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

import 'package:cw_core/cake_hive.dart';
import 'package:cw_core/crypto_currency.dart';
import 'package:cw_core/encryption_file_utils.dart';
import 'package:cw_core/node.dart';
import 'package:cw_core/pathForWallet.dart';
import 'package:cw_core/pending_transaction.dart';
import 'package:cw_core/sync_status.dart';
import 'package:cw_core/transaction_direction.dart';
import 'package:cw_core/transaction_priority.dart';
import 'package:cw_core/utils/print_verbose.dart';
import 'package:cw_core/wallet_addresses.dart';
import 'package:cw_core/wallet_base.dart';
import 'package:cw_core/wallet_info.dart';
import 'package:cw_core/wallet_keys_file.dart';
import 'package:cw_solana/default_spl_tokens.dart';
import 'package:cw_solana/solana_balance.dart';
import 'package:cw_solana/solana_client.dart';
import 'package:cw_solana/solana_exceptions.dart';
import 'package:cw_solana/solana_transaction_credentials.dart';
import 'package:cw_solana/solana_transaction_history.dart';
import 'package:cw_solana/solana_transaction_info.dart';
import 'package:cw_solana/solana_transaction_model.dart';
import 'package:cw_solana/solana_wallet_addresses.dart';
import 'package:cw_core/spl_token.dart';
import 'package:hex/hex.dart';
import 'package:hive/hive.dart';
import 'package:mobx/mobx.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:on_chain/solana/solana.dart' hide Store;
import 'package:bip39/bip39.dart' as bip39;
import 'package:blockchain_utils/blockchain_utils.dart';

part 'solana_wallet.g.dart';

class SolanaWallet = SolanaWalletBase with _$SolanaWallet;

abstract class SolanaWalletBase
    extends WalletBase<SolanaBalance, SolanaTransactionHistory, SolanaTransactionInfo>
    with Store, WalletKeysFile {
  SolanaWalletBase({
    required WalletInfo walletInfo,
    required DerivationInfo derivationInfo,
    String? mnemonic,
    String? privateKey,
    required String password,
    SolanaBalance? initialBalance,
    required this.encryptionFileUtils,
    this.passphrase,
  })  : syncStatus = const NotConnectedSyncStatus(),
        _password = password,
        _mnemonic = mnemonic,
        _hexPrivateKey = privateKey,
        _client = SolanaWalletClient(),
        walletAddresses = SolanaWalletAddresses(walletInfo),
        balance = ObservableMap<CryptoCurrency, SolanaBalance>.of(
            {CryptoCurrency.sol: initialBalance ?? SolanaBalance(BigInt.zero.toDouble(), false)}),
        super(walletInfo, derivationInfo) {
    this.walletInfo = walletInfo;
    transactionHistory = SolanaTransactionHistory(
      walletInfo: walletInfo,
      password: password,
      encryptionFileUtils: encryptionFileUtils,
    );

    if (!CakeHive.isAdapterRegistered(SPLToken.typeId)) {
      CakeHive.registerAdapter(SPLTokenAdapter());
    }

    _sharedPrefs.complete(SharedPreferences.getInstance());
  }

  final String _password;
  final String? _mnemonic;
  final String? _hexPrivateKey;
  final EncryptionFileUtils encryptionFileUtils;

  late final SolanaWalletClient _client;

  SolanaWalletClient get client => _client;

  @observable
  double? estimatedFee;

  Timer? _transactionsUpdateTimer;

  late final Box<SPLToken> splTokensBox;

  @override
  WalletAddresses walletAddresses;

  @override
  @observable
  SyncStatus syncStatus;

  @override
  @observable
  ObservableMap<CryptoCurrency, SolanaBalance> balance =
      ObservableMap<CryptoCurrency, SolanaBalance>();

  final Completer<SharedPreferences> _sharedPrefs = Completer();

  @override
  Object get keys => throw UnimplementedError("keys");

  late final SolanaPrivateKey _solanaPrivateKey;

  late final SolanaPublicKey _solanaPublicKey;

  SolanaPublicKey get solanaPublicKey => _solanaPublicKey;

  SolanaPrivateKey get solanaPrivateKey => _solanaPrivateKey;

  String get solanaAddress => _solanaPublicKey.toAddress().address;

  @override
  String? get seed => _mnemonic;

  @override
  String get privateKey => _solanaPrivateKey.seedHex();

  @override
  WalletKeysData get walletKeysData => WalletKeysData(
        mnemonic: _mnemonic,
        privateKey: privateKey,
        passphrase: passphrase,
      );

  Future<void> init() async {
    final boxName = "${walletInfo.name.replaceAll(" ", "_")}_${SPLToken.boxName}";

    splTokensBox = await CakeHive.openBox<SPLToken>(boxName);

    // Create the privatekey using either the mnemonic or the privateKey
    _solanaPrivateKey = await getPrivateKey(
      mnemonic: _mnemonic,
      privateKey: _hexPrivateKey,
      passphrase: passphrase,
    );

    // Extract the public key and wallet address
    _solanaPublicKey = _solanaPrivateKey.publicKey();

    walletInfo.address = _solanaPublicKey.toAddress().address;

    await walletAddresses.init();
    await transactionHistory.init();

    await save();
  }

  Future<SolanaPrivateKey> getPrivateKey({
    String? mnemonic,
    String? privateKey,
    String? passphrase,
  }) async {
    assert(mnemonic != null || privateKey != null);

    if (mnemonic != null) {
      final seed = bip39.mnemonicToSeed(mnemonic, passphrase: passphrase ?? '');

      // Derive a Solana private key from the seed
      final bip44 = Bip44.fromSeed(seed, Bip44Coins.solana);

      final childKey = bip44.deriveDefaultPath.change(Bip44Changes.chainExt);

      return SolanaPrivateKey.fromSeed(childKey.privateKey.raw);
    }

    try {
      final keypairBytes = Base58Decoder.decode(privateKey!);
      return SolanaPrivateKey.fromBytes(keypairBytes);
    } catch (_) {
      final privateKeyBytes = HEX.decode(privateKey!);
      return SolanaPrivateKey.fromSeed(privateKeyBytes);
    }
  }

  @override
  int calculateEstimatedFee(TransactionPriority priority, int? amount) => 0;

  @override
  Future<void> changePassword(String password) => throw UnimplementedError("changePassword");

  @override
  Future<void> close({bool shouldCleanup = false}) async {
    _client.stop();
    _transactionsUpdateTimer?.cancel();
  }

  @action
  @override
  Future<void> connectToNode({required Node node}) async {
    try {
      syncStatus = ConnectingSyncStatus();

      final isConnected = _client.connect(node);

      if (!isConnected) {
        throw Exception("Solana Node connection failed");
      }

      _setTransactionUpdateTimer();

      syncStatus = ConnectedSyncStatus();
    } catch (e) {
      syncStatus = FailedSyncStatus();
    }
  }

  Future<void> _getEstimatedFees() async {
    try {
      estimatedFee = await _client.getEstimatedFee(_solanaPublicKey, Commitment.confirmed);
      printV(estimatedFee.toString());
    } catch (e) {
      estimatedFee = 0.0;
    }
  }

  @override
  Future<PendingTransaction> createTransaction(Object credentials) async {
    final solCredentials = credentials as SolanaTransactionCredentials;

    final outputs = solCredentials.outputs;

    final hasMultiDestination = outputs.length > 1;

    await updateTokenBalance();

    final transactionCurrency = balance.keys.firstWhere(
        (currency) =>
            currency.title == credentials.currency.title &&
            currency.tag == credentials.currency.tag,
        orElse: () => throw Exception(
            'Currency ${credentials.currency.title} ${credentials.currency.tag} is not accessible in the wallet, try to enable it first.'));

    final walletBalanceForCurrency = balance[transactionCurrency]!.balance;

    final solBalance = balance[CryptoCurrency.sol]!.balance;

    double totalAmount = 0.0;

    bool isSendAll = false;

    if (hasMultiDestination) {
      if (outputs.any((item) => item.sendAll || (item.formattedCryptoAmount ?? 0) <= 0)) {
        throw SolanaTransactionWrongBalanceException(transactionCurrency);
      }

      final totalAmountFromCredentials =
          outputs.fold(0, (acc, value) => acc + (value.formattedCryptoAmount ?? 0));

      totalAmount = totalAmountFromCredentials.toDouble();

      if (walletBalanceForCurrency < totalAmount) {
        throw SolanaTransactionWrongBalanceException(transactionCurrency);
      }
    } else {
      final output = outputs.first;

      isSendAll = output.sendAll;

      if (isSendAll) {
        totalAmount = walletBalanceForCurrency;
      } else {
        final totalOriginalAmount = double.parse(output.cryptoAmount ?? '0.0');

        totalAmount = totalOriginalAmount;
      }

      if (walletBalanceForCurrency < totalAmount) {
        throw SolanaTransactionWrongBalanceException(transactionCurrency);
      }
    }

    String? tokenMint;
    // Token Mint is only needed for transactions that are not native tokens(non-SOL transactions)
    if (transactionCurrency.title != CryptoCurrency.sol.title) {
      tokenMint = (transactionCurrency as SPLToken).mintAddress;
    }

    final pendingSolanaTransaction = await _client.signSolanaTransaction(
      tokenMint: tokenMint,
      tokenTitle: transactionCurrency.title,
      inputAmount: totalAmount,
      ownerPrivateKey: _solanaPrivateKey,
      tokenDecimals: transactionCurrency.decimals,
      destinationAddress: solCredentials.outputs.first.isParsedAddress
          ? solCredentials.outputs.first.extractedAddress!
          : solCredentials.outputs.first.address,
      isSendAll: isSendAll,
      solBalance: solBalance,
    );

    return pendingSolanaTransaction;
  }

  @override
  Future<Map<String, SolanaTransactionInfo>> fetchTransactions() async => {};

  @override
  Future<void> updateTransactionsHistory({List<String>? specificTokenMints}) async {
    await Future.wait([
      _updateNativeSOLTransactions(),
      updateSPLTokenTransactions(specificMints: specificTokenMints),
    ]);
  }

  /// Polls for a specific transaction by signature with exponential backoff
  /// I'm using this in case we make the call to fetch the transaction and it has not finished its confirmations on the solana network and been indexed by the node networks we use.
  Future<void> pollForTransaction({
    required String signature,
    Duration initialDelay = const Duration(seconds: 1),
    int maxRetries = 5,
  }) async {
    final walletAddress = _solanaPublicKey.toAddress().address;

    for (int i = 0; i < maxRetries; i++) {
      await Future.delayed(initialDelay * (i + 1));

      try {
        final result = await _client.fetchTransactionBySignature(
          signature: signature,
          walletAddress: walletAddress,
        );

        if (result != null && result.transactions.isNotEmpty) {
          await addTransactionsToTransactionHistory(result.transactions);

          // Update only the tokens involved in this transaction
          if (result.tokenMints.isNotEmpty) {
            await Future.wait([
              updateSPLTokenTransactions(specificMints: result.tokenMints),
              updateTokenBalance(tokenMints: result.tokenMints),
            ]);
          } else {
            // If no token mints, still update SOL balance
            await updateTokenBalance(tokenMints: []);
          }

          return;
        }
      } catch (e) {
        printV('Error polling for transaction (attempt ${i + 1}/$maxRetries): $e');
      }
    }

    // Fallback to full refresh if not found after max retries
    printV('Transaction not found after $maxRetries attempts, falling back to full refresh');
    await updateTransactionsHistory();
  }

  void updateTransactions(List<SolanaTransactionModel> updatedTx) {
    addTransactionsToTransactionHistory(updatedTx);
  }

  /// Fetches the native SOL transactions linked to the wallet Public Key
  Future<void> _updateNativeSOLTransactions() async {
    final transactions =
        await _client.fetchTransactions(_solanaPublicKey.toAddress(), onUpdate: updateTransactions);

    await addTransactionsToTransactionHistory(transactions);
  }

  Future<void> updateSPLTokenTransactions({List<String>? specificMints}) async {
    final allTokens = balance.keys.whereType<SPLToken>().toList(growable: false);

    // Filter to specific mints if provided
    final tokens = specificMints != null
        ? allTokens.where((t) => specificMints.contains(t.mintAddress)).toList(growable: false)
        : allTokens;

    if (tokens.isEmpty) return;

    const int batchSize = 5;

    for (var i = 0; i < tokens.length; i += batchSize) {
      final batch = tokens.sublist(
        i,
        i + batchSize > tokens.length ? tokens.length : i + batchSize,
      );
      final results = await Future.wait(
        batch.map((token) async {
          try {
            return await _client.getSPLTokenTransfers(
              mintAddress: token.mintAddress,
              splTokenSymbol: token.symbol,
              splTokenDecimal: token.decimal,
              privateKey: _solanaPrivateKey,
              onUpdate: updateTransactions,
            );
          } catch (_) {
            return <SolanaTransactionModel>[];
          }
        }),
      );

      for (final list in results) {
        await addTransactionsToTransactionHistory(list);
      }
    }
  }

  Future<void> addTransactionsToTransactionHistory(
    List<SolanaTransactionModel> transactions,
  ) async {
    final Map<String, SolanaTransactionInfo> result = {};

    for (var transactionModel in transactions) {
      result[transactionModel.id] = SolanaTransactionInfo(
        id: transactionModel.id,
        to: transactionModel.to,
        from: transactionModel.from,
        blockTime: transactionModel.blockTime,
        direction: transactionModel.isOutgoingTx
            ? TransactionDirection.outgoing
            : TransactionDirection.incoming,
        solAmount: transactionModel.amount,
        isPending: false,
        txFee: transactionModel.fee,
        tokenSymbol: transactionModel.tokenSymbol,
      );
    }

    transactionHistory.addMany(result);

    await transactionHistory.save();
  }

  @override
  Future<void> rescan({required int height}) => throw UnimplementedError("rescan");

  @override
  Future<void> save() async {
    if (!(await WalletKeysFile.hasKeysFile(walletInfo.name, walletInfo.type))) {
      await saveKeysFile(_password, encryptionFileUtils);
      saveKeysFile(_password, encryptionFileUtils, true);
    }

    await walletAddresses.updateAddressesInBox();
    final path = await makePath();
    await encryptionFileUtils.write(path: path, password: _password, data: toJSON());
    await transactionHistory.save();
  }

  @action
  @override
  Future<void> startSync() async {
    try {
      syncStatus = AttemptingSyncStatus();

      // Verify node health before attempting to sync
      final isHealthy = await checkNodeHealth();
      if (!isHealthy) {
        syncStatus = FailedSyncStatus();
        return;
      }

      await Future.wait([
        updateTokenBalance(),
        _updateNativeSOLTransactions(),
        updateSPLTokenTransactions(),
        _getEstimatedFees(),
      ]);

      syncStatus = SyncedSyncStatus();
    } catch (e) {
      syncStatus = FailedSyncStatus();
    }
  }

  String toJSON() => json.encode({
        'mnemonic': _mnemonic,
        'private_key': _hexPrivateKey,
        'balance': balance[currency]!.toJSON(),
        'passphrase': passphrase,
      });

  static Future<SolanaWallet> open({
    required String name,
    required String password,
    required WalletInfo walletInfo,
    required EncryptionFileUtils encryptionFileUtils,
  }) async {
    final hasKeysFile = await WalletKeysFile.hasKeysFile(name, walletInfo.type);
    final path = await pathForWallet(name: name, type: walletInfo.type);

    Map<String, dynamic>? data;
    try {
      final jsonSource = await encryptionFileUtils.read(path: path, password: password);

      data = json.decode(jsonSource) as Map<String, dynamic>;
    } catch (e) {
      if (!hasKeysFile) rethrow;
    }

    final balance = SolanaBalance.fromJSON(data?['balance'] as String?, false) ?? SolanaBalance(0.0, false);

    final WalletKeysData keysData;
    // Migrate wallet from the old scheme to then new .keys file scheme
    if (!hasKeysFile) {
      final mnemonic = data!['mnemonic'] as String?;
      final privateKey = data['private_key'] as String?;
      final passphrase = data['passphrase'] as String?;

      keysData = WalletKeysData(mnemonic: mnemonic, privateKey: privateKey, passphrase: passphrase);
    } else {
      keysData = await WalletKeysFile.readKeysFile(
        name,
        walletInfo.type,
        password,
        encryptionFileUtils,
      );
    }

    final derivationInfo = await walletInfo.getDerivationInfo();

    return SolanaWallet(
      walletInfo: walletInfo,
      derivationInfo: derivationInfo,
      password: password,
      passphrase: keysData.passphrase,
      mnemonic: keysData.mnemonic,
      privateKey: keysData.privateKey,
      initialBalance: balance,
      encryptionFileUtils: encryptionFileUtils,
    );
  }

  Future<void> updateTokenBalance({List<String>? tokenMints}) async {
    // Fetch SOL and SPL token balances in parallel for better performance
    await Future.wait([
      _fetchSOLBalance().then((solBalance) {
        balance[CryptoCurrency.sol] = solBalance;
      }),
      _updateSplTokenBalancesInternal(tokenMints: tokenMints),
    ]);

    await save();
  }

  Future<SolanaBalance> _fetchSOLBalance() async {
    final balance = await _client.getBalance(solanaAddress);

    return SolanaBalance(balance, false);
  }

  /// Internal helper to update SPL token balances.
  /// When [tokenMints] is null or empty, updates all enabled tokens.
  Future<void> _updateSplTokenBalancesInternal({
    List<String>? tokenMints,
  }) async {
    // Remove disabled tokens first to keep state clean
    for (var token in splTokensBox.values.where((t) => !t.enabled)) {
      balance.remove(token);
    }

    final enabledTokens = splTokensBox.values.where((t) => t.enabled).toList(growable: false);
    if (enabledTokens.isEmpty) return;

    final tokens = tokenMints == null || tokenMints.isEmpty
        ? enabledTokens
        : enabledTokens.where((t) => tokenMints.contains(t.mintAddress)).toList(growable: false);

    if (tokens.isEmpty) return;

    const int batchSize = 5;

    for (var i = 0; i < tokens.length; i += batchSize) {
      final batch = tokens.sublist(
        i,
        i + batchSize > tokens.length ? tokens.length : i + batchSize,
      );

      final results = await Future.wait(batch.map((token) async {
        try {
          final fetched = await _client.getSplTokenBalance(token.mintAddress, solanaAddress);
          return MapEntry(token, fetched);
        } catch (e) {
          printV('Error fetching spl token (${token.symbol}) balance ${e.toString()}');
          return MapEntry<SPLToken, SolanaBalance?>(token, null);
        }
      }));

      for (final entry in results) {
        final token = entry.key;
        final fetchedBalance = entry.value;
        final currentBalance = balance[token] ??
            SolanaBalance.forToken(BigInt.zero, 0.0);
        balance[token] = fetchedBalance ?? currentBalance;
      }
    }
  }

  @override
  Future<void>? updateBalance() async => await updateTokenBalance();

  @override
  Future<bool> checkNodeHealth() async {
    try {
      // Check native balance
      await _client.getBalance(solanaAddress, throwOnError: true);

      // Check USDC token balance
      const usdcMintAddress = "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v";
      await _client.getSplTokenBalance(usdcMintAddress, solanaAddress, throwOnError: true);

      return true;
    } catch (e) {
      return false;
    }
  }

  List<SPLToken> get splTokenCurrencies => splTokensBox.values.toList();

  void addInitialTokens() {
    final initialSPLTokens = DefaultSPLTokens().initialSPLTokens;

    for (var token in initialSPLTokens) {
      if (!splTokensBox.containsKey(token.mintAddress)) {
        splTokensBox.put(token.mintAddress, token);
      } else {
        // update existing token
        final existingToken = splTokensBox.get(token.mintAddress);
        splTokensBox.put(
            token.mintAddress, SPLToken.copyWith(token, enabled: existingToken!.enabled));
      }
    }
  }

  Future<void> addSPLToken(SPLToken token) async {
    await splTokensBox.put(token.mintAddress, token);

    if (token.enabled) {
      final tokenBalance = await _client.getSplTokenBalance(token.mintAddress, solanaAddress) ??
          balance[token] ??
          SolanaBalance.forToken(BigInt.zero, 0.0);

      balance[token] = tokenBalance;
    } else {
      balance.remove(token);
    }
  }

  Future<void> deleteSPLToken(SPLToken token) async {
    if (splTokensBox.isOpen) {
      await splTokensBox.delete(token.mintAddress);
    }

    balance.remove(token);
    await _removeTokenTransactionsInHistory(token);
    updateTokenBalance();
  }

  Future<void> _removeTokenTransactionsInHistory(SPLToken token) async {
    transactionHistory.transactions.removeWhere((key, value) => value.tokenSymbol == token.title);
    await transactionHistory.save();
  }

  Future<SPLToken?> getSPLToken(String mintAddress) async {
    try {
      return await _client.fetchSPLTokenInfo(mintAddress);
    } catch (e, s) {
      printV('Error fetching token: ${e.toString()}, ${s.toString()}');
      return null;
    }
  }

  @override
  Future<void> renameWalletFiles(String newWalletName) async {
    final currentWalletPath = await pathForWallet(name: walletInfo.name, type: type);
    final currentWalletFile = File(currentWalletPath);

    final currentDirPath = await pathForWalletDir(name: walletInfo.name, type: type);
    final currentTransactionsFile = File('$currentDirPath/$transactionsHistoryFileName');

    // Copies current wallet files into new wallet name's dir and files
    if (currentWalletFile.existsSync()) {
      final newWalletPath = await pathForWallet(name: newWalletName, type: type);
      await currentWalletFile.copy(newWalletPath);
    }
    if (currentTransactionsFile.existsSync()) {
      final newDirPath = await pathForWalletDir(name: newWalletName, type: type);
      await currentTransactionsFile.copy('$newDirPath/$transactionsHistoryFileName');
    }

    // Delete old name's dir and files
    await Directory(currentDirPath).delete(recursive: true);
  }

  void _setTransactionUpdateTimer() {
    if (_transactionsUpdateTimer?.isActive ?? false) {
      _transactionsUpdateTimer!.cancel();
    }

    _transactionsUpdateTimer = Timer.periodic(const Duration(seconds: 30), (_) {
      updateTokenBalance();
      _updateNativeSOLTransactions();
      updateSPLTokenTransactions();
      _getEstimatedFees();
    });
  }

  @override
  Future<String> signMessage(String message, {String? address}) async {
    // Convert the message to bytes
    final messageBytes = utf8.encode(message);

    // Sign the message bytes with the wallet's private key
    final signature = (_solanaPrivateKey.sign(messageBytes));

    return Base58Encoder.encode(signature);
  }

  List<List<int>> bytesFromSigString(String signatureString) {
    final regex = RegExp(r'Signature\(\[(.+)\], publicKey: (.+)\)');
    final match = regex.firstMatch(signatureString);

    if (match != null) {
      final bytesString = match.group(1)!;
      final base58EncodedPublicKeyString = match.group(2)!;
      final sigBytes = bytesString.split(', ').map(int.parse).toList();

      List<int> pubKeyBytes = SolAddrDecoder().decodeAddr(base58EncodedPublicKeyString);

      return [sigBytes, pubKeyBytes];
    } else {
      throw const FormatException('Invalid Signature string format');
    }
  }

  @override
  Future<bool> verifyMessage(String message, String signature, {String? address}) async {
    String signatureString = utf8.decode(HEX.decode(signature));

    List<List<int>> bytes = bytesFromSigString(signatureString);

    final messageBytes = utf8.encode(message);
    final sigBytes = bytes[0];
    final pubKeyBytes = bytes[1];

    if (address == null) {
      return false;
    }

    // make sure the address derived from the public key provided matches the one we expect
    final pub = SolanaPublicKey.fromBytes(pubKeyBytes);
    if (address != pub.toAddress().address) {
      return false;
    }

    return pub.verify(
      message: messageBytes,
      signature: sigBytes,
    );
  }

  SolanaRPC? get solanaProvider => _client.getSolanaProvider;

  @override
  String get password => _password;

  @override
  final String? passphrase;
}