import 'package:decimal/decimal.dart';
import 'package:fintracker_api/fintracker_api.dart';
import 'package:fl_chart/fl_chart.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';

import '../../core/theme/chart_colors.dart';
import '../../core/utils/ru_date.dart';
import '../../core/widgets/async_value_view.dart';
import '../../core/widgets/empty_state.dart';
import '../../core/widgets/money_text.dart';
import 'benchmarks_card.dart';
import 'labels.dart';
import 'providers.dart';

double _d(String s) => Decimal.parse(s).toDouble();

/// Позиции: what the portfolio holds, what it is worth, and what it earned.
class HoldingsTab extends ConsumerWidget {
  const HoldingsTab({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final summary = ref.watch(portfolioSummaryProvider);
    final holdings = ref.watch(holdingsProvider);
    final series = ref.watch(valueSeriesProvider);
    final returns = ref.watch(portfolioReturnsProvider);

    return RefreshIndicator(
      onRefresh: () async => invalidatePortfolioProviders(ref),
      child: ListView(
        padding: const EdgeInsets.all(16),
        children: [
          AsyncValueView(
            value: summary,
            onRetry: () => ref.invalidate(portfolioSummaryProvider),
            data: (cached) => _SummaryTiles(summary: cached.data),
          ),
          const SizedBox(height: 20),
          _Card(
            title: 'Стоимость за 365 дней',
            child: AsyncValueView(
              value: series,
              onRetry: () => ref.invalidate(valueSeriesProvider),
              data: (cached) => cached.data.isEmpty
                  ? const EmptyState(icon: Icons.show_chart, message: 'Пока нет данных.')
                  : _ValueChart(rows: cached.data),
            ),
          ),
          const SizedBox(height: 16),
          _Card(
            title: 'Доходность',
            child: AsyncValueView(
              value: returns,
              onRetry: () => ref.invalidate(portfolioReturnsProvider),
              data: (cached) => cached.data.isEmpty
                  ? const EmptyState(icon: Icons.percent, message: 'Пока нечего считать.')
                  : _ReturnsTable(rows: cached.data),
            ),
          ),
          const SizedBox(height: 16),
          const _Card(
            title: 'Сравнение с бенчмарками',
            child: BenchmarksCard(),
          ),
          const SizedBox(height: 16),
          _Card(
            title: 'Позиции',
            child: AsyncValueView(
              value: holdings,
              onRetry: () => ref.invalidate(holdingsProvider),
              data: (cached) => cached.data.isEmpty
                  ? const EmptyState(
                      icon: Icons.inventory_2_outlined,
                      message: 'Открытых позиций нет — нужна синхронизация брокера.',
                    )
                  : _HoldingsTable(rows: cached.data),
            ),
          ),
        ],
      ),
    );
  }
}

class _SummaryTiles extends StatelessWidget {
  const _SummaryTiles({required this.summary});

  final SummaryOut summary;

  @override
  Widget build(BuildContext context) {
    final yearly = summary.returns.where((r) => r.period == '1y').firstOrNull;
    return Wrap(
      spacing: 12,
      runSpacing: 12,
      children: [
        _Tile(
          label: 'Стоимость',
          value: MoneyText(summary.totalRub, currency: 'RUB'),
          note: 'в т.ч. кэш ${MoneyText.format(summary.cashRub, 'RUB')}',
        ),
        _Tile(
          label: 'Вложено',
          value: MoneyText(summary.investedNetRub, currency: 'RUB'),
          note: 'внешние потоки нетто',
        ),
        _Tile(
          label: 'Прибыль',
          value: summary.pnlTotalRub == null
              ? const Text('—')
              : MoneyText(
                  summary.pnlTotalRub!,
                  currency: 'RUB',
                  style: TextStyle(color: signColor(context, summary.pnlTotalRub)),
                ),
          note: summary.pnlTotalRub == null
              ? 'часть позиций без цены'
              : 'реализовано ${MoneyText.format(summary.realizedPnlRub, 'RUB')}',
        ),
        _Tile(
          label: 'Выплаты',
          value: MoneyText(summary.incomeRub, currency: 'RUB'),
          note: 'дивиденды и купоны',
        ),
        _Tile(
          label: 'XIRR, год',
          value: Text(
            formatPercent(yearly?.xirr),
            style: TextStyle(color: signColor(context, yearly?.xirr)),
          ),
          note: 'денежно-взвешенная',
        ),
        _Tile(
          label: 'TWR, год',
          value: Text(
            formatPercent(yearly?.twr),
            style: TextStyle(color: signColor(context, yearly?.twr)),
          ),
          note: (yearly?.twrDaysSkipped ?? 0) > 0
              ? 'пропущено ${yearly!.twrDaysSkipped} дн.'
              : 'без учёта пополнений',
        ),
        if (summary.unpricedCount > 0 || summary.staleCount > 0)
          _Tile(
            label: 'Цены',
            value: Text('${summary.unpricedCount} / ${summary.staleCount}'),
            note: 'без цены / устаревших',
          ),
      ],
    );
  }
}

class _Tile extends StatelessWidget {
  const _Tile({required this.label, required this.value, this.note});

  final String label;
  final Widget value;
  final String? note;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return SizedBox(
      width: 184,
      child: Card(
        child: Padding(
          padding: const EdgeInsets.all(12),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text(label, style: theme.textTheme.bodySmall),
              const SizedBox(height: 4),
              DefaultTextStyle(style: theme.textTheme.titleMedium!, child: value),
              if (note != null) ...[
                const SizedBox(height: 2),
                Text(
                  note!,
                  style: theme.textTheme.bodySmall?.copyWith(color: theme.hintColor),
                  maxLines: 2,
                ),
              ],
            ],
          ),
        ),
      ),
    );
  }
}

class _ValueChart extends StatelessWidget {
  const _ValueChart({required this.rows});

  final List<ValueDay> rows;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final spots = <FlSpot>[];
    final invested = <FlSpot>[];
    for (var i = 0; i < rows.length; i++) {
      spots.add(FlSpot(i.toDouble(), _d(rows[i].totalRub)));
      invested.add(FlSpot(i.toDouble(), _d(rows[i].investedNetRub)));
    }
    return SizedBox(
      height: 220,
      child: LineChart(
        LineChartData(
          gridData: const FlGridData(show: true, drawVerticalLine: false),
          borderData: FlBorderData(show: false),
          titlesData: FlTitlesData(
            topTitles: const AxisTitles(),
            rightTitles: const AxisTitles(),
            leftTitles: const AxisTitles(
              sideTitles: SideTitles(showTitles: true, reservedSize: 56),
            ),
            bottomTitles: AxisTitles(
              sideTitles: SideTitles(
                showTitles: true,
                reservedSize: 28,
                interval: (rows.length / 4).clamp(1, double.infinity),
                getTitlesWidget: (value, meta) {
                  final i = value.round();
                  if (i < 0 || i >= rows.length) return const SizedBox.shrink();
                  return Text(ruMonthYearShort(rows[i].d), style: theme.textTheme.bodySmall);
                },
              ),
            ),
          ),
          lineBarsData: [
            LineChartBarData(
              spots: spots,
              isCurved: false,
              color: ChartColors.slot1Blue,
              barWidth: 2,
              dotData: const FlDotData(show: false),
            ),
            LineChartBarData(
              spots: invested,
              isCurved: false,
              color: ChartColors.slot4Yellow,
              barWidth: 1.5,
              dashArray: const [4, 3],
              dotData: const FlDotData(show: false),
            ),
          ],
          lineTouchData: LineTouchData(
            touchTooltipData: LineTouchTooltipData(
              getTooltipItems: (touched) => [
                for (final t in touched)
                  LineTooltipItem(
                    '${ruDate(rows[t.x.round()].d)}\n'
                    '${MoneyText.format(t.y.toStringAsFixed(2), 'RUB')}',
                    theme.textTheme.bodySmall ?? const TextStyle(),
                  ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}

class _ReturnsTable extends StatelessWidget {
  const _ReturnsTable({required this.rows});

  final List<ReturnsOut> rows;

  @override
  Widget build(BuildContext context) {
    final headerStyle = Theme.of(context).textTheme.labelMedium;
    return SingleChildScrollView(
      scrollDirection: Axis.horizontal,
      child: DataTable(
        columns: [
          DataColumn(label: Text('Период', style: headerStyle)),
          DataColumn(label: Text('Прибыль', style: headerStyle), numeric: true),
          DataColumn(label: Text('Потоки', style: headerStyle), numeric: true),
          DataColumn(label: Text('XIRR', style: headerStyle), numeric: true),
          DataColumn(label: Text('TWR', style: headerStyle), numeric: true),
        ],
        rows: [
          for (final r in rows)
            DataRow(
              cells: [
                DataCell(Text(periodLabel(r.period))),
                DataCell(MoneyText(
                  r.absPnlRub,
                  currency: 'RUB',
                  style: TextStyle(color: signColor(context, r.absPnlRub)),
                )),
                DataCell(MoneyText(r.externalFlowRub, currency: 'RUB')),
                DataCell(Text(
                  formatPercent(r.xirr),
                  style: TextStyle(color: signColor(context, r.xirr)),
                )),
                DataCell(Row(
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    Text(
                      formatPercent(r.twr),
                      style: TextStyle(color: signColor(context, r.twr)),
                    ),
                    if (r.twrDaysSkipped > 0) ...[
                      const SizedBox(width: 4),
                      Tooltip(
                        message: 'Пропущено ${r.twrDaysSkipped} дн.: '
                            'в эти дни часть позиции была без цены',
                        child: const Icon(Icons.info_outline, size: 14),
                      ),
                    ],
                  ],
                )),
              ],
            ),
        ],
      ),
    );
  }
}

class _HoldingsTable extends StatelessWidget {
  const _HoldingsTable({required this.rows});

  final List<HoldingOut> rows;

  @override
  Widget build(BuildContext context) {
    final headerStyle = Theme.of(context).textTheme.labelMedium;
    return SingleChildScrollView(
      scrollDirection: Axis.horizontal,
      child: DataTable(
        columns: [
          DataColumn(label: Text('Бумага', style: headerStyle)),
          DataColumn(label: Text('Класс', style: headerStyle)),
          DataColumn(label: Text('Кол-во', style: headerStyle), numeric: true),
          DataColumn(label: Text('Цена', style: headerStyle), numeric: true),
          DataColumn(label: Text('Стоимость', style: headerStyle), numeric: true),
          DataColumn(label: Text('Доля', style: headerStyle), numeric: true),
          DataColumn(label: Text('Нереализ.', style: headerStyle), numeric: true),
          DataColumn(label: Text('XIRR', style: headerStyle), numeric: true),
        ],
        rows: [
          for (final r in rows)
            DataRow(
              onSelectChanged: (_) => context.push('/portfolio/instrument/${r.instrumentId}'),
              cells: [
                DataCell(Row(
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    Flexible(
                      child: Text(
                        r.ticker ?? r.name,
                        overflow: TextOverflow.ellipsis,
                      ),
                    ),
                    const SizedBox(width: 6),
                    PriceStatusChip(status: r.priceStatus, priceDate: r.priceDate),
                  ],
                )),
                DataCell(Text(assetClassLabel(r.assetClass))),
                DataCell(Text(formatQty(r.qty))),
                DataCell(r.marketPrice == null
                    ? const Text('—')
                    : MoneyText(r.marketPrice!, currency: r.priceCurrency ?? r.currency)),
                // a position with no price shows nothing, never 0 ₽: it is absent from the
                // totals above, and a zero would read as "worthless" instead of "unknown"
                DataCell(r.valueRub == null
                    ? const Text('—')
                    : MoneyText(r.valueRub!, currency: 'RUB')),
                DataCell(Text(formatPercent(r.weight, signed: false))),
                DataCell(r.unrealizedPnlRub == null
                    ? const Text('—')
                    : MoneyText(
                        r.unrealizedPnlRub!,
                        currency: 'RUB',
                        style: TextStyle(color: signColor(context, r.unrealizedPnlRub)),
                      )),
                DataCell(Text(
                  formatPercent(r.xirr),
                  style: TextStyle(color: signColor(context, r.xirr)),
                )),
              ],
            ),
        ],
      ),
    );
  }
}

class _Card extends StatelessWidget {
  const _Card({required this.title, required this.child});

  final String title;
  final Widget child;

  @override
  Widget build(BuildContext context) {
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(title, style: Theme.of(context).textTheme.titleMedium),
            const SizedBox(height: 12),
            child,
          ],
        ),
      ),
    );
  }
}