"""inline help system, using ReST file in products `wdoc` directory

"""

__docformat__ = "restructuredtext en"

from itertools import chain

from os.path import join

from bisect import bisect_right

from datetime import date

from logilab.common.changelog import ChangeLog

from logilab.common.date import strptime, todate

from logilab.mtconverter import CHARSET_DECL_RGX

from cubicweb.selectors import match_form_params, yes

from cubicweb.view import StartupView

from cubicweb.uilib import rest_publish

from cubicweb.web import NotFound, action

_ = unicode

# table of content management #################################################

try:

    from xml.etree.ElementTree import parse

except ImportError:

    from elementtree.ElementTree import parse

def build_toc_index(node, index):

    try:

        nodeidx = node.attrib['resource']

        assert not nodeidx in index, nodeidx

        index[nodeidx] = node

    except KeyError:

        pass

    for child in node:

        build_toc_index(child, index)

        child.parent = node

def get_insertion_point(section, index):

    if section.attrib.get('insertafter'):

        snode = index[section.attrib['insertafter']]

        node = snode.parent

        idx = node.getchildren().index(snode) + 1

    elif section.attrib.get('insertbefore'):

        snode = index[section.attrib['insertbefore']]

        node = snode.parent

        idx = node.getchildren().index(snode)

    else:

        node = index[section.attrib['appendto']]

        idx = None

    return node, idx

def build_toc(config):

    alltocfiles = reversed(tuple(config.locate_all_files('toc.xml')))

    maintoc = parse(alltocfiles.next()).getroot()

    maintoc.parent = None

    index = {}

    build_toc_index(maintoc, index)

    # insert component documentation into the tree according to their toc.xml

    # file

    for fpath in alltocfiles:

        toc = parse(fpath).getroot()

        for section in toc:

            node, idx = get_insertion_point(section, index)

            if idx is None:

                node.append(section)

            else:

                node.insert(idx, section)

            section.parent = node

            build_toc_index(section, index)

    return index

def title_for_lang(node, lang):

    for title in node.findall('title'):

        if title.attrib['{http://www.w3.org/XML/1998/namespace}lang'] == lang:

            return unicode(title.text)

def subsections(node):

    return [child for child in node if child.tag == 'section']

# help views ##################################################################

class InlineHelpView(StartupView):

    __select__ = match_form_params('fid')

    __regid__ = 'wdoc'

    title = _('site documentation')

    def call(self):

        fid = self._cw.form['fid']

        vreg = self._cw.vreg

        for lang in chain((self._cw.lang, vreg.property_value('ui.language')),

                          vreg.config.available_languages()):

            rid = '%s_%s.rst' % (fid, lang)

            resourcedir = vreg.config.locate_doc_file(rid)

            if resourcedir:

                break

        else:

            raise NotFound

        self.tocindex = build_toc(vreg.config)

        try:

            node = self.tocindex[fid]

        except KeyError:

            node = None

        else:

            self.navigation_links(node)

            self.w(u'<div class="hr"></div>')

            self.w(u'<h1>%s</h1>' % (title_for_lang(node, self._cw.lang)))

        data = open(join(resourcedir, rid)).read()

        self.w(rest_publish(self, data))

        if node is not None:

            self.subsections_links(node)

            self.w(u'<div class="hr"></div>')

            self.navigation_links(node)

    def navigation_links(self, node):

        req = self._cw

        parent = node.parent

        if parent is None:

            return

        brothers = subsections(parent)

        self.w(u'<div class="docnav">\n')

        previousidx = brothers.index(node) - 1

        if previousidx >= 0:

            self.navsection(brothers[previousidx], 'prev')

        self.navsection(parent, 'up')

        nextidx = brothers.index(node) + 1

        if nextidx < len(brothers):

            self.navsection(brothers[nextidx], 'next')

        self.w(u'</div>\n')

    navinfo = {'prev': ('', 'data/previous.png', _('i18nprevnext_previous')),

               'next': ('', 'data/next.png', _('i18nprevnext_next')),

               'up': ('', 'data/up.png', _('i18nprevnext_up'))}

    def navsection(self, node, navtype):

        htmlclass, imgpath, msgid = self.navinfo[navtype]

        self.w(u'<span class="%s">' % htmlclass)

        self.w(u'%s : ' % self._cw._(msgid))

        self.w(u'<a href="%s">%s</a>' % (

            self._cw.build_url('doc/'+node.attrib['resource']),

            title_for_lang(node, self._cw.lang)))

        self.w(u'</span>\n')

    def subsections_links(self, node, first=True):

        sub = subsections(node)

        if not sub:

            return

        if first:

            self.w(u'<div class="hr"></div>')

        self.w(u'<ul class="docsum">')

        for child in sub:

            self.w(u'<li><a href="%s">%s</a>' % (

                self._cw.build_url('doc/'+child.attrib['resource']),

                title_for_lang(child, self._cw.lang)))

            self.subsections_links(child, False)

            self.w(u'</li>')

        self.w(u'</ul>\n')

class InlineHelpImageView(StartupView):

    __regid__ = 'wdocimages'

    __select__ = match_form_params('fid')

    binary = True

    templatable = False

    content_type = 'image/png'

    def call(self):

        fid = self._cw.form['fid']

        for lang in chain((self._cw.lang, self._cw.vreg.property_value('ui.language')),

                          self._cw.vreg.config.available_languages()):

            rid = join('images', '%s_%s.png' % (fid, lang))

            resourcedir = self._cw.vreg.config.locate_doc_file(rid)

            if resourcedir:

                break

        else:

            raise NotFound

        self.w(open(join(resourcedir, rid)).read())

class ChangeLogView(StartupView):

    __regid__ = 'changelog'

    title = _('What\'s new?')

    maxentries = 25

    def call(self):

        rid = 'ChangeLog_%s' % (self._cw.lang)

        allentries = []

        title = self._cw._(self.title)

        restdata = ['.. -*- coding: utf-8 -*-', '', title, '='*len(title), '']

        w = restdata.append

        today = date.today()

        for fpath in self._cw.vreg.config.locate_all_files(rid):

            cl = ChangeLog(fpath)

            encoding = 'utf-8'

            # additional content may be found in title

            for line in (cl.title + cl.additional_content).splitlines():

                m = CHARSET_DECL_RGX.search(line)

                if m is not None:

                    encoding = m.group(1)

                    continue

                elif line.startswith('.. '):

                    w(unicode(line, encoding))

            for entry in cl.entries:

                if entry.date:

                    edate = todate(strptime(entry.date, '%Y-%m-%d'))

                else:

                    edate = today

                messages = []

                for msglines, submsgs in entry.messages:

                    msgstr = unicode(' '.join(l.strip() for l in msglines), encoding)

                    msgstr += u'\n\n'

                    for submsglines in submsgs:

                        msgstr += '     - ' + unicode(' '.join(l.strip() for l in submsglines), encoding)

                        msgstr += u'\n'

                    messages.append(msgstr)

                entry = (edate, messages)

                allentries.insert(bisect_right(allentries, entry), entry)

        latestdate = None

        i = 0

        for edate, messages in reversed(allentries):

            if latestdate != edate:

                fdate = self._cw.format_date(edate)

                w(u'\n%s' % fdate)

                w('~' * len(fdate))

                latestdate = edate

            for msg in messages:

                w(u'* %s' % msg)

                i += 1

                if i > self.maxentries:

                    break

        w('') # blank line

        self.w(rest_publish(self, '\n'.join(restdata)))

class HelpAction(action.Action):

    __regid__ = 'help'

    __select__ = yes()

    category = 'footer'

    order = 0

    title = _('Help')

    def url(self):

        return self._cw.build_url('doc/main')

class ChangeLogAction(action.Action):

    __regid__ = 'changelog'

    __select__ = yes()

    category = 'footer'

    order = 1

    title = ChangeLogView.title

    def url(self):

        return self._cw.build_url('changelog')

class AboutAction(action.Action):

    __regid__ = 'about'

    __select__ = yes()

    category = 'footer'

    order = 2

    title = _('about this site')

    def url(self):

        return self._cw.build_url('doc/about')