import flask
from werkzeug.datastructures import CombinedMultiDict
from nyaa import app, db
from nyaa import models, forms
from nyaa import bencode, utils
from nyaa import torrents
from nyaa import api_handler
import config

import json
import re
from datetime import datetime
from collections import OrderedDict
import ipaddress
import os.path
import base64
from urllib.parse import quote
import sqlalchemy_fulltext.modes as FullTextMode
from sqlalchemy_fulltext import FullTextSearch
import shlex
from werkzeug import url_encode, secure_filename
from orderedset import OrderedSet

from itsdangerous import URLSafeSerializer, BadSignature

import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.utils import formatdate

DEBUG_API = False


def redirect_url():
    url = flask.request.args.get('next') or \
        flask.request.referrer or \
        '/'
    if url == flask.request.url:
        return '/'
    return url


@app.template_global()
def modify_query(**new_values):
    args = flask.request.args.copy()

    for key, value in new_values.items():
        args[key] = value

    return '{}?{}'.format(flask.request.path, url_encode(args))


def search(term='', user=None, sort='id', order='desc', category='0_0', filter='0', page=1, rss=False, admin=False):
    sort_keys = {
        'id': models.Torrent.id,
        'size': models.Torrent.filesize,
        'name': models.Torrent.display_name,
        'seeders': models.Statistic.seed_count,
        'leechers': models.Statistic.leech_count,
        'downloads': models.Statistic.download_count
    }

    sort_ = sort.lower()
    if sort_ not in sort_keys:
        flask.abort(400)
    sort = sort_keys[sort]

    order_keys = {
        'desc': 'desc',
        'asc': 'asc'
    }

    order_ = order.lower()
    if order_ not in order_keys:
        flask.abort(400)

    filter_keys = {
        '0': None,
        '1': (models.TorrentFlags.REMAKE, False),
        '2': (models.TorrentFlags.TRUSTED, True),
        '3': (models.TorrentFlags.COMPLETE, True)
    }

    filter_ = filter.lower()
    if filter_ not in filter_keys:
        flask.abort(400)
    filter = filter_keys[filter_]

    if user:
        user = models.User.by_id(user)
        if not user:
            flask.abort(404)
        user = user.id

    main_category = None
    sub_category = None
    main_cat_id = 0
    sub_cat_id = 0
    if category:
        cat_match = re.match(r'^(\d+)_(\d+)$', category)
        if not cat_match:
            flask.abort(400)

        main_cat_id = int(cat_match.group(1))
        sub_cat_id = int(cat_match.group(2))

        if main_cat_id > 0:
            if sub_cat_id > 0:
                sub_category = models.SubCategory.by_category_ids(main_cat_id, sub_cat_id)
            else:
                main_category = models.MainCategory.by_id(main_cat_id)

            if not category:
                flask.abort(400)

    # Force sort by id desc if rss
    if rss:
        sort = sort_keys['id']
        order = 'desc'
        page = 1

    same_user = False
    if flask.g.user:
        same_user = flask.g.user.id == user

    if term:
        query = db.session.query(models.TorrentNameSearch)
    else:
        query = models.Torrent.query

    # Filter by user
    if user:
        query = query.filter(models.Torrent.uploader_id == user)
        # If admin, show everything
        if not admin:
            # If user is not logged in or the accessed feed doesn't belong to user,
            # hide anonymous torrents belonging to the queried user
            if not same_user:
                query = query.filter(models.Torrent.flags.op('&')(
                    int(models.TorrentFlags.ANONYMOUS | models.TorrentFlags.DELETED)).is_(False))

    if main_category:
        query = query.filter(models.Torrent.main_category_id == main_cat_id)
    elif sub_category:
        query = query.filter((models.Torrent.main_category_id == main_cat_id) &
                             (models.Torrent.sub_category_id == sub_cat_id))

    if filter:
        query = query.filter(models.Torrent.flags.op('&')(int(filter[0])).is_(filter[1]))

    # If admin, show everything
    if not admin:
        query = query.filter(models.Torrent.flags.op('&')(
            int(models.TorrentFlags.HIDDEN | models.TorrentFlags.DELETED)).is_(False))

    if term:
        for item in shlex.split(term, posix=False):
            if len(item) >= 2:
                query = query.filter(FullTextSearch(
                    item, models.TorrentNameSearch, FullTextMode.NATURAL))

    # Sort and order
    if sort.class_ != models.Torrent:
        query = query.join(sort.class_)

    query = query.order_by(getattr(sort, order)())

    if rss:
        query = query.limit(app.config['RESULTS_PER_PAGE'])
    else:
        query = query.paginate_faste(page, per_page=app.config['RESULTS_PER_PAGE'], step=5)

    return query


@app.errorhandler(404)
def not_found(error):
    return flask.render_template('404.html'), 404


@app.before_request
def before_request():
    flask.g.user = None
    if 'user_id' in flask.session:
        user = models.User.by_id(flask.session['user_id'])
        if not user:
            return logout()

        flask.g.user = user
        flask.session.permanent = True
        flask.session.modified = True

        if flask.g.user.status == models.UserStatusType.BANNED:
            return 'You are banned.', 403


def _generate_query_string(term, category, filter, user):
    params = {}
    if term:
        params['q'] = str(term)
    if category:
        params['c'] = str(category)
    if filter:
        params['f'] = str(filter)
    if user:
        params['u'] = str(user)
    return params


@app.route('/rss', defaults={'rss': True})
@app.route('/', defaults={'rss': False})
def home(rss):
    if flask.request.args.get('page') == 'rss':
        rss = True

    term = flask.request.args.get('q')
    sort = flask.request.args.get('s')
    order = flask.request.args.get('o')
    category = flask.request.args.get('c')
    filter = flask.request.args.get('f')
    user_name = flask.request.args.get('u')
    page = flask.request.args.get('p')
    if page:
        page = int(page)

    user_id = None
    if user_name:
        user = models.User.by_username(user_name)
        if not user:
            flask.abort(404)
        user_id = user.id

    query_args = {
        'term': term or '',
        'user': user_id,
        'sort': sort or 'id',
        'order': order or 'desc',
        'category': category or '0_0',
        'filter': filter or '0',
        'page': page or 1,
        'rss': rss
    }

    # God mode
    if flask.g.user and flask.g.user.is_admin:
        query_args['admin'] = True

    query = search(**query_args)

    if rss:
        return render_rss('/', query)
    else:
        rss_query_string = _generate_query_string(term, category, filter, user_name)
        return flask.render_template('home.html',
                                     torrent_query=query,
                                     search=query_args,
                                     rss_filter=rss_query_string)


@app.route('/user/<user_name>')
def view_user(user_name):
    user = models.User.by_username(user_name)

    if not user:
        flask.abort(404)

    term = flask.request.args.get('q')
    sort = flask.request.args.get('s')
    order = flask.request.args.get('o')
    category = flask.request.args.get('c')
    filter = flask.request.args.get('f')
    page = flask.request.args.get('p')
    if page:
        page = int(page)

    query_args = {
        'term': term or '',
        'user': user.id,
        'sort': sort or 'id',
        'order': order or 'desc',
        'category': category or '0_0',
        'filter': filter or '0',
        'page': page or 1,
        'rss': False
    }

    # God mode
    if flask.g.user and flask.g.user.is_admin:
        query_args['admin'] = True

    query = search(**query_args)

    rss_query_string = _generate_query_string(term, category, filter, user_name)
    return flask.render_template('user.html',
                                 torrent_query=query,
                                 search=query_args,
                                 user=user,
                                 user_page=True,
                                 rss_filter=rss_query_string)


@app.template_filter('rfc822')
def _jinja2_filter_rfc822(date, fmt=None):
    return formatdate(float(date.strftime('%s')))


def render_rss(label, query):
    rss_xml = flask.render_template('rss.xml',
                                    term=label,
                                    site_url=flask.request.url_root,
                                    query=query)
    response = flask.make_response(rss_xml)
    response.headers['Content-Type'] = 'application/xml'
    return response


#@app.route('/about', methods=['GET'])
# def about():
#    return flask.render_template('about.html')


@app.route('/login', methods=['GET', 'POST'])
def login():
    if flask.g.user:
        return flask.redirect(redirect_url())

    form = forms.LoginForm(flask.request.form)
    if flask.request.method == 'POST' and form.validate():
        username = form.username.data.strip()
        password = form.password.data
        user = models.User.by_username(username)

        if not user:
            user = models.User.by_email(username)

        if not user or password != user.password_hash or user.status == models.UserStatusType.INACTIVE:
            flask.flash(flask.Markup(
                '<strong>Login failed!</strong> Incorrect username or password.'), 'danger')
            return flask.redirect(flask.url_for('login'))

        user.last_login_date = datetime.utcnow()
        user.last_login_ip = ipaddress.ip_address(flask.request.remote_addr).packed
        db.session.add(user)
        db.session.commit()

        flask.g.user = user
        flask.session['user_id'] = user.id

        return flask.redirect(redirect_url())

    return flask.render_template('login.html', form=form)


@app.route('/logout')
def logout():
    flask.g.user = None
    flask.session.permanent = False
    flask.session.modified = False

    response = flask.make_response(flask.redirect(redirect_url()))
    response.set_cookie(app.session_cookie_name, expires=0)
    return response


@app.route('/register', methods=['GET', 'POST'])
def register():
    if flask.g.user:
        return flask.redirect(redirect_url())

    form = forms.RegisterForm(flask.request.form)
    if flask.request.method == 'POST' and form.validate():
        user = models.User(username=form.username.data.strip(),
                           email=form.email.data.strip(), password=form.password.data)
        user.last_login_ip = ipaddress.ip_address(flask.request.remote_addr).packed
        db.session.add(user)
        db.session.commit()

        if config.USE_EMAIL_VERIFICATION:  # force verification, enable email
            activ_link = get_activation_link(user)
            send_verification_email(user.email, activ_link)
            return flask.render_template('waiting.html')
        else:  # disable verification, set user as active and auto log in
            user.status = models.UserStatusType.ACTIVE
            db.session.add(user)
            db.session.commit()
            flask.g.user = user
            flask.session['user_id'] = user.id
            return flask.redirect(redirect_url())

    return flask.render_template('register.html', form=form)


@app.route('/profile', methods=['GET', 'POST'])
def profile():
    if not flask.g.user:
        return flask.redirect('/')  # so we dont get stuck in infinite loop when signing out

    form = forms.ProfileForm(flask.request.form)
    if flask.request.method == 'POST' and form.validate():
        user = flask.g.user
        new_email = form.email.data
        new_password = form.new_password.data

        if new_email:
            user.email = form.email.data

        if new_password:
            if form.current_password.data != user.password_hash:
                flask.flash(flask.Markup(
                    '<strong>Password change failed!</strong> Incorrect password.'), 'danger')
                return flask.redirect('/profile')
            user.password_hash = form.new_password.data

        db.session.add(user)
        db.session.commit()

        flask.g.user = user
        flask.session['user_id'] = user.id

    return flask.render_template('profile.html', form=form)


@app.route('/user/activate/<payload>')
def activate_user(payload):
    s = get_serializer()
    try:
        user_id = s.loads(payload)
    except BadSignature:
        flask.abort(404)

    user = models.User.by_id(user_id)

    if not user:
        flask.abort(404)

    user.status = models.UserStatusType.ACTIVE

    db.session.add(user)
    db.session.commit()

    return flask.redirect('/login')


@utils.cached_function
def _create_upload_category_choices():
    ''' Turns categories in the database into a list of (id, name)s '''
    choices = [('', '[Select a category]')]
    for main_cat in models.MainCategory.query.order_by(models.MainCategory.id):
        choices.append((main_cat.id_as_string, main_cat.name, True))
        for sub_cat in main_cat.sub_categories:
            choices.append((sub_cat.id_as_string, ' - ' + sub_cat.name))
    return choices


def _replace_utf8_values(dict_or_list):
    ''' Will replace 'property' with 'property.utf-8' and remove latter if it exists.
        Thanks, bitcomet! :/ '''
    did_change = False
    if isinstance(dict_or_list, dict):
        for key in [key for key in dict_or_list.keys() if key.endswith('.utf-8')]:
            dict_or_list[key.replace('.utf-8', '')] = dict_or_list.pop(key)
            did_change = True
        for value in dict_or_list.values():
            did_change = _replace_utf8_values(value) or did_change
    elif isinstance(dict_or_list, list):
        for item in dict_or_list:
            did_change = _replace_utf8_values(item) or did_change
    return did_change


@app.route('/upload', methods=['GET', 'POST'])
def upload():
    current_user = flask.g.user
    form = forms.UploadForm(CombinedMultiDict((flask.request.files, flask.request.form)))
    form.category.choices = _create_upload_category_choices()
    if flask.request.method == 'POST' and form.validate():
        torrent_data = form.torrent_file.parsed_data

        # The torrent has been  validated and is safe to access with ['foo'] etc - all relevant
        # keys and values have been checked for (see UploadForm in forms.py for details)
        info_dict = torrent_data.torrent_dict['info']

        changed_to_utf8 = _replace_utf8_values(torrent_data.torrent_dict)

        # Use uploader-given name or grab it from the torrent
        display_name = form.display_name.data.strip() or info_dict['name'].decode('utf8').strip()
        information = (form.information.data or '').strip()
        description = (form.description.data or '').strip()

        torrent_filesize = info_dict.get('length') or sum(
            f['length'] for f in info_dict.get('files'))

        # In case no encoding, assume UTF-8.
        torrent_encoding = torrent_data.torrent_dict.get('encoding', b'utf-8').decode('utf-8')

        torrent = models.Torrent(info_hash=torrent_data.info_hash,
                                 display_name=display_name,
                                 torrent_name=torrent_data.filename,
                                 information=information,
                                 description=description,
                                 encoding=torrent_encoding,
                                 filesize=torrent_filesize,
                                 user=current_user)

        # Store bencoded info_dict
        torrent.info = models.TorrentInfo(info_dict=torrent_data.bencoded_info_dict)
        torrent.stats = models.Statistic()
        torrent.has_torrent = True

        # Fields with default value will be None before first commit, so set .flags
        torrent.flags = 0

        torrent.anonymous = form.is_anonymous.data if current_user else True
        torrent.hidden = form.is_hidden.data
        torrent.remake = form.is_remake.data
        torrent.complete = form.is_complete.data
        # Copy trusted status from user if possible
        torrent.trusted = (current_user.level >=
                           models.UserLevelType.TRUSTED) if current_user else False

        # Set category ids
        torrent.main_category_id, torrent.sub_category_id = form.category.parsed_data.get_category_ids()
        # print('Main cat id: {0}, Sub cat id: {1}'.format(
        #    torrent.main_category_id, torrent.sub_category_id))

        # To simplify parsing the filelist, turn single-file torrent into a list
        torrent_filelist = info_dict.get('files')

        used_path_encoding = changed_to_utf8 and 'utf-8' or torrent_encoding

        parsed_file_tree = dict()
        if not torrent_filelist:
            # If single-file, the root will be the file-tree (no directory)
            file_tree_root = parsed_file_tree
            torrent_filelist = [{'length': torrent_filesize, 'path': [info_dict['name']]}]
        else:
            # If multi-file, use the directory name as root for files
            file_tree_root = parsed_file_tree.setdefault(
                info_dict['name'].decode(used_path_encoding), {})

        # Parse file dicts into a tree
        for file_dict in torrent_filelist:
            # Decode path parts from utf8-bytes
            path_parts = [path_part.decode(used_path_encoding) for path_part in file_dict['path']]

            filename = path_parts.pop()
            current_directory = file_tree_root

            for directory in path_parts:
                current_directory = current_directory.setdefault(directory, {})

            current_directory[filename] = file_dict['length']

        parsed_file_tree = utils.sorted_pathdict(parsed_file_tree)

        json_bytes = json.dumps(parsed_file_tree, separators=(',', ':')).encode('utf8')
        torrent.filelist = models.TorrentFilelist(filelist_blob=json_bytes)

        db.session.add(torrent)
        db.session.flush()

        # Store the users trackers
        trackers = OrderedSet()
        announce = torrent_data.torrent_dict.get('announce', b'').decode('ascii')
        if announce:
            trackers.add(announce)

        # List of lists with single item
        announce_list = torrent_data.torrent_dict.get('announce-list', [])
        for announce in announce_list:
            trackers.add(announce[0].decode('ascii'))

        # Remove our trackers, maybe? TODO ?

        # Search for/Add trackers in DB
        db_trackers = OrderedSet()
        for announce in trackers:
            tracker = models.Trackers.by_uri(announce)

            # Insert new tracker if not found
            if not tracker:
                tracker = models.Trackers(uri=announce)
                db.session.add(tracker)

            db_trackers.add(tracker)

        db.session.flush()

        # Store tracker refs in DB
        for order, tracker in enumerate(db_trackers):
            torrent_tracker = models.TorrentTrackers(torrent_id=torrent.id,
                tracker_id=tracker.id, order=order)
            db.session.add(torrent_tracker)

        db.session.commit()

        torrent_file = form.torrent_file.data
        if app.config.get('BACKUP_TORRENT_FOLDER'):
            torrent_file.seek(0, 0)
            torrent_path = os.path.join(app.config['BACKUP_TORRENT_FOLDER'], '{}.{}'.format(torrent.id, secure_filename(torrent_file.filename)))
            torrent_file.save(torrent_path)
        torrent_file.close()

        return flask.redirect('/view/' + str(torrent.id))
    else:
        return flask.render_template('upload.html', form=form, user=flask.g.user)


@app.route('/view/<int:torrent_id>')
def view_torrent(torrent_id):
    torrent = models.Torrent.by_id(torrent_id)

    if not torrent:
        flask.abort(404)

    if torrent.deleted and (not flask.g.user or not flask.g.user.is_admin):
        flask.abort(404)

    if flask.g.user:
        can_edit = flask.g.user is torrent.user or flask.g.user.is_admin
    else:
        can_edit = False

    files = None
    if torrent.filelist:
        files = utils.flattenDict(json.loads(torrent.filelist.filelist_blob.decode('utf-8')))

    return flask.render_template('view.html', torrent=torrent,
                                 files=files,
                                 can_edit=can_edit)


@app.route('/view/<int:torrent_id>/edit', methods=['GET', 'POST'])
def edit_torrent(torrent_id):
    torrent = models.Torrent.by_id(torrent_id)
    form = forms.EditForm(flask.request.form)
    form.category.choices = _create_upload_category_choices()
    category = str(torrent.main_category_id) + "_" + str(torrent.sub_category_id)

    if not torrent:
        flask.abort(404)

    if torrent.deleted and (not flask.g.user or not flask.g.user.is_admin):
        flask.abort(404)

    if not flask.g.user or (flask.g.user is not torrent.user and not flask.g.user.is_admin):
        flask.abort(403)

    if flask.request.method == 'POST' and form.validate():
        # Form has been sent, edit torrent with data.
        torrent.main_category_id, torrent.sub_category_id = form.category.parsed_data.get_category_ids()
        torrent.display_name = (form.display_name.data or '').strip()
        torrent.information = (form.information.data or '').strip()
        torrent.description = (form.description.data or '').strip()
        if flask.g.user.is_admin:
            torrent.deleted = form.is_deleted.data
        torrent.hidden = form.is_hidden.data
        torrent.remake = form.is_remake.data
        torrent.complete = form.is_complete.data
        torrent.anonymous = form.is_anonymous.data

        db.session.commit()

        return flask.redirect('/view/' + str(torrent_id))
    else:
        # Setup form with pre-formatted form.
        form.category.data = category
        form.display_name.data = torrent.display_name
        form.information.data = torrent.information
        form.description.data = torrent.description
        form.is_hidden.data = torrent.hidden
        if flask.g.user.is_admin:
            form.is_deleted.data = torrent.deleted
        form.is_remake.data = torrent.remake
        form.is_complete.data = torrent.complete
        form.is_anonymous.data = torrent.anonymous

        return flask.render_template('edit.html', form=form, torrent=torrent, admin=flask.g.user.is_admin)


@app.route('/view/<int:torrent_id>/magnet')
def redirect_magnet(torrent_id):
    torrent = models.Torrent.by_id(torrent_id)

    if not torrent:
        flask.abort(404)

    return flask.redirect(torrents.create_magnet(torrent))


@app.route('/view/<int:torrent_id>/torrent')
def download_torrent(torrent_id):
    torrent = models.Torrent.by_id(torrent_id)

    if not torrent:
        flask.abort(404)

    resp = flask.Response(_get_cached_torrent_file(torrent))
    resp.headers['Content-Type'] = 'application/x-bittorrent'
    resp.headers['Content-Disposition'] = 'inline; filename*=UTF-8\'\'{}'.format(
        quote(torrent.torrent_name.encode('utf-8')))

    return resp


def _get_cached_torrent_file(torrent):
    # Note: obviously temporary
    cached_torrent = os.path.join(app.config['BASE_DIR'],
                                  'torrent_cache', str(torrent.id) + '.torrent')
    if not os.path.exists(cached_torrent):
        with open(cached_torrent, 'wb') as out_file:
            out_file.write(torrents.create_bencoded_torrent(torrent))

    return open(cached_torrent, 'rb')


def get_serializer(secret_key=None):
    if secret_key is None:
        secret_key = app.secret_key
    return URLSafeSerializer(secret_key)


def get_activation_link(user):
    s = get_serializer()
    payload = s.dumps(user.id)
    return flask.url_for('activate_user', payload=payload, _external=True)


def send_verification_email(to_address, activ_link):
    ''' this is until we have our own mail server, obviously. This can be greatly cut down if on same machine.
     probably can get rid of all but msg formatting/building, init line and sendmail line if local SMTP server '''

    msg_body = 'Please click on: ' + activ_link + ' to activate your account.\n\n\nUnsubscribe:'

    msg = MIMEMultipart()
    msg['Subject'] = 'Verification Link'
    msg['From'] = config.MAIL_FROM_ADDRESS
    msg['To'] = to_address
    msg.attach(MIMEText(msg_body, 'plain'))

    server = smtplib.SMTP(config.SMTP_SERVER, config.SMTP_PORT)
    server.set_debuglevel(1)
    server.ehlo()
    server.starttls()
    server.ehlo()
    server.login(config.SMTP_USERNAME, config.SMTP_PASSWORD)
    server.sendmail(config.SMTP_USERNAME, to_address, msg.as_string())
    server.quit()


#################################### STATIC PAGES ####################################
@app.route('/rules', methods=['GET'])
def site_rules():
    return flask.render_template('rules.html')


@app.route('/help', methods=['GET'])
def site_help():
    return flask.render_template('help.html')


#################################### API ROUTES ####################################
# DISABLED FOR NOW
@app.route('/api/upload', methods = ['POST'])
def api_upload():
    api_response = api_handler.api_upload(flask.request)
    return api_response