"""
Copyright 2007, 2008, 2009 Free Software Foundation, Inc.
This file is part of GNU Radio

SPDX-License-Identifier: GPL-2.0-or-later

"""

from gi.repository import Gtk, Gdk, GObject, Pango

from . import Actions, Utils, Constants
from .Dialogs import SimpleTextDisplay


class PropsDialog(Gtk.Dialog):
    """
    A dialog to set block parameters, view errors, and view documentation.
    """

    def __init__(self, parent, block):
        """
        Properties dialog constructor.

        Args:%
            block: a block instance
        """

        Gtk.Dialog.__init__(
            self,
            title='Properties: ' + block.label,
            transient_for=parent,
            modal=True,
            destroy_with_parent=True,
        )
        self.add_buttons(
            Gtk.STOCK_OK, Gtk.ResponseType.ACCEPT,
            Gtk.STOCK_CANCEL, Gtk.ResponseType.REJECT,
            Gtk.STOCK_APPLY, Gtk.ResponseType.APPLY,
        )
        self.set_response_sensitive(Gtk.ResponseType.APPLY, False)
        self.set_size_request(*Utils.scale(
            (Constants.MIN_DIALOG_WIDTH, Constants.MIN_DIALOG_HEIGHT)
        ))

        self._block = block
        self._hash = 0
        self._config = parent.config

        vpaned = Gtk.VPaned()
        self.vbox.pack_start(vpaned, True, True, 0)

        # Notebook to hold param boxes
        notebook = self.notebook = Gtk.Notebook()
        notebook.set_show_border(False)
        notebook.set_scrollable(True)  # scroll arrows for page tabs
        notebook.set_tab_pos(Gtk.PositionType.TOP)
        vpaned.pack1(notebook, True)

        # Params boxes for block parameters
        self._params_boxes = []
        self._build_param_tab_boxes()

        # Docs for the block
        self._docs_text_display = doc_view = SimpleTextDisplay()
        doc_view.get_buffer().create_tag('b', weight=Pango.Weight.BOLD)
        self._docs_box = Gtk.ScrolledWindow()
        self._docs_box.set_policy(Gtk.PolicyType.AUTOMATIC, Gtk.PolicyType.AUTOMATIC)
        self._docs_vbox = Gtk.VBox(homogeneous=False, spacing=0)
        self._docs_box.add(self._docs_vbox)
        self._docs_link = Gtk.Label(use_markup=True)
        self._docs_vbox.pack_start(self._docs_link, False, False, 0)
        self._docs_vbox.pack_end(self._docs_text_display, True, True, 0)
        notebook.append_page(self._docs_box, Gtk.Label(label="Documentation"))

        # Generated code for the block
        if Actions.TOGGLE_SHOW_CODE_PREVIEW_TAB.get_active():
            self._code_text_display = code_view = SimpleTextDisplay()
            code_view.set_wrap_mode(Gtk.WrapMode.NONE)
            code_view.get_buffer().create_tag('b', weight=Pango.Weight.BOLD)
            code_view.set_monospace(True)
            # todo: set font size in non-deprecated way
            # code_view.override_font(Pango.FontDescription('monospace %d' % Constants.FONT_SIZE))
            code_box = Gtk.ScrolledWindow()
            code_box.set_policy(Gtk.PolicyType.AUTOMATIC, Gtk.PolicyType.AUTOMATIC)
            code_box.add(self._code_text_display)
            notebook.append_page(code_box, Gtk.Label(label="Generated Code"))
        else:
            self._code_text_display = None

        # Error Messages for the block
        self._error_messages_text_display = SimpleTextDisplay()
        self._error_box = Gtk.ScrolledWindow()
        self._error_box.set_policy(Gtk.PolicyType.AUTOMATIC, Gtk.PolicyType.AUTOMATIC)
        self._error_box.add(self._error_messages_text_display)
        vpaned.pack2(self._error_box)
        vpaned.set_position(int(0.65 * Constants.MIN_DIALOG_HEIGHT))

        # Connect events
        self.connect('key-press-event', self._handle_key_press)
        self.connect('show', self.update_gui)
        self.connect('response', self._handle_response)
        self.show_all()  # show all (performs initial gui update)

    def _build_param_tab_boxes(self):
        categories = (p.category for p in self._block.params.values())

        def unique_categories():
            seen = {Constants.DEFAULT_PARAM_TAB}
            yield Constants.DEFAULT_PARAM_TAB
            for cat in categories:
                if cat in seen:
                    continue
                yield cat
                seen.add(cat)

        for category in unique_categories():
            label = Gtk.Label()
            vbox = Gtk.VBox()
            scroll_box = Gtk.ScrolledWindow()
            scroll_box.set_policy(Gtk.PolicyType.AUTOMATIC, Gtk.PolicyType.AUTOMATIC)
            scroll_box.add(vbox)
            self.notebook.append_page(scroll_box, label)
            self._params_boxes.append((category, label, vbox))

    def _params_changed(self):
        """
        Have the params in this dialog changed?
        Ex: Added, removed, type change, hide change...
        To the props dialog, the hide setting of 'none' and 'part' are identical.
        Therefore, the props dialog only cares if the hide setting is/not 'all'.
        Make a hash that uniquely represents the params' state.

        Returns:
            true if changed
        """
        old_hash = self._hash
        new_hash = self._hash = hash(tuple(
            (hash(param), param.name, param.dtype, param.hide == 'all',)
            for param in self._block.params.values()
        ))
        return new_hash != old_hash

    def _handle_changed(self, *args):
        """
        A change occurred within a param:
        Rewrite/validate the block and update the gui.
        """
        self._block.rewrite()
        self._block.validate()
        self.update_gui()

    def _activate_apply(self, *args):
        self.set_response_sensitive(Gtk.ResponseType.APPLY, True)

    def update_gui(self, widget=None, force=False):
        """
        Repopulate the parameters boxes (if changed).
        Update all the input parameters.
        Update the error messages box.
        Hide the box if there are no errors.
        Update the documentation block.
        Hide the box if there are no docs.
        """
        if force or self._params_changed():
            # hide params box before changing
            for category, label, vbox in self._params_boxes:
                vbox.hide()
                # empty the params box
                for child in vbox.get_children():
                    vbox.remove(child)
                    # child.destroy()   # disabled because it throws errors...
                # repopulate the params box
                box_all_valid = True
                force_show_id = Actions.TOGGLE_SHOW_BLOCK_IDS.get_active()

                for param in self._block.params.values():
                    if force_show_id and param.dtype == 'id':
                        param.hide = 'none'
                    # todo: why do we even rebuild instead of really hiding params?
                    if param.category != category or param.hide == 'all':
                        continue
                    box_all_valid = box_all_valid and param.is_valid()

                    input_widget = param.get_input(self._handle_changed, self._activate_apply,
                                                   transient_for=self.get_transient_for())
                    input_widget.show_all()
                    vbox.pack_start(input_widget, input_widget.expand, True, 1)

                label.set_markup('<span {color}>{name}</span>'.format(
                    color='foreground="red"' if not box_all_valid else '', name=Utils.encode(category)
                ))
                vbox.show()  # show params box with new params

        if self._block.is_valid():
            self._error_box.hide()
        else:
            self._error_box.show()
        messages = '\n\n'.join(self._block.get_error_messages())
        self._error_messages_text_display.set_text(messages)

        self._update_docs_page()
        self._update_generated_code_page()

    def _update_docs_page(self):
        """Show documentation from XML and try to display best matching docstring"""
        buf = self._docs_text_display.get_buffer()
        buf.delete(buf.get_start_iter(), buf.get_end_iter())
        pos = buf.get_end_iter()

        # Add link to wiki page for this block, at the top, as long as it's not an OOT block
        if self._block.category and self._block.category[0] == "Core":
            note = "Wiki Page for this Block: "
            prefix = self._config.wiki_block_docs_url_prefix
            suffix = self._block.label.replace(" ", "_")
            href = f'<a href="{prefix+suffix}">Visit Wiki Page</a>'
            self._docs_link.set_markup(href)
        else:
            self._docs_link.set_markup('Out of Tree Block')

        docstrings = self._block.documentation.copy()
        if not docstrings:
            return

        # show documentation string from block yaml
        from_yaml = docstrings.pop('', '')
        for line in from_yaml.splitlines():
            if line.lstrip() == line and line.endswith(':'):
                buf.insert_with_tags_by_name(pos, line + '\n', 'b')
            else:
                buf.insert(pos, line + '\n')
        if from_yaml:
            buf.insert(pos, '\n')

        # if given the current parameters an exact match can be made
        block_constructor = self._block.templates.render('make').rsplit('.', 2)[-1]
        block_class = block_constructor.partition('(')[0].strip()
        if block_class in docstrings:
            docstrings = {block_class: docstrings[block_class]}

        # show docstring(s) extracted from python sources
        for cls_name, docstring in docstrings.items():
            buf.insert_with_tags_by_name(pos, cls_name + '\n', 'b')
            buf.insert(pos, docstring + '\n\n')
        pos.backward_chars(2)
        buf.delete(pos, buf.get_end_iter())

    def _update_generated_code_page(self):
        if not self._code_text_display:
            return  # user disabled code preview

        buf = self._code_text_display.get_buffer()
        block = self._block
        key = block.key

        if key == 'epy_block':
            src = block.params['_source_code'].get_value()
        elif key == 'epy_module':
            src = block.params['source_code'].get_value()
        else:
            src = ''

        def insert(header, text):
            if not text:
                return
            buf.insert_with_tags_by_name(buf.get_end_iter(), header, 'b')
            buf.insert(buf.get_end_iter(), text)

        buf.delete(buf.get_start_iter(), buf.get_end_iter())
        insert('# Imports\n', block.templates.render('imports').strip('\n'))
        if block.is_variable:
            insert('\n\n# Variables\n', block.templates.render('var_make'))
        insert('\n\n# Blocks\n', block.templates.render('make'))
        if src:
            insert('\n\n# External Code ({}.py)\n'.format(block.name), src)

    def _handle_key_press(self, widget, event):
        close_dialog = (
            event.keyval == Gdk.KEY_Return and
            event.get_state() & Gdk.ModifierType.CONTROL_MASK == 0 and
            not isinstance(widget.get_focus(), Gtk.TextView)
        )
        if close_dialog:
            self.response(Gtk.ResponseType.ACCEPT)
            return True  # handled here

        return False  # forward the keypress

    def _handle_response(self, widget, response):
        if response in (Gtk.ResponseType.APPLY, Gtk.ResponseType.ACCEPT):
            for tab, label, vbox in self._params_boxes:
                for child in vbox.get_children():
                    child.apply_pending_changes()
            self.set_response_sensitive(Gtk.ResponseType.APPLY, False)
            return True
        return False
