#!/usr/bin/python

# 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 argparse
import logging
import os
import pathlib
import shutil
import subprocess
import warnings

from git import Repo
from git import SymbolicReference


import otc_metadata.services

data = otc_metadata.services.Services()


def process_repositories(args, service):
    """Checkout repositories

    """
    workdir = pathlib.Path(args.work_dir)
    workdir.mkdir(exist_ok=True)

    copy_from = None
    copy_to = None
    repo_to = None
    url_from = None
    url_to = None

    for repo in service["repositories"]:
        logging.debug(f"Processing repository {repo}")
        repo_dir = pathlib.Path(
            workdir, repo["type"], repo["repo"]
        )

        if repo["environment"] == args.source_environment:
            copy_from = repo_dir
        elif repo["environment"] == args.target_environment:
            copy_to = repo_dir
        else:
            continue

        checkout_exists = repo_dir.exists()
        repo_dir.mkdir(parents=True, exist_ok=True)
        if repo["type"] == 'gitea':
            repo_url = (
                f"ssh://git@gitea.eco.tsi-dev.otc-service.com:2222/"
                f"{repo['repo']}"
            )
        elif repo["type"] == 'github':
            repo_url = f"git@github.com:/{repo['repo']}"
        else:
            logging.error(f"Repository type {repo['type']} is not supported")
            exit(1)
        if not checkout_exists:
            git_repo = Repo.clone_from(
                repo_url,
                repo_dir, branch='main')
        else:
            logging.debug(f"Checkout already exists")
            git_repo = Repo(repo_dir)
            git_repo.remotes.origin.fetch()
            git_repo.heads.main.checkout()
            git_repo.remotes.origin.pull()

        if repo["environment"] == args.source_environment:
            url_from = repo_url
        elif repo["environment"] == args.target_environment:
            url_to = repo_url
            repo_to = git_repo
    logging.debug(f"Synchronizing from={url_from}, to={url_to}")

    if not copy_from or not copy_to:
        logging.warn(
            "Not synchronizing documents of the service. "
            "Target or source not known.")

    for doc in data.docs_by_service_type(service["service_type"]):
        logging.debug(f"Analyzing document {doc}")
        if args.document_type and doc.get("type") != args.document_type:
            logging.info(
                f"Skipping synchronizing {doc['title']} "
                f"due to the doc-type filter.")
            continue
        if doc.get("environment"):
            logging.info(
                f"Skipping synchronizing {doc['title']} "
                f"since it is environment bound.")
            continue

        branch_name = f"{args.branch_name}#{doc['type']}"
        remote_ref = SymbolicReference.create(
            repo_to, "refs/remotes/origin/%s" % branch_name)
        new_branch = repo_to.create_head(branch_name, 'main')
        remote_ref = repo_to.remotes[0].refs[branch_name]  # get correct type
        new_branch.set_tracking_branch(remote_ref)
        new_branch.checkout()

        shutil.copytree(
            pathlib.Path(copy_from, doc["rst_location"]),
            pathlib.Path(copy_to, doc["rst_location"]),
            ignore=lambda a, b: ["conf.py"],
            dirs_exist_ok=True
        )
        repo_to.index.add([doc["rst_location"]])
        repo_to.index.commit(
            (
                f"Synchronize {doc['title']}\n\n"
                f"Overwriting document\n"
                f"from: {url_from}\n"
                f"to:   {url_to}\n\n"
                "Performed-by: gitea/infra/otc-metadata/tools/sync_doc_repo.py"
            )
        )
        repo_to.remotes.origin.push(new_branch)
        if 'github' in url_to and args.open_pr_gh:
            subprocess.run(
                args=['gh', 'pr', 'create', '-f'],
                cwd=copy_to,
                check=True
            )


def main():
    parser = argparse.ArgumentParser(
        description='Synchronize document between environments.')
    parser.add_argument(
        '--source-environment',
        required=True,
        help='Environment to be used as a source'
    )
    parser.add_argument(
        '--target-environment',
        required=True,
        help='Environment to be used as a source'
    )
    parser.add_argument(
        '--service-type',
        required=True,
        help='Service to which document(s) belongs to'
    )
    parser.add_argument(
        '--document-type',
        help=(
            'Type of the document to synchronize. '
            'All will be synchronized if not set.'
        )
    )
    parser.add_argument(
        '--branch-name',
        required=True,
        help='Branch name to be used for synchronizing.'
    )
    parser.add_argument(
        '--work-dir',
        required=True,
        help='Working directory to use for repository checkout.'
    )
    parser.add_argument(
        '--open-pr-gh',
        action='store_true',
        help='Open Pull Request using `gh` utility (need to be present).'
    )
    args = parser.parse_args()
    logging.basicConfig(level=logging.DEBUG)
    service = data.service_dict.get(args.service_type)
    if not service:
        warnings.warn(f"Service {args.service_type} was not found in metadata")
        os.exit(1)

    process_repositories(args, service)


if __name__ == '__main__':
    main()