/* 
 * This file is part of Stack Wallet.
 * 
 * Copyright (c) 2023 Cypher Stack
 * All Rights Reserved.
 * The code is distributed under GPLv3 license, see LICENSE file for details.
 * Generated by Cypher Stack on 2023-05-26
 *
 */

import 'package:flutter/foundation.dart';
import 'package:isar/isar.dart';
import 'package:tuple/tuple.dart';

import '../../db/hive/db.dart';
import '../../models/exchange/active_pair.dart';
import '../../models/exchange/aggregate_currency.dart';
import '../../models/isar/exchange_cache/currency.dart';
import '../../models/isar/exchange_cache/pair.dart';
import '../../utilities/enums/exchange_rate_type_enum.dart';
import '../../utilities/logger.dart';
import '../../utilities/prefs.dart';
import '../../utilities/stack_file_system.dart';
import 'change_now/change_now_exchange.dart';
import 'majestic_bank/majestic_bank_exchange.dart';
import 'nanswap/nanswap_exchange.dart';
import 'trocador/trocador_exchange.dart';

class ExchangeDataLoadingService {
  ExchangeDataLoadingService._();
  static final ExchangeDataLoadingService _instance =
      ExchangeDataLoadingService._();
  static ExchangeDataLoadingService get instance => _instance;

  Isar? _isar;
  Isar get isar => _isar!;

  VoidCallback? onLoadingError;
  VoidCallback? onLoadingComplete;

  static const int cacheVersion = 1;

  static int get currentCacheVersion =>
      DB.instance.get<dynamic>(
        boxName: DB.boxNameDBInfo,
        key: "exchange_data_cache_version",
      ) as int? ??
      0;

  Future<void> _updateCurrentCacheVersion(int version) async {
    await DB.instance.put<dynamic>(
      boxName: DB.boxNameDBInfo,
      key: "exchange_data_cache_version",
      value: version,
    );
  }

  Future<void> initDB() async {
    if (_isar != null) return;
    await _isar?.close();
    _isar = await Isar.open(
      [
        CurrencySchema,
        // PairSchema,
      ],
      directory: (await StackFileSystem.applicationIsarDirectory()).path,
      // inspector: kDebugMode,
      inspector: false,
      name: "exchange_cache",
      maxSizeMiB: 64,
    );
  }

  Future<void> setCurrenciesIfEmpty(
    ActivePair? pair,
    ExchangeRateType rateType,
  ) async {
    if (pair?.send == null && pair?.receive == null) {
      if (await isar.currencies.count() > 0) {
        pair?.setSend(
          await getAggregateCurrency(
            "BTC",
            rateType,
            null,
          ),
          notifyListeners: false,
        );

        pair?.setReceive(
          await getAggregateCurrency(
            "XMR",
            rateType,
            null,
          ),
          notifyListeners: false,
        );
      }
    }
  }

  Future<AggregateCurrency?> getAggregateCurrency(
    String ticker,
    ExchangeRateType rateType,
    String? contract,
  ) async {
    final currencies = await ExchangeDataLoadingService.instance.isar.currencies
        .filter()
        .group(
          (q) => rateType == ExchangeRateType.fixed
              ? q
                  .rateTypeEqualTo(SupportedRateType.both)
                  .or()
                  .rateTypeEqualTo(SupportedRateType.fixed)
              : q
                  .rateTypeEqualTo(SupportedRateType.both)
                  .or()
                  .rateTypeEqualTo(SupportedRateType.estimated),
        )
        .and()
        .tickerEqualTo(
          ticker,
          caseSensitive: false,
        )
        .and()
        .tokenContractEqualTo(contract)
        .findAll();

    final items = currencies
        .map((e) => Tuple2(e.exchangeName, e))
        .toList(growable: false);

    return items.isNotEmpty
        ? AggregateCurrency(exchangeCurrencyPairs: items)
        : null;
  }

  bool get isLoading => _locked;

  bool _locked = false;

  Future<void> loadAll() async {
    if (!_locked) {
      _locked = true;
      if (_isar == null) {
        await initDB();
      }
      Logging.instance.log(
        "ExchangeDataLoadingService.loadAll starting...",
        level: LogLevel.Info,
      );
      final start = DateTime.now();
      try {
        /*
        // Old exchange data loading code.
        await Future.wait([
          _loadChangeNowCurrencies(),
          // _loadChangeNowFixedRatePairs(),
          // _loadChangeNowEstimatedRatePairs(),
          // loadSimpleswapFixedRateCurrencies(ref),
          // loadSimpleswapFloatingRateCurrencies(ref),
          loadMajesticBankCurrencies(),
          loadTrocadorCurrencies(),
        ]);

        // quicker to load available currencies on the fly for a specific base currency
        // await _loadChangeNowFixedRatePairs();
        // await _loadChangeNowEstimatedRatePairs();
         */

        // Exchanges which support Tor just get treated normally.
        final futures = [
          loadMajesticBankCurrencies(),
          loadTrocadorCurrencies(),
          loadNanswapCurrencies(),
        ];

        // If using Tor, don't load data for exchanges which don't support Tor.
        //
        // Add to this list when adding an exchange which doesn't supports Tor.
        if (!Prefs.instance.useTor) {
          futures.add(_loadChangeNowCurrencies());
        }

        // wait for all loading futures to complete
        await Future.wait(futures);

        Logging.instance.log(
          "ExchangeDataLoadingService.loadAll finished in ${DateTime.now().difference(start).inSeconds} seconds",
          level: LogLevel.Info,
        );
        onLoadingComplete?.call();
        await _updateCurrentCacheVersion(cacheVersion);
      } catch (e, s) {
        Logging.instance.log(
          "ExchangeDataLoadingService.loadAll failed after ${DateTime.now().difference(start).inSeconds} seconds: $e\n$s",
          level: LogLevel.Error,
        );
        onLoadingError?.call();
      }
      _locked = false;
    }
  }

  Future<void> _loadChangeNowCurrencies() async {
    if (_isar == null) {
      await initDB();
    }
    final exchange = ChangeNowExchange.instance;
    final responseCurrencies = await exchange.getAllCurrencies(false);
    if (responseCurrencies.value != null) {
      await isar.writeTxn(() async {
        final idsToDelete = await isar.currencies
            .where()
            .exchangeNameEqualTo(ChangeNowExchange.exchangeName)
            .idProperty()
            .findAll();
        await isar.currencies.deleteAll(idsToDelete);
        await isar.currencies.putAll(responseCurrencies.value!);
      });
    } else {
      Logging.instance.log(
        "Failed to load changeNOW currencies: ${responseCurrencies.exception?.message}",
        level: LogLevel.Error,
      );
      return;
    }
  }

  // Future<void> _loadChangeNowFixedRatePairs() async {
  //   final exchange = ChangeNowExchange.instance;
  //
  //   final responsePairs = await compute(exchange.getAllPairs, true);
  //
  //   if (responsePairs.value != null) {
  //     await isar.writeTxn(() async {
  //       final idsToDelete2 = await isar.pairs
  //           .where()
  //           .exchangeNameEqualTo(ChangeNowExchange.exchangeName)
  //           .filter()
  //           .rateTypeEqualTo(SupportedRateType.fixed)
  //           .idProperty()
  //           .findAll();
  //       await isar.pairs.deleteAll(idsToDelete2);
  //       await isar.pairs.putAll(responsePairs.value!);
  //     });
  //   } else {
  //     Logging.instance.log(
  //         "Failed to load changeNOW available fixed rate pairs: ${responsePairs.exception?.message}",
  //         level: LogLevel.Error);
  //     return;
  //   }
  // }

  // Future<void> _loadChangeNowEstimatedRatePairs() async {
  //   final exchange = ChangeNowExchange.instance;
  //
  //   final responsePairs = await compute(exchange.getAllPairs, false);
  //
  //   if (responsePairs.value != null) {
  //     await isar.writeTxn(() async {
  //       final idsToDelete = await isar.pairs
  //           .where()
  //           .exchangeNameEqualTo(ChangeNowExchange.exchangeName)
  //           .filter()
  //           .rateTypeEqualTo(SupportedRateType.estimated)
  //           .idProperty()
  //           .findAll();
  //       await isar.pairs.deleteAll(idsToDelete);
  //       await isar.pairs.putAll(responsePairs.value!);
  //     });
  //   } else {
  //     Logging.instance.log(
  //         "Failed to load changeNOW available floating rate pairs: ${responsePairs.exception?.message}",
  //         level: LogLevel.Error);
  //     return;
  //   }
  // }
  //
  // Future<void> loadSimpleswapFloatingRateCurrencies(WidgetRef ref) async {
  //   final exchange = SimpleSwapExchange();
  //   final responseCurrencies = await exchange.getAllCurrencies(false);
  //
  //   if (responseCurrencies.value != null) {
  //     ref
  //         .read(availableSimpleswapCurrenciesProvider)
  //         .updateFloatingCurrencies(responseCurrencies.value!);
  //
  //     final responsePairs = await exchange.getAllPairs(false);
  //
  //     if (responsePairs.value != null) {
  //       ref
  //           .read(availableSimpleswapCurrenciesProvider)
  //           .updateFloatingPairs(responsePairs.value!);
  //     } else {
  //       Logging.instance.log(
  //         "loadSimpleswapFloatingRateCurrencies: $responsePairs",
  //         level: LogLevel.Warning,
  //       );
  //     }
  //   } else {
  //     Logging.instance.log(
  //       "loadSimpleswapFloatingRateCurrencies: $responseCurrencies",
  //       level: LogLevel.Warning,
  //     );
  //   }
  // }
  //
  // Future<void> loadSimpleswapFixedRateCurrencies(WidgetRef ref) async {
  //   final exchange = SimpleSwapExchange();
  //   final responseCurrencies = await exchange.getAllCurrencies(true);
  //
  //   if (responseCurrencies.value != null) {
  //     ref
  //         .read(availableSimpleswapCurrenciesProvider)
  //         .updateFixedCurrencies(responseCurrencies.value!);
  //
  //     final responsePairs = await exchange.getAllPairs(true);
  //
  //     if (responsePairs.value != null) {
  //       ref
  //           .read(availableSimpleswapCurrenciesProvider)
  //           .updateFixedPairs(responsePairs.value!);
  //     } else {
  //       Logging.instance.log(
  //         "loadSimpleswapFixedRateCurrencies: $responsePairs",
  //         level: LogLevel.Warning,
  //       );
  //     }
  //   } else {
  //     Logging.instance.log(
  //       "loadSimpleswapFixedRateCurrencies: $responseCurrencies",
  //       level: LogLevel.Warning,
  //     );
  //   }
  // }

  Future<void> loadMajesticBankCurrencies() async {
    if (_isar == null) {
      await initDB();
    }
    final exchange = MajesticBankExchange.instance;
    final responseCurrencies = await exchange.getAllCurrencies(false);

    if (responseCurrencies.value != null) {
      await isar.writeTxn(() async {
        final idsToDelete = await isar.currencies
            .where()
            .exchangeNameEqualTo(MajesticBankExchange.exchangeName)
            .idProperty()
            .findAll();
        await isar.currencies.deleteAll(idsToDelete);
        await isar.currencies.putAll(responseCurrencies.value!);
      });
    } else {
      Logging.instance.log(
        "loadMajesticBankCurrencies: $responseCurrencies",
        level: LogLevel.Warning,
      );
    }
  }

  Future<void> loadTrocadorCurrencies() async {
    if (_isar == null) {
      await initDB();
    }
    final exchange = TrocadorExchange.instance;
    final responseCurrencies = await exchange.getAllCurrencies(false);

    if (responseCurrencies.value != null) {
      await isar.writeTxn(() async {
        final idsToDelete = await isar.currencies
            .where()
            .exchangeNameEqualTo(TrocadorExchange.exchangeName)
            .idProperty()
            .findAll();
        await isar.currencies.deleteAll(idsToDelete);
        await isar.currencies.putAll(responseCurrencies.value!);
      });
    } else {
      Logging.instance.log(
        "loadTrocadorCurrencies: $responseCurrencies",
        level: LogLevel.Warning,
      );
    }
  }

  Future<void> loadNanswapCurrencies() async {
    if (_isar == null) {
      await initDB();
    }
    final responseCurrencies =
        await NanswapExchange.instance.getAllCurrencies(false);

    if (responseCurrencies.value != null) {
      await isar.writeTxn(() async {
        final idsToDelete = await isar.currencies
            .where()
            .exchangeNameEqualTo(NanswapExchange.exchangeName)
            .idProperty()
            .findAll();
        await isar.currencies.deleteAll(idsToDelete);
        await isar.currencies.putAll(responseCurrencies.value!);
      });
    } else {
      Logging.instance.log(
        "loadNanswapCurrencies: $responseCurrencies",
        level: LogLevel.Warning,
      );
    }
  }

  // Future<void> loadMajesticBankPairs() async {
  //   final exchange = MajesticBankExchange.instance;
  //
  //   final responsePairs = await exchange.getAllPairs(false);
  //   if (responsePairs.value != null) {
  //     await isar.writeTxn(() async {
  //       final idsToDelete2 = await isar.pairs
  //           .where()
  //           .exchangeNameEqualTo(MajesticBankExchange.exchangeName)
  //           .idProperty()
  //           .findAll();
  //       await isar.pairs.deleteAll(idsToDelete2);
  //       await isar.pairs.putAll(responsePairs.value!);
  //     });
  //   } else {
  //     Logging.instance.log(
  //       "loadMajesticBankCurrencies: $responsePairs",
  //       level: LogLevel.Warning,
  //     );
  //   }
  // }
}