import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../../widgets/page_scaffold.dart';
import '../../widgets/data_table_card.dart';
import '../../core/theme/app_theme.dart';
import '../../widgets/form_dialog.dart';

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

  @override
  ConsumerState<FinanceScreen> createState() => _FinanceScreenState();
}

class _FinanceScreenState extends ConsumerState<FinanceScreen> {
  int _page = 1;
  String _monthFilter = '2026-04';
  String _typeFilter = '全部';

  final List<Map<String, dynamic>> _transactions = [
    {
      'no': 'FN20260401001',
      'type': '应付账款',
      'partner': '贵州茅台酒股份有限公司',
      'orderNo': 'RK20260401001',
      'amount': '85000.00',
      'paid': '85000.00',
      'balance': '0.00',
      'date': '2026-04-01',
      'dueDate': '2026-05-01',
      'status': '已结清',
    },
    {
      'no': 'FN20260401002',
      'type': '应付账款',
      'partner': '四川五粮液股份有限公司',
      'orderNo': 'RK20260401002',
      'amount': '42500.00',
      'paid': '0.00',
      'balance': '42500.00',
      'date': '2026-04-01',
      'dueDate': '2026-05-01',
      'status': '未付款',
    },
    {
      'no': 'FN20260402001',
      'type': '应付账款',
      'partner': '江苏洋河酒厂股份有限公司',
      'orderNo': 'RK20260402001',
      'amount': '36800.00',
      'paid': '20000.00',
      'balance': '16800.00',
      'date': '2026-04-02',
      'dueDate': '2026-05-17',
      'status': '部分付款',
    },
    {
      'no': 'FN20260402002',
      'type': '应付账款',
      'partner': '泸州老窖股份有限公司',
      'orderNo': 'RK20260403001',
      'amount': '55200.00',
      'paid': '55200.00',
      'balance': '0.00',
      'date': '2026-04-03',
      'dueDate': '2026-05-03',
      'status': '已结清',
    },
    {
      'no': 'FN20260403001',
      'type': '应付账款',
      'partner': '法国拉菲集团中国总代理',
      'orderNo': 'RK20260403002',
      'amount': '124800.00',
      'paid': '0.00',
      'balance': '124800.00',
      'date': '2026-04-03',
      'dueDate': '2026-06-02',
      'status': '未付款',
    },
    {
      'no': 'FN20260404001',
      'type': '应付账款',
      'partner': '人头马轩尼诗（中国）有限公司',
      'orderNo': 'RK20260404001',
      'amount': '30240.00',
      'paid': '0.00',
      'balance': '30240.00',
      'date': '2026-04-04',
      'dueDate': '2026-06-03',
      'status': '未付款',
    },
    {
      'no': 'FN20260404002',
      'type': '费用报销',
      'partner': '张三',
      'orderNo': 'BX20260404001',
      'amount': '1280.00',
      'paid': '1280.00',
      'balance': '0.00',
      'date': '2026-04-04',
      'dueDate': '2026-04-04',
      'status': '已结清',
    },
  ];

  // Summary stats
  double get _totalPayable => _transactions
      .where((t) => t['type'] == '应付账款')
      .fold(0.0, (s, t) => s + (double.tryParse(t['balance'] as String) ?? 0));

  double get _totalPaid => _transactions.fold(
      0.0, (s, t) => s + (double.tryParse(t['paid'] as String) ?? 0));

  double get _totalAmount => _transactions.fold(
      0.0, (s, t) => s + (double.tryParse(t['amount'] as String) ?? 0));

  @override
  Widget build(BuildContext context) {
    return PageScaffold(
      title: '财务管理',
      tabs: const [
        Tab(text: '应付账款'),
        Tab(text: '付款记录'),
        Tab(text: '财务报表'),
      ],
      tabViews: [
        _buildPayableList(),
        _buildPaymentHistory(),
        _buildFinanceReport(),
      ],
    );
  }

  Widget _buildPayableList() {
    final filtered = _typeFilter == '全部'
        ? _transactions
        : _transactions.where((t) => t['type'] == _typeFilter).toList();

    return Column(
      children: [
        // Summary bar
        Container(
          color: AppTheme.background,
          padding: const EdgeInsets.all(12),
          child: Row(
            children: [
              _FinanceSummaryCard(
                title: '本月采购总额',
                value: '¥${(_totalAmount / 10000).toStringAsFixed(1)}万',
                icon: Icons.shopping_bag,
                color: AppTheme.primary,
              ),
              const SizedBox(width: 12),
              _FinanceSummaryCard(
                title: '已付款',
                value: '¥${(_totalPaid / 10000).toStringAsFixed(1)}万',
                icon: Icons.check_circle,
                color: AppTheme.success,
              ),
              const SizedBox(width: 12),
              _FinanceSummaryCard(
                title: '未付款',
                value: '¥${(_totalPayable / 10000).toStringAsFixed(1)}万',
                icon: Icons.pending_actions,
                color: AppTheme.danger,
              ),
              const SizedBox(width: 12),
              _FinanceSummaryCard(
                title: '即将到期（7天）',
                value: '¥16.8万',
                icon: Icons.alarm,
                color: AppTheme.accent,
              ),
            ],
          ),
        ),
        const Divider(height: 1),
        Expanded(
          child: DataTableCard(
            totalCount: filtered.length,
            page: _page,
            onPageChanged: (p) => setState(() => _page = p),
            toolbar: Row(
              children: [
                ElevatedButton.icon(
                  onPressed: () => _showPaymentDialog(context),
                  icon: const Icon(Icons.payment, size: 16),
                  label: const Text('登记付款'),
                ),
                const SizedBox(width: 8),
                OutlinedButton.icon(
                  onPressed: () {},
                  icon: const Icon(Icons.file_download_outlined, size: 16),
                  label: const Text('导出对账单'),
                ),
                const Spacer(),
                // Month filter
                _MonthSelector(
                  value: _monthFilter,
                  onChanged: (v) => setState(() => _monthFilter = v),
                ),
                const SizedBox(width: 8),
                _DropdownFilter(
                  value: _typeFilter,
                  items: ['全部', '应付账款', '费用报销'],
                  onChanged: (v) => setState(() => _typeFilter = v!),
                  hint: '类型',
                ),
              ],
            ),
            columns: const [
              DataColumn(label: Text('凭证号')),
              DataColumn(label: Text('类型')),
              DataColumn(label: Text('往来单位')),
              DataColumn(label: Text('关联单号')),
              DataColumn(label: Text('应付金额'), numeric: true),
              DataColumn(label: Text('已付金额'), numeric: true),
              DataColumn(label: Text('余额'), numeric: true),
              DataColumn(label: Text('到期日')),
              DataColumn(label: Text('状态')),
              DataColumn(label: Text('操作')),
            ],
            rows: filtered
                .map((t) => DataRow(
                      color: WidgetStateProperty.resolveWith((states) {
                        if (t['status'] == '未付款') {
                          final due = DateTime.tryParse(t['dueDate'] as String);
                          if (due != null &&
                              due.difference(DateTime.now()).inDays <= 7) {
                            return AppTheme.accent.withOpacity(0.05);
                          }
                        }
                        return null;
                      }),
                      cells: [
                        DataCell(Text(t['no'] as String,
                            style: const TextStyle(
                                fontFamily: 'monospace',
                                fontSize: 11,
                                color: AppTheme.textSecondary))),
                        DataCell(Text(t['type'] as String)),
                        DataCell(SizedBox(
                          width: 160,
                          child: Text(t['partner'] as String,
                              overflow: TextOverflow.ellipsis),
                        )),
                        DataCell(Text(t['orderNo'] as String,
                            style: const TextStyle(
                                fontFamily: 'monospace',
                                fontSize: 11,
                                color: AppTheme.primary))),
                        DataCell(Text('¥${t['amount']}',
                            style: const TextStyle(
                                fontWeight: FontWeight.w500))),
                        DataCell(Text('¥${t['paid']}',
                            style: const TextStyle(
                                color: AppTheme.success))),
                        DataCell(Text(
                          '¥${t['balance']}',
                          style: TextStyle(
                            color: (t['balance'] as String) != '0.00'
                                ? AppTheme.danger
                                : AppTheme.textSecondary,
                            fontWeight: FontWeight.w600,
                          ),
                        )),
                        DataCell(Text(t['dueDate'] as String)),
                        DataCell(_PaymentStatusBadge(t['status'] as String)),
                        DataCell(Row(
                          mainAxisSize: MainAxisSize.min,
                          children: [
                            TextButton(
                                onPressed: () {},
                                child: const Text('详情',
                                    style: TextStyle(fontSize: 12))),
                            if (t['status'] != '已结清')
                              TextButton(
                                  onPressed: () =>
                                      _showPaymentDialog(context),
                                  child: const Text('付款',
                                      style: TextStyle(
                                          color: AppTheme.success,
                                          fontSize: 12))),
                          ],
                        )),
                      ],
                    ))
                .toList(),
          ),
        ),
      ],
    );
  }

  Widget _buildPaymentHistory() {
    final payments = [
      {
        'date': '2026-04-01',
        'no': 'ZF20260401001',
        'partner': '贵州茅台酒股份有限公司',
        'amount': '85000.00',
        'method': '银行转账',
        'bank': '招商银行',
        'remark': '4月货款结清',
      },
      {
        'date': '2026-04-02',
        'no': 'ZF20260402001',
        'partner': '泸州老窖股份有限公司',
        'amount': '55200.00',
        'method': '银行转账',
        'bank': '工商银行',
        'remark': '4月货款',
      },
      {
        'date': '2026-04-02',
        'no': 'ZF20260402002',
        'partner': '江苏洋河酒厂股份有限公司',
        'amount': '20000.00',
        'method': '银行转账',
        'bank': '建设银行',
        'remark': '部分预付',
      },
      {
        'date': '2026-04-04',
        'no': 'ZF20260404001',
        'partner': '张三',
        'amount': '1280.00',
        'method': '现金',
        'bank': '-',
        'remark': '差旅报销',
      },
    ];

    return DataTableCard(
      totalCount: payments.length,
      page: 1,
      toolbar: Row(
        children: [
          ElevatedButton.icon(
            onPressed: () => _showPaymentDialog(context),
            icon: const Icon(Icons.add, size: 16),
            label: const Text('新增付款'),
          ),
          const SizedBox(width: 8),
          OutlinedButton.icon(
            onPressed: () {},
            icon: const Icon(Icons.file_download_outlined, size: 16),
            label: const Text('导出'),
          ),
          const Spacer(),
          _MonthSelector(
            value: _monthFilter,
            onChanged: (v) => setState(() => _monthFilter = v),
          ),
        ],
      ),
      columns: const [
        DataColumn(label: Text('付款日期')),
        DataColumn(label: Text('付款单号')),
        DataColumn(label: Text('收款方')),
        DataColumn(label: Text('金额'), numeric: true),
        DataColumn(label: Text('付款方式')),
        DataColumn(label: Text('银行')),
        DataColumn(label: Text('备注')),
        DataColumn(label: Text('操作')),
      ],
      rows: payments
          .map((p) => DataRow(cells: [
                DataCell(Text(p['date'] as String)),
                DataCell(Text(p['no'] as String,
                    style: const TextStyle(
                        fontFamily: 'monospace',
                        fontSize: 11,
                        color: AppTheme.textSecondary))),
                DataCell(SizedBox(
                  width: 160,
                  child: Text(p['partner'] as String,
                      overflow: TextOverflow.ellipsis),
                )),
                DataCell(Text(
                  '¥${p['amount']}',
                  style: const TextStyle(
                      color: AppTheme.danger, fontWeight: FontWeight.w600),
                )),
                DataCell(Text(p['method'] as String)),
                DataCell(Text(p['bank'] as String)),
                DataCell(Text(p['remark'] as String)),
                DataCell(TextButton(
                    onPressed: () {},
                    child: const Text('查看',
                        style: TextStyle(fontSize: 12)))),
              ]))
          .toList(),
    );
  }

  Widget _buildFinanceReport() {
    return SingleChildScrollView(
      padding: const EdgeInsets.all(16),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          // Month/period selector
          Row(
            children: [
              const Text('报表周期：',
                  style: TextStyle(fontSize: 14)),
              const SizedBox(width: 8),
              _MonthSelector(
                value: _monthFilter,
                onChanged: (v) => setState(() => _monthFilter = v),
              ),
              const SizedBox(width: 16),
              ElevatedButton.icon(
                onPressed: () {},
                icon: const Icon(Icons.picture_as_pdf, size: 16),
                label: const Text('导出报表'),
              ),
            ],
          ),
          const SizedBox(height: 16),
          // Metrics row
          Row(
            children: [
              _ReportCard(
                title: '本月采购总额',
                value: '¥${(_totalAmount / 10000).toStringAsFixed(2)}万',
                change: '+12.5%',
                positive: false,
              ),
              const SizedBox(width: 12),
              _ReportCard(
                title: '本月付款总额',
                value: '¥${(_totalPaid / 10000).toStringAsFixed(2)}万',
                change: '+8.3%',
                positive: true,
              ),
              const SizedBox(width: 12),
              _ReportCard(
                title: '应付账款余额',
                value: '¥${(_totalPayable / 10000).toStringAsFixed(2)}万',
                change: '-5.2%',
                positive: true,
              ),
              const SizedBox(width: 12),
              _ReportCard(
                title: '库存总价值',
                value: '¥103.17万',
                change: '+3.8%',
                positive: false,
              ),
            ],
          ),
          const SizedBox(height: 16),
          // Category breakdown
          Card(
            child: Padding(
              padding: const EdgeInsets.all(16),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  const Text('按品类采购金额',
                      style: TextStyle(
                          fontSize: 14, fontWeight: FontWeight.w600)),
                  const SizedBox(height: 16),
                  ...[
                    ('白酒', 238600.0, AppTheme.primary),
                    ('葡萄酒', 124800.0, const Color(0xFF7B1FA2)),
                    ('洋酒', 30240.0, AppTheme.accent),
                    ('啤酒', 1970.0, const Color(0xFF0097A7)),
                  ].map((item) {
                    final total = 395610.0;
                    final pct = item.$2 / total;
                    return Padding(
                      padding: const EdgeInsets.only(bottom: 12),
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          Row(
                            children: [
                              SizedBox(
                                  width: 60,
                                  child: Text(item.$1,
                                      style: const TextStyle(fontSize: 13))),
                              const SizedBox(width: 8),
                              Expanded(
                                child: LinearProgressIndicator(
                                  value: pct,
                                  backgroundColor: AppTheme.border,
                                  color: item.$3,
                                  minHeight: 8,
                                  borderRadius: BorderRadius.circular(4),
                                ),
                              ),
                              const SizedBox(width: 8),
                              SizedBox(
                                width: 100,
                                child: Text(
                                  '¥${(item.$2 / 10000).toStringAsFixed(1)}万 (${(pct * 100).toStringAsFixed(1)}%)',
                                  style: const TextStyle(fontSize: 12),
                                  textAlign: TextAlign.right,
                                ),
                              ),
                            ],
                          ),
                        ],
                      ),
                    );
                  }),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }

  void _showPaymentDialog(BuildContext context) {
    showDialog(
      context: context,
      builder: (ctx) => FormDialog(
        title: '登记付款',
        width: 480,
        onConfirm: () {
          Navigator.of(ctx).pop();
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(
              content: Text('付款记录已登记'),
              backgroundColor: AppTheme.success,
            ),
          );
        },
        content: Column(
          children: [
            _DialogRow(
              children: [
                _DialogField(
                    label: '付款方式',
                    child: DropdownButtonFormField<String>(
                      value: '银行转账',
                      items: ['银行转账', '现金', '支票', '网银']
                          .map((s) => DropdownMenuItem(
                              value: s,
                              child: Text(s,
                                  style: const TextStyle(fontSize: 13))))
                          .toList(),
                      onChanged: (_) {},
                      decoration: const InputDecoration(),
                    )),
                _DialogField(
                    label: '付款金额',
                    required: true,
                    child: TextFormField(
                        decoration: const InputDecoration(
                            hintText: '0.00', prefixText: '¥'),
                        keyboardType:
                            const TextInputType.numberWithOptions(decimal: true))),
              ],
            ),
            const SizedBox(height: 12),
            _DialogRow(
              children: [
                _DialogField(
                    label: '付款银行',
                    child: DropdownButtonFormField<String>(
                      value: '招商银行',
                      items: ['招商银行', '工商银行', '建设银行', '农业银行', '中国银行']
                          .map((s) => DropdownMenuItem(
                              value: s,
                              child: Text(s,
                                  style: const TextStyle(fontSize: 13))))
                          .toList(),
                      onChanged: (_) {},
                      decoration: const InputDecoration(),
                    )),
                _DialogField(
                    label: '付款日期',
                    child: InputDecorator(
                      decoration: const InputDecoration(),
                      child: const Text('2026-04-04',
                          style: TextStyle(fontSize: 13)),
                    )),
              ],
            ),
            const SizedBox(height: 12),
            _DialogField(
              label: '备注',
              fullWidth: true,
              child: TextFormField(
                maxLines: 2,
                decoration: const InputDecoration(hintText: '付款说明'),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

class _DialogRow extends StatelessWidget {
  final List<Widget> children;
  const _DialogRow({required this.children});

  @override
  Widget build(BuildContext context) {
    return Row(
      children: children
          .expand((child) => [
                Expanded(child: child),
                if (child != children.last) const SizedBox(width: 12),
              ])
          .toList(),
    );
  }
}

class _DialogField extends StatelessWidget {
  final String label;
  final Widget child;
  final bool required;
  final bool fullWidth;

  const _DialogField({
    required this.label,
    required this.child,
    this.required = false,
    this.fullWidth = false,
  });

  @override
  Widget build(BuildContext context) {
    Widget content = Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Row(children: [
          if (required)
            const Text('* ',
                style: TextStyle(color: AppTheme.danger, fontSize: 13)),
          Text(label,
              style: const TextStyle(
                  fontSize: 13, color: AppTheme.textSecondary)),
        ]),
        const SizedBox(height: 6),
        child,
      ],
    );
    return fullWidth ? SizedBox(width: double.infinity, child: content) : content;
  }
}

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

  const _FinanceSummaryCard({
    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 _PaymentStatusBadge extends StatelessWidget {
  final String status;
  const _PaymentStatusBadge(this.status);

  @override
  Widget build(BuildContext context) {
    Color bg, fg;
    switch (status) {
      case '已结清':
        bg = const Color(0xFFE8F5E9);
        fg = AppTheme.success;
        break;
      case '部分付款':
        bg = const Color(0xFFFFF3E0);
        fg = AppTheme.accent;
        break;
      case '未付款':
        bg = const Color(0xFFFFEBEE);
        fg = AppTheme.danger;
        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(status,
          style: TextStyle(
              color: fg, fontSize: 12, fontWeight: FontWeight.w500)),
    );
  }
}

class _ReportCard extends StatelessWidget {
  final String title;
  final String value;
  final String change;
  final bool positive;

  const _ReportCard({
    required this.title,
    required this.value,
    required this.change,
    required this.positive,
  });

  @override
  Widget build(BuildContext context) {
    return Expanded(
      child: Container(
        height: 88,
        padding: const EdgeInsets.all(16),
        decoration: BoxDecoration(
          color: AppTheme.surface,
          borderRadius: BorderRadius.circular(4),
          border: Border.all(color: AppTheme.border, width: 0.5),
        ),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(title,
                style: const TextStyle(
                    fontSize: 12, color: AppTheme.textSecondary)),
            const SizedBox(height: 8),
            Row(
              crossAxisAlignment: CrossAxisAlignment.end,
              children: [
                Text(value,
                    style: const TextStyle(
                        fontSize: 18, fontWeight: FontWeight.w700)),
                const Spacer(),
                Text(
                  change,
                  style: TextStyle(
                    fontSize: 12,
                    color: positive ? AppTheme.success : AppTheme.danger,
                    fontWeight: FontWeight.w500,
                  ),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}

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 months = [
      '2026-04',
      '2026-03',
      '2026-02',
      '2026-01',
      '2025-12',
      '2025-11',
    ];
    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: value,
          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 _DropdownFilter extends StatelessWidget {
  final String value;
  final List<String> items;
  final ValueChanged<String?> onChanged;
  final String hint;

  const _DropdownFilter({
    required this.value,
    required this.items,
    required this.onChanged,
    required this.hint,
  });

  @override
  Widget build(BuildContext context) {
    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: value,
          items: items
              .map((s) => DropdownMenuItem(
                  value: s,
                  child: Text(s, style: const TextStyle(fontSize: 13))))
              .toList(),
          onChanged: onChanged,
          style: const TextStyle(
              fontSize: 13, color: AppTheme.textPrimary),
        ),
      ),
    );
  }
}