import 'package:enter_farma_plus_mobile/src/core/network/api_client.dart';
import 'package:enter_farma_plus_mobile/src/core/theme/app_tokens.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';

class StocktakeReportScreen extends ConsumerStatefulWidget {
  const StocktakeReportScreen({super.key, required this.countId});
  final int countId;

  @override
  ConsumerState<StocktakeReportScreen> createState() =>
      _StocktakeReportScreenState();
}

class _StocktakeReportScreenState
    extends ConsumerState<StocktakeReportScreen> {
  late Future<Map<String, dynamic>?> _future;

  @override
  void initState() {
    super.initState();
    _future = _load();
  }

  Future<Map<String, dynamic>?> _load() async {
    final response =
        await ref.read(apiClientProvider).physicalCountReport(widget.countId);
    if (!response.success) return null;
    return response.data;
  }

  void _refresh() => setState(() => _future = _load());

  @override
  Widget build(BuildContext context) {
    return FutureBuilder<Map<String, dynamic>?>(
      future: _future,
      builder: (context, snapshot) {
        final report = snapshot.data;
        final lines = List<Map<String, dynamic>>.from(
            report?['lines'] as List? ?? const []);
        final summary =
            Map<String, dynamic>.from(report?['summary'] as Map? ?? const {});

        final differences = lines.where((line) {
          final diff = double.tryParse('${line['difference_qty']}') ?? 0;
          return diff.abs() > 0.0001 || line['pending_lot'] == true;
        }).toList();
        final okLines = lines.where((line) {
          final diff = double.tryParse('${line['difference_qty']}') ?? 0;
          return diff.abs() <= 0.0001 && line['pending_lot'] != true;
        }).toList();

        return Scaffold(
          appBar: AppBar(
            title: Text('Reporte #${widget.countId}'),
            actions: [
              IconButton(
                  onPressed: _refresh, icon: const Icon(Icons.refresh_rounded)),
            ],
          ),
          body: RefreshIndicator(
            onRefresh: () async => _refresh(),
            child: ListView(
              padding: AppTokens.pagePadding,
              children: [
                if (snapshot.connectionState == ConnectionState.waiting)
                  const Center(child: CircularProgressIndicator())
                else if (report == null)
                  const _ErrorState()
                else ...[
                  _SummaryCard(summary: summary),
                  const SizedBox(height: 20),
                  if (differences.isNotEmpty) ...[
                    _SectionLabel(
                      label: 'Con diferencia',
                      count: differences.length,
                      color: AppTokens.warning,
                      icon: Icons.warning_amber_rounded,
                    ),
                    const SizedBox(height: 8),
                    ...differences.map((line) => _ReportLineCard(
                          countId: widget.countId,
                          line: line,
                        )),
                    const SizedBox(height: 16),
                  ],
                  if (okLines.isNotEmpty) ...[
                    _SectionLabel(
                      label: 'Sin diferencia',
                      count: okLines.length,
                      color: AppTokens.success,
                      icon: Icons.check_circle_outline_rounded,
                    ),
                    const SizedBox(height: 8),
                    ...okLines.map((line) => _ReportLineCard(
                          countId: widget.countId,
                          line: line,
                        )),
                  ],
                ],
                const SizedBox(height: 32),
              ],
            ),
          ),
        );
      },
    );
  }
}

// ── Summary card ───────────────────────────────────────────────────────────────

class _SummaryCard extends StatelessWidget {
  const _SummaryCard({required this.summary});
  final Map<String, dynamic> summary;

  @override
  Widget build(BuildContext context) {
    final totalLines = summary['total_lines'] ?? 0;
    final okLines = summary['ok_lines'] ?? 0;
    final diffLines = summary['difference_lines'] ?? 0;
    final pendingLot = summary['pending_lot_lines'] ?? 0;

    return Card(
      elevation: 0,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(14),
        side: BorderSide(color: Colors.grey.shade200),
      ),
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text('Resumen del conteo',
                style: Theme.of(context)
                    .textTheme
                    .labelLarge
                    ?.copyWith(color: Colors.grey.shade600)),
            const SizedBox(height: 12),
            Row(
              children: [
                Expanded(
                    child: _Metric(
                  label: 'Total items',
                  value: '$totalLines',
                  color: AppTokens.primary,
                )),
                Expanded(
                    child: _Metric(
                  label: 'Sin dif.',
                  value: '$okLines',
                  color: AppTokens.success,
                )),
                Expanded(
                    child: _Metric(
                  label: 'Con dif.',
                  value: '$diffLines',
                  color: diffLines > 0 ? AppTokens.warning : AppTokens.success,
                )),
                Expanded(
                    child: _Metric(
                  label: 'Pend. lote',
                  value: '$pendingLot',
                  color: pendingLot > 0 ? AppTokens.danger : AppTokens.secondary,
                )),
              ],
            ),
          ],
        ),
      ),
    );
  }
}

class _Metric extends StatelessWidget {
  const _Metric({required this.label, required this.value, required this.color});
  final String label;
  final String value;
  final Color color;

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(value,
            style: TextStyle(
                fontSize: 22, fontWeight: FontWeight.w800, color: color)),
        Text(label,
            style: TextStyle(fontSize: 11, color: Colors.grey.shade500)),
      ],
    );
  }
}

// ── Section label ──────────────────────────────────────────────────────────────

class _SectionLabel extends StatelessWidget {
  const _SectionLabel({
    required this.label,
    required this.count,
    required this.color,
    required this.icon,
  });
  final String label;
  final int count;
  final Color color;
  final IconData icon;

  @override
  Widget build(BuildContext context) {
    return Row(
      children: [
        Icon(icon, size: 16, color: color),
        const SizedBox(width: 6),
        Text(label,
            style: TextStyle(
                fontSize: 13,
                fontWeight: FontWeight.w700,
                color: color)),
        const SizedBox(width: 6),
        Container(
          padding: const EdgeInsets.symmetric(horizontal: 7, vertical: 1),
          decoration: BoxDecoration(
            color: color.withValues(alpha: 0.12),
            borderRadius: BorderRadius.circular(10),
          ),
          child: Text('$count',
              style: TextStyle(
                  fontSize: 11, fontWeight: FontWeight.w700, color: color)),
        ),
      ],
    );
  }
}

// ── Report line card ───────────────────────────────────────────────────────────

class _ReportLineCard extends StatelessWidget {
  const _ReportLineCard({required this.countId, required this.line});
  final int countId;
  final Map<String, dynamic> line;

  @override
  Widget build(BuildContext context) {
    final itemId = int.tryParse('${line['item_id']}') ?? 0;
    final diff = double.tryParse('${line['difference_qty']}') ?? 0;
    final pendingLot = line['pending_lot'] == true;
    final lot = line['lot_code']?.toString() ?? '';
    final lotDate = line['lot_date_of_due']?.toString() ?? '';

    final Color diffColor = pendingLot || diff < -0.0001
        ? AppTokens.danger
        : diff > 0.0001
            ? AppTokens.success
            : AppTokens.secondary;

    final String diffLabel = pendingLot
        ? 'Lote pendiente'
        : diff == 0
            ? 'OK'
            : (diff > 0 ? '+${diff.toStringAsFixed(2)}' : diff.toStringAsFixed(2));

    return Card(
      margin: const EdgeInsets.only(bottom: 8),
      elevation: 0,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(10),
        side: BorderSide(color: Colors.grey.shade200),
      ),
      child: InkWell(
        borderRadius: BorderRadius.circular(10),
        onTap: () =>
            context.go('/stocktake/$countId/items/$itemId/kardex'),
        child: Padding(
          padding: const EdgeInsets.fromLTRB(12, 10, 12, 10),
          child: Row(
            children: [
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      line['description']?.toString() ?? 'Producto',
                      style: const TextStyle(
                          fontWeight: FontWeight.w600, fontSize: 13),
                    ),
                    const SizedBox(height: 3),
                    Row(
                      children: [
                        Text(
                          'Contado ${line['counted_qty_base']} / Sistema ${line['system_qty_snapshot']}',
                          style: TextStyle(
                              fontSize: 11, color: Colors.grey.shade500),
                        ),
                      ],
                    ),
                    if (lot.isNotEmpty || lotDate.isNotEmpty) ...[
                      const SizedBox(height: 2),
                      Text(
                        [
                          if (lot.isNotEmpty) 'Lote $lot',
                          if (lotDate.isNotEmpty) 'Vence $lotDate',
                        ].join(' · '),
                        style: TextStyle(
                            fontSize: 11, color: Colors.grey.shade500),
                      ),
                    ],
                  ],
                ),
              ),
              const SizedBox(width: 10),
              Column(
                crossAxisAlignment: CrossAxisAlignment.end,
                children: [
                  Container(
                    padding: const EdgeInsets.symmetric(
                        horizontal: 8, vertical: 3),
                    decoration: BoxDecoration(
                      color: diffColor.withValues(alpha: 0.10),
                      borderRadius: BorderRadius.circular(12),
                      border: Border.all(
                          color: diffColor.withValues(alpha: 0.25)),
                    ),
                    child: Text(diffLabel,
                        style: TextStyle(
                            fontSize: 11,
                            fontWeight: FontWeight.w700,
                            color: diffColor)),
                  ),
                  const SizedBox(height: 4),
                  Icon(Icons.chevron_right_rounded,
                      size: 16, color: Colors.grey.shade400),
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }
}

// ── Error state ────────────────────────────────────────────────────────────────

class _ErrorState extends StatelessWidget {
  const _ErrorState();

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 48),
      child: Column(
        children: [
          Icon(Icons.error_outline_rounded,
              size: 48, color: Colors.grey.shade300),
          const SizedBox(height: 12),
          Text('No se pudo cargar el reporte.',
              style: TextStyle(color: Colors.grey.shade500)),
        ],
      ),
    );
  }
}