import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../../core/theme/app_theme.dart';
import '../../models/finance.dart';
import '../../providers/finance_provider.dart';
import '../../widgets/data_table_card.dart';
import '../../widgets/multi_select_dropdown.dart' show ColDef, ColumnToggleButton, FilterableColumnHeader;
import '../../widgets/page_scaffold.dart';
import '../../providers/connectivity_provider.dart';
import '../../core/utils/export_util.dart';

class FinanceScreen extends ConsumerWidget {
  const FinanceScreen({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    return PageScaffold(
      title: '财务管理',
      tabs: const [
        Tab(text: '全部记录'),
        Tab(text: '应付账款'),
        Tab(text: '应收账款'),
      ],
      tabViews: [
        _FinanceTab(typeFilter: ''),
        _FinanceTab(typeFilter: 'payable'),
        _FinanceTab(typeFilter: 'receivable'),
      ],
    );
  }
}

// Each tab has its own independent state — avoids shared-provider conflicts
class _FinanceTab extends ConsumerStatefulWidget {
  final String typeFilter;
  const _FinanceTab({required this.typeFilter});

  @override
  ConsumerState<_FinanceTab> createState() => _FinanceTabState();
}

class _FinanceTabState extends ConsumerState<_FinanceTab> {
  late String _month;
  int _page = 1;
  int _pageSize = 20;

  // We drive fetches by maintaining a Future locally, bypassing the global provider
  late Future<List<FinanceRecord>> _future;
  List<FinanceRecord> _allRecords = [];
  int _total = 0;

  Set<String> _filterType = {};
  Set<String> _filterPartner = {};
  Set<String> _hiddenCols = {};

  static const _colDefs = [
    ColDef('date', '日期', required: true),
    ColDef('type', '类型'),
    ColDef('partner', '往来单位'),
    ColDef('ref', '关联单据', minWidth: 900),
    ColDef('amount', '金额'),
    ColDef('balance', '余额'),
    ColDef('remark', '备注', minWidth: 1000),
  ];

  @override
  void initState() {
    super.initState();
    final now = DateTime.now();
    _month = '${now.year}-${now.month.toString().padLeft(2, '0')}';
    _fetch();
  }

  void _fetch() {
    _future = ref
        .read(financeRepositoryProvider)
        .listRecords(
          type: widget.typeFilter.isEmpty ? null : widget.typeFilter,
          month: _month,
          page: _page,
          pageSize: _pageSize,
        )
        .then((r) {
      _allRecords = r.data;
      _total = r.total;
      return r.data;
    });
  }

  void _refetch() {
    setState(() => _fetch());
  }

  List<FinanceRecord> _applyFilters(List<FinanceRecord> all) {
    return all.where((r) {
      if (_filterType.isNotEmpty && !_filterType.contains(r.typeLabel)) {
        return false;
      }
      if (_filterPartner.isNotEmpty &&
          !_filterPartner.contains(r.partnerName ?? '')) {
        return false;
      }
      return true;
    }).toList();
  }

  @override
  Widget build(BuildContext context) {
    // 网络恢复时自动刷新
    ref.listen(networkRecoveryCountProvider, (_, __) => _refetch());

    return FutureBuilder<List<FinanceRecord>>(
      future: _future,
      builder: (context, snap) {
        if (snap.connectionState == ConnectionState.waiting) {
          return const Center(child: CircularProgressIndicator());
        }
        if (snap.hasError) {
          if (_allRecords.isNotEmpty) {
            return Column(
              children: [
                _OfflineBanner(onRetry: _refetch),
                Expanded(child: _buildContent(_applyFilters(_allRecords))),
              ],
            );
          }
          return Center(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                const Icon(Icons.cloud_off, size: 40, color: AppTheme.textSecondary),
                const SizedBox(height: 12),
                const Text('暂无数据，网络不可用', style: TextStyle(color: AppTheme.textSecondary)),
                const SizedBox(height: 12),
                ElevatedButton(onPressed: _refetch, child: const Text('重试')),
              ],
            ),
          );
        }
        final filtered = _applyFilters(_allRecords);
        return _buildContent(filtered);
      },
    );
  }

  Widget _buildContent(List<FinanceRecord> records) {
    final totalAmount = records.fold(0.0, (s, r) => s + r.amount);
    final totalBalance = records.fold(0.0, (s, r) => s + r.balance);
    final totalPaid = totalAmount - totalBalance;

    // Derive filter options from all loaded records
    final typeOptions = _allRecords
        .map((r) => r.typeLabel)
        .toSet()
        .toList()
      ..sort();
    final partnerOptions = _allRecords
        .map((r) => r.partnerName ?? '')
        .where((s) => s.isNotEmpty)
        .toSet()
        .toList()
      ..sort();

    // Build visible columns (manual hide + responsive auto-hide by screen width)
    final screenWidth = MediaQuery.of(context).size.width;
    final visibleCols = _colDefs
        .where((c) =>
            !_hiddenCols.contains(c.key) &&
            (c.minWidth == null || screenWidth >= c.minWidth!))
        .toList();

    final columns = visibleCols.map((c) {
      final label = switch (c.key) {
        'type' => FilterableColumnHeader(
            text: c.label,
            options: typeOptions,
            selected: _filterType,
            onChanged: (v) => setState(() => _filterType = v),
          ),
        'partner' => FilterableColumnHeader(
            text: c.label,
            options: partnerOptions,
            selected: _filterPartner,
            onChanged: (v) => setState(() => _filterPartner = v),
          ),
        _ => Text(c.label),
      };
      return DataColumn(
          label: label,
          numeric: c.key == 'amount' || c.key == 'balance');
    }).toList();

    DataCell buildFinanceCell(String key, FinanceRecord r) {
      switch (key) {
        case 'date':
          return DataCell(Text(
            r.recordDate?.substring(0, 10) ?? '-',
            style: const TextStyle(fontSize: 12),
          ));
        case 'type':
          return DataCell(_TypeBadge(r.typeLabel));
        case 'partner':
          return DataCell(SizedBox(
            width: 160,
            child: Text(r.partnerName ?? '-',
                overflow: TextOverflow.ellipsis),
          ));
        case 'ref':
          return DataCell(Text(
            r.refType != null && r.refId != null
                ? '${r.refType!.replaceAll('_', '-')}#${r.refId}'
                : '-',
            style: const TextStyle(
                fontSize: 11,
                fontFamily: 'monospace',
                color: AppTheme.primary),
          ));
        case 'amount':
          return DataCell(Text(
            '¥${r.amount.toStringAsFixed(2)}',
            style: const TextStyle(fontWeight: FontWeight.w500),
          ));
        case 'balance':
          return DataCell(Text(
            '¥${r.balance.toStringAsFixed(2)}',
            style: TextStyle(
              color:
                  r.balance > 0 ? AppTheme.danger : AppTheme.textSecondary,
              fontWeight: FontWeight.w600,
            ),
          ));
        case 'remark':
          return DataCell(SizedBox(
            width: 160,
            child: Text(r.remark ?? '-',
                overflow: TextOverflow.ellipsis,
                style: const TextStyle(
                    fontSize: 12, color: AppTheme.textSecondary)),
          ));
        default:
          return const DataCell(SizedBox());
      }
    }

    final rows = records.isEmpty
        ? [
            DataRow(
              cells: List.generate(
                visibleCols.length,
                (i) => i == 0
                    ? const DataCell(Text('暂无记录',
                        style: TextStyle(color: AppTheme.textSecondary)))
                    : const DataCell(SizedBox()),
              ),
            ),
          ]
        : records
            .map((r) => DataRow(
                  cells: visibleCols
                      .map((c) => buildFinanceCell(c.key, r))
                      .toList(),
                ))
            .toList();

    return Column(
      children: [
        // Summary bar (only for type-filtered tabs)
        if (widget.typeFilter.isNotEmpty && records.isNotEmpty)
          Container(
            color: AppTheme.background,
            padding: const EdgeInsets.all(12),
            child: Row(
              children: [
                _SummaryCard(
                  title: '本期总额',
                  value: '¥${(totalAmount / 10000).toStringAsFixed(2)}万',
                  icon: Icons.account_balance_wallet,
                  color: AppTheme.primary,
                ),
                const SizedBox(width: 12),
                _SummaryCard(
                  title: '已结清',
                  value: '¥${(totalPaid / 10000).toStringAsFixed(2)}万',
                  icon: Icons.check_circle,
                  color: AppTheme.success,
                ),
                const SizedBox(width: 12),
                _SummaryCard(
                  title: '未结清',
                  value: '¥${(totalBalance / 10000).toStringAsFixed(2)}万',
                  icon: Icons.pending_actions,
                  color: AppTheme.danger,
                ),
              ],
            ),
          ),
        if (widget.typeFilter.isNotEmpty && records.isNotEmpty)
          const Divider(height: 1),
        Expanded(
          child: DataTableCard(
            totalCount: _total > 0 ? _total : records.length,
            page: _page,
            pageSize: _pageSize,
            onPageChanged: (p) {
              setState(() {
                _page = p;
                _fetch();
              });
            },
            onPageSizeChanged: (s) {
              setState(() {
                _pageSize = s;
                _page = 1;
                _fetch();
              });
            },
            toolbar: Row(
              children: [
                OutlinedButton.icon(
                  onPressed: () {
                    final tabName = widget.typeFilter.isEmpty
                        ? '财务全部记录'
                        : widget.typeFilter == 'payable'
                            ? '应付账款'
                            : '应收账款';
                    exportExcel(
                      filename: tabName,
                      headers: ['日期', '类型', '往来单位', '关联单据', '金额', '余额', '备注'],
                      rows: records.map((r) => [
                        r.recordDate?.substring(0, 10) ?? '',
                        r.typeLabel,
                        r.partnerName ?? '',
                        r.refType != null && r.refId != null
                            ? '${r.refType!.replaceAll('_', '-')}#${r.refId}'
                            : '',
                        r.amount,
                        r.balance,
                        r.remark ?? '',
                      ]).toList(),
                    );
                  },
                  icon: const Icon(Icons.download, size: 16),
                  label: const Text('导出'),
                ),
                const Spacer(),
                _MonthSelector(
                  value: _month,
                  onChanged: (v) {
                    _month = v;
                    _page = 1;
                    _refetch();
                  },
                ),
                const SizedBox(width: 8),
                ColumnToggleButton(
                  columns: _colDefs,
                  hidden: _hiddenCols,
                  onChanged: (v) => setState(() => _hiddenCols = v),
                ),
              ],
            ),
            columns: columns,
            rows: rows,
          ),
        ),
      ],
    );
  }
}

class _TypeBadge extends StatelessWidget {
  final String label;
  const _TypeBadge(this.label);

  @override
  Widget build(BuildContext context) {
    Color bg, fg;
    switch (label) {
      case '应收账款':
        bg = const Color(0xFFE3F2FD);
        fg = AppTheme.primary;
        break;
      case '应付账款':
        bg = const Color(0xFFFFEBEE);
        fg = AppTheme.danger;
        break;
      case '收款':
        bg = const Color(0xFFE8F5E9);
        fg = AppTheme.success;
        break;
      case '付款':
        bg = const Color(0xFFFFF3E0);
        fg = AppTheme.accent;
        break;
      default:
        bg = const Color(0xFFF5F5F5);
        fg = AppTheme.textSecondary;
    }
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
      decoration:
          BoxDecoration(color: bg, borderRadius: BorderRadius.circular(3)),
      child: Text(label,
          style: TextStyle(
              color: fg, fontSize: 12, fontWeight: FontWeight.w500)),
    );
  }
}

class _SummaryCard extends StatelessWidget {
  final String title;
  final String value;
  final IconData icon;
  final Color color;

  const _SummaryCard({
    required this.title,
    required this.value,
    required this.icon,
    required this.color,
  });

  @override
  Widget build(BuildContext context) {
    return Expanded(
      child: Container(
        height: 72,
        padding: const EdgeInsets.symmetric(horizontal: 16),
        decoration: BoxDecoration(
          color: AppTheme.surface,
          borderRadius: BorderRadius.circular(4),
          border: Border.all(color: AppTheme.border, width: 0.5),
        ),
        child: Row(
          children: [
            Container(
              width: 40,
              height: 40,
              decoration: BoxDecoration(
                color: color.withOpacity(0.1),
                borderRadius: BorderRadius.circular(8),
              ),
              child: Icon(icon, color: color, size: 22),
            ),
            const SizedBox(width: 12),
            Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                Text(title,
                    style: const TextStyle(
                        fontSize: 12, color: AppTheme.textSecondary)),
                const SizedBox(height: 4),
                Text(value,
                    style: TextStyle(
                        fontSize: 18,
                        fontWeight: FontWeight.w700,
                        color: color)),
              ],
            ),
          ],
        ),
      ),
    );
  }
}

class _MonthSelector extends StatelessWidget {
  final String value;
  final ValueChanged<String> onChanged;

  const _MonthSelector({required this.value, required this.onChanged});

  @override
  Widget build(BuildContext context) {
    final now = DateTime.now();
    final months = List.generate(12, (i) {
      final d = DateTime(now.year, now.month - i, 1);
      return '${d.year}-${d.month.toString().padLeft(2, '0')}';
    });
    final safeValue = months.contains(value) ? value : months.first;

    return Container(
      height: 36,
      padding: const EdgeInsets.symmetric(horizontal: 8),
      decoration: BoxDecoration(
        border: Border.all(color: AppTheme.border),
        borderRadius: BorderRadius.circular(4),
        color: AppTheme.surface,
      ),
      child: DropdownButtonHideUnderline(
        child: DropdownButton<String>(
          value: safeValue,
          items: months
              .map((m) => DropdownMenuItem(
                  value: m,
                  child: Text(m, style: const TextStyle(fontSize: 13))))
              .toList(),
          onChanged: (v) => onChanged(v!),
          style:
              const TextStyle(fontSize: 13, color: AppTheme.textPrimary),
        ),
      ),
    );
  }
}

class _OfflineBanner extends StatelessWidget {
  final VoidCallback onRetry;
  const _OfflineBanner({required this.onRetry});

  @override
  Widget build(BuildContext context) {
    return Container(
      width: double.infinity,
      color: const Color(0xFFFFF8E1),
      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 6),
      child: Row(
        children: [
          const Icon(Icons.cloud_off, size: 14, color: Color(0xFFF57F17)),
          const SizedBox(width: 8),
          const Expanded(
            child: Text('网络不可用，当前显示离线缓存数据',
                style: TextStyle(color: Color(0xFFF57F17), fontSize: 12)),
          ),
          TextButton(
            onPressed: onRetry,
            style: TextButton.styleFrom(
                foregroundColor: const Color(0xFFF57F17),
                padding: const EdgeInsets.symmetric(horizontal: 8)),
            child: const Text('重试', style: TextStyle(fontSize: 12)),
          ),
        ],
      ),
    );
  }
}