"""Build the website's deterministic, allowlisted source ZIP and text browser.

Run from a complete monorepo checkout. The source archive deliberately excludes
private runtime archives and separately licensed reference corpora.
"""
import argparse
import hashlib
import importlib.util
import json
from pathlib import Path
import shutil
import tempfile
import zipfile

SITE = Path(__file__).resolve().parents[1]
LIMIT = 25 * 1024 * 1024
ARCHIVE = 'nichijoyaku-source.zip'
PREFIX = 'nichijoyaku-source'
BROWSER_SUFFIXES = {'.py': 'python', '.json': 'json', '.yaml': 'yaml', '.yml': 'yaml',
                    '.toml': 'toml', '.md': 'markdown'}


def digest(data):
    return hashlib.sha256(data).hexdigest()


def browser_language(name):
    path = Path(name)
    if name in ('README.md', 'CONTRIBUTING.md', 'LICENSE'):
        return 'markdown' if path.suffix == '.md' else 'text'
    if path.parts[0] not in ('software', 'tools'):
        return None
    if path.name == 'LICENSE':
        return 'text'
    return BROWSER_SUFFIXES.get(path.suffix)


def archive(source, destination):
    """Freeze an already allowlisted directory; no unreviewed tree is read here."""
    destination.mkdir(parents=True, exist_ok=True)
    code = destination / 'code'
    if code.exists():
        shutil.rmtree(code)
    files = {}
    browser = []
    with zipfile.ZipFile(destination / ARCHIVE, 'w', compression=zipfile.ZIP_DEFLATED, compresslevel=9) as bundle:
        for path in sorted(source.rglob('*')):
            if path.is_symlink():
                raise ValueError('Source package cannot contain symlinks')
            if not path.is_file():
                continue
            name = path.relative_to(source).as_posix()
            data = path.read_bytes()
            files[name] = {'sha256': digest(data), 'bytes': len(data)}
            info = zipfile.ZipInfo(f'{PREFIX}/{name}', date_time=(2026, 10, 5, 0, 0, 0))
            info.create_system = 3
            info.external_attr = 0o100644 << 16
            info.compress_type = zipfile.ZIP_DEFLATED
            bundle.writestr(info, data, compresslevel=9)
            language = browser_language(name)
            if language:
                data.decode('utf-8')  # Fail rather than silently corrupt binary text.
                if len(data) >= LIMIT:
                    raise ValueError('Browser source exceeds hosting file limit')
                raw = code / (name + '.txt')
                raw.parent.mkdir(parents=True, exist_ok=True)
                raw.write_bytes(data)
                browser.append({'file': name, 'url': '/downloads/source-v1/code/' + name + '.txt',
                                'language': language, **files[name]})
    data = (destination / ARCHIVE).read_bytes()
    if len(data) >= LIMIT:
        raise ValueError('Source archive exceeds hosting file limit')
    record = {'schema_version': 1, 'archive': {'file': ARCHIVE,
              'url': '/downloads/source-v1/' + ARCHIVE, 'sha256': digest(data),
              'bytes': len(data), 'file_count': len(files)}, 'files': files,
              'browser_files': browser,
              'scope': 'Reviewed source allowlist, edition 1, and retained public provenance; no private prompts or reference Bible corpora.'}
    (destination / 'index.json').write_text(json.dumps(record, ensure_ascii=False, indent=2) + '\n')
    return record


def build(destination):
    spec = importlib.util.spec_from_file_location('source_package', SITE / 'scripts/package-source.py')
    package = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(package)
    with tempfile.TemporaryDirectory() as temporary:
        source = Path(temporary) / 'source'
        package.package(source)
        return archive(source, destination)


if __name__ == '__main__':
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument('--destination', type=Path, default=SITE / 'public/downloads/source-v1')
    record = build(parser.parse_args().destination)
    print(json.dumps(record['archive']))
    print('Browsable files:', len(record['browser_files']))