// SPDX-FileCopyrightText: 2019-Present Christian Kußowski
// SPDX-FileCopyrightText: 2019-Present Contributors to FluffyChat
//
// SPDX-License-Identifier: AGPL-3.0-or-later

import 'package:matrix/matrix.dart';
import 'package:tatchat/utils/miniapp_meta.dart';

/// Account data key that holds the list of installed mini app IDs.
const String installedMiniAppsKey = 'im.tatuchat.miniapps.installed';

/// Prefix of the account data keys that hold a mini app's JSON document.
const String miniAppDataKeyPrefix = 'im.tatuchat.miniapps.data.';

/// Prefix of the account data keys that hold the HTML source of an imported
/// mini app. The key is ``{prefix}{appId}`` and the content is
/// `{name: '...', html: '...'}`.
const String miniAppSourceKeyPrefix = 'im.tatuchat.miniapps.source.';

/// Extension that gives every [Client] access to the mini apps store which is
/// persisted in the user's account data ("localStorage on the server").
extension MiniAppStoreExtension on Client {
  List<String> get installedMiniApps {
    final apps = accountData[installedMiniAppsKey]?.content['apps'];
    if (apps is List) return [...apps.whereType<String>()];
    return [];
  }

  bool isMiniAppInstalled(String appId) => installedMiniApps.contains(appId);

  Future<void> installMiniApp(String appId) async {
    final apps = installedMiniApps;
    if (apps.contains(appId)) return;
    apps.add(appId);
    await setAccountData(userID!, installedMiniAppsKey, {'apps': apps});
    _cacheAccountData(installedMiniAppsKey, {'apps': apps});
  }

  Future<void> uninstallMiniApp(String appId) async {
    final apps = installedMiniApps..remove(appId);
    await setAccountData(userID!, installedMiniAppsKey, {'apps': apps});
    _cacheAccountData(installedMiniAppsKey, {'apps': apps});
    // Clear the custom HTML source if present.
    await setAccountData(userID!, '$miniAppSourceKeyPrefix$appId', {
      'html': '',
      'name': '',
    });
    _cacheAccountData(
      '$miniAppSourceKeyPrefix$appId',
      {'html': '', 'name': ''},
    );
  }

  /// Reads the JSON document of the given mini app. Returns an empty map if
  /// the app never stored anything.
  Map<String, dynamic> getMiniAppData(String appId) =>
      accountData['$miniAppDataKeyPrefix$appId']?.content ?? const {};

  /// Overwrites the JSON document of the given mini app.
  Future<void> setMiniAppData(String appId, Map<String, Object?> data) async {
    final key = '$miniAppDataKeyPrefix$appId';
    await setAccountData(userID!, key, data);
    _cacheAccountData(key, data);
  }

  // ---------- Imported (custom) apps ----------

  /// Stores the HTML source and the manifest of a user-imported mini app and
  /// adds it to the installed list if not already present. The manifest's
  /// [MiniAppMeta.id] is used as the account data key for the app.
  Future<void> importMiniApp({
    required MiniAppMeta meta,
    required String html,
  }) async {
    final sourceKey = '$miniAppSourceKeyPrefix${meta.id}';
    final content = <String, Object?>{
      'name': meta.name,
      'category': meta.category,
      'description': meta.description,
      'logo': meta.logo,
      'inChat': meta.inChat,
      'html': html,
    };
    await setAccountData(userID!, sourceKey, content);
    _cacheAccountData(sourceKey, content);
    final apps = installedMiniApps;
    if (!apps.contains(meta.id)) {
      apps.add(meta.id);
      await setAccountData(userID!, installedMiniAppsKey, {'apps': apps});
      _cacheAccountData(installedMiniAppsKey, {'apps': apps});
    }
  }

  /// Mirrors the just-written account data into the in-memory cache so that
  /// reads right after a write (e.g. a mini app saving and immediately
  /// loading its store) see the new value without waiting for the next sync.
  void _cacheAccountData(String key, Map<String, Object?> content) {
    accountData[key] = BasicEvent(type: key, content: content);
  }

  /// Returns the raw HTML source of an imported mini app, or null if the app
  /// is a built-in app or was never imported.
  String? getMiniAppSource(String appId) {
    final content =
        accountData['$miniAppSourceKeyPrefix$appId']?.content;
    if (content == null) return null;
    final html = content['html'];
    return (html is String && html.isNotEmpty) ? html : null;
  }

  /// Returns the display name of an imported mini app, or null.
  String? getMiniAppName(String appId) {
    final content = accountData['$miniAppSourceKeyPrefix$appId']?.content;
    return _stringContent(content, 'name');
  }

  /// Returns the category of an imported mini app, or null.
  String? getMiniAppCategory(String appId) {
    final content = accountData['$miniAppSourceKeyPrefix$appId']?.content;
    return _stringContent(content, 'category');
  }

  /// Returns the description of an imported mini app, or null.
  String? getMiniAppDescription(String appId) {
    final content = accountData['$miniAppSourceKeyPrefix$appId']?.content;
    return _stringContent(content, 'description');
  }

  /// Returns the logo (data URI or URL) of an imported mini app, or null.
  String? getMiniAppLogo(String appId) {
    final content = accountData['$miniAppSourceKeyPrefix$appId']?.content;
    return _stringContent(content, 'logo');
  }

  /// Whether an imported mini app declares that it can run inside a chat.
  bool getMiniAppInChat(String appId) {
    final content = accountData['$miniAppSourceKeyPrefix$appId']?.content;
    return content?['inChat'] == true;
  }

  String? _stringContent(Map<String, Object?>? content, String key) {
    final value = content?[key];
    return (value is String && value.isNotEmpty) ? value : null;
  }
}