# -*- encoding: utf-8 -*-
# Description:
# Web stuff related to the cache.
#
# Authors:
# Benoît Allard <benoit.allard@greenbone.net>
#
# Copyright:
# Copyright (C) 2014 Greenbone Networks GmbH
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

"""\
The caching stuff ...
"""

import os

from flask import (Blueprint, current_app, session, flash, redirect, url_for,
    render_template, request, abort)
from werkzeug import secure_filename

from farolluz.parsers.cvrf import parse
from farolluz.renderer import render

from .session import get_current, set_current, del_current, has_current, document_required

mod = Blueprint('cache', __name__)

def caching_type():
    """\
    Returns the type of caching we are using:
    None, 'session' or 'global'
    """
    c_type = current_app.config.get('CACHING', 'global')
    return {'disabled': None}.get(c_type, c_type)

def _caching_dir():
    """\
    Returns the current caching directory
    """
    c_type = caching_type()
    if c_type is None: return None
    root_dir = current_app.config.get('CACHE_DIRECTORY',
        os.path.join(current_app.instance_path, '_cache'))
    if c_type == 'global': return root_dir
    uid = session.get('id')
    # No uid yet, so no cache ...
    if uid is None: return None
    return os.path.join(root_dir, uid.hex)

def cache_content():
    """\
    The content of the cache
    """
    dirname = _caching_dir()
    if dirname is None: return []
    if not os.path.exists(dirname):
        os.makedirs(dirname)
    l = []
    for path in os.listdir(dirname):
        name, ext = os.path.splitext(path)
        if ext == '.xml':
            l.append(name)
    return l

def cleanup_cache():
    """\
    Remove old documents ... maybe ... from time to time ...
    """
    pass

@mod.route('/save', methods=['GET', 'POST'])
@document_required
def save():
    if caching_type() is None:
        current_app.logger.warning('Tried to save although caching is disabled.')
        flash('This version does not allow you to save your document !', 'danger')
        abort(403)
    if request.method != 'POST':
        return render_template('cache/save.j2',
                               id_=get_current().getDocId())
    # Get some kind of filename, and save the cvrf on cache (disk)
    path = secure_filename(request.form['fname'])
    path, _ = os.path.splitext(path)
    dirname = _caching_dir()
    with open(os.path.join(dirname, path + '.xml'), 'wt') as f:
        f.write(render(get_current(), 'cvrf.j2').encode('utf-8'))
    flash('File saved as %s' % path)
    del_current()
    return redirect(url_for('new'))

@mod.route('/load/<element>', methods=['POST'])
def load(element):
    dirname = _caching_dir()
    element = secure_filename(element)
    if dirname is None:
        current_app.logger.warning('Tried to load something although no'
            ' caching dir present: %s' % element)
        flash('Not able to load %s' % element)
        abort(404)
    fpath = os.path.join(dirname, element+'.xml')
    if not os.path.exists(fpath):
        current_app.logger.warning('Tried to load an unexisting document: %s' % element)
        flash('Document %s does not exists !' % element)
        abort(404)
    with open(fpath, 'rt') as f:
        set_current(parse(f))
    os.remove(fpath)
    flash('"%s" has been removed from cache' % element)
    # Get some kind of id, and load the file.
    return redirect(url_for('document.view'))