# This program is free software; you can redistribute it and/or modify
# it under the terms of the (LGPL) GNU Lesser General Public License as
# published by the Free Software Foundation; either version 3 of the
# License, or (at your option) any later version.
#
# This program 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 Library Lesser General Public License for more details at
# ( http://www.gnu.org/licenses/lgpl.html ).
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
# written by: Jeff Ortel ( jortel@redhat.com )

"""
The I{sxbase} module provides I{base} classes that represent
schema objects.
"""

from logging import getLogger
from suds import objid, Repr
from suds.compat import unicode
from suds.xsd import isqref, Filter, qualify
from suds.sax.element import Element
from suds.sax import Namespace

log = getLogger(__name__)


class SchemaObject(object):
    """
    A schema object is an extension to object object with
    with schema awareness.
    @ivar root: The XML root element.
    @type root: L{Element}
    @ivar schema: The schema containing this object.
    @type schema: L{schema.Schema}
    @ivar form_qualified: A flag that inidcates that @elementFormDefault
        has a value of I{qualified}.
    @type form_qualified: boolean
    @ivar nillable: A flag that inidcates that @nillable
        has a value of I{true}.
    @type nillable: boolean
    @ivar default: The default value.
    @type default: object
    @ivar rawchildren: A list raw of all children.
    @type rawchildren: [L{SchemaObject},...]
    """

    @classmethod
    def prepend(cls, d, s, filter=Filter()):
        """
        Prepend schema object's from B{s}ource list to
        the B{d}estination list while applying the filter.
        @param d: The destination list.
        @type d: list
        @param s: The source list.
        @type s: list
        @param filter: A filter that allows items to be prepended.
        @type filter: L{Filter}
        """
        i = 0
        for x in s:
            if x in filter:
                d.insert(i, x)
                i += 1

    @classmethod
    def append(cls, d, s, filter=Filter()):
        """
        Append schema object's from B{s}ource list to
        the B{d}estination list while applying the filter.
        @param d: The destination list.
        @type d: list
        @param s: The source list.
        @type s: list
        @param filter: A filter that allows items to be appended.
        @type filter: L{Filter}
        """
        for item in s:
            if item in filter:
                d.append(item)

    def __init__(self, schema, root):
        """
        @param schema: The containing schema.
        @type schema: L{schema.Schema}
        @param root: The xml root node.
        @type root: L{Element}
        """
        self.schema = schema
        self.root = root
        self.id = objid(self)
        self.name = root.get('name')
        self.qname = (self.name, schema.tns[1])
        self.min = root.get('minOccurs')
        self.max = root.get('maxOccurs')
        self.type = root.get('type')
        self.ref = root.get('ref')
        self.form_qualified = schema.form_qualified
        self.nillable = False
        self.default = root.get('default')
        self.rawchildren = []
        self.cache = {}

    def attributes(self, filter=Filter()):
        """
        Get only the attribute content.
        @param filter: A filter to constrain the result.
        @type filter: L{Filter}
        @return: A list of tuples (attr, ancestry)
        @rtype: [(L{SchemaObject}, [L{SchemaObject},..]),..]
        """
        result = []
        for child, ancestry in self:
            if child.isattr() and child in filter:
                result.append((child, ancestry))
        return result

    def children(self, filter=Filter()):
        """
        Get only the I{direct} or non-attribute content.
        @param filter: A filter to constrain the result.
        @type filter: L{Filter}
        @return: A list tuples: (child, ancestry)
        @rtype: [(L{SchemaObject}, [L{SchemaObject},..]),..]
        """
        result = []
        for child, ancestry in self:
            if not child.isattr() and child in filter:
                result.append((child, ancestry))
        return result

    def get_attribute(self, name):
        """
        Get (find) a I{non-attribute} attribute by name.
        @param name: A attribute name.
        @type name: str
        @return: A tuple: the requested (attribute, ancestry).
        @rtype: (L{SchemaObject}, [L{SchemaObject},..])
        """
        for child, ancestry in self.attributes():
            if child.name == name:
                return (child, ancestry)
        return (None, [])

    def get_child(self, name):
        """
        Get (find) a I{non-attribute} child by name.
        @param name: A child name.
        @type name: str
        @return: A tuple: the requested (child, ancestry).
        @rtype: (L{SchemaObject}, [L{SchemaObject},..])
        """
        for child, ancestry in self.children():
            if child.any() or child.name == name:
                return (child, ancestry)
        return (None, [])

    def namespace(self, prefix=None):
        """
        Get this properties namespace
        @param prefix: The default prefix.
        @type prefix: str
        @return: The schema's target namespace
        @rtype: (I{prefix},I{URI})
        """
        ns = self.schema.tns
        if ns[0] is None:
            ns = (prefix, ns[1])
        return ns

    def default_namespace(self):
        return self.root.defaultNamespace()

    def unbounded(self):
        """
        Get whether this node is unbounded I{(a collection)}
        @return: True if unbounded, else False.
        @rtype: boolean
        """
        max = self.max
        if max is None:
            max = '1'
        if max.isdigit():
            return (int(max) > 1)
        else:
            return max == 'unbounded'

    def optional(self):
        """
        Get whether this type is optional.
        @return: True if optional, else False
        @rtype: boolean
        """
        min = self.min
        if min is None:
            min = '1'
        return min == '0'

    def required(self):
        """
        Get whether this type is required.
        @return: True if required, else False
        @rtype: boolean
        """
        return not self.optional()

    def resolve(self, nobuiltin=False):
        """
        Resolve and return the nodes true self.
        @param nobuiltin: Flag indicates that resolution must
            not continue to include xsd builtins.
        @return: The resolved (true) type.
        @rtype: L{SchemaObject}
        """
        return self.cache.get(nobuiltin, self)

    def sequence(self):
        """
        Get whether this is an <xs:sequence/>
        @return: True if <xs:sequence/>, else False
        @rtype: boolean
        """
        return False

    def xslist(self):
        """
        Get whether this is an <xs:list/>
        @return: True if any, else False
        @rtype: boolean
        """
        return False

    def all(self):
        """
        Get whether this is an <xs:all/>
        @return: True if any, else False
        @rtype: boolean
        """
        return False

    def choice(self):
        """
        Get whether this is n <xs:choice/>
        @return: True if any, else False
        @rtype: boolean
        """
        return False

    def any(self):
        """
        Get whether this is an <xs:any/>
        @return: True if any, else False
        @rtype: boolean
        """
        return False

    def builtin(self):
        """
        Get whether this is a schema-instance (xs) type.
        @return: True if any, else False
        @rtype: boolean
        """
        return False

    def enum(self):
        """
        Get whether this is a simple-type containing an enumeration.
        @return: True if any, else False
        @rtype: boolean
        """
        return False

    def isattr(self):
        """
        Get whether the object is a schema I{attribute} definition.
        @return: True if an attribute, else False.
        @rtype: boolean
        """
        return False

    def extension(self):
        """
        Get whether the object is an extension of another type.
        @return: True if an extension, else False.
        @rtype: boolean
        """
        return False

    def restriction(self):
        """
        Get whether the object is an restriction of another type.
        @return: True if an restriction, else False.
        @rtype: boolean
        """
        return False

    def mixed(self):
        """
        Get whether this I{mixed} content.
        """
        return False

    def find(self, qref, classes=()):
        """
        Find a referenced type in self or children.
        @param qref: A qualified reference.
        @type qref: qref
        @param classes: A list of classes used to qualify the match.
        @type classes: [I{class},...]
        @return: The referenced type.
        @rtype: L{SchemaObject}
        @see: L{qualify()}
        """
        if not len(classes):
            classes = (self.__class__,)
        if self.qname == qref and self.__class__ in classes:
            return self
        for c in self.rawchildren:
            p = c.find(qref, classes)
            if p is not None:
                return p
        return None

    def translate(self, value, topython=True):
        """
        Translate a value (type) to/from a python type.
        @param value: A value to translate.
        @return: The converted I{language} type.
        """
        return value

    def childtags(self):
        """
        Get a list of valid child tag names.
        @return: A list of child tag names.
        @rtype: [str,...]
        """
        return ()

    def dependencies(self):
        """
        Get a list of dependancies for dereferencing.
        @return: A merge dependancy index and a list of dependancies.
        @rtype: (int, [L{SchemaObject},...])
        """
        return (None, [])

    def autoqualified(self):
        """
        The list of I{auto} qualified attribute values.
        Qualification means to convert values into I{qref}.
        @return: A list of attibute names.
        @rtype: list
        """
        return ['type', 'ref']

    def qualify(self):
        """
        Convert attribute values, that are references to other
        objects, into I{qref}.  Qualfied using default document namespace.
        Since many wsdls are written improperly: when the document does
        not define a default namespace, the schema target namespace is used
        to qualify references.
        """
        defns = self.root.defaultNamespace()
        if Namespace.none(defns):
            defns = self.schema.tns
        for a in self.autoqualified():
            ref = getattr(self, a)
            if ref is None:
                continue
            if isqref(ref):
                continue
            qref = qualify(ref, self.root, defns)
            log.debug('%s, convert %s="%s" to %s', self.id, a, ref, qref)
            setattr(self, a, qref)

    def merge(self, other):
        """
        Merge another object as needed.
        """
        other.qualify()
        for n in ('name',
                  'qname',
                  'min',
                  'max',
                  'default',
                  'type',
                  'nillable',
                  'form_qualified',):
            if getattr(self, n) is not None:
                continue
            v = getattr(other, n)
            if v is None:
                continue
            setattr(self, n, v)

    def content(self, collection=None, filter=Filter(), history=None):
        """
        Get a I{flattened} list of this nodes contents.
        @param collection: A list to fill.
        @type collection: list
        @param filter: A filter used to constrain the result.
        @type filter: L{Filter}
        @param history: The history list used to prevent cyclic dependency.
        @type history: list
        @return: The filled list.
        @rtype: list
        """
        if collection is None:
            collection = []
        if history is None:
            history = []
        if self in history:
            return collection
        history.append(self)
        if self in filter:
            collection.append(self)
        for c in self.rawchildren:
            c.content(collection, filter, history[:])
        return collection

    def str(self, indent=0, history=None):
        """
        Get a string representation of this object.
        @param indent: The indent.
        @type indent: int
        @return: A string.
        @rtype: str
        """
        if history is None:
            history = []
        if self in history:
            return '%s ...' % Repr(self)
        history.append(self)
        tab = '%*s' % (indent * 3, '')
        result = []
        result.append('%s<%s' % (tab, self.id))
        for n in self.description():
            if not hasattr(self, n):
                continue
            v = getattr(self, n)
            if v is None:
                continue
            result.append(' %s="%s"' % (n, v))
        if len(self):
            result.append('>')
            for c in self.rawchildren:
                result.append('\n')
                result.append(c.str(indent+1, history[:]))
                if c.isattr():
                    result.append('@')
            result.append('\n%s' % tab)
            result.append('</%s>' % self.__class__.__name__)
        else:
            result.append(' />')
        return ''.join(result)

    def description(self):
        """
        Get the names used for str() and repr() description.
        @return:  A dictionary of relavent attributes.
        @rtype: [str,...]
        """
        return ()

    def __str__(self):
        return self.__repr__()

    def __unicode__(self):
         return self.__repr__()

    def __repr__(self):
        s = []
        s.append('<%s' % self.id)
        for n in self.description():
            if not hasattr(self, n):
                continue
            v = getattr(self, n)
            if v is None:
                continue
            s.append(' %s="%s"' % (n, v))
        s.append(' />')
        myrep = ''.join(s)
        return myrep

    def __len__(self):
        n = 0
        for x in self:
            n += 1
        return n

    def __iter__(self):
        return Iter(self)

    def __getitem__(self, index):
        i = 0
        for c in self:
            if i == index:
                return c


class Iter:
    """
    The content iterator - used to iterate the L{Content} children.  The
    iterator provides a I{view} of the children that is free of container
    elements such as <sequence/> and <choice/>.
    @ivar stack: A stack used to control nesting.
    @type stack: list
    """

    class Frame:
        """ A content iterator frame. """

        def __init__(self, sx):
            """
            @param sx: A schema object.
            @type sx: L{SchemaObject}
            """
            self.sx = sx
            self.items = sx.rawchildren
            self.index = 0

        def next(self):
            """
            Get the I{next} item in the frame's collection.
            @return: The next item or None
            @rtype: L{SchemaObject}
            """
            if self.index < len(self.items):
                result = self.items[self.index]
                self.index += 1
                return result

    def __init__(self, sx):
        """
        @param sx: A schema object.
        @type sx: L{SchemaObject}
        """
        self.stack = []
        self.push(sx)

    def push(self, sx):
        """
        Create a frame and push the specified object.
        @param sx: A schema object to push.
        @type sx: L{SchemaObject}
        """
        self.stack.append(Iter.Frame(sx))

    def pop(self):
        """
        Pop the I{top} frame.
        @return: The popped frame.
        @rtype: L{Frame}
        @raise StopIteration: when stack is empty.
        """
        if len(self.stack):
            return self.stack.pop()
        else:
            raise StopIteration()

    def top(self):
        """
        Get the I{top} frame.
        @return: The top frame.
        @rtype: L{Frame}
        @raise StopIteration: when stack is empty.
        """
        if len(self.stack):
            return self.stack[-1]
        else:
            raise StopIteration()

    def __next__(self):
        return self.next()

    def next(self):
        """
        Get the next item.
        @return: A tuple: the next (child, ancestry).
        @rtype: (L{SchemaObject}, [L{SchemaObject},..])
        @raise StopIteration: A the end.
        """
        frame = self.top()
        while True:
            result = frame.next()
            if result is None:
                self.pop()
                return self.next()
            if isinstance(result, Content):
                ancestry = [f.sx for f in self.stack]
                return (result, ancestry)
            self.push(result)
            return self.next()

    def __iter__(self):
        return self


class XBuiltin(SchemaObject):
    """
    Represents an (xsd) schema <xs:*/> node
    """

    def __init__(self, schema, name):
        """
        @param schema: The containing schema.
        @type schema: L{schema.Schema}
        """
        root = Element(name)
        SchemaObject.__init__(self, schema, root)
        self.name = name
        self.nillable = True

    def namespace(self, prefix=None):
        return Namespace.xsdns

    def builtin(self):
        return True

    def resolve(self, nobuiltin=False):
        return self


class Content(SchemaObject):
    """
    This class represents those schema objects that represent
    real XML document content.
    """
    pass


class NodeFinder:
    """
    Find nodes based on flexable criteria.  The I{matcher} is
    may be any object that implements a match(n) method.
    @ivar matcher: An object used as criteria for match.
    @type matcher: I{any}.match(n)
    @ivar limit: Limit the number of matches.  0=unlimited.
    @type limit: int
    """
    def __init__(self, matcher, limit=0):
        """
        @param matcher: An object used as criteria for match.
        @type matcher: I{any}.match(n)
        @param limit: Limit the number of matches.  0=unlimited.
        @type limit: int
        """
        self.matcher = matcher
        self.limit = limit

    def find(self, node, list):
        """
        Traverse the tree looking for matches.
        @param node: A node to match on.
        @type node: L{SchemaObject}
        @param list: A list to fill.
        @type list: list
        """
        if self.matcher.match(node):
            list.append(node)
            self.limit -= 1
            if self.limit == 0:
                return
        for c in node.rawchildren:
            self.find(c, list)
        return self
