#! /usr/bin/env python
# -*- coding: utf-8 -*-

# jarr - A Web based news aggregator.
# Copyright (C) 2010-2015  Cédric Bonhomme - https://www.JARR-aggregator.org
#
# For more information : https://github.com/JARR-aggregator/JARR
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

__author__ = "Cedric Bonhomme"
__version__ = "$Revision: 5.3 $"
__date__ = "$Date: 2010/01/29 $"
__revision__ = "$Date: 2014/08/27 $"
__copyright__ = "Copyright (c) Cedric Bonhomme"
__license__ = "AGPLv3"

import os
import string
import random
import hashlib
import logging
import datetime
from collections import OrderedDict

from bootstrap import application as app, db
from flask import render_template, request, flash, session, \
                  url_for, redirect, g, current_app, make_response
from flask.ext.login import LoginManager, login_user, logout_user, \
                            login_required, current_user, AnonymousUserMixin
from flask.ext.principal import Principal, Identity, AnonymousIdentity, \
                                identity_changed, identity_loaded, Permission,\
                                RoleNeed, UserNeed
from flask.ext.babel import gettext
from sqlalchemy import or_, and_
from sqlalchemy.exc import IntegrityError
from werkzeug import generate_password_hash

import conf
from web.lib.utils import redirect_url
from web import utils, notifications, export
from web.lib.view_utils import etag_match
from web.models import User, Feed, Article, Role
from web.decorators import feed_access_required
from web.forms import SignupForm, SigninForm

from web.controllers import UserController, FeedController, \
                                     ArticleController


Principal(app)
# Create a permission with a single Need, in this case a RoleNeed.
admin_permission = Permission(RoleNeed('admin'))

login_manager = LoginManager()
login_manager.init_app(app)
login_manager.login_message = gettext('Authentication required.')
login_manager.login_message_category = "info"
login_manager.login_view = 'login'

logger = logging.getLogger(__name__)

#
# Management of the user's session.
#
@identity_loaded.connect_via(app)
def on_identity_loaded(sender, identity):
    # Set the identity user object
    identity.user = current_user

    # Add the UserNeed to the identity
    if hasattr(current_user, 'id'):
        identity.provides.add(UserNeed(current_user.id))

    # Assuming the User model has a list of roles, update the
    # identity with the roles that the user provides
    if hasattr(current_user, 'roles'):
        for role in current_user.roles:
            identity.provides.add(RoleNeed(role.name))


@app.before_request
def before_request():
    g.user = current_user
    if g.user.is_authenticated:
        g.user.last_seen = datetime.datetime.utcnow()
        db.session.add(g.user)
        db.session.commit()


@login_manager.user_loader
def load_user(id):
    # Return an instance of the User model
    return UserController().get(id=id)

#
# Custom error pages.
#
@app.errorhandler(401)
def authentication_required(e):
    flash(gettext('Authentication required.'), 'info')
    return redirect(url_for('login'))


@app.errorhandler(403)
def authentication_failed(e):
    flash(gettext('Forbidden.'), 'danger')
    return redirect(url_for('login'))


@app.errorhandler(404)
def page_not_found(e):
    return render_template('errors/404.html'), 404


@app.errorhandler(500)
def internal_server_error(e):
    return render_template('errors/500.html'), 500


@g.babel.localeselector
def get_locale():
    """
    Called before each request to give us a chance to choose
    the language to use when producing its response.
    """
    return request.accept_languages.best_match(conf.LANGUAGES.keys())


@g.babel.timezoneselector
def get_timezone():
    try:
        return conf.TIME_ZONE[get_locale()]
    except:
        return conf.TIME_ZONE["en"]

#
# Views.
#
@app.route('/login', methods=['GET', 'POST'])
def login():
    """
    Log in view.
    """
    if g.user is not None and g.user.is_authenticated:
        return redirect(url_for('home'))
    g.user = AnonymousUserMixin()
    form = SigninForm()
    if form.validate_on_submit():
        user = UserController().get(email=form.email.data)
        login_user(user)
        g.user = user
        session['email'] = form.email.data
        identity_changed.send(current_app._get_current_object(),
                              identity=Identity(user.id))
        return form.redirect('home')
    return render_template('login.html', form=form)


@app.route('/logout')
@login_required
def logout():
    """
    Log out view. Removes the user information from the session.
    """
    session.pop('email', None)

    # Remove the user information from the session
    logout_user()

    # Remove session keys set by Flask-Principal
    for key in ('identity.name', 'identity.auth_type'):
        session.pop(key, None)

    # Tell Flask-Principal the user is anonymous
    identity_changed.send(current_app._get_current_object(),
                          identity=AnonymousIdentity())

    flash(gettext("Logged out successfully."), 'success')
    return redirect(url_for('login'))


@app.route('/signup', methods=['GET', 'POST'])
def signup():
    """
    Signup page.
    """
    if int(os.environ.get("SELF_REGISTRATION", 0)) != 1:
        flash(gettext("Self-registration is disabled."), 'warning')
        return redirect(url_for('home'))
    if g.user is not None and g.user.is_authenticated:
        return redirect(url_for('home'))

    form = SignupForm()

    if form.validate_on_submit():
        role_user = Role.query.filter(Role.name == "user").first()
        user = User(nickname=form.nickname.data,
                    email=form.email.data,
                    pwdhash=generate_password_hash(form.password.data))
        user.roles = [role_user]
        db.session.add(user)
        try:
            db.session.commit()
        except IntegrityError:
            flash(gettext('Email already used.'), 'warning')
            return render_template('signup.html', form=form)

        # Send the confirmation email
        try:
            notifications.new_account_notification(user)
        except Exception as error:
            flash(gettext('Problem while sending activation email: %(error)s',
                          error=error), 'danger')
            return redirect(url_for('home'))

        flash(gettext('Your account has been created. '
                      'Check your mail to confirm it.'), 'success')
        return redirect(url_for('home'))

    return render_template('signup.html', form=form)


@etag_match
def render_home(filters=None, head_titles=None,
                page_to_render='home', **kwargs):
    if filters is None:
        filters = {}
    if head_titles is None:
        head_titles = []
    feed_contr = FeedController(g.user.id)
    arti_contr = ArticleController(g.user.id)
    feeds = {feed.id: feed.title for feed in feed_contr.read()}

    in_error = {feed.id: feed.error_count for feed in
                feed_contr.read(error_count__gt=2)}

    filter_ = request.args.get('filter_',
                               'unread' if page_to_render == 'home' else 'all')
    sort_ = request.args.get('sort_', 'date')
    feed_id = int(request.args.get('feed_id', 0))
    limit = request.args.get('limit', 1000)

    if filter_ != 'all':
        filters['readed'] = filter_ == 'read'
    if feed_id:
        filters['feed_id'] = feed_id
        head_titles.append(feed_contr.get(id=feed_id).title)

    sort_param = {"feed": Feed.title.desc(),
                  "date": Article.date.desc(),
                  "article": Article.title.desc(),
                  "-feed": Feed.title.asc(),
                  "-date": Article.date.asc(),
                  "-article": Article.title.asc()
                  }.get(sort_, Article.date.desc())

    articles = arti_contr.read(**filters).join(Article.source). \
                                            order_by(sort_param)
    if limit != 'all':
        limit = int(limit)
        articles = articles.limit(limit)

    def gen_url(filter_=filter_, sort_=sort_, limit=limit, feed_id=feed_id,
                **kwargs):
        o_kwargs = OrderedDict()
        for key in sorted(kwargs):
            o_kwargs[key] = kwargs[key]
        if page_to_render == 'search':
            o_kwargs['query'] = request.args.get('query', '')
            o_kwargs['search_title'] = request.args.get('search_title', 'off')
            o_kwargs['search_content'] = request.args.get(
                    'search_content', 'off')
            # if nor title and content are selected, selecting title
            if o_kwargs['search_title'] == o_kwargs['search_content'] == 'off':
                o_kwargs['search_title'] = 'on'
        o_kwargs['filter_'] = filter_
        o_kwargs['sort_'] = sort_
        o_kwargs['limit'] = limit
        o_kwargs['feed_id'] = feed_id
        return url_for(page_to_render, **o_kwargs)

    articles = list(articles)
    if (page_to_render == 'home' and feed_id or page_to_render == 'search') \
            and filter_ != 'all' and not articles:
        return redirect(gen_url(filter_='all'))

    return render_template('home.html', gen_url=gen_url,
                           feed_id=feed_id, page_to_render=page_to_render,
                           filter_=filter_, limit=limit, feeds=feeds,
                           unread=arti_contr.count_by_feed(readed=False),
                           articles=articles, in_error=in_error,
                           head_titles=head_titles, sort_=sort_, **kwargs)


@app.route('/')
@login_required
def home():
    "Home page for connected users. Displays by default unread articles."
    return render_home()


@app.route('/favorites')
@login_required
def favorites():
    return render_home({'like': True}, [gettext('Favorites')], 'favorites')


@app.route('/search', methods=['GET'])
@login_required
def search():
    "Search articles corresponding to the query."
    if 'query' not in request.args:
        flash(gettext("No text to search were provided."), "warning")
        return render_home()
    query = request.args['query']
    filters = {}
    search_title = request.args.get('search_title', 'off')
    search_content = request.args.get('search_content', 'off')
    if search_title == 'on':
        filters['title__ilike'] = "%%%s%%" % query
    if search_content == 'on':
        filters['content__ilike'] = "%%%s%%" % query
    if len(filters) == 0:
        search_title = 'on'
        filters['title__ilike'] = "%%%s%%" % query
    if len(filters) > 1:
        filters = {"__or__": filters}
    return render_home(filters, ["%s %s" % (gettext('Search:'), query)],
                       'search', search_query=query, search_title=search_title,
                       search_content=search_content)


@app.route('/fetch', methods=['GET'])
@app.route('/fetch/<int:feed_id>', methods=['GET'])
@login_required
def fetch(feed_id=None):
    """
    Triggers the download of news.
    News are downloaded in a separated process, mandatory for Heroku.
    """
    if conf.CRAWLING_METHOD == "classic" \
            and (not conf.ON_HEROKU or g.user.is_admin()):
        utils.fetch(g.user.id, feed_id)
        flash(gettext("Downloading articles..."), "info")
    else:
        flash(gettext("The manual retrieving of news is only available " +
                      "for administrator, on the Heroku platform."), "info")
    return redirect(redirect_url())


@app.route('/about', methods=['GET'])
@etag_match
def about():
    """
    'About' page.
    """
    return render_template('about.html')


@app.route('/export', methods=['GET'])
@login_required
def export_articles():
    """
    Export all articles to HTML or JSON.
    """
    user = UserController(g.user.id).get(id=g.user.id)
    if request.args.get('format') == "HTML":
        # Export to HTML
        try:
            archive_file, archive_file_name = export.export_html(user)
        except:
            flash(gettext("Error when exporting articles."), 'danger')
            return redirect(redirect_url())
        response = make_response(archive_file)
        response.headers['Content-Type'] = 'application/x-compressed'
        response.headers['Content-Disposition'] = 'attachment; filename=%s' \
                % archive_file_name
    elif request.args.get('format') == "JSON":
        # Export to JSON
        try:
            json_result = export.export_json(user)
        except:
            flash(gettext("Error when exporting articles."), 'danger')
            return redirect(redirect_url())
        response = make_response(json_result)
        response.mimetype = 'application/json'
        response.headers["Content-Disposition"] \
                = 'attachment; filename=account.json'
    else:
        flash(gettext('Export format not supported.'), 'warning')
        return redirect(redirect_url())
    return response


@app.route('/export_opml', methods=['GET'])
@login_required
def export_opml():
    """
    Export all feeds to OPML.
    """
    user = UserController(g.user.id).get(id=g.user.id)
    response = make_response(render_template('opml.xml', user=user,
                                             now=datetime.datetime.now()))
    response.headers['Content-Type'] = 'application/xml'
    response.headers['Content-Disposition'] = 'attachment; filename=feeds.opml'
    return response