// screens/finance/finance_screen.dart — 财务管理（照原型 finance.html 重建）。
// 版式：head + 时间范围 chips + KPI 4 卡 + 收支趋势柱状图 + 应收/应付汇总表
// + 收支流水表 + 往来抽屉。无分页（原型无 .pager，流水按当前范围一次取）。
// 已知差异（记 design/CONTRACT.md）：KPI3/4 delta 用「未结清 N 笔」（原型 逾期/到期额
// 无数据源）；流水类型 chips 扩到 5（含应收/应付）并追加 状态/操作 列（结清能力不回退）；
// 时间范围真实过滤流水（原型只改文案）。
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:intl/intl.dart';
import 'package:lucide_icons_flutter/lucide_icons.dart';

import '../../core/responsive/responsive.dart';
import '../../core/theme/app_dims.g.dart';
import '../../core/theme/context_tokens.dart';
import '../../core/utils/clock.dart';
import '../../core/utils/export_util.dart';
import '../../models/finance.dart';
import '../../providers/finance_provider.dart';
import '../../providers/stock_in_provider.dart';
import '../../providers/stock_out_provider.dart';
import '../../widgets/ds/ds_atoms.dart';
import '../../widgets/ds/ds_bar_chart.dart';
import '../../widgets/ds/ds_kpi.dart';
import '../../widgets/ds/ds_table.dart';
import '../../widgets/finance_entry_dialog.dart';
import '../../widgets/finance_partner_drawer.dart';
import '../../widgets/mobile_list_card.dart';
import '../../widgets/write_guard.dart';
import '../../core/theme/app_fonts.dart';
import '../../widgets/ds/ds_toast.dart';

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

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

class _FinanceScreenState extends ConsumerState<FinanceScreen> {
  // 时间范围（原型 .timerow chips）：真实过滤流水表；KPI 恒本月、趋势恒近 6 月
  String _range = '本月';
  String _rangeLabel = '本月';
  // 流水类型筛选（原型 3 chips 扩到 5）
  String _flowChip = '全部';

  static const _flowChips = ['全部', '应收', '应付', '收款', '付款'];
  static const _chipToType = {
    '全部': '',
    '应收': 'receivable',
    '应付': 'payable',
    '收款': 'receipt',
    '付款': 'payment',
  };

  static final _ymd = DateFormat('yyyy-MM-dd');

  @override
  void initState() {
    super.initState();
    // 默认本月（与 KPI 口径一致）
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (mounted) _applyRange('本月');
    });
  }

  Future<void> _applyRange(String range) async {
    final now = appNow();
    final notifier = ref.read(financeListProvider.notifier);
    switch (range) {
      case '本月':
        final start = DateTime(now.year, now.month, 1);
        notifier.setRange(_ymd.format(start), _ymd.format(now));
        setState(() {
          _range = range;
          _rangeLabel = '本月';
        });
      case '本季':
        final qMonth = ((now.month - 1) ~/ 3) * 3 + 1;
        final start = DateTime(now.year, qMonth, 1);
        notifier.setRange(_ymd.format(start), _ymd.format(now));
        setState(() {
          _range = range;
          _rangeLabel = '本季';
        });
      case '自定义':
        final picked = await showDateRangePicker(
          context: context,
          firstDate: DateTime(now.year - 3),
          lastDate: now,
          initialDateRange:
              DateTimeRange(start: DateTime(now.year, now.month, 1), end: now),
        );
        if (picked == null) return;
        notifier.setRange(_ymd.format(picked.start), _ymd.format(picked.end));
        setState(() {
          _range = range;
          _rangeLabel =
              '${_ymd.format(picked.start)} ~ ${_ymd.format(picked.end)}';
        });
    }
  }

  void _reload() {
    ref.read(financeListProvider.notifier).reload();
    ref.invalidate(financePartnerRowsProvider);
    ref.invalidate(financeTrendProvider);
    ref.invalidate(stockInSummaryProvider);
    ref.invalidate(stockOutSummaryProvider);
  }

  // ── 金额格式 ──
  String _yuan(double v) => '¥${NumberFormat.decimalPattern().format(
        v == v.roundToDouble() ? v.round() : v,
      )}';

  /// KPI 大数：¥186万 / ¥48.6万（<1万显示整数元）。
  String _yuanWan(double v) {
    if (v >= 10000) {
      final wan = v / 10000;
      return '¥${wan == wan.roundToDouble() ? wan.round() : wan.toStringAsFixed(1)}万';
    }
    return _yuan(v);
  }

  (String, DsKpiDelta) _momDelta(double cur, double last) {
    if (last <= 0) return ('较上月 —', DsKpiDelta.neutral);
    final pct = (cur - last) / last * 100;
    if (pct == 0) return ('与上月持平', DsKpiDelta.neutral);
    return (
      '${pct.abs().toStringAsFixed(1)}% 较上月',
      pct > 0 ? DsKpiDelta.up : DsKpiDelta.down,
    );
  }

  @override
  Widget build(BuildContext context) {
    final t = context.tokens;
    final mobile = context.isMobile;
    final flowsAsync = ref.watch(financeListProvider);
    final flows = flowsAsync.valueOrNull?.data ?? const <FinanceRecord>[];

    final content = Container(
      color: t.bg,
      child: SingleChildScrollView(
        padding: mobile
            ? const EdgeInsets.all(AppDims.sp4)
            : const EdgeInsets.fromLTRB(26, 22, 26, 22),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            _head(t, mobile, flows),
            _timeRow(t, mobile),
            _kpis(t, mobile),
            _secHead(t, '收支趋势', '近 6 个月 · 单位 万元'),
            _trendChart(),
            const SizedBox(height: 22),
            _secHead(t, '应收 / 应付 汇总', '按往来单位 · 点击行查看流水'),
            _summaryTable(t, mobile),
            const SizedBox(height: 22),
            _secHead(t, '收支流水', _flowSub(flows)),
            _flowTable(t, mobile, flows, flowsAsync.valueOrNull?.total ?? 0),
          ],
        ),
      ),
    );
    return Stack(children: [
      content,
      if (flowsAsync.isLoading) const Positioned.fill(child: DsLoadingScrim()),
    ]);
  }

  // ── head ──
  Widget _head(dynamic t, bool mobile, List<FinanceRecord> flows) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 18),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.end,
        children: [
          Text('财务管理',
              style: TextStyle(
                  fontSize: AppDims.fsH1,
                  fontWeight: FontWeight.w700,
                  color: t.heading)),
          const SizedBox(width: AppDims.sp3),
          Expanded(
            child: Padding(
              padding: const EdgeInsets.only(bottom: 2),
              child: Text('应收/应付概览 · $_rangeLabel',
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                  style: TextStyle(fontSize: AppDims.fsSm, color: t.muted)),
            ),
          ),
          if (!mobile) ...[
            DsButton('刷新', icon: LucideIcons.refreshCw, onPressed: _reload),
            const SizedBox(width: 10),
            DsButton('导出报表',
                icon: LucideIcons.download, onPressed: () => _export(flows)),
            const SizedBox(width: 10),
            WriteGuard(
              child: DsButton('登记收支',
                  icon: LucideIcons.plus,
                  variant: DsBtnVariant.primary,
                  onPressed: () => showFinanceEntryDialog(context)),
            ),
          ],
        ],
      ),
    );
  }

  void _export(List<FinanceRecord> flows) {
    exportExcel(
      filename: '财务流水',
      headers: ['日期', '类型', '往来单位', '金额', '关联单据', '状态', '备注'],
      rows: flows
          .map((r) => [
                (r.recordDate ?? '').split('T').first,
                r.typeLabel,
                r.partnerName ?? '',
                r.amount,
                r.refType != null ? '${r.docTitle}#${r.refId ?? ''}' : '',
                r.status == 'open' ? '未结清' : '已结清',
                r.remark ?? '',
              ])
          .toList(),
    );
  }

  // ── 时间范围 chips（原型 .timerow）──
  Widget _timeRow(dynamic t, bool mobile) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 18),
      child: Row(children: [
        Text('时间范围', style: TextStyle(fontSize: AppDims.fsSm, color: t.muted)),
        const SizedBox(width: 12),
        for (final r in const ['本月', '本季', '自定义']) ...[
          DsChip(
              label: r,
              selected: _range == r,
              caret: r == '自定义',
              onTap: () => _applyRange(r)),
          const SizedBox(width: 10),
        ],
        if (mobile) ...[
          const Spacer(),
          WriteGuard(
            child: DsButton('登记',
                small: true,
                icon: LucideIcons.plus,
                variant: DsBtnVariant.primary,
                onPressed: () => showFinanceEntryDialog(context)),
          ),
        ],
      ]),
    );
  }

  // ── KPI 4 卡 ──
  Widget _kpis(dynamic t, bool mobile) {
    final outSum = ref.watch(stockOutSummaryProvider).valueOrNull;
    final inSum = ref.watch(stockInSummaryProvider).valueOrNull;
    final rows = ref.watch(financePartnerRowsProvider).valueOrNull ?? const [];
    var recv = 0.0, pay = 0.0, openCount = 0;
    for (final r in rows) {
      recv += r.recv;
      pay += r.pay;
      openCount += r.openCount;
    }
    final (saleDelta, saleTone) = outSum != null
        ? _momDelta(outSum.monthAmount, outSum.lastMonthAmount)
        : ('较上月 —', DsKpiDelta.neutral);
    final (buyDelta, buyTone) = inSum != null
        ? _momDelta(inSum.monthAmount, inSum.lastMonthAmount)
        : ('较上月 —', DsKpiDelta.neutral);

    final cards = <Widget>[
      DsKpi(
        title: '本月销售额',
        value: outSum != null ? _yuanWan(outSum.monthAmount) : '—',
        icon: LucideIcons.box,
        tone: DsKpiTone.info,
        delta: saleDelta,
        deltaTone: saleTone,
      ),
      DsKpi(
        title: '本月采购额',
        value: inSum != null ? _yuanWan(inSum.monthAmount) : '—',
        icon: LucideIcons.shoppingCart,
        tone: DsKpiTone.blue,
        delta: buyDelta,
        deltaTone: buyTone,
      ),
      // 原型 delta「逾期 ¥9.2万」无数据源 → 未结清笔数（已知差异）
      DsKpi(
        title: '应收账款 · 待收',
        value: _yuanWan(recv),
        icon: LucideIcons.circleDollarSign,
        tone: DsKpiTone.alert,
        delta: '未结清 $openCount 笔',
        deltaTone: DsKpiDelta.down,
      ),
      DsKpi(
        title: '应付账款',
        value: _yuanWan(pay),
        icon: LucideIcons.receipt,
        tone: DsKpiTone.ok,
        delta: '按到期及时结清',
        deltaTone: DsKpiDelta.up,
      ),
    ];
    if (mobile) {
      return Padding(
        padding: const EdgeInsets.only(bottom: 20),
        child: SingleChildScrollView(
          scrollDirection: Axis.horizontal,
          child: IntrinsicHeight(
            child: Row(children: [
              for (var i = 0; i < cards.length; i++) ...[
                if (i > 0) const SizedBox(width: AppDims.sp3),
                SizedBox(width: 170, child: cards[i]),
              ],
            ]),
          ),
        ),
      );
    }
    return Padding(
      padding: const EdgeInsets.only(bottom: 20),
      child: IntrinsicHeight(
        child: Row(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            for (var i = 0; i < cards.length; i++) ...[
              if (i > 0) const SizedBox(width: 14),
              Expanded(child: cards[i]),
            ],
          ],
        ),
      ),
    );
  }

  /// 原型 .sec-head：h2 17/700 + 副标 fs-xs muted，下距 12。
  Widget _secHead(dynamic t, String title, String sub) => Padding(
        padding: const EdgeInsets.only(bottom: 12),
        child: Row(
          crossAxisAlignment: CrossAxisAlignment.end,
          children: [
            Text(title,
                style: TextStyle(
                    fontSize: AppDims.fsH2,
                    fontWeight: FontWeight.w700,
                    color: t.heading)),
            const SizedBox(width: 10),
            Padding(
              padding: const EdgeInsets.only(bottom: 1),
              child: Text(sub,
                  style: TextStyle(fontSize: AppDims.fsXs, color: t.muted)),
            ),
          ],
        ),
      );

  // ── 收支趋势 ──
  Widget _trendChart() {
    final t = context.tokens;
    final trend = ref.watch(financeTrendProvider);
    Widget placeholder(Widget child) => Container(
          height: 120,
          alignment: Alignment.center,
          decoration: BoxDecoration(
            color: t.surface,
            border: Border.all(color: t.border),
            borderRadius: BorderRadius.circular(AppDims.rLg),
          ),
          child: child,
        );
    return trend.when(
      loading: () => placeholder(const SizedBox(
          width: 20,
          height: 20,
          child: CircularProgressIndicator(strokeWidth: 2))),
      error: (e, _) => placeholder(Text('趋势加载失败',
          style: TextStyle(color: t.muted, fontSize: AppDims.fsSm))),
      data: (points) => DsBarChart(
        groups: [
          for (final p in points)
            DsBarGroup(_monthLabel(p.month), p.inAmount, p.outAmount),
        ],
        legendA: '收入',
        legendB: '支出',
        // 柱顶标签：万元取整（原型 TREND 值即万元整数）
        format: (v) => '${(v / 10000).round()}',
      ),
    );
  }

  String _monthLabel(String ym) {
    final parts = ym.split('-');
    return parts.length == 2 ? '${int.tryParse(parts[1]) ?? parts[1]}月' : ym;
  }

  // ── 应收/应付汇总表 ──
  Widget _summaryTable(dynamic t, bool mobile) {
    final async = ref.watch(financePartnerRowsProvider);
    return async.when(
      loading: () => const Padding(
          padding: EdgeInsets.all(24),
          child: Center(child: CircularProgressIndicator())),
      error: (e, _) => Row(children: [
        Text('汇总加载失败',
            style: TextStyle(color: t.muted, fontSize: AppDims.fsSm)),
        const SizedBox(width: 10),
        DsButton('重试',
            small: true,
            onPressed: () => ref.invalidate(financePartnerRowsProvider)),
      ]),
      data: (rows) => DsTable(
        shrinkWrap: true,
        emptyText: '暂无未结清的应收 / 应付',
        mobileCards: rows
            .map((r) => MobileListCard(
                  title: Text(r.name),
                  trailing: Text(signedYuan(r.net),
                      style: TextStyle(
                          fontWeight: FontWeight.w600,
                          fontFamily: AppFonts.mono,
                          fontFamilyFallback: AppFonts.monoFallback,
                          color: r.net > 0
                              ? t.success
                              : (r.net < 0 ? t.danger : t.text))),
                  fields: [
                    MobileCardField('应收', r.recv > 0 ? _yuan(r.recv) : '—'),
                    MobileCardField('应付', r.pay > 0 ? _yuan(r.pay) : '—'),
                  ],
                  onTap: () => showFinancePartnerDrawer(context, row: r),
                ))
            .toList(),
        columns: const [
          DsColumn('name', '往来单位'),
          DsColumn('recv', '应收', numeric: true),
          DsColumn('pay', '应付', numeric: true),
          DsColumn('net', '净额', numeric: true),
          DsColumn('actions', '操作', action: true),
        ],
        rows: rows.map((r) {
          return DsRow(
            onTap: () => showFinancePartnerDrawer(context, row: r),
            cells: [
              Text(r.name,
                  style:
                      TextStyle(fontWeight: FontWeight.w600, color: t.heading)),
              Text(r.recv > 0 ? _yuan(r.recv) : '—',
                  style: const TextStyle(
                      fontFamily: AppFonts.mono,
                      fontFamilyFallback: AppFonts.monoFallback)),
              Text(r.pay > 0 ? _yuan(r.pay) : '—',
                  style: const TextStyle(
                      fontFamily: AppFonts.mono,
                      fontFamilyFallback: AppFonts.monoFallback)),
              Text(signedYuan(r.net),
                  style: TextStyle(
                      fontFamily: AppFonts.mono,
                      fontFamilyFallback: AppFonts.monoFallback,
                      fontWeight: FontWeight.w600,
                      color: r.net > 0
                          ? t.success
                          : (r.net < 0 ? t.danger : t.text))),
              InkWell(
                onTap: () => showFinancePartnerDrawer(context, row: r),
                child: Text('查看',
                    style: TextStyle(
                        fontSize: AppDims.fsBody,
                        fontWeight: FontWeight.w600,
                        color: t.primary)),
              ),
            ],
          );
        }).toList(),
      ),
    );
  }

  String _flowSub(List<FinanceRecord> flows) {
    final receipts = flows.where((r) => r.type == 'receipt').length;
    final payments = flows.where((r) => r.type == 'payment').length;
    return '$_rangeLabel ${flows.length} 笔 · 收 $receipts / 付 $payments';
  }

  // ── 收支流水表 ──
  Widget _flowTable(
      dynamic t, bool mobile, List<FinanceRecord> flows, int total) {
    final chips = [
      for (final c in _flowChips) ...[
        DsChip(
            label: c,
            selected: _flowChip == c,
            caret: false,
            onTap: () => _setFlowChip(c)),
        const SizedBox(width: 10),
      ],
    ];
    final toolbar = mobile
        ? SingleChildScrollView(
            scrollDirection: Axis.horizontal, child: Row(children: chips))
        : Row(children: [
            Text('类型',
                style: TextStyle(fontSize: AppDims.fsSm, color: t.muted)),
            const SizedBox(width: 12),
            ...chips,
            const Spacer(),
            Text('共 $total 条',
                style: TextStyle(
                    fontSize: AppDims.fsSm,
                    color: t.muted,
                    fontFamily: AppFonts.mono,
                    fontFamilyFallback: AppFonts.monoFallback)),
          ]);

    return DsTable(
      shrinkWrap: true,
      emptyText: '没有匹配的流水记录',
      toolbar: toolbar,
      mobileCards: flows.map((r) => _flowCard(t, r)).toList(),
      columns: const [
        DsColumn('date', '日期'),
        DsColumn('type', '类型'),
        DsColumn('partner', '往来单位'),
        DsColumn('amount', '金额', numeric: true),
        DsColumn('ref', '关联单号'),
        DsColumn('remark', '备注'),
        DsColumn('status', '状态'),
        DsColumn('actions', '操作', action: true),
      ],
      rows: flows.map((r) {
        final isIn = r.type == 'receipt' || r.type == 'receivable';
        return DsRow(cells: [
          Text((r.recordDate ?? '').split('T').first,
              style: const TextStyle(
                  fontFamily: AppFonts.mono,
                  fontFamilyFallback: AppFonts.monoFallback)),
          financeTypeBadge(r),
          Text((r.partnerName?.isNotEmpty == true) ? r.partnerName! : '—'),
          // 原型 .qty：+/- 前缀、恒 heading 色（不上正负色）
          Text('${isIn ? '+' : '-'}${_yuan(r.amount.abs())}',
              style: TextStyle(
                  fontFamily: AppFonts.mono,
                  fontFamilyFallback: AppFonts.monoFallback,
                  fontWeight: FontWeight.w600,
                  color: t.heading)),
          Text(
              r.refType != null && r.refId != null
                  ? '${r.docTitle} #${r.refId}'
                  : '—',
              style: TextStyle(
                  fontFamily: AppFonts.mono,
                  fontFamilyFallback: AppFonts.monoFallback,
                  fontSize: AppDims.fsSm,
                  color: t.muted)),
          Text((r.remark?.isNotEmpty == true) ? r.remark! : '—',
              style: TextStyle(color: t.muted)),
          r.status == 'open'
              ? const DsBadge('未结清', tone: DsBadgeTone.warn)
              : const DsBadge('已结清', tone: DsBadgeTone.muted),
          _closeAction(t, r),
        ]);
      }).toList(),
    );
  }

  void _setFlowChip(String c) {
    setState(() => _flowChip = c);
    ref.read(financeListProvider.notifier).setType(_chipToType[c] ?? '');
  }

  Widget _closeAction(dynamic t, FinanceRecord r) {
    final closable =
        r.status == 'open' && (r.type == 'receivable' || r.type == 'payable');
    if (!closable) return Text('—', style: TextStyle(color: t.faint));
    return WriteGuard(
      child: InkWell(
        onTap: () => _confirmClose(r),
        child: Text('结清',
            style: TextStyle(
                fontSize: AppDims.fsBody,
                fontWeight: FontWeight.w600,
                color: t.primary)),
      ),
    );
  }

  Future<void> _confirmClose(FinanceRecord r) async {
    final ok = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('确认结清'),
        content: Text('确认将「${r.partnerName ?? ''} ${r.typeLabel} '
            '${_yuan(r.amount.abs())}」标记为已结清？'),
        actions: [
          DsButton('取消', onPressed: () => Navigator.of(ctx).pop(false)),
          DsButton('结清',
              variant: DsBtnVariant.primary,
              onPressed: () => Navigator.of(ctx).pop(true)),
        ],
      ),
    );
    if (ok != true || !mounted) return;
    try {
      await ref.read(financeRepositoryProvider).close(r.id);
      ref.read(financeListProvider.notifier).reload();
      ref.invalidate(financePartnerRowsProvider);
      if (mounted) {
        showDsToast(context, '已结清 ✓', bg: context.tokens.success);
      }
    } catch (e) {
      if (mounted) {
        showDsToast(context, '操作失败：$e', bg: context.tokens.danger);
      }
    }
  }

  Widget _flowCard(dynamic t, FinanceRecord r) {
    final isIn = r.type == 'receipt' || r.type == 'receivable';
    return MobileListCard(
      title: Text(
          (r.partnerName?.isNotEmpty == true) ? r.partnerName! : r.typeLabel),
      subtitle: Text((r.recordDate ?? '').split('T').first),
      trailing: financeTypeBadge(r),
      fields: [
        MobileCardField('金额', '${isIn ? '+' : '-'}${_yuan(r.amount.abs())}'),
        MobileCardField('状态', r.status == 'open' ? '未结清' : '已结清'),
        if (r.remark?.isNotEmpty == true) MobileCardField('备注', r.remark),
      ],
      actions: (r.status == 'open' &&
              (r.type == 'receivable' || r.type == 'payable'))
          ? [
              WriteGuard(
                child: TextButton(
                  onPressed: () => _confirmClose(r),
                  child: const Text('结清', style: TextStyle(fontSize: 13)),
                ),
              ),
            ]
          : null,
    );
  }
}