# songs/ui/song.qpy
# For further information -
# - QPY templates: http://www.mems-exchange.org/software/qpy/
# - QP Python web framework: http://www.mems-exchange.org/software/qpy/

import sys
from qp.fill.css import BASIC_FORM_CSS
from qp.fill.directory import Directory
from qp.fill.form import Form
from qp.pub.common import header, footer, page, redirect
from qp.sites.songs.song import get_song_db
from qp.sites.songs.api import SongDatabaseResource

class SongDatabaseDirectory(Directory):

    def get_exports(self):
        yield ('', 'index', 'Song List', 'This is the root / page of this site.')
        yield ('api', 'api', 'API', 'API documentation and entry point')
        yield ('new', 'new', 'New', 'Add a song to collection')
        yield ('delete', 'clear', 'Delete', 'Delete all songs from collection')

    def index:xml(self):
        header('Song Database')
        '<h1>Songs</h1>'
        '<ul>'
        for song in get_song_db().itervalues():
            '<li>%s: <a href="%s/">%s</a></li>' % (
                song.key, song.key, song.title)
        '</ul>'
        footer()

    def clear:xml(self):
        form = Form()
        form.add_submit('clear', "Yes, I'm certain, clear the database!")
        form.add_submit('cancel', 'Cancel')
        if form.get('cancel'):
            redirect('.')
        if not form.is_submitted():
            page('Delete all songs from collection',
                 '<p>Are you certain you wish to delete '
                 'all songs from the collection?</p>',
                 form.render(), style=BASIC_FORM_CSS)
        else:
            get_song_db().clear()
            redirect('.')

    def new:xml(self):
        _edit_form(get_song_db().create_song())

    def _q_lookup(self, component):
        try:
            component = int(component)
            song = get_song_db().get(component)
            if song:
                return SongDirectory(song)
        except ValueError:
            # None / an empty '' response being returned from _q_lookup
            # will result in 404 not_found being delivered as the response.
            return None

    api = SongDatabaseResource()


class SongDirectory(Directory):

        def __init__(self, song):
            self.song = song

        def get_exports(self):
            yield ('', 'index', 'Song Info', None)
            yield ('edit', 'edit', 'Edit', 'Edit song data')
            yield ('listened', 'next', 'Listened',
                   "Add to the song's listened-to count")
            yield ('remove', 'delete', 'Delete', 'Remove song from collection')

        def _header:xml(self):
            '<h1><a href=".">'
            self.song.title
            '</a></h1>'

        def index:xml(self):
            header(self.song.title)
            self._header()
            '<p>This tune has been heard %d times.</p>' % \
            self.song.was_heard()
            footer()

        def edit:xml(self):
            _edit_form(self.song, header=self._header())

        def next(self):
            form = Form()
            form.add_submit('heard_it', 'I listened to this song!')
            form.add_submit('cancel', 'Cancel')
            def render:xml():
                page('Did you hear it?',
                     self._header(),
                     '<p>Keep track of how many times you heard '
                     '<strong>%s</strong>! So far it has been '
                     'listened to <strong>%d</strong> times.</p>' % (
                         self.song.title, self.song.was_heard()),
                     form.render(), style=BASIC_FORM_CSS)
            if form.get('cancel'):
                redirect('.')
            if not form.has_errors() and form.get('heard_it'):
                self.song.counter.next()
            return render()

        def delete:xml(self):
            form = Form()
            form.add_submit('delete', 'Yes, remove this song from the collection.')
            form.add_submit('cancel', 'No, get me out of here!')
            def render:xml():
                page('Delete %s?' % self.song.title,
                     self._header(),
                     '<h2>Confirm Deletion</h2>'
                     '<p>Do you really want to permanently remove '
                     '<strong>%s</strong> from the collection?</p>' % self.song.title,
                     form.render(), style=BASIC_FORM_CSS)
            if form.get('cancel'):
                redirect('.')
            if not form.has_errors() and form.get('delete'):
                get_song_db().remove(self.song)
                redirect('..')
            return render()


def _edit_form:xml(song, header=None):
    form = Form()
    form.add_string('song_title', song.title, title='Song Title', required=True)
    form.add_submit('save', 'Save')
    form.add_submit('cancel', 'Cancel')
    def render():
        title = 'Add Song' if not song.key else 'Edit %s' % song.title
        return page(title, header, form.render(), style=BASIC_FORM_CSS)

    if form.get('cancel'):
        redirect('.')
    if form.is_submitted():
        # basic validation
        existing = get_song_db().get_by_title(form.get('song_title'))
        if existing and song.key != existing.key:
            form.set_error('song_title', 'Song with this title already exists.')
    if not form.is_submitted() or form.has_errors():
        render()
    else:
        song.title = form.get('song_title')
        try:
            if not song.key:
                get_song_db().add(song)
                redirect('./%s/' % song.key)
            else:
                redirect('.')
        except ValueError:
            form.set_error('song_title', sys.exc_info()[1])
            render()