import 'dart:convert';
import 'dart:math';

import 'package:decimal/decimal.dart';
import 'package:http/http.dart';
import 'package:stackwallet/models/ethereum/erc20_token.dart';
import 'package:stackwallet/models/ethereum/erc721_token.dart';
import 'package:stackwallet/models/ethereum/eth_token.dart';
import 'package:stackwallet/models/paymint/fee_object_model.dart';
import 'package:stackwallet/utilities/default_nodes.dart';
import 'package:stackwallet/utilities/eth_commons.dart';
import 'package:stackwallet/utilities/logger.dart';

class EthTokenTx {
  final String blockHash;
  final int blockNumber;
  final int confirmations;
  final String contractAddress;
  final int cumulativeGasUsed;
  final String from;
  final int gas;
  final BigInt gasPrice;
  final int gasUsed;
  final String hash;
  final String input;
  final int logIndex;
  final int nonce;
  final int timeStamp;
  final String to;
  final int tokenDecimal;
  final String tokenName;
  final String tokenSymbol;
  final int transactionIndex;
  final BigInt value;

  EthTokenTx({
    required this.blockHash,
    required this.blockNumber,
    required this.confirmations,
    required this.contractAddress,
    required this.cumulativeGasUsed,
    required this.from,
    required this.gas,
    required this.gasPrice,
    required this.gasUsed,
    required this.hash,
    required this.input,
    required this.logIndex,
    required this.nonce,
    required this.timeStamp,
    required this.to,
    required this.tokenDecimal,
    required this.tokenName,
    required this.tokenSymbol,
    required this.transactionIndex,
    required this.value,
  });

  factory EthTokenTx.fromMap({
    required Map<String, dynamic> map,
  }) {
    try {
      return EthTokenTx(
        blockHash: map["blockHash"] as String,
        blockNumber: int.parse(map["blockNumber"] as String),
        confirmations: int.parse(map["confirmations"] as String),
        contractAddress: map["contractAddress"] as String,
        cumulativeGasUsed: int.parse(map["cumulativeGasUsed"] as String),
        from: map["from"] as String,
        gas: int.parse(map["gas"] as String),
        gasPrice: BigInt.parse(map["gasPrice"] as String),
        gasUsed: int.parse(map["gasUsed"] as String),
        hash: map["hash"] as String,
        input: map["input"] as String,
        logIndex: int.parse(map["logIndex"] as String? ?? "-1"),
        nonce: int.parse(map["nonce"] as String),
        timeStamp: int.parse(map["timeStamp"] as String),
        to: map["to"] as String,
        tokenDecimal: int.parse(map["tokenDecimal"] as String),
        tokenName: map["tokenName"] as String,
        tokenSymbol: map["tokenSymbol"] as String,
        transactionIndex: int.parse(map["transactionIndex"] as String),
        value: BigInt.parse(map["value"] as String),
      );
    } catch (e, s) {
      Logging.instance.log(
        "EthTokenTx.fromMap() failed: $e\n$s",
        level: LogLevel.Fatal,
      );
      rethrow;
    }
  }
}

class EthApiException with Exception {
  EthApiException(this.message);

  final String message;

  @override
  String toString() => "$runtimeType: $message";
}

class EthereumResponse<T> {
  EthereumResponse(this.value, this.exception);

  final T? value;
  final EthApiException? exception;

  @override
  toString() => "EthereumResponse: { value: $value, exception: $exception }";
}

abstract class EthereumAPI {
  static String get stackBaseServer => DefaultNodes.ethereum.host;

  static String stackURI = "$stackBaseServer/eth/mainnet/api";

  // static const blockScout = "https://blockscout.com/eth/mainnet/api";
  static const etherscanApi =
      "https://api.etherscan.io/api"; //TODO - Once our server has abi functionality update

  static const gasTrackerUrl =
      "https://blockscout.com/eth/mainnet/api/v1/gas-price-oracle";

  static Future<AddressTransaction> fetchAddressTransactions(
      String address) async {
    try {
      final response = await get(
        Uri.parse(
          // "$blockScout?module=account&action=txlist&address=$address"));
          // "stackURI?module=account&action=txlist&address=$address"));
          "$stackBaseServer/export?addrs=$address",
        ),
      );

      // "$etherscanApi?module=account&action=txlist&address=$address&apikey=EG6J7RJIQVSTP2BS59D3TY2G55YHS5F2HP"));
      if (response.statusCode == 200) {
        return AddressTransaction.fromJson(
            jsonDecode(response.body)["data"] as List);
      } else {
        throw Exception(
            'ERROR GETTING TRANSACTIONS WITH STATUS ${response.statusCode}');
      }
    } catch (e, s) {
      throw Exception('ERROR GETTING TRANSACTIONS ${e.toString()}');
    }
  }

  static Future<EthereumResponse<List<EthTokenTx>>> getTokenTransactions({
    required String address,
    String? contractAddress,
    int? startBlock,
    int? endBlock,
    // todo add more params?
  }) async {
    try {
      String uriString =
          // "$blockScout?module=account&action=tokentx&address=$address";
          // "stackURI?module=account&action=tokentx&address=$address";
          "$etherscanApi?module=account&action=tokentx&address=$address&apikey=EG6J7RJIQVSTP2BS59D3TY2G55YHS5F2HP";
      if (contractAddress != null) {
        uriString += "&contractAddress=$contractAddress";
      }
      final uri = Uri.parse(uriString);
      final response = await get(uri);

      if (response.statusCode == 200) {
        final json = jsonDecode(response.body);
        if (json["message"] == "OK") {
          final result =
              List<Map<String, dynamic>>.from(json["result"] as List);
          final List<EthTokenTx> tokenTxns = [];
          for (final map in result) {
            tokenTxns.add(EthTokenTx.fromMap(map: map));
          }

          return EthereumResponse(
            tokenTxns,
            null,
          );
        } else {
          throw EthApiException(json["message"] as String);
        }
      } else {
        throw EthApiException(
          "getTokenTransactions($address) failed with status code: "
          "${response.statusCode}",
        );
      }
    } on EthApiException catch (e) {
      return EthereumResponse(
        null,
        e,
      );
    } catch (e, s) {
      Logging.instance.log(
        "getTokenTransactions(): $e\n$s",
        level: LogLevel.Error,
      );
      return EthereumResponse(
        null,
        EthApiException(e.toString()),
      );
    }
  }

// ONLY FETCHES WALLET TOKENS WITH A NON ZERO BALANCE
  // static Future<EthereumResponse<List<EthToken>>> getWalletTokens({
  //   required String address,
  // }) async {
  //   try {
  //     final uri = Uri.parse(
  //       "$blockExplorer?module=account&action=tokenlist&address=$address",
  //     );
  //     final response = await get(uri);
  //
  //     if (response.statusCode == 200) {
  //       final json = jsonDecode(response.body);
  //       if (json["message"] == "OK") {
  //         final result =
  //             List<Map<String, dynamic>>.from(json["result"] as List);
  //         final List<EthToken> tokens = [];
  //         for (final map in result) {
  //           if (map["type"] == "ERC-20") {
  //             tokens.add(
  //               Erc20Token(
  //                 balance: int.parse(map["balance"] as String),
  //                 contractAddress: map["contractAddress"] as String,
  //                 decimals: int.parse(map["decimals"] as String),
  //                 name: map["name"] as String,
  //                 symbol: map["symbol"] as String,
  //               ),
  //             );
  //           } else if (map["type"] == "ERC-721") {
  //             tokens.add(
  //               Erc721Token(
  //                 balance: int.parse(map["balance"] as String),
  //                 contractAddress: map["contractAddress"] as String,
  //                 decimals: int.parse(map["decimals"] as String),
  //                 name: map["name"] as String,
  //                 symbol: map["symbol"] as String,
  //               ),
  //             );
  //           } else {
  //             throw EthApiException(
  //                 "Unsupported token type found: ${map["type"]}");
  //           }
  //         }
  //
  //         return EthereumResponse(
  //           tokens,
  //           null,
  //         );
  //       } else {
  //         throw EthApiException(json["message"] as String);
  //       }
  //     } else {
  //       throw EthApiException(
  //         "getWalletTokens($address) failed with status code: "
  //         "${response.statusCode}",
  //       );
  //     }
  //   } on EthApiException catch (e) {
  //     return EthereumResponse(
  //       null,
  //       e,
  //     );
  //   } catch (e, s) {
  //     Logging.instance.log(
  //       "getWalletTokens(): $e\n$s",
  //       level: LogLevel.Error,
  //     );
  //     return EthereumResponse(
  //       null,
  //       EthApiException(e.toString()),
  //     );
  //   }
  // }

  static Future<EthereumResponse<int>> getWalletTokenBalance({
    required String address,
    required String contractAddress,
  }) async {
    try {
      final uri = Uri.parse(
        "$stackBaseServer/tokens?addrs=$contractAddress $address",
      );
      final response = await get(uri);

      if (response.statusCode == 200) {
        final json = jsonDecode(response.body);
        if (json["data"] is List) {
          final map = json["data"].first as Map;

          final bal = Decimal.tryParse(map["balance"].toString());
          final int balance;
          if (bal == null) {
            balance = 0;
          } else {
            final int decimals = map["decimals"] as int;
            balance = (bal * Decimal.fromInt(pow(10, decimals).truncate()))
                .toBigInt()
                .toInt();
          }

          return EthereumResponse(
            balance,
            null,
          );
        } else {
          throw EthApiException(json["message"] as String);
        }
      } else {
        throw EthApiException(
          "getWalletTokenBalance($address) failed with status code: "
          "${response.statusCode}",
        );
      }
    } on EthApiException catch (e) {
      return EthereumResponse(
        null,
        e,
      );
    } catch (e, s) {
      Logging.instance.log(
        "getWalletTokenBalance(): $e\n$s",
        level: LogLevel.Error,
      );
      return EthereumResponse(
        null,
        EthApiException(e.toString()),
      );
    }
  }

  static Future<GasTracker> getGasOracle() async {
    final response = await get(Uri.parse(gasTrackerUrl));
    if (response.statusCode == 200) {
      return GasTracker.fromJson(
          json.decode(response.body) as Map<String, dynamic>);
    } else {
      throw Exception('Failed to load gas oracle');
    }
  }

  static Future<FeeObject> getFees() async {
    GasTracker fees = await getGasOracle();
    final feesFast = fees.fast * (pow(10, 9));
    final feesStandard = fees.average * (pow(10, 9));
    final feesSlow = fees.slow * (pow(10, 9));

    return FeeObject(
        numberOfBlocksFast: 1,
        numberOfBlocksAverage: 3,
        numberOfBlocksSlow: 3,
        fast: feesFast.toInt(),
        medium: feesStandard.toInt(),
        slow: feesSlow.toInt());
  }

  static Future<EthereumResponse<EthContractInfo>> getTokenByContractAddress(
      String contractAddress) async {
    try {
      final response = await get(Uri.parse(
          "$etherscanApi?module=token&action=getToken&contractaddress=$contractAddress&apikey=EG6J7RJIQVSTP2BS59D3TY2G55YHS5F2HP"));
      // "stackURI?module=token&action=getToken&contractaddress=$contractAddress"));
      // "$blockScout?module=token&action=getToken&contractaddress=$contractAddress"));
      if (response.statusCode == 200) {
        final json = jsonDecode(response.body);
        if (json["message"] == "OK") {
          final map = Map<String, dynamic>.from(json["result"] as Map);
          EthContractInfo? token;
          if (map["type"] == "ERC-20") {
            token = Erc20ContractInfo(
              contractAddress: map["contractAddress"] as String,
              decimals: int.parse(map["decimals"] as String),
              name: map["name"] as String,
              symbol: map["symbol"] as String,
            );
          } else if (map["type"] == "ERC-721") {
            token = Erc721ContractInfo(
              contractAddress: map["contractAddress"] as String,
              decimals: int.parse(map["decimals"] as String),
              name: map["name"] as String,
              symbol: map["symbol"] as String,
            );
          } else {
            throw EthApiException(
                "Unsupported token type found: ${map["type"]}");
          }

          return EthereumResponse(
            token,
            null,
          );
        } else {
          throw EthApiException(json["message"] as String);
        }
      } else {
        throw EthApiException(
          "getTokenByContractAddress($contractAddress) failed with status code: "
          "${response.statusCode}",
        );
      }
    } on EthApiException catch (e) {
      return EthereumResponse(
        null,
        e,
      );
    } catch (e, s) {
      Logging.instance.log(
        "getTokenByContractAddress(): $e\n$s",
        level: LogLevel.Error,
      );
      return EthereumResponse(
        null,
        EthApiException(e.toString()),
      );
    }
  }

  static Future<EthereumResponse<String>> getTokenAbi(
      String contractAddress) async {
    try {
      final response = await get(
        Uri.parse(
          "$stackBaseServer/abis?addrs=$contractAddress",
        ),
      );

      if (response.statusCode == 200) {
        final json = jsonDecode(response.body)["data"] as List;

        // trueblocks api does not contain the `anonymous` value
        // web3dart expects it so hack it in
        // TODO: fix this if we ever actually need to use contract ABI events
        for (final map in json) {
          if (map["type"] == "event") {
            map["anonymous"] = false;
          }
        }

        return EthereumResponse(
          jsonEncode(json),
          null,
        );
      } else {
        throw EthApiException(
          "getTokenAbi($contractAddress) failed with status code: "
          "${response.statusCode}",
        );
      }
    } on EthApiException catch (e) {
      return EthereumResponse(
        null,
        e,
      );
    } catch (e, s) {
      Logging.instance.log(
        "getTokenAbi(): $e\n$s",
        level: LogLevel.Error,
      );
      return EthereumResponse(
        null,
        EthApiException(e.toString()),
      );
    }
  }

  static Future<EthereumResponse<String>> getProxyTokenImplementation(
      String contractAddress) async {
    try {
      final response = await get(Uri.parse(
          // "$stackURI?module=contract&action=getsourcecode&address=$contractAddress"));
          "$etherscanApi?module=contract&action=getsourcecode&address=$contractAddress&apikey=EG6J7RJIQVSTP2BS59D3TY2G55YHS5F2HP"));
      if (response.statusCode == 200) {
        final json = jsonDecode(response.body);
        if (json["message"] == "OK") {
          final list = json["result"] as List;
          final map = Map<String, dynamic>.from(list.first as Map);

          return EthereumResponse(
            map["Implementation"] as String,
            null,
          );
        } else {
          throw EthApiException(json["message"] as String);
        }
      } else {
        throw EthApiException(
          "fetchProxyTokenImplementation($contractAddress) failed with status code: "
          "${response.statusCode}",
        );
      }
    } on EthApiException catch (e) {
      return EthereumResponse(
        null,
        e,
      );
    } catch (e, s) {
      Logging.instance.log(
        "fetchProxyTokenImplementation(): $e\n$s",
        level: LogLevel.Error,
      );
      return EthereumResponse(
        null,
        EthApiException(e.toString()),
      );
    }
  }
}