# Copyright (c) 2013 Mirantis Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import base64
import git
import os
import requests
import shutil
import urlparse

from oslo_log import log as logging

from muranoagent.common import config

CONF = config.CONF
LOG = logging.getLogger(__name__)


class FilesManager(object):
    def __init__(self, execution_plan):
        self._fetched_files = {}
        self._files = execution_plan.get('Files') or {}

        self._cache_folder = os.path.join(
            CONF.storage, 'files', execution_plan.ID)
        if os.path.exists(self._cache_folder):
            self.clear()
        os.makedirs(self._cache_folder)

    def put_file(self, file_id, script):
        if type(file_id) is dict:
            file_name = file_id.keys()[0]
            file_def = file_id[file_name]
        else:
            file_def = self._files[file_id]
            file_name = file_def['Name']

        if file_def.get('Type') == 'Downloadable':
            self._download_url_file(file_def)
            return self._cache_folder
        else:
            return self._make_symlink(file_id, file_name, script)

    def _make_symlink(self, file_id, file_name, script):
        cache_path = self._fetch_file(file_id)
        script_folder = os.path.join(self._cache_folder, script)
        if not os.path.isdir(script_folder):
            os.mkdir(script_folder)

        file_folder = os.path.join(script_folder,
                                   os.path.dirname(file_name))
        if not os.path.isdir(file_folder):
            os.makedirs(file_folder)

        if cache_path is not None:
            script_path = os.path.join(script_folder, file_name)
            if not os.path.lexists(script_path):
                os.symlink(cache_path, script_path)
            return script_path

    def _fetch_file(self, file_id):
        if file_id in self._fetched_files:
            return self._fetched_files[file_id]

        filedef = self._files[file_id]
        out_path = os.path.join(self._cache_folder, file_id)
        body_type = filedef.get('BodyType', 'Text')
        with open(out_path, 'w') as out_file:
            if body_type == 'Text':
                out_file.write(filedef['Body'])
            elif body_type == 'Base64':
                out_file.write(base64.b64decode(filedef['Body']))

        self._fetched_files[file_id] = out_path
        return out_path

    def _download_url_file(self, file_def):
        """It download the file in the murano-agent.

        It can proceed from a git file or any other internal URL

        """

        if 'URL' not in file_def:
            raise ValueError("No valid URL in file {0}".
                             format(file_def))
        url_file = file_def['URL']

        if not self._url(url_file):
            raise ValueError("Provided URL is not valid {0}".
                             format(url_file))

        if not os.path.isdir(os.path.join(self._cache_folder, 'files')):
            os.makedirs(os.path.join(self._cache_folder, 'files'))

        folder = self._get_file_folder(url_file, file_def['Name'])

        if not os.path.isdir(folder):
            os.makedirs(folder)

        try:
            if self._is_git_repository(url_file):
                git.Git().clone(url_file, folder)
            else:
                self._download_file(url_file, folder)
        except Exception as e:
            if self._is_git_repository(url_file):
                mns = ("Error to clone the git repository {0}: {1}".
                       format(url_file, e.message))
            else:
                mns = ("Error to download the file {0}: {1}".
                       format(url_file, e.message))
            LOG.warn(mns)
            raise ValueError(mns)

    def clear(self):
        shutil.rmtree(self._cache_folder, ignore_errors=True)
        shutil.rmtree(self._cache_folder, ignore_errors=True)

    def _download_file(self, url, path):
        local_filename = url.split('/')[-1]
        r = requests.get(url, stream=True)
        with open(os.path.join(path, local_filename), 'wb') as f:
            for chunk in r.iter_content(chunk_size=1024):
                if chunk:
                    f.write(chunk)
                    f.flush()
        return local_filename

    def _url(self, file):
        return (urlparse.urlsplit(file).scheme or
                urlparse.urlsplit(file).netloc)

    def _get_file_folder(self, file_url, folder_name):
        if folder_name is None:
            if file_url.endswith('.git'):
                file_folder = file_url[file_url.rfind('/') +
                                       1: file_url.find('.git')]
            else:
                file_folder = file_url[file_url.rfind('/') + 1:]

            folder = os.path.join(self._cache_folder, 'files', file_folder)
        else:
            folder = os.path.join(self._cache_folder, 'files', folder_name)
        return folder

    def _is_git_repository(self, url):
        return (url.startswith(("git://",
                               "git+http://", "git+https:/"))
                or url.endswith('.git'))