# SPDX-License-Identifier: AGPL-3.0-or-later
"""Configuration helper for Gitweb."""

import configparser
import logging
import os
import pathlib
import re
import shutil
import subprocess
import time
from typing import Any
from urllib import parse

from plinth import action_utils
from plinth.actions import privileged, secret_str
from plinth.modules.gitweb.forms import RepositoryValidator, get_name_from_url
from plinth.modules.gitweb.manifest import GIT_REPO_PATH, REPO_DIR_OWNER

logger = logging.getLogger(__name__)


def validate_repo_name(name: str) -> str:
    """Validate a repository name and add .git extension if necessary."""
    RepositoryValidator()(name)
    if not name.endswith('.git'):
        name = name + '.git'

    return name


def validate_repo_url(url: secret_str) -> secret_str:
    """Validate a repository URL."""
    RepositoryValidator(input_should_be='url')(url)
    return url


@privileged
def setup():
    """Configure Gitweb module."""
    # Disable default Apache2 Gitweb configuration.
    action_utils.webserver_disable('gitweb')

    # Configure Git client.
    if not _get_git_global_config('init.defaultBranch'):
        _set_git_global_config('init.defaultBranch', 'main')
    if not _get_git_global_config('credential.helper'):
        _set_git_global_config('credential.helper', 'cache')


def _get_git_global_config(key: str) -> str | None:
    """Return a value from Git global configuration."""
    try:
        value = action_utils.run(['git', 'config', '--global', '--get', key],
                                 check=True).stdout.decode().strip()
    except subprocess.CalledProcessError as exception:
        if exception.returncode == 1:  # Configuration option doesn't exist
            return None
        raise

    return value


def _set_git_global_config(key: str, value: str) -> None:
    """Set a Git global configuration value."""
    action_utils.run(['git', 'config', '--global', key, value], check=True)


def _setup_git_credentials(url: secret_str) -> str:
    """Set up git credential helper and return URL without credentials."""
    url_parts = parse.urlsplit(url)
    safe_netloc = url_parts.netloc.split('@')[-1]
    safe_url = url_parts._replace(netloc=safe_netloc).geturl()
    username = url_parts.username or ''
    password = url_parts.password or ''

    if username or password:
        # Feed credentials to Git credential helper
        input = (f'protocol={url_parts.scheme}\n'
                 f'host={safe_netloc}\n'
                 f'username={username}\n'
                 f'password={password}\n\n')
        env = dict(os.environ, GIT_TERMINAL_PROMPT='0')
        action_utils.run(['git', 'credential', 'approve'],
                         input=input.encode(), stdout=subprocess.DEVNULL,
                         check=True, env=env)

    return safe_url


def _clone_with_progress_report(url: secret_str, repo_dir: pathlib.Path):
    """Clone a repository and write progress info to the file."""
    starttime = time.time()
    status_file = repo_dir / 'clone_progress'
    repo_temp_dir = repo_dir / '.temp'
    # do not ask for credidentials and set low speed timeout
    env = dict(os.environ, GIT_TERMINAL_PROMPT='0', LC_ALL='C',
               GIT_HTTP_LOW_SPEED_LIMIT='100', GIT_HTTP_LOW_SPEED_TIME='60')

    safe_url = _setup_git_credentials(url)
    logger.info(f'Cloning Git repository {safe_url} ...')
    proc = subprocess.Popen(
        ['git', 'clone', '--bare', '--progress', safe_url,
         str(repo_temp_dir)], stderr=subprocess.PIPE, text=True, env=env)
    assert proc.stderr is not None

    # write clone progress to the file
    errors = []
    while True:
        line = proc.stderr.readline()
        if not line:
            break

        if 'error:' in line or 'fatal:' in line:
            errors.append(line.strip())

        currenttime = time.time()
        if currenttime - starttime > 1:
            elapsed = _clone_status_line_to_percent(line)
            if elapsed is not None:
                try:
                    status_file.write_text(elapsed)
                except OSError as error:
                    errors.append(str(error))

            starttime = currenttime

    # make sure process is ended
    try:
        proc.communicate(timeout=10)
    except subprocess.TimeoutExpired:
        proc.kill()

    status_file.unlink()
    if proc.returncode != 0:
        shutil.rmtree(repo_dir)
        logger.error('Git repository cloning failed: %s', '\n'.join(errors))
        raise RuntimeError('Git repository cloning failed.', errors)


def _prepare_clone_repo(url: secret_str, is_private: bool):
    """Prepare cloning a repository."""
    repo_name = get_name_from_url(url)
    if not repo_name.endswith('.git'):
        repo_name = repo_name + '.git'

    repo_dir = GIT_REPO_PATH / repo_name
    os.mkdir(repo_dir)

    status_file = repo_dir / 'clone_progress'
    try:
        if is_private:
            _set_access_status(repo_name, 'private')

        status_file.write_text('0')
    except OSError:
        shutil.rmtree(repo_dir)
        raise


def _clone_status_line_to_percent(line):
    """Parse Git clone command output."""
    result = re.match(r'.* ([0-9]+)% ', line)
    if result is not None:
        text = result.group(0)
        progress = int(result.group(1))
        if 'Counting objects' in text:
            total_progress = 0.05 * progress
        elif 'Compressing objects' in text:
            total_progress = 5 + 0.05 * progress
        elif 'Receiving objects' in text:
            total_progress = 10 + 0.6 * progress
        elif 'Resolving deltas' in text:
            total_progress = 70 + 0.3 * progress
        else:
            return None

        return str(int(total_progress))

    return None


def _clone_repo(url: secret_str, description: str, owner: str,
                keep_ownership: bool):
    """Clone a repository."""
    repo = get_name_from_url(url)
    if not repo.endswith('.git'):
        repo = repo + '.git'

    repo_path = GIT_REPO_PATH / repo
    repo_temp_path = repo_path / '.temp'

    _clone_with_progress_report(url, repo_path)

    for item in os.listdir(repo_temp_path):
        shutil.move(os.path.join(repo_temp_path, item), repo_path)

    shutil.rmtree(repo_temp_path)
    if not keep_ownership:
        action_utils.run(
            ['chown', '-R', f'{REPO_DIR_OWNER}:{REPO_DIR_OWNER}', repo],
            cwd=GIT_REPO_PATH, check=True)

    _set_repo_description(repo, description)
    _set_repo_owner(repo, owner)


def _create_repo(repo: str, description: str, owner: str, is_private: bool,
                 keep_ownership: bool):
    """Create an empty repository."""
    try:
        action_utils.run(['git', 'init', '-q', '--bare', repo],
                         cwd=GIT_REPO_PATH, check=True)
        if not keep_ownership:
            action_utils.run(
                ['chown', '-R', f'{REPO_DIR_OWNER}:{REPO_DIR_OWNER}', repo],
                cwd=GIT_REPO_PATH, check=True)
        _set_repo_description(repo, description)
        _set_repo_owner(repo, owner)
        if is_private:
            _set_access_status(repo, 'private')
    except (subprocess.CalledProcessError, OSError):
        repo_path = GIT_REPO_PATH / repo
        if repo_path.is_dir():
            shutil.rmtree(repo_path)
        raise


def _get_default_branch(repo):
    """Get default branch of the repository."""
    repo_path = GIT_REPO_PATH / repo

    return action_utils.run_as_user(
        ['git', '-C',
         str(repo_path), 'symbolic-ref', '--short', 'HEAD'],
        username=REPO_DIR_OWNER, check=True).stdout.decode().strip()


def _get_repo_description(repo):
    """Set description of the repository."""
    description_file = GIT_REPO_PATH / repo / 'description'
    if description_file.exists():
        description = description_file.read_text()
    else:
        description = ''

    return description


def _set_repo_description(repo, description):
    """Set description of the repository."""
    description_file = GIT_REPO_PATH / repo / 'description'
    description_file.write_text(description)


def _get_repo_owner(repo):
    """Set repository's owner name."""
    repo_config = GIT_REPO_PATH / repo / 'config'
    config = configparser.ConfigParser()
    config.read(repo_config)
    try:
        owner = config['gitweb']['owner']
    except KeyError:
        owner = ''

    return owner


def _set_repo_owner(repo, owner):
    """Set repository's owner name."""
    repo_config = GIT_REPO_PATH / repo / 'config'
    config = configparser.ConfigParser()
    config.read(repo_config)
    if not config.has_section('gitweb'):
        config.add_section('gitweb')

    config['gitweb']['owner'] = owner
    with repo_config.open('w', encoding='utf-8') as file_handle:
        config.write(file_handle)


def _get_access_status(repo):
    """Get repository's access status."""
    private_file = GIT_REPO_PATH / repo / 'private'
    if private_file.exists():
        return 'private'

    return 'public'


def _set_access_status(repo, status):
    """Set repository as private or public."""
    private_file = GIT_REPO_PATH / repo / 'private'
    if status == 'private':
        private_file.touch()
    elif status == 'public':
        private_file.unlink(missing_ok=True)


def _get_branches(repo):
    """Return list of the branches in the repository."""
    process = action_utils.run_as_user(
        ['git', '-C', repo, 'branch', '--format=%(refname:short)'],
        cwd=GIT_REPO_PATH, username=REPO_DIR_OWNER, check=True)

    return process.stdout.decode().strip().split()


@privileged
def get_branches(name: str) -> dict[str, Any]:
    """Check whether a branch exists in the repository."""
    repo = validate_repo_name(name)
    return dict(default_branch=_get_default_branch(repo),
                branches=_get_branches(repo))


@privileged
def rename_repo(old_name: str, new_name: str):
    """Rename a repository."""
    old_name = validate_repo_name(old_name)
    new_name = validate_repo_name(new_name)
    oldpath = GIT_REPO_PATH / old_name
    newpath = GIT_REPO_PATH / new_name
    oldpath.rename(newpath)


@privileged
def set_default_branch(name: str, branch: str):
    """Set description of the repository."""
    repo = validate_repo_name(name)
    if branch not in _get_branches(repo):
        raise ValueError('No such branch')

    action_utils.run_as_user(
        ['git', '-C', repo, 'symbolic-ref', 'HEAD', f'refs/heads/{branch}'],
        cwd=GIT_REPO_PATH, check=True, username=REPO_DIR_OWNER)


@privileged
def set_repo_description(name: str, description: str):
    """Set description of the repository."""
    repo = validate_repo_name(name)
    _set_repo_description(repo, description)


@privileged
def set_repo_owner(name: str, owner: str):
    """Set repository's owner name."""
    repo = validate_repo_name(name)
    _set_repo_owner(repo, owner)


@privileged
def set_repo_access(name: str, access: str):
    """Set repository's access status."""
    repo = validate_repo_name(name)
    if access not in ('public', 'private'):
        raise ValueError('Invalid access parameter')

    _set_access_status(repo, access)


@privileged
def repo_info(name: str) -> dict[str, str]:
    """Get information about repository."""
    repo = validate_repo_name(name)
    repo_path = GIT_REPO_PATH / repo
    if not repo_path.exists():
        raise RuntimeError('Repository not found')

    return dict(name=repo[:-4], description=_get_repo_description(repo),
                owner=_get_repo_owner(repo), access=_get_access_status(repo),
                default_branch=_get_default_branch(repo))


@privileged
def create_repo(url: secret_str | None = None, name: str | None = None,
                description: str = '', owner: str = '',
                keep_ownership: bool = False, is_private: bool = False,
                skip_prepare: bool = False, prepare_only: bool = False):
    """Create a new or clone a remote repository."""
    if url:
        url = validate_repo_url(url)

    if name:
        repo = validate_repo_name(name)

    if url:
        if not skip_prepare:
            _prepare_clone_repo(url, is_private)

        if not prepare_only:
            _clone_repo(url, description, owner, keep_ownership)
    elif repo is not None:
        _create_repo(repo, description, owner, is_private, keep_ownership)


@privileged
def repo_exists(url: secret_str) -> bool:
    """Return whether remote repository exists."""
    url = validate_repo_url(url)
    safe_url = _setup_git_credentials(url)
    env = dict(os.environ, GIT_TERMINAL_PROMPT='0')
    try:
        action_utils.run(['git', 'ls-remote', safe_url, 'HEAD'], timeout=10,
                         env=env, check=True)
        return True
    except subprocess.CalledProcessError:
        return False


@privileged
def delete_repo(name: str):
    """Delete a git repository."""
    repo = validate_repo_name(name)
    repo_path = GIT_REPO_PATH / repo
    shutil.rmtree(repo_path)


@privileged
def uninstall():
    """Remove git repositories."""
    for item in GIT_REPO_PATH.iterdir():
        shutil.rmtree(item, ignore_errors=True)