#!/usr/bin/env python3
"""Create a local project from the engineering recipe. Never creates remote repositories."""
import argparse
import importlib.util
import json
from pathlib import Path
import re
import shutil
import subprocess

HOME = Path(__file__).resolve().parent


def create(destination, name, components, repository, tag, runner, landscape):
    destination = Path(destination).resolve()
    if not re.fullmatch('[a-z][a-z0-9-]*', name):
        raise ValueError('Use a lowercase project name with optional digits and hyphens')
    if destination.exists():
        raise ValueError('Destination must not exist; existing project files are never overwritten')
    commit = subprocess.check_output(['git', '-C', str(HOME), 'rev-parse', tag + '^{commit}'], text=True).strip()
    replacements = {'@PROJECT@': name, '@RUNNER@': runner, '@RUNNER_NAME@': runner, '@LANDSCAPE@': landscape,
                    '@ENGINEERING@': repository.removesuffix('.git'),
                    '@MODULES@': '<module>backend</module>' if 'backend' in components else ''}
    try:
        destination.mkdir(parents=True)
        for part in ['common', *components]:
            for source in (HOME / 'templates' / part).rglob('*'):
                if source.is_file():
                    target = destination / source.relative_to(HOME / 'templates' / part)
                    target.parent.mkdir(parents=True, exist_ok=True)
                    text = source.read_text()
                    for before, after in replacements.items():
                        text = text.replace(before, after)
                    target.write_text(text)
        lock = {'repository': repository, 'tag': tag, 'commit': commit}
        (destination / 'engineering.lock.json').write_text(json.dumps(lock, indent=2) + '\n')
        (destination / 'scripts').mkdir()
        shutil.copy2(HOME / 'bootstrap.py', destination / 'scripts/engineering.py')
        settings = {'PROJECT_NAME': name, 'BACKEND_MODULE': 'backend' if 'backend' in components else '',
                    'FRONTEND_MODULE': 'frontend' if 'frontend' in components else '',
                    'FORMAT_DIRECTORIES': 'backend/src', 'COMPOSE_PROJECT': name + '-production',
                    'BROWSER_TESTS': 'false', 'CI_DATABASE': 'false',
                    'TARGET_PLATFORM': 'linux/amd64', 'RUNNER_LABEL': runner,
                    'RUNNER_NAME': runner, 'RUNNER_SCOPE': 'user',
                    'FRONTEND_TEST_COMMAND': '["npm","test"]', 'DEPENDENCY_SERVICES': '',
                    'REQUIRED_DEPLOY_SECRETS': ''}
        (destination / 'engineering.properties').write_text(''.join(k + '=' + v + '\n' for k, v in settings.items()))
        services = []
        published_role = 'frontend' if 'frontend' in components else 'backend'
        for role in components:
            services.append(f'''  {role}:
    image: ${{{role.upper()}_IMAGE:?Required verified digest}}
    platform: linux/amd64
    restart: unless-stopped
    labels:
      nl.agilecc.release: ${{RELEASE_VERSION:?Required version}}
      nl.agilecc.revision: ${{RELEASE_SHA:?Required SHA}}
''')
            if role == published_role:
                services.append("    ports:\n      - '${BIND_IP:?Required private IP}:${FRONTEND_PORT:?Required port}:8080'\n")
        (destination / 'deploy/compose.yaml').write_text('services:\n' + ''.join(services))
        if published_role == 'backend':
            p = destination / 'deploy/health.sh'
            p.write_text(p.read_text().replace('$FRONTEND_PORT/', '$FRONTEND_PORT/hello'))
        spec = importlib.util.spec_from_file_location('bootstrap', HOME / 'bootstrap.py')
        module = importlib.util.module_from_spec(spec)
        spec.loader.exec_module(module)
        module.materialize(destination)
    except BaseException:
        shutil.rmtree(destination)
        raise
    return destination


def main():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument('name')
    parser.add_argument('destination', type=Path)
    parser.add_argument('--components', choices=['backend', 'frontend', 'both'], default='both')
    parser.add_argument('--repository', default='http://192.168.2.28:3000/wanjakrah/engineering.git')
    parser.add_argument('--version', required=True)
    parser.add_argument('--runner', default='mini-pc', help='Shared Gitea host runner label (default: mini-pc)')
    parser.add_argument('--landscape', default='http://192.168.2.28:3000/wanjakrah/landscape')
    args = parser.parse_args()
    try:
        path = create(args.destination, args.name,
                      ['backend', 'frontend'] if args.components == 'both' else [args.components],
                      args.repository, args.version, args.runner, args.landscape)
        print('Created ' + str(path))
    except (ValueError, OSError, subprocess.CalledProcessError) as error:
        parser.exit(1, str(error) + '\n')


if __name__ == '__main__':
    main()