import 'dart:developer';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:flutter_svg/svg.dart';
import 'package:kmobile/data/repositories/transaction_repository.dart';
import 'package:kmobile/di/injection.dart';
import 'package:kmobile/features/accounts/screens/account_info_screen.dart';
import 'package:kmobile/features/accounts/screens/account_statement_screen.dart';
import 'package:kmobile/features/auth/controllers/auth_cubit.dart';
import 'package:kmobile/features/auth/controllers/auth_state.dart';
import 'package:kmobile/features/customer_info/screens/customer_info_screen.dart';
import 'package:kmobile/features/beneficiaries/screens/manage_beneficiaries_screen.dart';
import 'package:kmobile/features/enquiry/screens/enquiry_screen.dart';
import 'package:kmobile/features/fund_transfer/screens/fund_transfer_beneficiary_screen.dart';
import 'package:kmobile/features/profile/profile_screen.dart';
import 'package:kmobile/features/quick_pay/screens/quick_pay_screen.dart';
import 'package:kmobile/security/secure_storage.dart';
import 'package:local_auth/local_auth.dart';
import 'package:material_symbols_icons/material_symbols_icons.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:shimmer/shimmer.dart';
import 'package:kmobile/data/models/transaction.dart';
import '../../../l10n/app_localizations.dart';

class DashboardScreen extends StatefulWidget {
  const DashboardScreen({super.key});

  @override
  State<DashboardScreen> createState() => _DashboardScreenState();
}

class _DashboardScreenState extends State<DashboardScreen> {
  int selectedAccountIndex = 0;
  bool isVisible = false;
  bool isRefreshing = false;
  bool isBalanceLoading = false;
  bool _biometricPromptShown = false;
  bool _txLoading = false;
  List<Transaction> _transactions = [];
  bool _txInitialized = false;

  Future<void> _loadTransactions(String accountNo) async {
    setState(() {
      _txLoading = true;
      _transactions = [];
    });
    try {
      final repo = getIt<TransactionRepository>();
      final txs = await repo.fetchTransactions(accountNo);
      var fiveTxns = <Transaction>[];
      //only take the first 5 transactions
      if (txs.length > 5) {
        fiveTxns = txs.sublist(0, 5);
      } else {
        fiveTxns = txs;
      }
      setState(() => _transactions = fiveTxns);
    } catch (e) {
      log(accountNo, error: e);
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(
            AppLocalizations.of(context).failedToLoad(e.toString()),
          ),
        ),
      );
    } finally {
      if (mounted) {
        setState(() => _txLoading = false);
      }
    }
  }

  Future<void> _refreshAccountData(BuildContext context) async {
    setState(() {
      isRefreshing = true;
    });
    try {
      // Call your AuthCubit or repository to refresh user/accounts data
      await context.read<AuthCubit>().refreshUserData();
    } catch (e) {
      ScaffoldMessenger.of(context).showSnackBar(
        /*const*/ SnackBar(
          content: Text(AppLocalizations.of(context).failedToRefresh),
        ),
      );
    }
    setState(() {
      isRefreshing = false;
    });
  }

  Widget _buildBalanceShimmer() {
    return Shimmer.fromColors(
      baseColor: Theme.of(context).dialogBackgroundColor,
      highlightColor: Theme.of(context).dialogBackgroundColor,
      child: Container(width: 100, height: 32, color: Theme.of(context).scaffoldBackgroundColor),
    );
  }

  String getProcessedFirstName(String? name) {
    if (name == null || name.trim().isEmpty) return '';
    // Remove common titles
    final titles = [
      'mr.',
      'mrs.',
      'ms.',
      'miss',
      'dr.',
      'shri',
      'smt.',
      'kumari',
    ];
    String processed = name.trim().toLowerCase();
    for (final title in titles) {
      if (processed.startsWith(title)) {
        processed = processed.replaceFirst(title, '').trim();
        break;
      }
    }
    // Take the first word (first name)
    final firstName = processed.split(' ').first;
    // Convert to title case
    if (firstName.isEmpty) return '';
    return firstName[0].toUpperCase() + firstName.substring(1);
  }

  String getFullAccountType(String? accountType) {
    if (accountType == null || accountType.isEmpty) return 'N/A';
    // Convert to title case
    switch (accountType.toLowerCase()) {
      case 'sa':
        return AppLocalizations.of(context).savingsAccount;
      case 'ln':
        return AppLocalizations.of(context).loanAccount;
      case 'td':
        return AppLocalizations.of(context).termDeposit;
      case 'rd':
        return AppLocalizations.of(context).recurringDeposit;
      default:
        return AppLocalizations.of(context).unknownAccount;
    }
  }

  Future<void> _showBiometricOptInDialog() async {
    final storage = SecureStorage();
    showDialog(
      context: context,
      barrierDismissible: false,
      builder: (_) => AlertDialog(
        title: Text(AppLocalizations.of(context).enableBiometric),
        content: Text(AppLocalizations.of(context).useBiometricPrompt),
        actions: [
          TextButton(
            onPressed: () async {
              await storage.write('biometric_prompt_shown', 'true');
              if (!mounted) return;
              Navigator.of(context).pop();
            },
            child: Text(AppLocalizations.of(context).later),
          ),
          TextButton(
            onPressed: () async {
              final auth = LocalAuthentication();
              final canCheck = await auth.canCheckBiometrics;
              bool ok = false;
              if (canCheck) {
                ok = await auth.authenticate(
                  localizedReason: AppLocalizations.of(context).scanBiometric,
                );
              }
              if (ok) {
                await storage.write('biometric_enabled', 'true');
              }
              await storage.write('biometric_prompt_shown', 'true');
              Navigator.of(context).pop();
            },
            child: Text(AppLocalizations.of(context).enable),
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return BlocListener<AuthCubit, AuthState>(
      listener: (context, state) async {
        if (state is Authenticated && !_biometricPromptShown) {
          _biometricPromptShown = true;
          final storage = getIt<SecureStorage>();
          final already = await storage.read('biometric_prompt_shown');
          if (already == null) {
            _showBiometricOptInDialog();
          }
        }
      },
      child: Scaffold(
        backgroundColor: Theme.of(context).scaffoldBackgroundColor,
        appBar: AppBar(
          backgroundColor:Theme.of(context).scaffoldBackgroundColor,
          automaticallyImplyLeading: false,
          title: Text(
            AppLocalizations.of(context).kMobile,
            style: TextStyle(
              color: Theme.of(context).primaryColor,
              fontWeight: FontWeight.w500,
            ),
          ),
          centerTitle: true,
          actions: [
            Padding(
              padding: const EdgeInsets.only(right: 10.0),
              child: InkWell(
                borderRadius: BorderRadius.circular(20),
                onTap: () {
                  Navigator.push(
                    context,
                    MaterialPageRoute(
                      builder: (context) => const ProfileScreen(),
                    ),
                  );
                },
                child: CircleAvatar(
                  backgroundColor: Colors.grey[200],
                  radius: 20,
                  child: SvgPicture.asset(
                    'assets/images/avatar_male.svg',
                    width: 40,
                    height: 40,
                    fit: BoxFit.cover,
                  ),
                ),
              ),
            ),
          ],
        ),
        body: BlocBuilder<AuthCubit, AuthState>(
          builder: (context, state) {
            if (state is AuthLoading || state is AuthInitial) {
              return const Center(child: CircularProgressIndicator());
            }
            if (state is Authenticated) {
              final users = state.users;
              final currAccount = users[selectedAccountIndex];
              // first‐time load
              if (!_txInitialized) {
                _txInitialized = true;
                WidgetsBinding.instance.addPostFrameCallback((_) {
                  _loadTransactions(currAccount.accountNo!);
                });
              }
              final firstName = getProcessedFirstName(currAccount.name);

              return SingleChildScrollView(
                physics: const AlwaysScrollableScrollPhysics(),
                child: Padding(
                  padding: const EdgeInsets.symmetric(horizontal: 16.0),
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Padding(
                        padding: const EdgeInsets.only(left: 8.0),
                        child: Text(
                          "${AppLocalizations.of(context).hi} $firstName",
                          style: GoogleFonts.montserrat().copyWith(
                            fontSize: 25,
                            color: Theme.of(context).primaryColor,
                            fontWeight: FontWeight.w700,
                          ),
                        ),
                      ),
                      const SizedBox(height: 16),

                      // Account Info Card
                      Container(
                        padding: const EdgeInsets.symmetric(
                          horizontal: 18,
                          vertical: 10,
                        ),
                        decoration: BoxDecoration(
                          color: Theme.of(context).primaryColor,
                          borderRadius: BorderRadius.circular(16),
                        ),
                        child: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            Row(
                              children: [
                                Text(
                                  "${AppLocalizations.of(context).accountNumber}: ",
                                  style: TextStyle(
                                    color: Theme.of(context).dialogBackgroundColor,
                                    fontSize: 12,
                                  ),
                                ),
                                DropdownButton<int>(
                                  value: selectedAccountIndex,
                                  dropdownColor: Theme.of(context).primaryColor,
                                  underline: const SizedBox(),
                                  icon: const Icon(Icons.keyboard_arrow_down),
                                  iconEnabledColor:Theme.of(context).dialogBackgroundColor,
                                  style: TextStyle(
                                    color: Theme.of(context).dialogBackgroundColor,
                                    fontSize: 14,
                                  ),
                                  items: List.generate(users.length, (index) {
                                    return DropdownMenuItem<int>(
                                      value: index,
                                      child: Text(
                                        users[index].accountNo ?? 'N/A',
                                        style: TextStyle(
                                          color: Theme.of(context).dialogBackgroundColor,
                                          fontSize: 14,
                                        ),
                                      ),
                                    );
                                  }),
                                  onChanged: (int? newIndex) async {
                                    if (newIndex == null ||
                                        newIndex == selectedAccountIndex) {
                                      return;
                                    }
                                    if (isBalanceLoading) return;
                                    if (isVisible) {
                                      setState(() {
                                        isBalanceLoading = true;
                                        selectedAccountIndex = newIndex;
                                      });
                                      await Future.delayed(
                                        const Duration(milliseconds: 200),
                                      );
                                      setState(() {
                                        isBalanceLoading = false;
                                      });
                                    } else {
                                      setState(() {
                                        selectedAccountIndex = newIndex;
                                      });
                                    }
                                    await _loadTransactions(
                                      users[newIndex].accountNo!,
                                    );
                                  },
                                ),
                                const Spacer(),
                                IconButton(
                                  icon: isRefreshing
                                      ? SizedBox(
                                          width: 20,
                                          height: 20,
                                          child: CircularProgressIndicator(
                                            color: Theme.of(context).dialogBackgroundColor,
                                            strokeWidth: 2,
                                          ),
                                        )
                                      :  Icon(
                                          Icons.refresh,
                                          color: Theme.of(context).dialogBackgroundColor,
                                        ),
                                  onPressed: isRefreshing
                                      ? null
                                      : () => _refreshAccountData(context),
                                  tooltip: 'Refresh',
                                ),
                              ],
                            ),
                            Text(
                              getFullAccountType(currAccount.accountType),
                              style: TextStyle(
                                color: Theme.of(context).dialogBackgroundColor,
                                fontSize: 16,
                              ),
                            ),
                            const SizedBox(height: 4),
                            Row(
                              mainAxisAlignment: MainAxisAlignment.start,
                              children: [
                                Text(
                                  "₹ ",
                                  style: TextStyle(
                                    color: Theme.of(context).dialogBackgroundColor,
                                    fontSize: 40,
                                    fontWeight: FontWeight.w700,
                                  ),
                                ),
                                isRefreshing || isBalanceLoading
                                    ? _buildBalanceShimmer()
                                    : Text(
                                        isVisible
                                            ? currAccount.currentBalance ??
                                                '0.00'
                                            : '********',
                                        style: TextStyle(
                                          color: Theme.of(context).dialogBackgroundColor,
                                          fontSize: 40,
                                          fontWeight: FontWeight.w700,
                                        ),
                                      ),
                                const Spacer(),
                                InkWell(
                                  onTap: () async {
                                    if (isBalanceLoading) return;
                                    if (!isVisible) {
                                      setState(() {
                                        isBalanceLoading = true;
                                      });
                                      await Future.delayed(
                                        const Duration(seconds: 1),
                                      );
                                      setState(() {
                                        isVisible = true;
                                        isBalanceLoading = false;
                                      });
                                    } else {
                                      setState(() {
                                        isVisible = false;
                                      });
                                    }
                                  },
                                  child: Icon(
                                    isVisible
                                        ? Symbols.visibility_lock
                                        : Symbols.visibility,
                                    color: Theme.of(context).scaffoldBackgroundColor,
                                  ),
                                ),
                              ],
                            ),
                            const SizedBox(height: 15),
                          ],
                        ),
                      ),
                      const SizedBox(height: 18),
                      Text(
                        AppLocalizations.of(context).quickLinks,
                        style: const TextStyle(fontSize: 17),
                      ),
                      const SizedBox(height: 16),

                      // Quick Links
                      GridView.count(
                        crossAxisCount: 4,
                        shrinkWrap: true,
                        physics: const NeverScrollableScrollPhysics(),
                        children: [
                          _buildQuickLink(
                            Symbols.id_card,
                            AppLocalizations.of(context).customerInfo,
                            () {
                              Navigator.push(
                                context,
                                MaterialPageRoute(
                                  builder: (context) => CustomerInfoScreen(
                                    user: users[selectedAccountIndex],
                                  ),
                                ),
                              );
                            },
                          ),
                          _buildQuickLink(
                            Symbols.currency_rupee,
                            AppLocalizations.of(context).quickPay,
                            () {
                              Navigator.push(
                                context,
                                MaterialPageRoute(
                                  builder: (context) => QuickPayScreen(
                                    debitAccount: currAccount.accountNo!,
                                  ),
                                ),
                              );
                            },
                          ),
                          _buildQuickLink(
                            Symbols.send_money,
                            AppLocalizations.of(context).fundTransfer,
                            () {
                              Navigator.push(
                                context,
                                MaterialPageRoute(
                                  builder: (context) =>
                                      const FundTransferBeneficiaryScreen()));
                        }, disable: false),
                        _buildQuickLink(Symbols.server_person,
                            AppLocalizations.of(context).accountInfo, () {
                          Navigator.push(
                              context,
                              MaterialPageRoute(
                                  builder: (context) => AccountInfoScreen(
                                    users: users,
                                    selectedIndex: selectedAccountIndex,
                                  ),
                                ),
                              );
                            },
                          ),
                          _buildQuickLink(
                            Symbols.receipt_long,
                            AppLocalizations.of(context).accountStatement,
                            () {
                              Navigator.push(
                                context,
                                MaterialPageRoute(
                                  builder: (context) => AccountStatementScreen(
                                        accountNo: users[selectedAccountIndex]
                                            .accountNo!,
                                      )));
                        }),
                        _buildQuickLink(Symbols.checkbook,
                            AppLocalizations.of(context).handleCheque, () {},
                            disable: true),
                        _buildQuickLink(Icons.group,
                            AppLocalizations.of(context).manageBeneficiary, () {
                          Navigator.push(
                              context,
                              MaterialPageRoute(
                                  builder: (context) =>
                                      const ManageBeneficiariesScreen()));
                        }, disable: false),
                        _buildQuickLink(Symbols.support_agent,
                            AppLocalizations.of(context).contactUs, () {
                          Navigator.push(
                              context,
                              MaterialPageRoute(
                                  builder: (context) => const EnquiryScreen()));
                        }),
                      ],
                    ),
                    const SizedBox(height: 5),

                      // Recent Transactions
                      Text(
                        AppLocalizations.of(context).recentTransactions,
                        style: const TextStyle(fontSize: 17),
                      ),
                      const SizedBox(height: 16),
                      if (_txLoading)
                        ..._buildTransactionShimmer()
                      else if (_transactions.isNotEmpty)
                        ..._transactions.map(
                          (tx) => ListTile(
                            leading: Icon(
                              tx.type == 'CR'
                                  ? Symbols.call_received
                                  : Symbols.call_made,
                              color:
                                  tx.type == 'CR' ? Colors.green : Colors.red,
                            ),
                            title: Text(
                              tx.name != null
                                  ? (tx.name!.length > 18
                                      ? tx.name!.substring(0, 20)
                                      : tx.name!)
                                  : '',
                              style: const TextStyle(fontSize: 14),
                            ),
                            subtitle: Text(
                              tx.date ?? '',
                              style: const TextStyle(fontSize: 12),
                            ),
                            trailing: Text(
                              "₹${tx.amount}",
                              style: const TextStyle(fontSize: 16),
                            ),
                          ),
                        )
                      else
                        Padding(
                          padding: const EdgeInsets.symmetric(vertical: 24.0),
                          child: Center(
                            child: Text(
                              AppLocalizations.of(context).noTransactions,
                              style: TextStyle(
                                fontSize: 16,
                                color: Colors.grey[600],
                              ),
                            ),
                          ),
                        ),
                    ],
                  ),
                ),
              );
            }
            return Center(
              child: Text(AppLocalizations.of(context).somethingWentWrong),
            );
          },
        ),
      ),
    );
  }

  List<Widget> _buildTransactionShimmer() {
    return List.generate(3, (i) {
      return ListTile(
        leading: Shimmer.fromColors(
          baseColor: Colors.grey[300]!,
          highlightColor: Colors.grey[100]!,
          child: CircleAvatar(radius: 12, backgroundColor: Theme.of(context).scaffoldBackgroundColor),
        ),
        title: Shimmer.fromColors(
          baseColor: Colors.grey[300]!,
          highlightColor: Colors.grey[100]!,
          child: Container(height: 10, width: 100, color: Theme.of(context).scaffoldBackgroundColor),
        ),
        subtitle: Shimmer.fromColors(
          baseColor: Colors.grey[300]!,
          highlightColor: Colors.grey[100]!,
          child: Container(height: 8, width: 60, color: Theme.of(context).scaffoldBackgroundColor),
        ),
      );
    });
  }

  Widget _buildQuickLink(
    IconData icon,
    String label,
    VoidCallback onTap, {
    bool disable = false,
  }) {
    return InkWell(
      onTap: disable ? null : onTap,
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          Icon(
            icon,
            size: 30,
            color: disable ? Colors.grey : Theme.of(context).primaryColor,
          ),
          const SizedBox(height: 4),
          Text(
            label,
            textAlign: TextAlign.center,
            style: const TextStyle(fontSize: 13),
          ),
        ],
      ),
    );
  }
}