#!/usr/bin/env python3
"""Generate Firefox update metadata from LinkLog signed XPI artifacts."""

import hashlib
import json
import re
import sys
import zipfile
from pathlib import Path


ROOT = Path(__file__).resolve().parents[2]
SIGNED_DIR = ROOT / 'XPI' / 'signed'
MANIFEST_PATH = ROOT / 'webextension' / 'manifest.json'
UPDATES_PATH = ROOT / 'webextension' / 'updates.json'
ABOUT_TEMPLATE_PATH = ROOT / 'frontend' / 'templates' / 'about.html'
RAW_BASE_URL = 'https://git.kolkman.org/olaf/Link-Log/raw/branch/main'
XPI_NAME_RE = re.compile(r'LinkLog-(\d+\.\d+\.\d+)\.xpi')
ABOUT_XPI_URL_RE = re.compile(rf'{re.escape(RAW_BASE_URL)}/XPI/signed/LinkLog-\d+\.\d+\.\d+\.xpi')


def fail(message: str) -> None:
    raise SystemExit(f'update metadata generation failed: {message}')


def version_key(version: str) -> tuple[int, int, int]:
    return tuple(int(part) for part in version.split('.'))


def read_packaged_manifest(xpi_path: Path) -> dict:
    try:
        with zipfile.ZipFile(xpi_path) as archive:
            if archive.testzip() is not None:
                fail(f'{xpi_path.relative_to(ROOT)} contains a corrupt member')
            return json.loads(archive.read('manifest.json'))
    except (OSError, KeyError, json.JSONDecodeError, zipfile.BadZipFile) as error:
        fail(f'could not read {xpi_path.relative_to(ROOT)}: {error}')


def sha256_digest(xpi_path: Path) -> str:
    with xpi_path.open('rb') as xpi_file:
        return hashlib.file_digest(xpi_file, 'sha256').hexdigest()


def update_about_plugin_link(xpi_path: Path) -> None:
    about_template = ABOUT_TEMPLATE_PATH.read_text()
    latest_xpi_url = f'{RAW_BASE_URL}/{xpi_path.relative_to(ROOT).as_posix()}'
    updated_template, replacements = ABOUT_XPI_URL_RE.subn(latest_xpi_url, about_template)
    if replacements != 1:
        fail(f'expected one signed XPI link in {ABOUT_TEMPLATE_PATH.relative_to(ROOT)}; found {replacements}')
    ABOUT_TEMPLATE_PATH.write_text(updated_template)


def main() -> None:
    source_manifest = json.loads(MANIFEST_PATH.read_text())
    addon_id = source_manifest.get('browser_specific_settings', {}).get('gecko', {}).get('id')
    if not addon_id:
        fail('webextension/manifest.json is missing browser_specific_settings.gecko.id')

    releases = []
    for xpi_path in SIGNED_DIR.glob('LinkLog-*.xpi'):
        match = XPI_NAME_RE.fullmatch(xpi_path.name)
        if not match:
            continue
        version = match.group(1)
        manifest = read_packaged_manifest(xpi_path)
        if manifest.get('version') != version:
            fail(f'{xpi_path.relative_to(ROOT)} manifest version does not match its filename')
        gecko = manifest.get('browser_specific_settings', {}).get('gecko', {})
        if gecko.get('id') != addon_id:
            fail(f'{xpi_path.relative_to(ROOT)} add-on id does not match webextension/manifest.json')
        strict_min_version = gecko.get('strict_min_version')
        if not strict_min_version:
            fail(f'{xpi_path.relative_to(ROOT)} is missing browser_specific_settings.gecko.strict_min_version')
        releases.append((version, xpi_path, strict_min_version, sha256_digest(xpi_path)))

    if not releases:
        fail(f'no signed LinkLog release artifacts found in {SIGNED_DIR.relative_to(ROOT)}')

    releases.sort(key=lambda release: version_key(release[0]), reverse=True)
    updates = [
        {
            'version': version,
            'update_link': f'{RAW_BASE_URL}/{xpi_path.relative_to(ROOT).as_posix()}',
            'update_hash': f'sha256:{digest}',
            'applications': {
                'gecko': {
                    'strict_min_version': strict_min_version,
                },
            },
        }
        for version, xpi_path, strict_min_version, digest in releases
    ]
    UPDATES_PATH.write_text(json.dumps({'addons': {addon_id: {'updates': updates}}}, indent=2) + '\n')
    update_about_plugin_link(releases[0][1])
    print(f'updated {UPDATES_PATH.relative_to(ROOT)} with {len(updates)} signed release(s)')


if __name__ == '__main__':
    main()