#!/usr/bin/env python3
"""Run registered imports in the existing, resource-limited batch profile."""
import json
import os
import pathlib
import shutil
import signal
import subprocess
import sys
import tempfile
import uuid


def available_memory_kib():
    meminfo = dict(line.split(':', 1) for line in pathlib.Path('/proc/meminfo').read_text().splitlines())
    return int(meminfo['MemAvailable'].split()[0])


def main():
    arguments = sys.argv[1:]
    registry = json.loads(pathlib.Path(__file__).with_name('finance-batch-imports.json').read_text())
    if not arguments or arguments[0] not in registry:
        print('Unsupported import; register the command in finance-batch-imports.json first.', file=sys.stderr)
        return 64

    # Keep a GiB available to the host in addition to this import's one-GiB cap.
    if available_memory_kib() < 2 * 1024 * 1024:
        print('Available memory is below 2GiB; no import container started. Retry after other tasks finish.', file=sys.stderr)
        return 75

    environment = os.environ.copy()
    environment['FINANCE_BATCH_MEMORY_LIMIT'] = '1g'
    environment['RUN_MIGRATIONS'] = '0'
    image = subprocess.check_output(['docker', 'inspect', 'caiwu_app', '--format', '{{.Config.Image}}'], text=True).strip()
    if not image.startswith('caiwu_akaunting:'):
        print('Unsupported active finance image; no import container started.', file=sys.stderr)
        return 65
    environment['IMAGE_TAG'] = image.split(':', 1)[1]
    container_name = 'caiwu_import_' + uuid.uuid4().hex
    command = ['docker', 'compose', '-f', 'compose.jiangling.yml', '--profile', 'batch', 'run', '--rm', '-T', '--no-deps', '--name', container_name]

    # Copy explicit host input files into a private per-run directory. The source
    # is never modified; the container gets read-only copies readable by www-data.
    with tempfile.TemporaryDirectory(prefix='caiwu-import-') as staging:
        inputs = pathlib.Path(staging) / 'inputs'
        inputs.mkdir(mode=0o755)
        staged_arguments = [arguments[0]]
        staged_count = 0
        for argument in arguments[1:]:
            prefix = ''
            value = argument
            if argument.startswith(('--file=', '--path=')):
                prefix, value = argument.split('=', 1)
                prefix += '='
            source = pathlib.Path(value)
            if not source.is_absolute():
                source = pathlib.Path(os.environ.get('CAIWU_BATCH_CALLER_DIR', os.getcwd())) / source
            if (prefix or not argument.startswith('-')) and source.is_file():
                parent = inputs / str(staged_count)
                parent.mkdir(mode=0o755)
                destination = parent / source.name
                shutil.copyfile(source, destination)
                destination.chmod(0o444)
                staged_arguments.append(prefix + '/run/caiwu-import/' + parent.name + '/' + destination.name)
                staged_count += 1
            else:
                staged_arguments.append(argument)
        if staged_count:
            command += ['--volume', str(inputs) + ':/run/caiwu-import:ro']
        command += ['--entrypoint', 'php', 'batch', '-d', 'memory_limit=512M', 'artisan', *staged_arguments]
        print('Import limits: 1 CPU, 1GiB RAM, no Swap, PHP 512MiB; existing synchronization lock held.', flush=True)
        try:
            return subprocess.run(command, env=environment, timeout=3600).returncode
        except subprocess.TimeoutExpired:
            print('Import exceeded one hour; stop and inspect its checkpoint before retrying.', file=sys.stderr)
            return 124
        except KeyboardInterrupt:
            return 130
        finally:
            # Killing only the Compose client would leave the job consuming RAM.
            subprocess.run(['docker', 'rm', '--force', container_name], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, timeout=15)


if __name__ == '__main__':
    def interrupted(signum, frame):
        raise KeyboardInterrupt
    signal.signal(signal.SIGTERM, interrupted)
    signal.signal(signal.SIGHUP, interrupted)
    sys.exit(main())