// fuel_drawdowns_page.dart — حركة القسائم وملخّص الائتمان
//
// ‏الشاشة التي تُجيب: كم أقرضنا؟ كم استُرد؟ وكم بقي في الشارع؟
import 'package:flutter/material.dart';
import 'package:get/get.dart';

import '../../../controller/fuel/fuel_admin_controller.dart';
import '../../../controller/fuel/fuel_admin_models.dart';

class FuelDrawdownsPageView extends StatefulWidget {
  const FuelDrawdownsPageView({super.key});

  @override
  State<FuelDrawdownsPageView> createState() => _FuelDrawdownsPageViewState();
}

class _FuelDrawdownsPageViewState extends State<FuelDrawdownsPageView> {
  String? _status;

  @override
  void initState() {
    super.initState();
    Get.find<FuelAdminController>().fetchDrawdowns();
  }

  @override
  Widget build(BuildContext context) {
    final cs = Theme.of(context).colorScheme;

    return GetBuilder<FuelAdminController>(
      builder: (c) => Scaffold(
        backgroundColor: cs.surface,
        appBar: AppBar(
          backgroundColor: cs.surface,
          foregroundColor: cs.onSurface,
          title: const Text('حركة القسائم'),
        ),
        body: Column(
          children: [
            if (c.drawdowns != null) _summary(c.drawdowns!, cs),
            _filters(c, cs),
            Expanded(
              child: c.isLoadingDrawdowns
                  ? Center(child: CircularProgressIndicator(color: cs.primary))
                  : (c.drawdowns?.vouchers.isEmpty ?? true)
                      ? Center(
                          child: Text('لا توجد قسائم',
                              style: TextStyle(color: cs.onSurfaceVariant)))
                      : ListView.builder(
                          padding: const EdgeInsets.symmetric(horizontal: 12),
                          itemCount: c.drawdowns!.vouchers.length,
                          itemBuilder: (_, i) =>
                              _voucherCard(c.drawdowns!.vouchers[i], cs),
                        ),
            ),
          ],
        ),
      ),
    );
  }

  /// ‏الملخّص على كامل المنتج لا على القائمة المعروضة: رقم يتغيّر بتغيّر
  /// ‏الفلتر يُقرأ كأنه حقيقة عن المنصة وهو ليس كذلك.
  Widget _summary(FuelDrawdownsPage d, ColorScheme cs) => Container(
        margin: const EdgeInsets.fromLTRB(12, 12, 12, 4),
        padding: const EdgeInsets.all(14),
        decoration: BoxDecoration(
          color: cs.surfaceContainerHighest,
          borderRadius: BorderRadius.circular(14),
        ),
        child: Row(
          children: [
            _stat('أُقرض', d.lentTotal.toString(), cs.onSurface, cs),
            _stat('استُرد', d.collectedTotal.toString(), cs.primary, cs),
            _stat('قائم', d.outstandingTotal.toString(), cs.tertiary, cs),
            _stat('سائق', d.driversCount.toString(), cs.onSurfaceVariant, cs),
          ],
        ),
      );

  Widget _stat(String label, String value, Color color, ColorScheme cs) =>
      Expanded(
        child: Column(
          children: [
            Text(value,
                style: TextStyle(
                    color: color, fontSize: 16, fontWeight: FontWeight.w700)),
            const SizedBox(height: 2),
            Text(label,
                style: TextStyle(color: cs.onSurfaceVariant, fontSize: 11)),
          ],
        ),
      );

  Widget _filters(FuelAdminController c, ColorScheme cs) {
    const options = {
      null: 'الكل',
      'issued': 'سارية',
      'redeemed': 'مصروفة',
      'expired': 'منتهية',
      'cancelled': 'ملغاة',
    };

    return SizedBox(
      height: 46,
      child: ListView(
        scrollDirection: Axis.horizontal,
        padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
        children: options.entries.map((e) {
          final selected = _status == e.key;
          return Padding(
            padding: const EdgeInsets.only(left: 8),
            child: ChoiceChip(
              label: Text(e.value),
              selected: selected,
              onSelected: (_) {
                setState(() => _status = e.key);
                c.fetchDrawdowns(status: e.key);
              },
            ),
          );
        }).toList(),
      ),
    );
  }

  Widget _voucherCard(FuelVoucher v, ColorScheme cs) {
    final (color, label) = switch (v.status) {
      'redeemed' => (cs.primary, 'مصروفة'),
      'issued' => (cs.tertiary, 'سارية'),
      'cancelled' => (cs.error, 'ملغاة'),
      _ => (cs.onSurfaceVariant, 'منتهية'),
    };

    // ‏المصروف لا المأذون: السائق قد يطلب عشرين ويتزوّد بخمسة عشر،
    // ‏والدَّين على ما صُرف. عرض المأذون هنا يضخّم الأرقام في عين القارئ.
    final amount = v.status == 'redeemed' ? v.amountRedeemed : v.amountAuthorized;

    return Card(
      color: cs.surfaceContainerHighest,
      margin: const EdgeInsets.only(bottom: 8),
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
      child: ListTile(
        title: Row(
          children: [
            Text('$amount ${v.currency}',
                style: TextStyle(
                    color: cs.onSurface, fontWeight: FontWeight.bold)),
            const SizedBox(width: 8),
            Container(
              padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
              decoration: BoxDecoration(
                color: color.withValues(alpha: 0.15),
                borderRadius: BorderRadius.circular(6),
              ),
              child: Text(label, style: TextStyle(color: color, fontSize: 11)),
            ),
          ],
        ),
        subtitle: Padding(
          padding: const EdgeInsets.only(top: 4),
          child: Text(
            [
              'سائق ${v.driverId}',
              if (v.station != null && v.station!.isNotEmpty) v.station!,
              v.redeemedAt ?? v.createdAt ?? '',
            ].where((s) => s.isNotEmpty).join(' · '),
            style: TextStyle(color: cs.onSurfaceVariant, fontSize: 11),
          ),
        ),
      ),
    );
  }
}