import 'dart:async';
import 'dart:convert';

import 'package:decimal/decimal.dart';
import 'package:http/http.dart' as http;
import 'package:stackwallet/models/buy/response_objects/crypto.dart';
import 'package:stackwallet/models/buy/response_objects/fiat.dart';
import 'package:stackwallet/models/buy/response_objects/order.dart';
import 'package:stackwallet/models/buy/response_objects/quote.dart';
import 'package:stackwallet/services/buy/buy_response.dart';
import 'package:stackwallet/utilities/enums/coin_enum.dart';
import 'package:stackwallet/utilities/enums/fiat_enum.dart';
import 'package:stackwallet/utilities/logger.dart';
import 'package:stackwallet/utilities/prefs.dart';
import 'package:url_launcher/url_launcher.dart';

class SimplexAPI {
  static const String authority = "simplex-sandbox.stackwallet.com";
  // static const String authority = "localhost";
  static const String scheme = authority == "localhost" ? "http" : "https";

  final _prefs = Prefs.instance;

  SimplexAPI._();
  static final SimplexAPI _instance = SimplexAPI._();
  static SimplexAPI get instance => _instance;

  /// set this to override using standard http client. Useful for testing
  http.Client? client;

  Uri _buildUri(String path, Map<String, String>? params) {
    if (scheme == "http") {
      return Uri.http(authority, path, params);
    }
    return Uri.https(authority, path, params);
  }

  Future<BuyResponse<List<Crypto>>> getSupportedCryptos() async {
    try {
      Map<String, String> headers = {
        'Content-Type': 'application/x-www-form-urlencoded',
      };
      Map<String, String> data = {
        'ROUTE': 'supported_cryptos',
      };
      Uri url = _buildUri('api.php', data);

      var res = await http.post(url, headers: headers);
      if (res.statusCode != 200) {
        throw Exception(
            'getAvailableCurrencies exception: statusCode= ${res.statusCode}');
      }
      final jsonArray = jsonDecode(res.body); // TODO handle if invalid json

      return _parseSupportedCryptos(jsonArray);
    } catch (e, s) {
      Logging.instance.log("getAvailableCurrencies exception: $e\n$s",
          level: LogLevel.Error);
      return BuyResponse(
        exception: BuyException(
          e.toString(),
          BuyExceptionType.generic,
        ),
      );
    }
  }

  BuyResponse<List<Crypto>> _parseSupportedCryptos(dynamic jsonArray) {
    try {
      List<Crypto> cryptos = [];
      List<Fiat> fiats = [];

      for (final crypto in jsonArray as List) {
        // TODO validate jsonArray
        if (isStackCoin("${crypto['ticker_symbol']}")) {
          cryptos.add(Crypto.fromJson({
            'ticker': "${crypto['ticker_symbol']}",
            'name': crypto['name'],
            'network': "${crypto['network']}",
            'contractAddress': "${crypto['contractAddress']}",
            'image': "",
          }));
        }
      }

      return BuyResponse(value: cryptos);
    } catch (e, s) {
      Logging.instance
          .log("_parseSupported exception: $e\n$s", level: LogLevel.Error);
      return BuyResponse(
        exception: BuyException(
          e.toString(),
          BuyExceptionType.generic,
        ),
      );
    }
  }

  Future<BuyResponse<List<Fiat>>> getSupportedFiats() async {
    try {
      Map<String, String> headers = {
        'Content-Type': 'application/x-www-form-urlencoded',
      };
      Map<String, String> data = {
        'ROUTE': 'supported_fiats',
      };
      Uri url = _buildUri('api.php', data);

      var res = await http.post(url, headers: headers);
      if (res.statusCode != 200) {
        throw Exception(
            'getAvailableCurrencies exception: statusCode= ${res.statusCode}');
      }
      final jsonArray = jsonDecode(res.body); // TODO validate json

      return _parseSupportedFiats(jsonArray);
    } catch (e, s) {
      Logging.instance.log("getAvailableCurrencies exception: $e\n$s",
          level: LogLevel.Error);
      return BuyResponse(
        exception: BuyException(
          e.toString(),
          BuyExceptionType.generic,
        ),
      );
    }
  }

  BuyResponse<List<Fiat>> _parseSupportedFiats(dynamic jsonArray) {
    try {
      List<Crypto> cryptos = [];
      List<Fiat> fiats = [];

      for (final fiat in jsonArray as List) {
        if (isSimplexFiat("${fiat['ticker_symbol']}")) {
          // TODO validate list
          fiats.add(Fiat.fromJson({
            'ticker': "${fiat['ticker_symbol']}",
            'name': fiatFromTickerCaseInsensitive("${fiat['ticker_symbol']}")
                .prettyName,
            'minAmount': "${fiat['min_amount']}",
            'maxAmount': "${fiat['max_amount']}",
            'image': "",
          }));
        } // TODO handle else
      }

      return BuyResponse(value: fiats);
    } catch (e, s) {
      Logging.instance
          .log("_parseSupported exception: $e\n$s", level: LogLevel.Error);
      return BuyResponse(
        exception: BuyException(
          e.toString(),
          BuyExceptionType.generic,
        ),
      );
    }
  }

  Future<BuyResponse<SimplexQuote>> getQuote(SimplexQuote quote) async {
    try {
      await _prefs.init();
      String? userID = _prefs.userID;

      Map<String, String> headers = {
        'Content-Type': 'application/x-www-form-urlencoded',
      };
      Map<String, String> data = {
        'ROUTE': 'quote',
        'CRYPTO_TICKER': quote.crypto.ticker.toUpperCase(),
        'FIAT_TICKER': quote.fiat.ticker.toUpperCase(),
        'REQUESTED_TICKER': quote.buyWithFiat
            ? quote.fiat.ticker.toUpperCase()
            : quote.crypto.ticker.toUpperCase(),
        'REQUESTED_AMOUNT': quote.buyWithFiat
            ? "${quote.youPayFiatPrice}"
            : "${quote.youReceiveCryptoAmount}",
      };
      if (userID != null) {
        data['USER_ID'] = userID;
      }
      Uri url = _buildUri('api.php', data);

      var res = await http.get(url, headers: headers);
      if (res.statusCode != 200) {
        throw Exception('getQuote exception: statusCode= ${res.statusCode}');
      }
      final jsonArray = jsonDecode(res.body);
      if (jsonArray.containsKey('error') as bool) {
        throw Exception('getQuote exception: ${jsonArray['error']}');
      }

      jsonArray['quote'] = quote; // Add and pass this on

      return _parseQuote(jsonArray);
    } catch (e, s) {
      Logging.instance.log("getQuote exception: $e\n$s", level: LogLevel.Error);
      return BuyResponse(
        exception: BuyException(
          e.toString(),
          BuyExceptionType.generic,
        ),
      );
    }
  }

  BuyResponse<SimplexQuote> _parseQuote(dynamic jsonArray) {
    try {
      String cryptoAmount = "${jsonArray['digital_money']['amount']}";

      SimplexQuote quote = jsonArray['quote'] as SimplexQuote;
      final SimplexQuote _quote = SimplexQuote(
        crypto: quote.crypto,
        fiat: quote.fiat,
        youPayFiatPrice: quote.buyWithFiat
            ? quote.youPayFiatPrice
            : Decimal.parse("${jsonArray['fiat_money']['base_amount']}"),
        youReceiveCryptoAmount:
            Decimal.parse("${jsonArray['digital_money']['amount']}"),
        id: jsonArray['quote_id'] as String,
        receivingAddress: quote.receivingAddress,
        buyWithFiat: quote.buyWithFiat,
      );

      return BuyResponse(value: _quote);
    } catch (e, s) {
      Logging.instance
          .log("_parseQuote exception: $e\n$s", level: LogLevel.Error);
      return BuyResponse(
        exception: BuyException(
          e.toString(),
          BuyExceptionType.generic,
        ),
      );
    }
  }

  Future<BuyResponse<SimplexOrder>> newOrder(SimplexQuote quote) async {
    // Calling Simplex's API manually:
    // curl --request POST \
    //      --url https://sandbox.test-simplexcc.com/wallet/merchant/v2/payments/partner/data \
    //      --header 'Authorization: ApiKey $apiKey' \
    //      --header 'accept: application/json' \
    //      --header 'content-type: application/json' \
    //      -d '{"account_details": {"app_provider_id": "$publicKey", "app_version_id": "123", "app_end_user_id": "01e7a0b9-8dfc-4988-a28d-84a34e5f0a63", "signup_login": {"timestamp": "1994-11-05T08:15:30-05:00", "ip": "207.66.86.226"}}, "transaction_details": {"payment_details": {"quote_id": "3b58f4b4-ed6f-447c-b96a-ffe97d7b6803", "payment_id": "baaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa", "order_id": "789", "original_http_ref_url": "https://stackwallet.com/simplex", "destination_wallet": {"currency": "BTC", "address": "bc1qjvj9ca8gdsv3g58yrzrk6jycvgnjh9uj35rja2"}}}}'
    try {
      await _prefs.init();
      String? userID = _prefs.userID;
      int? signupEpoch = _prefs.signupEpoch;

      Map<String, String> headers = {
        'Content-Type': 'application/x-www-form-urlencoded',
      };
      Map<String, String> data = {
        'ROUTE': 'order',
        'QUOTE_ID': quote.id,
        'ADDRESS': quote.receivingAddress,
        'CRYPTO_TICKER': quote.crypto.ticker.toUpperCase(),
      };
      if (userID != null) {
        data['USER_ID'] = userID;
      }
      if (signupEpoch != null && signupEpoch != 0) {
        DateTime date = DateTime.fromMillisecondsSinceEpoch(signupEpoch * 1000);
        data['SIGNUP_TIMESTAMP'] =
            date.toIso8601String() + timeZoneFormatter(date.timeZoneOffset);
      }
      Uri url = _buildUri('api.php', data);
      print(data);

      var res = await http.get(url, headers: headers);
      if (res.statusCode != 200) {
        throw Exception('newOrder exception: statusCode= ${res.statusCode}');
      }
      final jsonArray = jsonDecode(res.body); // TODO check if valid json

      SimplexOrder _order = SimplexOrder(
        quote: quote,
        paymentId: "${jsonArray['paymentId']}",
        orderId: "${jsonArray['orderId']}",
        userId: "${jsonArray['userId']}",
      );

      return BuyResponse(value: _order);
    } catch (e, s) {
      Logging.instance.log("newOrder exception: $e\n$s", level: LogLevel.Error);
      return BuyResponse(
        exception: BuyException(
          e.toString(),
          BuyExceptionType.generic,
        ),
      );
    }
  }

  Future<BuyResponse<bool>> redirect(SimplexOrder order) async {
    try {
      Map<String, String> headers = {
        'Content-Type': 'application/x-www-form-urlencoded',
      };
      Map<String, String> data = {
        'ROUTE': 'redirect',
        'PAYMENT_ID': order.paymentId,
      };
      Uri url = _buildUri('api.php', data);

      bool status = await launchUrl(
        url,
        mode: LaunchMode.externalApplication,
      );

      return BuyResponse(value: status);
    } catch (e, s) {
      Logging.instance.log("newOrder exception: $e\n$s", level: LogLevel.Error);
      return BuyResponse(
          exception: BuyException(
        e.toString(),
        BuyExceptionType.generic,
      ));
    }
  }

  bool isSimplexFiat(String ticker) {
    try {
      fiatFromTickerCaseInsensitive(ticker);
      return true;
    } on ArgumentError catch (_) {
      return false;
    }
  }

  // See https://github.com/dart-lang/sdk/issues/43391#issuecomment-1229656422
  String timeZoneFormatter(Duration offset) =>
      "${offset.isNegative ? "-" : "+"}${offset.inHours.abs().toString().padLeft(2, "0")}:${(offset.inMinutes - offset.inHours * 60).abs().toString().padLeft(2, "0")}";
}

bool isStackCoin(String? ticker) {
  if (ticker == null) return false;

  try {
    coinFromTickerCaseInsensitive(ticker);
    return true;
  } on ArgumentError catch (_) {
    return false;
  }
}