import 'dart:typed_data';

import 'package:flutter/material.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:http/http.dart' as http;

import '../../customAppBar/base_layout.dart';
import '../../customAppBar/toastHelper.dart';
import '../../service/api_service.dart';
import '../../service/secure_pop_scope.dart';
import '../../service/token_storage_service.dart';
import 'claims_collection_kpi.dart';
import 'enrollment_collection_kpi.dart';
import 'claims_overview_animations.dart';
import 'claims_overview_pdf_export.dart';
import 'claims_overview_scope.dart';
import 'claims_overview_tabs.dart';
import 'claims_overview_theme.dart';

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

  @override
  State<ClaimsOverviewDashboard> createState() =>
      _ClaimsOverviewDashboardState();
}

class _ClaimsOverviewDashboardState extends State<ClaimsOverviewDashboard>
    with TickerProviderStateMixin {
  late TabController _tabController;
  late AnimationController _headerFadeController;
  late Animation<double> _headerFade;
  late final ScrollController _scrollController;
  late final List<GlobalKey> _sectionKeys;

  late final ApiService _apiService;
  final _tokenService = TokenStorageService();

  bool _isLoading = true;
  bool _isRefreshing = false;
  bool _isExportingPdf = false;
  int _replayToken = 0;
  int _currentTab = 0;

  ClaimsOverviewViewData _viewData = ClaimsOverviewViewData.empty();
  EnrollmentOverviewViewData _enrollmentViewData =
      EnrollmentOverviewViewData.empty();
  String? _clientId;
  String? _clientBranchId;
  String? _selectedPolicyId;
  List<Map<String, dynamic>> _activePolicies = [];
  Uint8List? _clientLogoBytes;

  static const _tabs = [
    (Icons.dashboard_outlined, 'Overview'),
    (Icons.timeline, 'Claims Overview'),
    (Icons.analytics_outlined, 'Claims Analysis'),
    (Icons.people_outline, 'Demographics'),
    (Icons.location_city_outlined, 'Hospitals & Geography'),
    (Icons.medical_services_outlined, 'Specialty Analysis'),
    (Icons.group_add_outlined, 'Insured'),
  ];

  @override
  void initState() {
    super.initState();
    _apiService = ApiService(context);
    _scrollController = ScrollController();
    _sectionKeys = List.generate(_tabs.length, (_) => GlobalKey());
    _tabController = TabController(length: _tabs.length, vsync: this);
    _tabController.addListener(_onTabChanged);

    _headerFadeController = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 600),
    );
    _headerFade = CurvedAnimation(
      parent: _headerFadeController,
      curve: Curves.easeOut,
    );
    _headerFadeController.forward();

    _loadDashboard();
  }

  void _onTabChanged() {
    if (_tabController.indexIsChanging) return;
    final index = _tabController.index;
    if (_currentTab != index) {
      setState(() => _currentTab = index);
    }
  }

  void _scrollToSection(int index) {
    setState(() => _currentTab = index);
    WidgetsBinding.instance.addPostFrameCallback((_) {
      final sectionContext = _sectionKeys[index].currentContext;
      if (sectionContext == null) return;
      Scrollable.ensureVisible(
        sectionContext,
        duration: const Duration(milliseconds: 450),
        curve: Curves.easeInOut,
        alignment: 0.02,
      );
    });
  }

  Future<void> _loadDashboard({bool reloadPolicies = false}) async {
    final isInitialLoad = _replayToken == 0;
    setState(() {
      if (isInitialLoad) {
        _isLoading = true;
      } else {
        _isRefreshing = true;
      }
    });

    try {
      _clientId ??= await _tokenService.readValue('empClientId');
      _clientBranchId ??= await _tokenService.readValue('empClientBranchId');
      final hrId = await _tokenService.readValue('empHrId');
      final token = await _tokenService.getCurrentToken();
      if (token != null && token.isNotEmpty) {
        await _apiService.getTokenLoadAPI(token);
      }

      if (isInitialLoad || reloadPolicies || _activePolicies.isEmpty) {
        await _loadPolicyList(token ?? '', hrId ?? '');
        if (isInitialLoad && _activePolicies.isNotEmpty) {
          _selectedPolicyId =
              _activePolicies.first['client_policy_id'].toString();
        }
        if (!mounted) return;
        setState(() {});
      }

      if (_selectedPolicyId == null) {
        if (!mounted) return;
        setState(() {
          _viewData = ClaimsOverviewViewData.empty(
            error: 'No active policy found',
          );
          _enrollmentViewData = EnrollmentOverviewViewData.empty();
          _isLoading = false;
          _isRefreshing = false;
        });
        return;
      }

      final policyId = _selectedPolicyId!;
      final response = await _apiService.getClaimsCollectionV2All(
        clientPolicyId: policyId,
      );
      final enrollmentResponse =
          await _apiService.getEnrollmentCollectionV1All(
        clientPolicyId: policyId,
      );

      if (!mounted) return;

      final claimsOk = ClaimsKpiParser.isSuccessResponse(response);
      var claimsData = await ClaimsOverviewViewData.enrichFromApiResponse(
        response,
        fetchKpi: (slug) => _apiService.getClaimsCollectionV2Kpi(
          slug,
          clientPolicyId: policyId,
        ),
      );
      var enrollmentData = _parseEnrollmentResponse(enrollmentResponse);

      final selectedPolicy = _selectedPolicy();
      if (selectedPolicy != null) {
        claimsData = claimsData.withPolicyFallback(selectedPolicy);
        enrollmentData = enrollmentData.withPolicyFallback(selectedPolicy);
      }

      if (!claimsOk) {
        final message =
            response['message']?.toString() ?? 'Failed to load claims data';
        claimsData = ClaimsOverviewViewData(
          kpiBySlug: claimsData.kpiBySlug,
          loadError: message,
        );
        if (claimsData.kpiBySlug.isEmpty) {
          if (!mounted) return;
          setState(() {
            _viewData = claimsData;
            _enrollmentViewData = enrollmentData;
            _isLoading = false;
            _isRefreshing = false;
            _replayToken++;
          });
          ToastHelper.showErrorToast(context, message);
          return;
        }
      }

      if (!mounted) return;
      setState(() {
        _viewData = claimsData;
        _enrollmentViewData = enrollmentData;
        _isLoading = false;
        _isRefreshing = false;
        _replayToken++;
      });
    } catch (e) {
      if (!mounted) return;
      setState(() {
        _viewData = ClaimsOverviewViewData.empty(error: e.toString());
        _enrollmentViewData =
            EnrollmentOverviewViewData.empty(error: e.toString());
        _isLoading = false;
        _isRefreshing = false;
      });
      ToastHelper.showErrorToast(context, 'Failed to load claims overview');
    }
  }

  Future<void> _loadPolicyList(String token, String hrId) async {
    _clientId ??= await _tokenService.readValue('empClientId');
    _clientBranchId ??= await _tokenService.readValue('empClientBranchId');

    if (_clientId == null || _clientBranchId == null) return;

    final policyRes = await _apiService.getActiveCashDepositDetailsToApi(
      _clientId!,
      _clientBranchId!,
      hrId,
      token,
      1,
    );

    if (policyRes['status'] != 'success' || policyRes['data'] is! List) {
      _activePolicies = [];
      _selectedPolicyId = null;
      return;
    }

    _activePolicies = List<Map<String, dynamic>>.from(policyRes['data'])
      ..sort((a, b) {
        final aLabel = '${a['type']} - ${a['policy_no']}';
        final bLabel = '${b['type']} - ${b['policy_no']}';
        return aLabel.compareTo(bLabel);
      });

    if (_activePolicies.isNotEmpty) {
      final firstId =
          _activePolicies.first['client_policy_id'].toString();
      final stillValid = _selectedPolicyId != null &&
          _activePolicies.any(
            (p) => p['client_policy_id'].toString() == _selectedPolicyId,
          );
      if (!stillValid) {
        _selectedPolicyId = firstId;
      }
      await _loadClientLogoForSelectedPolicy();
    } else {
      _selectedPolicyId = null;
      _clientLogoBytes = null;
    }
  }

  EnrollmentOverviewViewData _parseEnrollmentResponse(
    Map<String, dynamic> response,
  ) {
    if (!ClaimsKpiParser.isSuccessResponse(response)) {
      return EnrollmentOverviewViewData.empty(
        error: response['message']?.toString() ??
            'Failed to load enrollment data',
      );
    }
    return EnrollmentOverviewViewData.fromApiResponse(response);
  }

  Map<String, dynamic>? _selectedPolicy() {
    if (_selectedPolicyId == null) return null;
    for (final policy in _activePolicies) {
      if (policy['client_policy_id'].toString() == _selectedPolicyId) {
        return policy;
      }
    }
    return null;
  }

  Future<void> _loadClientLogoForSelectedPolicy() async {
    final url = _selectedPolicy()?['client_logo']?.toString().trim();
    if (url == null || url.isEmpty) {
      if (mounted) setState(() => _clientLogoBytes = null);
      return;
    }

    try {
      final response = await http.get(Uri.parse(url));
      if (!mounted) return;
      if (response.statusCode == 200 && response.bodyBytes.isNotEmpty) {
        setState(() => _clientLogoBytes = response.bodyBytes);
      } else {
        setState(() => _clientLogoBytes = null);
      }
    } catch (_) {
      if (mounted) setState(() => _clientLogoBytes = null);
    }
  }

  void _onPolicySelected(String policyId) {
    if (policyId == _selectedPolicyId) return;
    setState(() => _selectedPolicyId = policyId);
    _loadClientLogoForSelectedPolicy();
    _loadDashboard();
  }

  String _selectedPolicyLabel() {
    if (_selectedPolicyId == null) return 'Select Policy';
    for (final policy in _activePolicies) {
      if (policy['client_policy_id'].toString() == _selectedPolicyId) {
        return '${policy['type']} - ${policy['policy_no']}';
      }
    }
    return 'Policy $_selectedPolicyId';
  }

  Future<void> _downloadChartsPdf() async {
    if (_isExportingPdf || _isLoading) return;

    setState(() => _isExportingPdf = true);

    if (!mounted) return;

    final navigator = Navigator.of(context, rootNavigator: true);
    final overlay = navigator.overlay;
    if (overlay == null) {
      setState(() => _isExportingPdf = false);
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(
            'Could not generate PDF. Overlay unavailable.',
            style: GoogleFonts.poppins(),
          ),
          backgroundColor: Colors.red.shade700,
          behavior: SnackBarBehavior.floating,
        ),
      );
      return;
    }
    var progressLabel = 'Preparing PDF…';
    void Function(void Function())? updateProgressDialog;
    showDialog<void>(
      context: context,
      barrierDismissible: false,
      useRootNavigator: true,
      builder: (ctx) => PopScope(
        canPop: false,
        child: StatefulBuilder(
          builder: (context, setDialogState) {
            updateProgressDialog = setDialogState;
            return AlertDialog(
              content: Row(
                children: [
                  const CircularProgressIndicator(),
                  const SizedBox(width: 20),
                  Expanded(
                    child: Text(
                      'Generating PDF…\n$progressLabel',
                      style: GoogleFonts.poppins(fontSize: 14),
                    ),
                  ),
                ],
              ),
            );
          },
        ),
      ),
    );

    try {
      if (_clientLogoBytes == null) {
        await _loadClientLogoForSelectedPolicy();
      }

      await exportClaimsOverviewChartsPdf(
        overlay: overlay,
        replayToken: _replayToken,
        viewData: _viewData,
        enrollmentViewData: _enrollmentViewData,
        policyId: _selectedPolicyId ?? '',
        clientLogoBytes: _clientLogoBytes,
        onProgress: (_, __, label) {
          updateProgressDialog?.call(() {
            progressLabel = label;
          });
        },
      );
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(
            'Claims Overview PDF downloaded',
            style: GoogleFonts.poppins(),
          ),
          behavior: SnackBarBehavior.floating,
        ),
      );
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(
            'Could not generate PDF. Please try again. ($e)',
            style: GoogleFonts.poppins(),
          ),
          backgroundColor: Colors.red.shade700,
          behavior: SnackBarBehavior.floating,
        ),
      );
    } finally {
      if (mounted && navigator.canPop()) {
        navigator.pop();
      }
      if (mounted) setState(() => _isExportingPdf = false);
    }
  }

  @override
  void dispose() {
    _tabController.removeListener(_onTabChanged);
    _tabController.dispose();
    _scrollController.dispose();
    _headerFadeController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return BaseLayout(
      child: SecurePopScope(
        child: Container(
          color: ClaimsOverviewTheme.pageBg,
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              FadeTransition(
                opacity: _headerFade,
                child: _buildHeader(),
              ),
              ClaimsTopLoadingBar(visible: _isRefreshing),
              _buildTabBar(),
              Expanded(
                child: ClaimsOverviewScope(
                  key: ValueKey('claims-$_selectedPolicyId-$_replayToken'),
                  data: _viewData,
                  child: EnrollmentOverviewScope(
                    key: ValueKey('enrollment-$_selectedPolicyId-$_replayToken'),
                    data: _enrollmentViewData,
                    child: ClaimsTabAnimatedShell(
                      isLoading: _isLoading,
                      skeletonBlocks: 5,
                      child: Scrollbar(
                        controller: _scrollController,
                        thumbVisibility: true,
                        child: SingleChildScrollView(
                          controller: _scrollController,
                          physics: _isRefreshing
                              ? const NeverScrollableScrollPhysics()
                              : const ClampingScrollPhysics(),
                          child: Column(
                            crossAxisAlignment: CrossAxisAlignment.stretch,
                            children: [
                              for (var i = 0; i < _tabs.length; i++) ...[
                                _buildSection(
                                  index: i,
                                  replayToken: _replayToken,
                                ),
                                if (i < _tabs.length - 1)
                                  const SizedBox(height: 8),
                              ],
                              const SizedBox(height: 24),
                            ],
                          ),
                        ),
                      ),
                    ),
                  ),
                ),
              ),
              // _buildFooter(),
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildHeader() {
    return Container(
      padding: const EdgeInsets.fromLTRB(20, 16, 20, 12),
      decoration: BoxDecoration(
        color: ClaimsOverviewTheme.cardBg,
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: ClaimsOverviewTheme.border),
      ),
      child: Column(
        children: [
          Row(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              TweenAnimationBuilder<double>(
                tween: Tween(begin: 0.85, end: 1),
                duration: const Duration(milliseconds: 500),
                curve: Curves.elasticOut,
                builder: (_, scale, child) =>
                    Transform.scale(scale: scale, child: child),
                child: Container(
                  padding: const EdgeInsets.all(10),
                  decoration: BoxDecoration(
                    color: ClaimsOverviewTheme.primary.withValues(alpha: 0.12),
                    borderRadius: BorderRadius.circular(10),
                  ),
                  child: const Icon(
                    Icons.shield_outlined,
                    color: ClaimsOverviewTheme.primary,
                    size: 28,
                  ),
                ),
              ),
              const SizedBox(width: 14),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      'Claims Overview',
                      style: GoogleFonts.poppins(
                        fontSize: 22,
                        fontWeight: FontWeight.w700,
                        color: ClaimsOverviewTheme.textPrimary,
                      ),
                    ),
                    const SizedBox(height: 4),
                    Row(
                      children: [
                        Text(
                          'Real-time policy & claims analytics',
                          style: GoogleFonts.poppins(
                            fontSize: 13,
                            color: ClaimsOverviewTheme.textSecondary,
                          ),
                        ),
                        if (_viewData.liveUpdatedAt != null &&
                            _viewData.liveUpdatedAt!.isNotEmpty) ...[
                          const SizedBox(width: 12),
                          ClaimsLiveIndicator(
                            createdAt: _viewData.liveUpdatedAt,
                          ),
                        ],
                      ],
                    ),
                  ],
                ),
              ),
              _buildPolicyBadge(),
              const SizedBox(width: 12),
              _headerActions(),
            ],
          ),
        ],
      ),
    );
  }

  Widget _buildPolicyBadge() {
    if (_activePolicies.isEmpty) {
      return Material(
        color: ClaimsOverviewTheme.pageBg,
        borderRadius: BorderRadius.circular(24),
        child: Container(
          padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 8),
          decoration: BoxDecoration(
            border: Border.all(color: ClaimsOverviewTheme.border),
            borderRadius: BorderRadius.circular(24),
          ),
          child: Row(
            mainAxisSize: MainAxisSize.min,
            children: [
              Text(
                _selectedPolicyLabel(),
                style: GoogleFonts.poppins(
                  fontSize: 13,
                  fontWeight: FontWeight.w600,
                ),
              ),
              const SizedBox(width: 4),
              ClaimsRefreshIcon(
                isRefreshing: _isRefreshing,
                onPressed: _loadDashboard,
              ),
            ],
          ),
        ),
      );
    }

    return Material(
      color: ClaimsOverviewTheme.pageBg,
      borderRadius: BorderRadius.circular(24),
      child: SizedBox(
        width: 320,
        height: 40,
        child: SearchAnchor(
          viewBackgroundColor: ClaimsOverviewTheme.cardBg,
          viewConstraints: const BoxConstraints(maxHeight: 260),
          builder: (context, controller) {
            return InkWell(
              onTap: controller.openView,
              borderRadius: BorderRadius.circular(24),
              child: Container(
                padding: const EdgeInsets.symmetric(horizontal: 14),
                decoration: BoxDecoration(
                  border: Border.all(color: ClaimsOverviewTheme.border),
                  borderRadius: BorderRadius.circular(24),
                ),
                child: Row(
                  children: [
                    Expanded(
                      child: Text(
                        _selectedPolicyLabel(),
                        style: GoogleFonts.poppins(
                          fontSize: 13,
                          fontWeight: FontWeight.w600,
                        ),
                        overflow: TextOverflow.ellipsis,
                      ),
                    ),
                    const Icon(
                      Icons.arrow_drop_down,
                      color: ClaimsOverviewTheme.textSecondary,
                    ),
                    ClaimsRefreshIcon(
                      isRefreshing: _isRefreshing,
                      onPressed: _loadDashboard,
                    ),
                  ],
                ),
              ),
            );
          },
          suggestionsBuilder: (context, controller) {
            final input = controller.text.toLowerCase();
            return _activePolicies
                .where((policy) {
                  final type = policy['type'].toString().toLowerCase();
                  final policyNo = policy['policy_no'].toString().toLowerCase();
                  return type.contains(input) || policyNo.contains(input);
                })
                .map((policy) {
                  final label = '${policy['type']} - ${policy['policy_no']}';
                  return ListTile(
                    dense: true,
                    title: Text(
                      label,
                      style: GoogleFonts.poppins(fontSize: 13),
                    ),
                    onTap: () {
                      controller.closeView(label);
                      _onPolicySelected(
                        policy['client_policy_id'].toString(),
                      );
                    },
                  );
                })
                .toList();
          },
        ),
      ),
    );
  }

  Widget _headerActions() {
    return Padding(
      padding: const EdgeInsets.only(left: 4),
      child: IconButton(
        tooltip: 'Download all charts as PDF',
        icon: _isExportingPdf
            ? const SizedBox(
                width: 20,
                height: 20,
                child: CircularProgressIndicator(strokeWidth: 2),
              )
            : const Icon(Icons.download_outlined, size: 20),
        style: IconButton.styleFrom(
          foregroundColor: ClaimsOverviewTheme.textSecondary,
        ),
        onPressed: (_isRefreshing || _isExportingPdf || _isLoading)
            ? null
            : _downloadChartsPdf,
      ),
    );
  }

  Widget _buildTabBar() {
    return Container(
      margin: const EdgeInsets.only(top: 12),
      decoration: BoxDecoration(
        color: ClaimsOverviewTheme.cardBg,
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: ClaimsOverviewTheme.border),
      ),
      child: Column(
        children: [
          if (_isRefreshing)
            Padding(
              padding: const EdgeInsets.fromLTRB(16, 8, 16, 0),
              child: Align(
                alignment: Alignment.centerRight,
                child: Text(
                  'Updating…',
                  style: GoogleFonts.poppins(
                    fontSize: 11,
                    color: ClaimsOverviewTheme.textSecondary,
                  ),
                ),
              ),
            ),
          TabBar(
            controller: _tabController,
            onTap: _scrollToSection,
            isScrollable: true,
            tabAlignment: TabAlignment.start,
            labelColor: ClaimsOverviewTheme.primary,
            unselectedLabelColor: ClaimsOverviewTheme.textSecondary,
            indicatorColor: ClaimsOverviewTheme.primary,
            indicatorWeight: 3,
            indicatorSize: TabBarIndicatorSize.label,
            labelStyle: GoogleFonts.poppins(
              fontSize: 13,
              fontWeight: FontWeight.w600,
            ),
            unselectedLabelStyle: GoogleFonts.poppins(fontSize: 13),
            tabs: List.generate(_tabs.length, (i) {
              final t = _tabs[i];
              final selected = _currentTab == i;
              return Tab(
                height: 48,
                child: AnimatedScale(
                  scale: selected ? 1.02 : 1.0,
                  duration: const Duration(milliseconds: 200),
                  curve: Curves.easeOut,
                  child: Row(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      AnimatedSwitcher(
                        duration: const Duration(milliseconds: 200),
                        child: Icon(
                          t.$1,
                          key: ValueKey('$i-$selected'),
                          size: 18,
                          color: selected
                              ? ClaimsOverviewTheme.primary
                              : ClaimsOverviewTheme.textSecondary,
                        ),
                      ),
                      const SizedBox(width: 6),
                      Text(t.$2),
                    ],
                  ),
                ),
              );
            }),
          ),
        ],
      ),
    );
  }

  Widget _buildSection({
    required int index,
    required int replayToken,
  }) {
    final tab = _tabs[index];
    return Container(
      key: _sectionKeys[index],
      margin: const EdgeInsets.only(top: 16),
      decoration: BoxDecoration(
        color: ClaimsOverviewTheme.cardBg,
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: ClaimsOverviewTheme.border),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Padding(
            padding: const EdgeInsets.fromLTRB(20, 16, 20, 0),
            child: Row(
              children: [
                Icon(
                  tab.$1,
                  size: 22,
                  color: ClaimsOverviewTheme.primary,
                ),
                const SizedBox(width: 10),
                Text(
                  tab.$2,
                  style: GoogleFonts.poppins(
                    fontSize: 18,
                    fontWeight: FontWeight.w700,
                    color: ClaimsOverviewTheme.textPrimary,
                  ),
                ),
              ],
            ),
          ),
          const SizedBox(height: 12),
          ClaimsOverviewTab(
            index: index,
            replayToken: replayToken,
            isActive: true,
            scrollable: false,
          ),
          const SizedBox(height: 16),
        ],
      ),
    );
  }

  Widget _buildFooter() {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 12),
      child: Center(
        child: RichText(
          text: TextSpan(
            style: GoogleFonts.poppins(
              fontSize: 12,
              color: ClaimsOverviewTheme.textSecondary,
            ),
            children: [
              const TextSpan(text: 'Powered by '),
              TextSpan(
                text: 'Nhance',
                style: GoogleFonts.poppins(
                  fontWeight: FontWeight.w700,
                  color: ClaimsOverviewTheme.orange,
                ),
              ),
              const TextSpan(text: ' Insights · Light Theme'),
            ],
          ),
        ),
      ),
    );
  }
}