#!/usr/bin/env python3
"""Finish isolated Classic prerequisites. Never starts a realm or edits live data."""
import argparse
import hashlib
import json
import pathlib
import shutil
import subprocess
import time

parser = argparse.ArgumentParser()
parser.add_argument('--root', required=True)
args = parser.parse_args()
root = pathlib.Path(args.root).resolve()

def status(stage, **extra):
    value = {'at': time.time(), 'stage': stage, 'cutover': False, **extra}
    temporary = root / 'prerequisites-status.tmp'
    temporary.write_text(json.dumps(value, indent=2))
    temporary.replace(root / 'prerequisites-status.json')
    print(stage, flush=True)

def run(*command):
    return subprocess.check_output(command, text=True).strip()

try:
    status('waiting for Classic compilation and client transfer')
    deadline = time.monotonic() + 6 * 3600
    while True:
        state = json.loads(run('docker', 'inspect', 'azerothai-classic-build'))[0]['State']
        if not state['Running']:
            if state['ExitCode'] != 0:
                raise RuntimeError('Classic build failed; inspect docker logs azerothai-classic-build')
            break
        if time.monotonic() > deadline:
            raise RuntimeError('Classic build exceeded six-hour observation window')
        time.sleep(30)
    manifest = json.loads((root / 'client-manifest.json').read_text())
    while not all((root / 'client' / f).exists() and (root / 'client' / f).stat().st_size == v['size'] for f, v in manifest.items()):
        if time.monotonic() > deadline:
            raise RuntimeError('Client transfer incomplete after six hours')
        time.sleep(30)
    status('verifying transferred client archives')
    for filename, expected in manifest.items():
        with (root / 'client' / filename).open('rb') as stream:
            actual = hashlib.file_digest(stream, 'sha256').hexdigest()
        if actual != expected['sha256']:
            raise RuntimeError('Client archive checksum mismatch: ' + filename)
    if shutil.disk_usage(root).free < 8 * 1024**3:
        raise RuntimeError('Less than 8 GiB free for extracted Vanilla data')
    output = root / 'extracted'; output.mkdir(exist_ok=True)
    status('extracting Vanilla maps and navigation data; realm not switched')
    with (root / 'data-extraction.log').open('w') as log:
        subprocess.run([
            'docker', 'run', '--name', 'azerothai-classic-extract', '--cpus', '2', '--memory', '4g',
            '--user', '1000:1000', '-i', '-v', str(root) + ':/work', '-w', '/work/run/bin/tools',
            'azerothai-classic-builder:local', 'bash', './ExtractResources.sh', '/work/client', '/work/extracted'
        ], input='y\n2\n\nn\nn\n\n', text=True, stdout=log, stderr=subprocess.STDOUT, check=True)
    counts = {name: sum(1 for f in (output / name).rglob('*') if f.is_file()) for name in ('dbc', 'maps', 'vmaps', 'mmaps')}
    if not all(counts.values()):
        raise RuntimeError('An extracted data directory is empty: ' + str(counts))
    status('prerequisites extracted; database, connector, roster and gameplay validation remain', files=counts)
except Exception as error:
    status('blocked', error=str(error))
    raise