import 'dart:ffi';
import 'dart:io';

import 'package:jadb/_data_ingestion/jmdict/table_names.dart';
import 'package:jadb/_data_ingestion/kanjidic/table_names.dart';
import 'package:jadb/_data_ingestion/radkfile/table_names.dart';
import 'package:jadb/_data_ingestion/tanos-jlpt/table_names.dart';
import 'package:sqflite_common_ffi/sqflite_ffi.dart';
import 'package:sqlite3/open.dart';

Future<Database> openLocalDb({
  String? libsqlitePath,
  String? jadbPath,
  bool readWrite = false,
  bool assertTablesExist = true,
  bool walMode = false,
}) async {
  libsqlitePath ??= Platform.environment['LIBSQLITE_PATH'];
  jadbPath ??= Platform.environment['JADB_PATH'];
  jadbPath ??= Directory.current.uri.resolve('jadb.sqlite').path;

  libsqlitePath = (libsqlitePath == null)
      ? null
      : File(libsqlitePath).resolveSymbolicLinksSync();
  jadbPath = File(jadbPath).resolveSymbolicLinksSync();

  if (libsqlitePath == null) {
    throw Exception("LIBSQLITE_PATH is not set");
  }

  if (!File(libsqlitePath).existsSync()) {
    throw Exception("LIBSQLITE_PATH does not exist: $libsqlitePath");
  }

  if (!File(jadbPath).existsSync()) {
    throw Exception("JADB_PATH does not exist: $jadbPath");
  }

  final db = await createDatabaseFactoryFfi(
    ffiInit: () =>
        open.overrideForAll(() => DynamicLibrary.open(libsqlitePath!)),
  ).openDatabase(
    jadbPath,
    options: OpenDatabaseOptions(
      onConfigure: (db) async {
        if (walMode) {
          await db.execute("PRAGMA journal_mode = WAL");
        }
        await db.execute("PRAGMA foreign_keys = ON");
      },
      readOnly: !readWrite,
    ),
  );

  if (assertTablesExist) {
    await _assertTablesExist(db);
  }

  return db;
}

Future<void> _assertTablesExist(Database db) async {
  final Set<String> tables = await db
      .query(
    'sqlite_master',
    columns: ['name'],
    where: 'type = ?',
    whereArgs: ['table'],
  )
      .then((result) {
    return result.map((row) => row['name'] as String).toSet();
  });

  final Set<String> expectedTables = {
    ...JMdictTableNames.allTables,
    ...KANJIDICTableNames.allTables,
    ...RADKFILETableNames.allTables,
    ...TanosJLPTTableNames.allTables,
  };

  final missingTables = expectedTables.difference(tables);

  if (missingTables.isNotEmpty) {
    throw Exception([
      'Missing tables:',
      missingTables.map((table) => '  - $table').join('\n'),
      '',
      'Found tables:\n',
      tables.map((table) => '  - $table').join('\n'),
      '',
      'Please ensure the database is correctly set up.',
    ].join('\n'));
  }
}