# GNU MediaGoblin -- federated, autonomous media hosting
# Copyright (C) 2011 Free Software Foundation, Inc
#
# 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/>.

from mediagoblin import mg_globals
from mediagoblin.db.open import setup_connection_and_db_from_config
from mediagoblin.init.config import read_mediagoblin_config
from mediagoblin.storage import BasicFileStorage
from mediagoblin.init import setup_storage, setup_global_and_app_config

import shutil
import tarfile
import subprocess
import os.path
import os
import sys
from contextlib import closing


def import_export_parse_setup(subparser):
    # TODO: Add default
    subparser.add_argument(
        'tar_file')
    subparser.add_argument(
        '-cf', '--conf_file', default='mediagoblin.ini',
        help='Config file used to set up environment')
    subparser.add_argument(
        '--mongodump_path', default='mongodump',
        help='mongodump binary')
    subparser.add_argument(
        '--mongorestore_path', default='mongorestore',
        help='mongorestore binary')
    subparser.add_argument(
        '--cache_path', default='/tmp/mediagoblin/',
        help='')


def _import_media(db, args):
    """
    Import media files

    Must be called after _import_database()
    """
    print "\n== Importing media ==\n"

    media_cache = BasicFileStorage(
        args._cache_path['media'])

    # TODO: Add import of queue files
    queue_cache = BasicFileStorage(
        args._cache_path['queue'])

    for entry in db.media_entries.find():
        for name, path in entry['media_files'].items():
            media_file = mg_globals.public_store.get_file(path, mode='wb')
            media_file.write(
                media_cache.get_file(path, mode='rb').read())

            print(media_file)
        print(entry)

    print "\n== Media imported ==\n"


def _import_database(db, args):
    """
    Restore mongo database from ___.bson files
    """
    print "\n== Importing database ==\n"

    p = subprocess.Popen([
            args.mongorestore_path,
            '-d', db.name,
            os.path.join(args._cache_path['database'], db.name)])
    
    print p

    p.wait()

    print "\n== Database imported ==\n"


def env_import(args):
    """
    Restore mongo database and media files from a tar archive
    """
    # args.cache_path += 'mediagoblin-data'
    setup_global_and_app_config(args.conf_file)

    # Creates mg_globals.public_store and mg_globals.queue_store
    setup_storage()

    config, validation_result = read_mediagoblin_config(args.conf_file)
    connection, db = setup_connection_and_db_from_config(
        config['mediagoblin'], use_pymongo=True)

    tf = tarfile.open(
        args.tar_file,
        mode='r|gz')

    tf.extractall(args.cache_path)

    args.cache_path += 'mediagoblin-data'
    args = _setup_paths(args)

    # Import database from extracted data
    _import_database(db, args)

    _import_media(db, args)

    # _clean(args)

def _setup_paths(args):
    """
    Populate ``args`` variable with cache subpaths
    """
    args._cache_path = dict()
    PATH_MAP = {
        'media': 'media',
        'queue': 'queue',
        'database': 'database'}

    for key, val in PATH_MAP.items():
        args._cache_path[key] = os.path.join(args.cache_path, val)

    return args


def _create_archive(args):
    """
    Create the tar archive
    """
    print "\n== Compressing to archive ==\n"

    tf = tarfile.open(
        args.tar_file,
        mode='w|gz')

    with closing(tf):
        tf.add(args.cache_path, 'mediagoblin-data/')

    print "\n== Archiving done ==\n"


def _clean(args):
    """
    Remove cache directory
    """
    shutil.rmtree(args.cache_path)


def _export_check(args):
    """
    Run security checks for export command
    """
    if os.path.exists(args.tar_file):
        overwrite = raw_input(
            'The output file already exists. '
            'Are you **SURE** you want to overwrite it? '
            '(yes/no)> ')
        if not overwrite == 'yes':
            print "Aborting."

            return False

    if os.path.exists(args.cache_path):
        print 'The cache directory must not exist before you run this script'
        print 'Cache directory: ', args.cache_path

        return False

    return True


def _export_database(db, args):
    print "\n== Exporting database ==\n"

    command = '{mongodump_path} -d {database} -o {mongodump_cache}'.format(
        mongodump_path=args.mongodump_path,
        database=db.name,
        mongodump_cache=args._cache_path['database'])

    p = subprocess.Popen([
            args.mongodump_path,
            '-d', db.name,
            '-o', args._cache_path['database']])

    p.wait()

    print "\n== Database exported ==\n"


def _export_media(db, args):
    print "\n== Exporting media ==\n"

    media_cache = BasicFileStorage(
        args._cache_path['media'])

    # TODO: Add export of queue files
    queue_cache = BasicFileStorage(
        args._cache_path['queue'])

    for entry in db.media_entries.find():
        for name, path in entry['media_files'].items():
            mc_file = media_cache.get_file(path, mode='wb')
            mc_file.write(
                mg_globals.public_store.get_file(path, mode='rb').read())

            print(mc_file)
        print(entry)

    print "\n== Media exported ==\n"


def env_export(args):
    """
    Export database and media files to a tar archive
    """
    args = _setup_paths(args)

    if not _export_check(args):
        print "\n== Checks did not pass, exiting ==\n"
        sys.exit(0)

    setup_global_and_app_config(args.conf_file)
    setup_storage()

    config, validation_result = read_mediagoblin_config(args.conf_file)
    connection, db = setup_connection_and_db_from_config(
        config['mediagoblin'], use_pymongo=True)

    _export_database(db, args)

    _export_media(db, args)

    _create_archive(args)

    _clean(args)