import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:qpay/screens/groups/models/group_batch_model.dart';
import 'package:qpay/screens/groups/models/recipient_group_model.dart';
import 'package:qpay/models/responsive_policy.dart';
import 'package:qpay/screens/groups/controllers/batch_controller.dart';
import 'package:qpay/screens/groups/controllers/group_controller.dart';
import 'package:qpay/widgets/status_chip_widget.dart';

class GroupDetailScreen extends StatefulWidget {
  final RecipientGroup group;

  const GroupDetailScreen({super.key, required this.group});

  @override
  State<GroupDetailScreen> createState() => _GroupDetailScreenState();
}

class _GroupDetailScreenState extends State<GroupDetailScreen> {
  late GroupController groupController;
  late BatchController batchController;
  final _searchController = TextEditingController();
  final _scrollController = ScrollController();
  String? _statusFilter;
  String? _currencyFilter;

  static const _statusFilterItems = <DropdownMenuItem<String?>>[
    DropdownMenuItem(value: null, child: Text('All')),
    DropdownMenuItem(value: 'CREATED', child: Text('Created')),
    DropdownMenuItem(value: 'PENDING', child: Text('Pending')),
    DropdownMenuItem(value: 'CONFIRMED_ALL', child: Text('Confirmed')),
    DropdownMenuItem(value: 'REQUESTED', child: Text('Requested')),
    DropdownMenuItem(value: 'PROCESSING', child: Text('Processing')),
    DropdownMenuItem(value: 'COMPLETED', child: Text('Completed')),
    DropdownMenuItem(value: 'FAILED', child: Text('Failed')),
  ];

  static const _currencyFilterItems = <DropdownMenuItem<String?>>[
    DropdownMenuItem(value: null, child: Text('All')),
    DropdownMenuItem(value: 'USD', child: Text('USD')),
    DropdownMenuItem(value: 'ZWL', child: Text('ZWL')),
    DropdownMenuItem(value: 'ZAR', child: Text('ZAR')),
  ];

  @override
  void initState() {
    super.initState();
    groupController = GroupController(context);
    batchController = BatchController(context);
    _loadData();
    _scrollController.addListener(_onScroll);
    _searchController.addListener(() => setState(() {}));
  }

  void _onScroll() {
    if (_scrollController.position.pixels >=
        _scrollController.position.maxScrollExtent - 200) {
      batchController.loadNextPage(widget.group.id ?? '');
    }
  }

  Future<void> _loadData() async {
    final groupId = widget.group.id ?? '';
    await Future.wait([
      batchController.listBatches(groupId),
      groupController.listMembers(groupId),
    ]);
  }

  void _onSearchChanged(String value) {
    batchController.searchBatches(
      widget.group.id ?? '',
      search: value.isNotEmpty ? value : null,
      status: _statusFilter,
      currency: _currencyFilter,
    );
  }

  void _showMembersSheet() {
    showModalBottomSheet(
      context: context,
      isScrollControlled: true,
      shape: const RoundedRectangleBorder(
        borderRadius: BorderRadius.vertical(top: Radius.circular(20)),
      ),
      builder: (ctx) => DraggableScrollableSheet(
        initialChildSize: 0.6,
        minChildSize: 0.3,
        maxChildSize: 0.85,
        expand: false,
        builder: (context, scrollController) {
          return Padding(
            padding: const EdgeInsets.all(16),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Row(
                  children: [
                    const Text(
                      'Members',
                      style: TextStyle(
                        fontSize: 20,
                        fontWeight: FontWeight.w600,
                      ),
                    ),
                    const Spacer(),
                    IconButton(
                      icon: const Icon(Icons.close),
                      onPressed: () => Navigator.of(context).pop(),
                    ),
                  ],
                ),
                const SizedBox(height: 4),
                Text(
                  '${groupController.model.members.length} member(s)',
                  style: TextStyle(fontSize: 14, color: Colors.grey.shade600),
                ),
                const SizedBox(height: 12),
                const Divider(),
                Expanded(
                  child: ListenableBuilder(
                    listenable: groupController,
                    builder: (context, _) {
                      if (groupController.model.isLoading) {
                        return const Center(child: CircularProgressIndicator());
                      }

                      if (groupController.model.members.isEmpty) {
                        return Center(
                          child: Padding(
                            padding: const EdgeInsets.all(32),
                            child: Column(
                              mainAxisSize: MainAxisSize.min,
                              children: [
                                Icon(
                                  Icons.person_outline,
                                  size: 48,
                                  color: Colors.grey.shade400,
                                ),
                                const SizedBox(height: 16),
                                const Text(
                                  'No members found.',
                                  style: TextStyle(
                                    fontSize: 16,
                                    fontWeight: FontWeight.w600,
                                  ),
                                ),
                              ],
                            ),
                          ),
                        );
                      }

                      return ListView.separated(
                        controller: scrollController,
                        itemCount: groupController.model.members.length,
                        separatorBuilder: (_, __) => const Divider(height: 1),
                        itemBuilder: (context, index) {
                          final member = groupController.model.members[index];
                          return ListTile(
                            contentPadding: const EdgeInsets.symmetric(
                              vertical: 2,
                              horizontal: 4,
                            ),
                            leading: CircleAvatar(
                              backgroundColor: Theme.of(
                                context,
                              ).colorScheme.primary.withAlpha(30),
                              child: Text(
                                member.recipient.name?.isNotEmpty == true
                                    ? member.recipient.name![0].toUpperCase()
                                    : '?',
                                style: TextStyle(
                                  color: Theme.of(context).colorScheme.primary,
                                  fontWeight: FontWeight.w600,
                                ),
                              ),
                            ),
                            title: Text(
                              member.recipient.name ?? '',
                              style: const TextStyle(
                                fontWeight: FontWeight.w500,
                              ),
                            ),
                            subtitle: Text(member.recipient.account ?? ''),
                            trailing:
                                member.recipient.latestProviderLabel != null &&
                                    member
                                        .recipient
                                        .latestProviderLabel!
                                        .isNotEmpty
                                ? Chip(
                                    label: Text(
                                      member.recipient.latestProviderLabel!,
                                      style: const TextStyle(fontSize: 11),
                                    ),
                                    visualDensity: VisualDensity.compact,
                                  )
                                : null,
                          );
                        },
                      );
                    },
                  ),
                ),
              ],
            ),
          );
        },
      ),
    );
  }

  void _onDeleteSelected() async {
    final userId = widget.group.userId ?? '';
    final count = batchController.model.selectedBatchIds.length;

    final confirmed = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('Delete batches'),
        content: Text('Are you sure you want to delete $count batch(es)?'),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(ctx).pop(false),
            child: const Text('Cancel'),
          ),
          TextButton(
            onPressed: () => Navigator.of(ctx).pop(true),
            style: TextButton.styleFrom(foregroundColor: Colors.red),
            child: const Text('Delete'),
          ),
        ],
      ),
    );

    if (confirmed == true) {
      await batchController.deleteSelectedBatches(
        groupId: widget.group.id ?? '',
        userId: userId,
      );
    }
  }

  void _showFilterSheet() {
    showModalBottomSheet(
      context: context,
      shape: const RoundedRectangleBorder(
        borderRadius: BorderRadius.vertical(top: Radius.circular(20)),
      ),
      builder: (ctx) {
        return StatefulBuilder(
          builder: (context, setSheetState) {
            return Padding(
              padding: const EdgeInsets.all(20),
              child: Column(
                mainAxisSize: MainAxisSize.min,
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Row(
                    children: [
                      const Text(
                        'Filter Batches',
                        style: TextStyle(
                          fontSize: 18,
                          fontWeight: FontWeight.w600,
                        ),
                      ),
                      const Spacer(),
                      TextButton(
                        onPressed: () {
                          setSheetState(() {
                            _statusFilter = null;
                            _currencyFilter = null;
                          });
                        },
                        child: const Text('Clear All'),
                      ),
                    ],
                  ),
                  const SizedBox(height: 16),
                  DropdownButtonFormField<String?>(
                    initialValue: _statusFilter,
                    decoration: InputDecoration(
                      labelText: 'Status',
                      filled: true,
                      fillColor: Colors.grey.shade100,
                      border: OutlineInputBorder(
                        borderRadius: BorderRadius.circular(12),
                        borderSide: BorderSide.none,
                      ),
                      contentPadding: const EdgeInsets.symmetric(
                        horizontal: 16,
                        vertical: 14,
                      ),
                    ),
                    items: _statusFilterItems,
                    onChanged: (v) {
                      setSheetState(() => _statusFilter = v);
                    },
                  ),
                  const SizedBox(height: 16),
                  DropdownButtonFormField<String?>(
                    initialValue: _currencyFilter,
                    decoration: InputDecoration(
                      labelText: 'Currency',
                      filled: true,
                      fillColor: Colors.grey.shade100,
                      border: OutlineInputBorder(
                        borderRadius: BorderRadius.circular(12),
                        borderSide: BorderSide.none,
                      ),
                      contentPadding: const EdgeInsets.symmetric(
                        horizontal: 16,
                        vertical: 14,
                      ),
                    ),
                    items: _currencyFilterItems,
                    onChanged: (v) {
                      setSheetState(() => _currencyFilter = v);
                    },
                  ),
                  const SizedBox(height: 24),
                  SizedBox(
                    width: double.infinity,
                    child: ElevatedButton(
                      onPressed: () => _applyFilters(ctx),
                      child: const Text('Apply Filters'),
                    ),
                  ),
                  const SizedBox(height: 8),
                ],
              ),
            );
          },
        );
      },
    );
  }

  void _applyFilters(BuildContext ctx) {
    Navigator.of(ctx).pop();
    batchController.searchBatches(
      widget.group.id ?? '',
      search: _searchController.text.isNotEmpty ? _searchController.text : null,
      status: _statusFilter,
      currency: _currencyFilter,
    );
  }

  @override
  void dispose() {
    _searchController.dispose();
    _scrollController.dispose();
    groupController.dispose();
    batchController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.group.name),
        centerTitle: true,
        actions: [
          IconButton(
            icon: const Icon(Icons.people_outline),
            tooltip: 'View members',
            onPressed: _showMembersSheet,
          ),
        ],
      ),
      body: ListenableBuilder(
        listenable: batchController,
        builder: (context, _) {
          return Column(
            children: [
              Expanded(
                child: CustomScrollView(
                  controller: _scrollController,
                  slivers: [
                    SliverToBoxAdapter(
                      child: Center(
                        child: LayoutBuilder(
                          builder: (context, constraints) {
                            final width =
                                constraints.maxWidth > ResponsivePolicy.md
                                ? ResponsivePolicy.md.toDouble()
                                : constraints.maxWidth;
                            return SizedBox(
                              width: width,
                              child: Padding(
                                padding: const EdgeInsets.all(16),
                                child: Column(
                                  crossAxisAlignment: CrossAxisAlignment.start,
                                  children: [
                                    _buildSearchRow(),
                                    const SizedBox(height: 16),
                                    _buildContent(),
                                  ],
                                ),
                              ),
                            );
                          },
                        ),
                      ),
                    ),
                  ],
                ),
              ),
              if (batchController.model.selectMode) _buildSelectionBottomBar(),
            ],
          );
        },
      ),
    );
  }

  Widget _buildSearchRow() {
    return Row(
      children: [
        Expanded(
          child: TextFormField(
            controller: _searchController,
            decoration: InputDecoration(
              hintText: 'Search batches by description...',
              prefixIcon: const Icon(Icons.search),
              suffixIcon: _searchController.text.isNotEmpty
                  ? IconButton(
                      icon: const Icon(Icons.clear),
                      onPressed: () {
                        _searchController.clear();
                        _onSearchChanged('');
                      },
                    )
                  : null,
              filled: true,
              fillColor: Colors.grey.shade100,
              border: OutlineInputBorder(
                borderRadius: BorderRadius.circular(12),
                borderSide: BorderSide.none,
              ),
              focusedBorder: OutlineInputBorder(
                borderRadius: BorderRadius.circular(12),
                borderSide: BorderSide(
                  color: Theme.of(context).colorScheme.primary,
                ),
              ),
            ),
            onChanged: _onSearchChanged,
          ),
        ),
        const SizedBox(width: 8),
        _buildIconButton(
          icon: Icons.filter_list,
          tooltip: 'Filter batches',
          isActive: _statusFilter != null || _currencyFilter != null,
          onPressed: _showFilterSheet,
        ),
        const SizedBox(width: 8),
        _buildIconButton(
          icon: batchController.model.selectMode
              ? Icons.checklist
              : Icons.checklist_outlined,
          tooltip: 'Select batches',
          isActive: batchController.model.selectMode,
          onPressed: () => batchController.toggleSelectMode(),
        ),
        const SizedBox(width: 8),
        _buildIconButton(
          icon: Icons.add,
          tooltip: 'Create batch',
          isActive: false,
          onPressed: () async {
            final result = await context.push(
              '/groups/${widget.group.id}/batches/create',
              extra: widget.group,
            );
            if (result == true) {
              _loadData();
            }
          },
        ),
      ],
    );
  }

  Widget _buildIconButton({
    required IconData icon,
    required String tooltip,
    required bool isActive,
    required VoidCallback onPressed,
  }) {
    return Container(
      decoration: BoxDecoration(
        color: isActive
            ? Theme.of(context).colorScheme.primary
            : Colors.grey.shade100,
        borderRadius: BorderRadius.circular(12),
      ),
      child: IconButton(
        icon: Icon(icon, color: isActive ? Colors.white : Colors.grey.shade700),
        tooltip: tooltip,
        onPressed: onPressed,
      ),
    );
  }

  Widget _buildContent() {
    if (batchController.model.isLoading) {
      return const Center(
        child: Padding(
          padding: EdgeInsets.symmetric(vertical: 60),
          child: CircularProgressIndicator(),
        ),
      );
    }

    if (batchController.model.batches.isEmpty) {
      return Center(
        child: Padding(
          padding: const EdgeInsets.symmetric(vertical: 40),
          child: Column(
            children: [
              Icon(
                Icons.receipt_long_outlined,
                size: 64,
                color: Colors.grey.shade400,
              ),
              const SizedBox(height: 16),
              const Text(
                'No batches yet.',
                style: TextStyle(fontSize: 18, fontWeight: FontWeight.w600),
              ),
              const SizedBox(height: 8),
              Text(
                'Tap + to create a new batch payment.',
                style: TextStyle(fontSize: 14, color: Colors.grey.shade600),
              ),
            ],
          ),
        ),
      );
    }

    return Column(
      children: [
        if (batchController.model.selectMode)
          Padding(
            padding: const EdgeInsets.only(bottom: 8),
            child: Row(
              children: [
                Text(
                  '${batchController.model.selectedBatchIds.length} selected',
                  style: TextStyle(
                    fontSize: 13,
                    fontWeight: FontWeight.w500,
                    color: Colors.grey.shade600,
                  ),
                ),
              ],
            ),
          ),
        if (_statusFilter != null || _currencyFilter != null)
          Padding(
            padding: const EdgeInsets.only(bottom: 8),
            child: Row(
              children: [
                if (_statusFilter != null)
                  _activeFilterChip('Status: $_statusFilter', () {
                    setState(() => _statusFilter = null);
                    _onSearchChanged(_searchController.text);
                  }),
                if (_currencyFilter != null) const SizedBox(width: 6),
                if (_currencyFilter != null)
                  _activeFilterChip('Currency: $_currencyFilter', () {
                    setState(() => _currencyFilter = null);
                    _onSearchChanged(_searchController.text);
                  }),
              ],
            ),
          ),
        ListView.separated(
          shrinkWrap: true,
          physics: const NeverScrollableScrollPhysics(),
          itemCount: batchController.model.batches.length,
          separatorBuilder: (_, __) => const SizedBox(height: 8),
          itemBuilder: (context, index) {
            return _buildBatchCard(
              context,
              batchController.model.batches[index],
              widget.group,
            );
          },
        ),
        if (batchController.model.isLoadingMore)
          const Padding(
            padding: EdgeInsets.symmetric(vertical: 16),
            child: Center(child: CircularProgressIndicator(strokeWidth: 2)),
          ),
      ],
    );
  }

  Widget _activeFilterChip(String label, VoidCallback onRemove) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 4),
      decoration: BoxDecoration(
        color: Theme.of(context).colorScheme.primary.withAlpha(20),
        borderRadius: BorderRadius.circular(20),
        border: Border.all(
          color: Theme.of(context).colorScheme.primary.withAlpha(60),
        ),
      ),
      child: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          Text(
            label,
            style: TextStyle(
              fontSize: 12,
              color: Theme.of(context).colorScheme.primary,
              fontWeight: FontWeight.w500,
            ),
          ),
          const SizedBox(width: 4),
          InkWell(
            onTap: onRemove,
            borderRadius: BorderRadius.circular(10),
            child: Padding(
              padding: const EdgeInsets.all(2),
              child: Icon(
                Icons.close,
                size: 14,
                color: Theme.of(context).colorScheme.primary,
              ),
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildBatchCard(
    BuildContext context,
    GroupBatch batch,
    RecipientGroup group,
  ) {
    final isSelected = batchController.model.selectedBatchIds.contains(
      batch.id,
    );
    final inSelectMode = batchController.model.selectMode;

    final status = batch.status ?? 'UNKNOWN';
    return Card(
      elevation: 0,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(12),
        side: BorderSide(
          color: inSelectMode && isSelected
              ? Theme.of(context).colorScheme.primary
              : Colors.black12.withAlpha(30),
          width: inSelectMode && isSelected ? 2 : 1,
        ),
      ),
      child: InkWell(
        borderRadius: BorderRadius.circular(12),
        onTap: inSelectMode
            ? () => batchController.toggleBatchSelection(batch.id!)
            : () => context.push('/groups/${group.id}/batches/${batch.id}'),
        child: Padding(
          padding: const EdgeInsets.all(10),
          child: Row(
            children: [
              if (inSelectMode)
                Padding(
                  padding: const EdgeInsets.only(right: 8),
                  child: Icon(
                    isSelected
                        ? Icons.check_box
                        : Icons.check_box_outline_blank,
                    size: 20,
                    color: isSelected
                        ? Theme.of(context).colorScheme.primary
                        : Colors.grey.shade400,
                  ),
                ),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Row(
                      children: [
                        if (batch.description != null &&
                            batch.description!.isNotEmpty)
                          Flexible(
                            child: Text(
                              batch.description!,
                              style: const TextStyle(
                                fontSize: 15,
                                fontWeight: FontWeight.w700,
                              ),
                              maxLines: 1,
                              overflow: TextOverflow.ellipsis,
                            ),
                          ),
                        const SizedBox(width: 6),
                        StatusChip(status: status),
                      ],
                    ),
                    const SizedBox(height: 4),
                    Text(
                      '${batch.currency ?? 'USD'} ${batch.value?.toStringAsFixed(2) ?? '—'}',
                      style: TextStyle(
                        fontSize: 13,
                        color: Colors.grey.shade600,
                      ),
                    ),
                    if (batch.count != null)
                      Padding(
                        padding: const EdgeInsets.only(top: 4),
                        child: Row(
                          children: [
                            _countPill('${batch.count}', Colors.blue),
                            const SizedBox(width: 3),
                            _countPill(
                              '${batch.successfulCount ?? 0} ok',
                              Colors.green,
                            ),
                            const SizedBox(width: 3),
                            _countPill(
                              '${batch.failedCount ?? 0} failed',
                              Colors.red,
                            ),
                          ],
                        ),
                      ),
                  ],
                ),
              ),
              if (!inSelectMode)
                Icon(Icons.chevron_right, color: Colors.grey.shade400),
            ],
          ),
        ),
      ),
    );
  }

  Widget _countPill(String label, Color color) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 2),
      decoration: BoxDecoration(
        color: color.withAlpha(20),
        borderRadius: BorderRadius.circular(4),
        border: Border.all(color: color.withAlpha(60)),
      ),
      child: Text(
        label,
        style: TextStyle(
          fontSize: 11,
          color: color,
          fontWeight: FontWeight.w500,
        ),
      ),
    );
  }

  Widget _buildSelectionBottomBar() {
    final selectedCount = batchController.model.selectedBatchIds.length;
    return Container(
      decoration: BoxDecoration(
        color: Colors.white,
        boxShadow: [
          BoxShadow(
            color: Colors.black.withValues(alpha: 0.08),
            blurRadius: 8,
            offset: const Offset(0, -2),
          ),
        ],
      ),
      child: SafeArea(
        child: Padding(
          padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
          child: Row(
            children: [
              Text(
                '$selectedCount selected',
                style: const TextStyle(
                  fontSize: 14,
                  fontWeight: FontWeight.w500,
                ),
              ),
              const Spacer(),
              TextButton.icon(
                onPressed: selectedCount > 0 ? _onDeleteSelected : null,
                icon: const Icon(Icons.delete_outline, size: 20),
                label: const Text('Delete'),
                style: TextButton.styleFrom(foregroundColor: Colors.red),
              ),
            ],
          ),
        ),
      ),
    );
  }
}