# Copyright (C) 2011-2012  Patrick Totzke <patricktotzke@gmail.com>
# This file is released under the GNU GPL, version 3 or a later revision.
# For further details see the COPYING file
"""
Widgets specific to thread mode
"""
import logging
import re
import urwid

from .globals import TagWidget
from .globals import AttachmentWidget
from ..settings.const import settings
from ..db.utils import X_SIGNATURE_MESSAGE_HEADER
from ..helper import string_sanitize

class MessageSummaryWidget(urwid.WidgetWrap):
    """
    one line summary of a :class:`~alot.db.message.Message`.
    """

    def __init__(self, message, odd):
        """
        :param message: a message
        :type message: alot.db.Message
        :param odd: odd entry in a pile of messages? Used for theming.
        :type odd: bool
        """
        self.message = message
        self.odd = odd
        if odd:
            attr = settings.get_theming_attribute('thread', 'summary', 'odd')
        else:
            attr = settings.get_theming_attribute('thread', 'summary', 'even')
        focus_att = settings.get_theming_attribute('thread', 'summary',
                                                   'focus')
        cols = []

        sumstr = self.__str__()
        txt = urwid.Text(sumstr)
        cols.append(txt)

        if settings.get('msg_summary_hides_threadwide_tags'):
            thread_tags = message.thread.get_tags(intersection=True)
            outstanding_tags = set(message.get_tags()).difference(thread_tags)
            tag_widgets = sorted(TagWidget(t, attr, focus_att)
                                 for t in outstanding_tags)
        else:
            tag_widgets = sorted(TagWidget(t, attr, focus_att)
                                 for t in message.get_tags())
        for tag_widget in tag_widgets:
            if not tag_widget.hidden:
                cols.append(('fixed', tag_widget.width(), tag_widget))
        line = urwid.AttrMap(urwid.Columns(cols, dividechars=1), attr,
                             focus_att)
        super().__init__(line)

    def __str__(self):
        mail = self.message.get_email()

        subj = mail.get_all('subject', [''])
        subj = re.sub(r'\n\s+', r' ', ','.join(subj))

        author, address = self.message.get_author()
        date = self.message.get_datestring()
        rep = '%s: %s' % (author if author != '' else address, subj)
        if date is not None:
            rep += " (%s)" % date
        return rep

    def selectable(self):
        return True

    def keypress(self, size, key):
        return key


class FocusableText(urwid.WidgetWrap):
    """Selectable Text used for nodes in our example"""
    def __init__(self, txt, att, att_focus):
        t = urwid.Text(txt)
        w = urwid.AttrMap(t, att, att_focus)
        super().__init__(w)

    def selectable(self):
        return True

    def keypress(self, size, key):
        return key


class HeadersWidget(urwid.WidgetWrap):
    """
    A flow widget displaying message headers.
    """

    _key_attr   = None
    _value_attr = None
    _gaps_attr  = None

    def __init__(self, key_attr, value_attr, gaps_attr):
        """
        :param headerslist: list of key/value pairs to display
        :type headerslist: list of (str, str)
        :param key_attr: theming attribute to use for keys
        :type key_attr: urwid.AttrSpec
        :param value_attr: theming attribute to use for values
        :type value_attr: urwid.AttrSpec
        :param gaps_attr: theming attribute to wrap lines in
        :type gaps_attr: urwid.AttrSpec
        """
        self._key_attr   = key_attr
        self._value_attr = value_attr
        self._gaps_attr  = gaps_attr

        super().__init__(urwid.Pile([]))

    def set_headers(self, headers):
        if len(headers) == 0:
            self._w.contents.clear()
            return

        max_key_len = max(map(lambda x: len(x[0]), headers))

        widgets = []
        for key, value in headers:
            # TODO even/odd
            keyw   = ('fixed', max_key_len + 1,
                      urwid.Text((self._key_attr, key)))
            valuew = urwid.Text((self._value_attr, value))
            linew  = urwid.AttrMap(urwid.Columns([keyw, valuew]), self._gaps_attr)
            widgets.append(linew)

        self._w.contents = [(w, ('pack', None)) for w in widgets]

class MessageWidget(urwid.WidgetWrap):
    """
    A flow widget displaying the contents of a single :class:`alot.db.Message`.

    Collapsing this message corresponds to showing the summary only.
    """

    _display_all_headers = None
    _display_source      = None

    _headers_wgt = None
    _source_wgt  = None
    _body_wgt    = None
    _attach_wgt  = None

    _QUOTE_CHARS = '>|:}#'
    _QUOTE_REGEX = '(([ \t]*[{quote_chars}])+)'.format(quote_chars = _QUOTE_CHARS)

    def __init__(self, message):
        """
        :param message: Message to display
        :type message: alot.db.Message
        """
        self._message       = message

        self._headers_wgt = self._get_headers()
        self._source_wgt  = self._get_source()
        self._body_wgt    = self._get_body()
        self._attach_wgt  = self._get_attachments()

        super().__init__(urwid.ListBox(urwid.SimpleListWalker([])))

        self.display_all_headers = False
        self.display_source      = False

    def get_message(self):
        return self._message

    def _reassemble(self, display_source):
        widgets = []

        if display_source:
            widgets.append(self._source_wgt)
        else:
            widgets.append(self._headers_wgt)

            if self._attach_wgt is not None:
                widgets.append(self._attach_wgt)

            widgets.append(self._body_wgt)

        self._w.body[:] = widgets

    def _get_source(self):
        sourcetxt = self._message.get_email().as_string()
        sourcetxt = string_sanitize(sourcetxt)
        att = settings.get_theming_attribute('thread', 'body')
        att_focus = settings.get_theming_attribute('thread', 'body_focus')
        return FocusableText(sourcetxt, att, att_focus)

    def _get_body(self):
        attr_body   = settings.get_theming_attribute('thread', 'body')
        attrs_quote = settings.get_quote_theming()

        body_lines = self._message.get_body_text().splitlines()

        quote_levels = []
        for line in body_lines:
            level = 0
            m = re.match(self._QUOTE_REGEX, line)
            if m is not None:
                g = m.group(0)
                for c in self._QUOTE_CHARS:
                    level += g.count(c)

            quote_levels.append(level)

        line_widgets = []

        for level, line in zip(quote_levels, body_lines):
            if level == 0 or len(attrs_quote) < 1:
                attr = attr_body
            else:
                attr = attrs_quote[(level - 1) % len(attrs_quote)]
            line_widgets.append(urwid.Text((attr, line)))

        return urwid.Pile(line_widgets)

    def _get_headers(self):
        key_attr   = settings.get_theming_attribute('thread', 'header_key')
        value_attr = settings.get_theming_attribute('thread', 'header_value')
        gaps_attr  = settings.get_theming_attribute('thread', 'header')
        return HeadersWidget(key_attr, value_attr, gaps_attr)

    def _get_attachments(self):
        alist = []
        for a in self._message.get_attachments():
            alist.append(AttachmentWidget(a))
        if alist:
            return urwid.Pile(alist)
        return None

    @property
    def display_all_headers(self):
        return self._display_all_headers
    @display_all_headers.setter
    def display_all_headers(self, val):
        val = bool(val)

        if val == self._display_all_headers:
            return

        mail = self._message.get_email()
        lines = []

        if val:
            # collect all header/value pairs in the order they appear
            lines = list(mail.items())
        else:
            # only a selection of headers should be displayed.
            # use order of the `headers` parameter
            for key in settings.get('displayed_headers'):
                if key in mail:
                    if key.lower() in ['cc', 'bcc', 'to']:
                        lines.append((key, ', '.join(mail.get_all(key))))
                    else:
                        for value in mail.get_all(key):
                            lines.append((key, value))
                elif key.lower() == 'tags':
                    # TODO this should be in a separate widget
                    logging.debug('want tags header')
                    values = []
                    for t in self._message.get_tags():
                        tagrep = settings.get_tagstring_representation(t)
                        if t is not tagrep['translated']:
                            t = '%s (%s)' % (tagrep['translated'], t)
                        values.append(t)
                    lines.append((key, ', '.join(values)))

        # OpenPGP pseudo headers
        # TODO this should be in a separate widget
        if mail[X_SIGNATURE_MESSAGE_HEADER]:
            lines.append(('PGP-Signature', mail[X_SIGNATURE_MESSAGE_HEADER]))

        self._headers_wgt.set_headers(lines)

        self._display_all_headers = val

    @property
    def display_source(self):
        return self._display_source
    @display_source.setter
    def display_source(self, val):
        val = bool(val)

        if val == self._display_source:
            return

        self._reassemble(val)
        self._display_source = val

    def get_selected_attachment(self):
        """
        If an AttachmentWidget is currently focused, return it. Otherwise return
        None.
        """
        if self._w.focus is self._attach_wgt:
            return self._attach_wgt.focus.attachment
        return None

class ThreadNode(urwid.WidgetWrap):
    _ARROW  = '➤'
    _HBAR   = '─'
    _VBAR   = '│'
    _TNODE  = '├'
    _CORNER = '└'

    _decor_text        = None
    _have_next_sibling = None

    def __init__(self, msg, thread, pos, indent):
        msg_summary = MessageSummaryWidget(msg, pos & 1)

        if msg.depth == 0:
            wgt = msg_summary
        else:
            self._decor_text = urwid.Text('')
            wgt = urwid.Columns([('pack', self._decor_text), msg_summary])

            ancestor_chain = [msg]
            for p in msg.parents():
                ancestor_chain.insert(0, p)

            have_sibling = []
            for d, m in enumerate(ancestor_chain):
                if d == 0:
                    have_sibling.append(m != thread.toplevel_messages[-1])
                else:
                    have_sibling.append(m != ancestor_chain[d - 1].replies[-1])

            self._have_next_sibling = have_sibling

        super().__init__(wgt)

        self.set_indent(indent)

    def set_indent(self, indent):
        if self._decor_text is None:
            return

        seg_text = []
        if indent > 0:
            depth = len(self._have_next_sibling) - 1
            for d in range(depth):
                if d == depth - 1:
                    corner = self._TNODE if self._have_next_sibling[d + 1] else self._CORNER
                    seg_text.append(corner + self._ARROW)
                else:
                    bar = self._VBAR if self._have_next_sibling[d + 1] else ' '
                    seg_text.append(bar + ' ')

        self._decor_text.set_text(''.join(seg_text))