v);
	}

	va_end (ap);

	e_vcard_attribute_add_param (attr, param);
}

/**
 * e_vcard_attribute_param_remove_values:
 * @param: an #EVCardAttributeParam
 *
 * Removes and frees all values from @param.
 **/
void
e_vcard_attribute_param_remove_values (EVCardAttributeParam *param)
{
	g_return_if_fail (param != NULL);

	g_list_foreach (param->values, (GFunc) g_free, NULL);
	g_list_free (param->values);
	param->values = NULL;
}

/**
 * e_vcard_attribute_remove_param_value:
 * @attr: an #EVCardAttribute
 * @param_name: a parameter name
 * @s: a value
 *
 * Removes the value @s from the parameter @param_name on the attribute @attr.
 * If @s was the only value for parameter @param_name, that parameter is removed
 * entirely from @attr and freed.
 **/
void
e_vcard_attribute_remove_param_value (EVCardAttribute *attr,
                                      const gchar *param_name,
                                      const gchar *s)
{
	GList *l, *params;
	EVCardAttributeParam *param;

	g_return_if_fail (attr != NULL);
	g_return_if_fail (param_name != NULL);
	g_return_if_fail (s != NULL);

	params = e_vcard_attribute_get_params (attr);

	for (l = params; l; l = l->next) {
		param = l->data;
		if (g_ascii_strcasecmp (e_vcard_attribute_param_get_name (param), param_name) == 0) {
			l = g_list_find_custom (param->values, s, (GCompareFunc) g_ascii_strcasecmp);
			if (l == NULL) {
				return;
			}

			g_free (l->data);
			param->values = g_list_delete_link (param->values, l);

			if (param->values == NULL) {
				e_vcard_attribute_param_free (param);
				attr->params = g_list_remove (attr->params, param);
			}
			break;
		}
	}
	return;
}

/**
 * e_vcard_get_attributes:
 * @evcard: an #EVCard
 *
 * Gets the list of all attributes from @evcard. The list and its
 * contents are owned by @evcard, and must not be freed.
 *
 * Returns: (transfer none) (element-type EVCardAttribute): A list of attributes
 * of type #EVCardAttribute.
 **/
GList *
e_vcard_get_attributes (EVCard *evcard)
{
	g_return_val_if_fail (E_IS_VCARD (evcard), NULL);

	return e_vcard_ensure_attributes (evcard);
}

/**
 * e_vcard_get_attribute:
 * @evc: an #EVCard
 * @name: the name of the attribute to get
 *
 * Get the attribute @name from @evc.  The #EVCardAttribute is owned by
 * @evcard and should not be freed. If the attribute does not exist, %NULL is
 * returned.
 *
 * <note><para>This will only return the <emphasis>first</emphasis> attribute
 * with the given @name. To get other attributes of that name (for example,
 * other <code>TEL</code> attributes if a contact has multiple telephone
 * numbers), use e_vcard_get_attributes() and iterate over the list searching
 * for matching attributes.</para>
 * <para>This method iterates over all attributes in the #EVCard, so should not
 * be called often. If extracting a large number of attributes from a vCard, it
 * is more efficient to iterate once over the list returned by
 * e_vcard_get_attributes().</para></note>
 *
 * Returns: (transfer none) (nullable): An #EVCardAttribute if found, or %NULL.
 **/
EVCardAttribute *
e_vcard_get_attribute (EVCard *evc,
                       const gchar *name)
{
	GList *attrs, *l;
	EVCardAttribute *attr;

	g_return_val_if_fail (E_IS_VCARD (evc), NULL);
	g_return_val_if_fail (name != NULL, NULL);

	/* Handle UID special case */
	if (evc->priv->vcard != NULL && g_ascii_strcasecmp (name, EVC_UID) == 0) {
		for (l = evc->priv->attributes; l != NULL; l = l->next) {
			attr = (EVCardAttribute *) l->data;
			if (g_ascii_strcasecmp (attr->name, name) == 0)
				return attr;
		}
	}

	attrs = e_vcard_ensure_attributes (evc);
	for (l = attrs; l; l = l->next) {
		attr = (EVCardAttribute *) l->data;
		if (g_ascii_strcasecmp (attr->name, name) == 0)
			return attr;
	}

	return NULL;
}

/**
 * e_vcard_get_attribute_if_parsed:
 * @evc: an #EVCard
 * @name: the name of the attribute to get
 *
 * Similar to e_vcard_get_attribute() but this method will not attempt to
 * parse the vCard if it is not already parsed.
 *
 * Returns: (transfer none) (nullable): An #EVCardAttribute if found, or %NULL.
 *
 * Since: 3.4
 **/
EVCardAttribute *
e_vcard_get_attribute_if_parsed (EVCard *evc,
                                 const gchar *name)
{
	GList *l;
	EVCardAttribute *attr;

	g_return_val_if_fail (E_IS_VCARD (evc), NULL);
	g_return_val_if_fail (name != NULL, NULL);

	for (l = evc->priv->attributes; l != NULL; l = l->next) {
		attr = (EVCardAttribute *) l->data;
		if (g_ascii_strcasecmp (attr->name, name) == 0)
			return attr;
	}

	return NULL;
}

/**
 * e_vcard_attribute_get_group:
 * @attr: an #EVCardAttribute
 *
 * Gets the group name of @attr.
 *
 * Returns: (nullable): The attribute's group name, or %NULL.
 **/
const gchar *
e_vcard_attribute_get_group (EVCardAttribute *attr)
{
	g_return_val_if_fail (attr != NULL, NULL);

	return attr->group;
}

/**
 * e_vcard_attribute_get_name:
 * @attr: an #EVCardAttribute
 *
 * Gets the name of @attr.
 *
 * Returns: The attribute's name.
 **/
const gchar *
e_vcard_attribute_get_name (EVCardAttribute *attr)
{
	g_return_val_if_fail (attr != NULL, NULL);

	return attr->name;
}

/**
 * e_vcard_attribute_get_values:
 * @attr: an #EVCardAttribute
 *
 * Gets the ordered list of values from @attr. The list and its
 * contents are owned by @attr, and must not be freed.
 *
 * For example, for an <code>ADR</code> (postal address) attribute, this will
 * return the components of the postal address.
 *
 * This may be called on a single-valued attribute (i.e. one for which
 * e_vcard_attribute_is_single_valued() returns %TRUE) and will return a
 * one-element list in that case. Alternatively, use
 * e_vcard_attribute_get_value() in such cases.
 *
 * Returns: (transfer none) (element-type utf8): A list of string values. They
 * will all be non-%NULL, but may be empty strings. The list itself may be
 * empty.
 **/
GList *
e_vcard_attribute_get_values (EVCardAttribute *attr)
{
	g_return_val_if_fail (attr != NULL, NULL);

	return attr->values;
}

/**
 * e_vcard_attribute_get_values_decoded:
 * @attr: an #EVCardAttribute
 *
 * Gets the ordered list of values from @attr, decoding them if
 * necessary according to the encoding given in the vCard’s
 * <code>ENCODING</code> attribute. The list and its contents are owned by
 * @attr, and must not be freed.
 *
 * This may be called on a single-valued attribute (i.e. one for which
 * e_vcard_attribute_is_single_valued() returns %TRUE) and will return a
 * one-element list in that case. Alternatively, use
 * e_vcard_attribute_get_value_decoded() in such cases.
 *
 * Returns: (transfer none) (element-type GString): A list of values of type #GString.
 **/
GList *
e_vcard_attribute_get_values_decoded (EVCardAttribute *attr)
{
	g_return_val_if_fail (attr != NULL, NULL);

	if (!attr->decoded_values) {
		GList *l;
		switch (attr->encoding) {
		case EVC_ENCODING_RAW:
			for (l = attr->values; l; l = l->next)
				attr->decoded_values = g_list_prepend (attr->decoded_values, g_string_new ((gchar *) l->data));
			attr->decoded_values = g_list_reverse (attr->decoded_values);
			break;
		case EVC_ENCODING_BASE64:
			for (l = attr->values; l; l = l->next) {
				guchar *decoded;
				gsize len = 0;

				decoded = g_base64_decode (l->data, &len);
				attr->decoded_values = g_list_prepend (attr->decoded_values, g_string_new_len ((gchar *) decoded, len));
				g_free (decoded);
			}
			attr->decoded_values = g_list_reverse (attr->decoded_values);
			break;
		case EVC_ENCODING_QP:
			for (l = attr->values; l; l = l->next) {
				gchar *decoded;

				decoded = e_vcard_qp_decode (l->data);
				attr->decoded_values = g_list_prepend (attr->decoded_values, g_string_new (decoded));
				g_free (decoded);
			}
			attr->decoded_values = g_list_reverse (attr->decoded_values);
			break;
		}
	}

	return attr->decoded_values;
}

/**
 * e_vcard_attribute_is_single_valued:
 * @attr: an #EVCardAttribute
 *
 * Checks if @attr has a single value.
 *
 * Returns: %TRUE if the attribute has exactly one value, %FALSE otherwise.
 **/
gboolean
e_vcard_attribute_is_single_valued (EVCardAttribute *attr)
{
	g_return_val_if_fail (attr != NULL, FALSE);

	if (attr->values == NULL
	    || attr->values->next != NULL)
		return FALSE;

	return TRUE;
}

/**
 * e_vcard_attribute_get_value:
 * @attr: an #EVCardAttribute
 *
 * Gets the value of a single-valued #EVCardAttribute, @attr.
 *
 * For example, for a <code>FN</code> (full name) attribute, this will
 * return the contact’s full name as a single string.
 *
 * This will print a warning if called on an #EVCardAttribute which is not
 * single-valued (i.e. for which e_vcard_attribute_is_single_valued() returns
 * %FALSE). Use e_vcard_attribute_get_values() in such cases instead.
 *
 * Returns: (nullable): A newly allocated string representing
 * the value, or %NULL if the attribute has no value.
 **/
gchar *
e_vcard_attribute_get_value (EVCardAttribute *attr)
{
	GList *values;

	g_return_val_if_fail (attr != NULL, NULL);

	values = e_vcard_attribute_get_values (attr);

	if (!e_vcard_attribute_is_single_valued (attr))
		g_warning ("e_vcard_attribute_get_value called on multivalued attribute");

	return values ? g_strdup ((gchar *) values->data) : NULL;
}

/**
 * e_vcard_attribute_get_value_decoded:
 * @attr: an #EVCardAttribute
 *
 * Gets the value of a single-valued #EVCardAttribute, @attr, decoding
 * it if necessary according to the encoding given in the vCard’s
 * <code>ENCODING</code> attribute.
 *
 * This will print a warning if called on an #EVCardAttribute which is not
 * single-valued (i.e. for which e_vcard_attribute_is_single_valued() returns
 * %FALSE). Use e_vcard_attribute_get_values_decoded() in such cases instead.
 *
 * Returns: (nullable) (transfer full): A newly allocated #GString
 * representing the value, or %NULL if the attribute has no value.
 **/
GString *
e_vcard_attribute_get_value_decoded (EVCardAttribute *attr)
{
	GList *values;
	GString *str = NULL;

	g_return_val_if_fail (attr != NULL, NULL);

	values = e_vcard_attribute_get_values_decoded (attr);

	if (!e_vcard_attribute_is_single_valued (attr))
		g_warning ("e_vcard_attribute_get_value_decoded called on multivalued attribute");

	if (values)
		str = values->data;

	return str ? g_string_new_len (str->str, str->len) : NULL;
}

/**
 * e_vcard_attribute_has_type:
 * @attr: an #EVCardAttribute
 * @typestr: a string representing the type
 *
 * Checks if @attr has an #EVCardAttributeParam with name %EVC_TYPE and @typestr
 * as one of its values.
 *
 * For example, for the vCard attribute:
 * |[
 * TEL;TYPE=WORK,VOICE:(111) 555-1212
 * ]|
 * the following holds true:
 * |[
 * g_assert_true (e_vcard_attribute_has_type (attr, "WORK") == TRUE);
 * g_assert_true (e_vcard_attribute_has_type (attr, "voice") == TRUE);
 * g_assert_true (e_vcard_attribute_has_type (attr, "HOME") == FALSE);
 * ]|
 *
 * Comparisons against @typestr are case-insensitive.
 *
 * Returns: %TRUE if such a parameter exists, %FALSE otherwise.
 **/
gboolean
e_vcard_attribute_has_type (EVCardAttribute *attr,
                            const gchar *typestr)
{
	GList *params;
	GList *p;

	g_return_val_if_fail (attr != NULL, FALSE);
	g_return_val_if_fail (typestr != NULL, FALSE);

	params = e_vcard_attribute_get_params (attr);

	for (p = params; p; p = p->next) {
		EVCardAttributeParam *param = p->data;

		if (!g_ascii_strcasecmp (e_vcard_attribute_param_get_name (param), EVC_TYPE)) {
			GList *values = e_vcard_attribute_param_get_values (param);
			GList *v;

			for (v = values; v; v = v->next) {
				if (!g_ascii_strcasecmp ((gchar *) v->data, typestr))
					return TRUE;
			}
		}
	}

	return FALSE;
}

/**
 * e_vcard_attribute_get_params:
 * @attr: an #EVCardAttribute
 *
 * Gets the list of parameters (of type #EVCardAttributeParam) from @attr. The
 * list and its contents are owned by @attr, and must not be freed.
 *
 * Returns: (transfer none) (element-type EVCardAttributeParam): A list of
 * elements of type #EVCardAttributeParam.
 **/
GList *
e_vcard_attribute_get_params (EVCardAttribute *attr)
{
	g_return_val_if_fail (attr != NULL, NULL);

	return attr->params;
}

/**
 * e_vcard_attribute_get_param:
 * @attr: an #EVCardAttribute
 * @name: a parameter name
 *
 * Gets the list of values for the paramater @name from @attr. The list and its
 * contents are owned by @attr, and must not be freed. If no parameter with the
 * given @name exists, %NULL is returned.
 *
 * Returns: (transfer none) (element-type utf8) (nullable): A list of string
 * elements representing the parameter's values, or %NULL.
 **/
GList *
e_vcard_attribute_get_param (EVCardAttribute *attr,
                             const gchar *name)
{
	GList *params, *p;

	g_return_val_if_fail (attr != NULL, NULL);
	g_return_val_if_fail (name != NULL, NULL);

	params = e_vcard_attribute_get_params (attr);

	for (p = params; p; p = p->next) {
		EVCardAttributeParam *param = p->data;
		if (g_ascii_strcasecmp (e_vcard_attribute_param_get_name (param), name) == 0) {
			return e_vcard_attribute_param_get_values (param);
		}
	}

	return NULL;
}

/**
 * e_vcard_is_parsed:
 * @evc: an #EVCard
 *
 * Check if the @evc has been parsed already, as #EVCard implements lazy parsing
 * of its vCard data. Used for debugging.
 *
 * Return value: %TRUE if @evc has been parsed, %FALSE otherwise.
 *
 * Since: 3.2
 **/
gboolean
e_vcard_is_parsed (EVCard *evc)
{
	g_return_val_if_fail (E_IS_VCARD (evc), FALSE);

	return (!evc->priv->vcard && evc->priv->attributes);
}

/**
 * e_vcard_attribute_param_get_name:
 * @param: an #EVCardAttributeParam
 *
 * Gets the name of @param.
 *
 * For example, for the only parameter of the vCard attribute:
 * |[
 * TEL;TYPE=WORK,VOICE:(111) 555-1212
 * ]|
 * this would return <code>TYPE</code> (which is string-equivalent to
 * %EVC_TYPE).
 *
 * Returns: The name of the parameter.
 **/
const gchar *
e_vcard_attribute_param_get_name (EVCardAttributeParam *param)
{
	g_return_val_if_fail (param != NULL, NULL);

	return param->name;
}

/**
 * e_vcard_attribute_param_get_values:
 * @param: an #EVCardAttributeParam
 *
 * Gets the list of values from @param. The list and its
 * contents are owned by @param, and must not be freed.
 *
 * For example, for the <code>TYPE</code> parameter of the vCard attribute:
 * |[
 * TEL;TYPE=WORK,VOICE:(111) 555-1212
 * ]|
 * this would return the list <code>WORK</code>, <code>VOICE</code>.
 *
 * Returns: (transfer none) (element-type utf8): A list of string elements
 * representing the parameter's values.
 **/
GList *
e_vcard_attribute_param_get_values (EVCardAttributeParam *param)
{
	g_return_val_if_fail (param != NULL, NULL);

	return param->values;
}

/**
 * e_vcard_util_set_x_attribute:
 * @vcard: an #EVCard
 * @x_name: the attribute name, which starts with "X-"
 * @value: (nullable): the value to set, or %NULL to unset
 *
 * Sets an "X-" attribute @x_name to value @value in @vcard, or
 * removes it from @vcard, when @value is %NULL.
 *
 * Since: 3.26
 **/
void
e_vcard_util_set_x_attribute (EVCard *vcard,
			      const gchar *x_name,
			      const gchar *value)
{
	EVCardAttribute *attr;

	g_return_if_fail (E_IS_VCARD (vcard));
	g_return_if_fail (x_name != NULL);
	g_return_if_fail (g_str_has_prefix (x_name, "X-"));

	attr = e_vcard_get_attribute (vcard, x_name);

	if (attr) {
		e_vcard_attribute_remove_values (attr);
		if (value) {
			e_vcard_attribute_add_value (attr, value);
		} else {
			e_vcard_remove_attribute (vcard, attr);
		}
	} else if (value) {
		e_vcard_append_attribute_with_value (
			vcard,
			e_vcard_attribute_new (NULL, x_name),
			value);
	}
}

/**
 * e_vcard_util_dup_x_attribute:
 * @vcard: an #EVCard
 * @x_name: the attribute name, which starts with "X-"
 *
 * Returns: (nullable): Value of attribute @x_name, or %NULL,
 *    when there is no such attribute. Free the returned pointer with g_free(),
 *    when no longer needed.
 *
 * Since: 3.26
 **/
gchar *
e_vcard_util_dup_x_attribute (EVCard *vcard,
			      const gchar *x_name)
{
	EVCardAttribute *attr;
	GList *v = NULL;

	g_return_val_if_fail (E_IS_VCARD (vcard), NULL);
	g_return_val_if_fail (x_name != NULL, NULL);
	g_return_val_if_fail (g_str_has_prefix (x_name, "X-"), NULL);

	attr = e_vcard_get_attribute (vcard, x_name);

	if (attr)
		v = e_vcard_attribute_get_values (attr);

	return ((v && v->data) ? g_strstrip (g_strdup (v->data)) : NULL);
}
