import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:intl/intl.dart';

import '../../core/providers/auth_provider.dart';
import '../../core/theme/app_theme.dart';
import '../../core/widgets/gradient_app_bar.dart';
import '../../models/job.dart';
import '../../models/tenant.dart';
import 'reports_repository.dart';

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

  @override
  ConsumerState<ReportsScreen> createState() => _ReportsScreenState();
}

class _ReportsScreenState extends ConsumerState<ReportsScreen>
    with SingleTickerProviderStateMixin {
  late TabController _tabController;
  late Future<ReportMetrics> _future;

  @override
  void initState() {
    super.initState();
    _tabController = TabController(length: 4, vsync: this);
    _tabController.addListener(() { if (mounted) setState(() {}); });
    _load();
  }

  @override
  void dispose() {
    _tabController.dispose();
    super.dispose();
  }

  void _load() {
    final auth = ref.read(authProvider);
    final tenantId = auth.activeTenant!.tenant.id;
    final kind = auth.activeTenant!.tenant.kind;
    setState(() {
      _future = ReportsRepository.instance.load(tenantId, kind);
    });
  }

  @override
  Widget build(BuildContext context) {
    final kind = ref.watch(authProvider).activeTenant?.tenant.kind ?? TenantKind.lab;
    final counterpartLabel = kind == TenantKind.lab ? 'Klinikler' : 'Laboratuvarlar';

    return Scaffold(
      backgroundColor: AppColors.background,
      appBar: GradientAppBar(
        title: 'Raporlar',
        category: 'YÖNETİCİ',
        actions: [
          IconButton(
            icon: const Icon(Icons.refresh_rounded),
            onPressed: _load,
            tooltip: 'Yenile',
          ),
        ],
      ),
      body: FutureBuilder<ReportMetrics>(
        future: _future,
        builder: (context, snap) {
          if (snap.connectionState == ConnectionState.waiting) {
            return const Center(child: CircularProgressIndicator(color: AppColors.accent));
          }
          if (snap.hasError) {
            return Center(
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: [
                  const Icon(Icons.error_outline_rounded, color: AppColors.cancelled, size: 48),
                  const SizedBox(height: 12),
                  Text('Veriler yüklenemedi', style: const TextStyle(color: AppColors.textSecondary)),
                  const SizedBox(height: 12),
                  FilledButton.icon(
                    onPressed: _load,
                    icon: const Icon(Icons.refresh_rounded, size: 18),
                    label: const Text('Tekrar Dene'),
                  ),
                ],
              ),
            );
          }
          final m = snap.data!;
          return Column(
            children: [
              // Tab bar
              Container(
                color: AppColors.surface,
                child: TabBar(
                  controller: _tabController,
                  labelColor: AppColors.accent,
                  unselectedLabelColor: AppColors.textSecondary,
                  indicatorColor: AppColors.accent,
                  indicatorSize: TabBarIndicatorSize.tab,
                  labelStyle: const TextStyle(fontSize: 13, fontWeight: FontWeight.w600),
                  tabs: [
                    const Tab(text: 'Özet'),
                    const Tab(text: 'Finans'),
                    const Tab(text: 'Aktivite'),
                    Tab(text: counterpartLabel),
                  ],
                ),
              ),
              Expanded(
                child: TabBarView(
                  controller: _tabController,
                  children: [
                    _SummaryTab(metrics: m),
                    _FinanceTab(metrics: m),
                    _ActivityTab(metrics: m),
                    _CounterpartTab(metrics: m, label: counterpartLabel),
                  ],
                ),
              ),
            ],
          );
        },
      ),
    );
  }
}

// ── Shared layout helpers ─────────────────────────────────────────────────────

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

  @override
  Widget build(BuildContext context) => ListView(
        padding: const EdgeInsets.fromLTRB(16, 16, 16, 32),
        children: children,
      );
}

class _Card extends StatelessWidget {
  const _Card({required this.child, this.padding = const EdgeInsets.all(16)});
  final Widget child;
  final EdgeInsets padding;

  @override
  Widget build(BuildContext context) => Container(
        margin: const EdgeInsets.only(bottom: 12),
        padding: padding,
        decoration: BoxDecoration(
          color: AppColors.surface,
          borderRadius: BorderRadius.circular(16),
          border: Border.all(color: AppColors.border),
          boxShadow: [BoxShadow(color: Colors.black.withValues(alpha: 0.03), blurRadius: 8, offset: const Offset(0, 2))],
        ),
        child: child,
      );
}

class _SectionHeader extends StatelessWidget {
  const _SectionHeader(this.title, {this.subtitle});
  final String title;
  final String? subtitle;

  @override
  Widget build(BuildContext context) => Padding(
        padding: const EdgeInsets.only(bottom: 10, top: 4),
        child: Row(
          children: [
            Expanded(
              child: Text(title, style: const TextStyle(fontSize: 15, fontWeight: FontWeight.w700, color: AppColors.textPrimary)),
            ),
            if (subtitle != null)
              Text(subtitle!, style: const TextStyle(fontSize: 12, color: AppColors.textMuted)),
          ],
        ),
      );
}

// ── KPI Chips ─────────────────────────────────────────────────────────────────

class _KpiRow extends StatelessWidget {
  const _KpiRow({required this.metrics});
  final ReportMetrics metrics;

  @override
  Widget build(BuildContext context) {
    final fmt = NumberFormat.currency(locale: 'tr_TR', symbol: metrics.currency, decimalDigits: 0);
    return SingleChildScrollView(
      scrollDirection: Axis.horizontal,
      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
      child: Row(
        children: [
          _Kpi(label: 'Aktif İşler', value: '${metrics.activeJobs}', icon: Icons.work_outline_rounded, color: AppColors.inProgress),
          const SizedBox(width: 10),
          _Kpi(label: 'Bu Ay Tamamlandı', value: '${metrics.completedThisMonth}', icon: Icons.check_circle_outline_rounded, color: AppColors.success),
          const SizedBox(width: 10),
          _Kpi(label: 'Bekleyen Gelir', value: fmt.format(metrics.pendingRevenue), icon: Icons.hourglass_empty_rounded, color: AppColors.pending),
          const SizedBox(width: 10),
          _Kpi(label: 'Ort. Süre', value: '${metrics.avgCompletionDays.toStringAsFixed(1)} gün', icon: Icons.timer_outlined, color: AppColors.accent),
          const SizedBox(width: 10),
          _Kpi(label: 'Revizyon Oranı', value: '%${metrics.revisionRate.toStringAsFixed(0)}', icon: Icons.loop_rounded, color: metrics.revisionRate > 20 ? AppColors.cancelled : AppColors.textSecondary),
          if (metrics.overdueJobs > 0) ...[
            const SizedBox(width: 10),
            _Kpi(label: 'Gecikmiş', value: '${metrics.overdueJobs}', icon: Icons.schedule_rounded, color: AppColors.cancelled),
          ],
        ],
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) => Container(
        padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 12),
        decoration: BoxDecoration(
          color: AppColors.surface,
          borderRadius: BorderRadius.circular(14),
          border: Border.all(color: AppColors.border),
          boxShadow: [BoxShadow(color: Colors.black.withValues(alpha: 0.03), blurRadius: 6)],
        ),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              mainAxisSize: MainAxisSize.min,
              children: [
                Icon(icon, size: 14, color: color),
                const SizedBox(width: 4),
                Text(label, style: const TextStyle(fontSize: 11, color: AppColors.textMuted)),
              ],
            ),
            const SizedBox(height: 6),
            Text(value, style: TextStyle(fontSize: 20, fontWeight: FontWeight.w800, color: color)),
          ],
        ),
      );
}

// ── Özet Tab ──────────────────────────────────────────────────────────────────

class _SummaryTab extends StatelessWidget {
  const _SummaryTab({required this.metrics});
  final ReportMetrics metrics;

  @override
  Widget build(BuildContext context) {
    return _TabBody(children: [
      _KpiRow(metrics: metrics),
      const _SectionHeader('İş Durumu Dağılımı'),
      _Card(
        child: Column(
          children: _statusOrder.where((s) => metrics.jobsByStatus.containsKey(s)).map((s) {
            final count = metrics.jobsByStatus[s] ?? 0;
            final total = metrics.jobsByStatus.values.fold(0, (a, b) => a + b);
            return _HBarRow(
              label: _statusLabel(s),
              value: count,
              max: total,
              color: _statusColor(s),
            );
          }).toList(),
        ),
      ),
      const _SectionHeader('Son 6 Aylık İş Trendi'),
      _Card(child: _VBarChart(data: metrics.monthlyCounts, color: AppColors.accent)),
    ]);
  }

  static const _statusOrder = ['in_progress', 'pending', 'sent', 'delivered', 'cancelled'];

  static String _statusLabel(String s) => switch (s) {
    'pending'     => 'Bekliyor',
    'in_progress' => 'İşlemde',
    'sent'        => 'Gönderildi',
    'delivered'   => 'Teslim',
    'cancelled'   => 'İptal',
    _             => s,
  };

  static Color _statusColor(String s) => switch (s) {
    'pending'     => AppColors.pending,
    'in_progress' => AppColors.inProgress,
    'sent'        => AppColors.accent,
    'delivered'   => AppColors.success,
    'cancelled'   => AppColors.cancelled,
    _             => AppColors.textMuted,
  };
}

// ── Finans Tab ────────────────────────────────────────────────────────────────

class _FinanceTab extends StatelessWidget {
  const _FinanceTab({required this.metrics});
  final ReportMetrics metrics;

  @override
  Widget build(BuildContext context) {
    final fmt = NumberFormat.currency(locale: 'tr_TR', symbol: metrics.currency, decimalDigits: 0);
    final total = metrics.totalRevenue + metrics.pendingRevenue;
    return _TabBody(children: [
      const _SectionHeader('Gelir Özeti'),
      Row(
        children: [
          Expanded(
            child: _Card(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Row(children: [
                    Container(width: 8, height: 8, decoration: BoxDecoration(color: AppColors.success, shape: BoxShape.circle)),
                    const SizedBox(width: 6),
                    const Text('Tahsil Edildi', style: TextStyle(fontSize: 12, color: AppColors.textMuted)),
                  ]),
                  const SizedBox(height: 6),
                  Text(fmt.format(metrics.totalRevenue),
                      style: const TextStyle(fontSize: 18, fontWeight: FontWeight.w800, color: AppColors.success)),
                ],
              ),
            ),
          ),
          const SizedBox(width: 10),
          Expanded(
            child: _Card(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Row(children: [
                    Container(width: 8, height: 8, decoration: BoxDecoration(color: AppColors.pending, shape: BoxShape.circle)),
                    const SizedBox(width: 6),
                    const Text('Bekleyen', style: TextStyle(fontSize: 12, color: AppColors.textMuted)),
                  ]),
                  const SizedBox(height: 6),
                  Text(fmt.format(metrics.pendingRevenue),
                      style: const TextStyle(fontSize: 18, fontWeight: FontWeight.w800, color: AppColors.pending)),
                ],
              ),
            ),
          ),
        ],
      ),
      if (total > 0) _Card(
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            const Text('Tahsilat Oranı', style: TextStyle(fontSize: 13, fontWeight: FontWeight.w600)),
            const SizedBox(height: 10),
            ClipRRect(
              borderRadius: BorderRadius.circular(6),
              child: LinearProgressIndicator(
                value: total > 0 ? metrics.totalRevenue / total : 0,
                minHeight: 12,
                backgroundColor: AppColors.pendingBg,
                valueColor: const AlwaysStoppedAnimation<Color>(AppColors.success),
              ),
            ),
            const SizedBox(height: 6),
            Text('${(metrics.totalRevenue / total * 100).toStringAsFixed(0)}% tahsil edildi',
                style: const TextStyle(fontSize: 12, color: AppColors.textMuted)),
          ],
        ),
      ),
      const SizedBox(height: 4),
      const _SectionHeader('Aylık Gelir Trendi'),
      _Card(child: _VBarChart(
        data: metrics.monthlyRevenue.map((m) => MonthlyCount(year: m.year, month: m.month, count: m.amount.round())).toList(),
        color: AppColors.success,
        formatValue: (v) => NumberFormat.compactCurrency(locale: 'tr_TR', symbol: metrics.currency, decimalDigits: 0).format(v),
      )),
    ]);
  }
}

// ── Aktivite Tab ──────────────────────────────────────────────────────────────

class _ActivityTab extends StatelessWidget {
  const _ActivityTab({required this.metrics});
  final ReportMetrics metrics;

  @override
  Widget build(BuildContext context) {
    final items = metrics.recentActivity;
    if (items.isEmpty) {
      return const Center(
        child: Text('Henüz aktivite kaydı yok.', style: TextStyle(color: AppColors.textMuted)),
      );
    }
    return _TabBody(children: [
      const _SectionHeader('Son İşlemler'),
      _Card(
        padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
        child: Column(
          children: items.asMap().entries.map((entry) {
            final i = entry.key;
            final item = entry.value;
            return _ActivityRow(item: item, isLast: i == items.length - 1);
          }).toList(),
        ),
      ),
    ]);
  }
}

class _ActivityRow extends StatelessWidget {
  const _ActivityRow({required this.item, required this.isLast});
  final ActivityItem item;
  final bool isLast;

  @override
  Widget build(BuildContext context) {
    final color = item.isNegative ? AppColors.cancelled : item.isPositive ? AppColors.success : AppColors.accent;
    final icon = switch (item.action) {
      'accepted'           => Icons.check_circle_outline_rounded,
      'handed_to_clinic'   => Icons.send_rounded,
      'approved'           => Icons.thumb_up_outlined,
      'revision_requested' => Icons.loop_rounded,
      'delivered'          => Icons.local_shipping_outlined,
      'cancelled'          => Icons.cancel_outlined,
      _                    => Icons.history_rounded,
    };
    final df = DateFormat('dd.MM.yy HH:mm');

    return IntrinsicHeight(
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          // Timeline line + dot
          SizedBox(
            width: 28,
            child: Column(
              children: [
                Container(
                  width: 24, height: 24,
                  decoration: BoxDecoration(
                    color: color.withValues(alpha: 0.12),
                    shape: BoxShape.circle,
                  ),
                  child: Icon(icon, size: 13, color: color),
                ),
                if (!isLast)
                  Expanded(child: Container(width: 1.5, color: AppColors.border)),
              ],
            ),
          ),
          const SizedBox(width: 10),
          Expanded(
            child: Padding(
              padding: EdgeInsets.only(bottom: isLast ? 0 : 10),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(item.actionLabel,
                      style: const TextStyle(fontSize: 13, fontWeight: FontWeight.w600, color: AppColors.textPrimary)),
                  if (item.patientCode != null && item.patientCode!.isNotEmpty)
                    Text(item.patientCode!, style: const TextStyle(fontSize: 11, color: AppColors.accent)),
                  if (item.note != null && item.note!.isNotEmpty)
                    Text(item.note!, style: const TextStyle(fontSize: 11, color: AppColors.textMuted)),
                  const SizedBox(height: 2),
                  Text(df.format(item.createdAt), style: const TextStyle(fontSize: 10, color: AppColors.textMuted)),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }
}

// ── Counterpart Tab ───────────────────────────────────────────────────────────

class _CounterpartTab extends StatelessWidget {
  const _CounterpartTab({required this.metrics, required this.label});
  final ReportMetrics metrics;
  final String label;

  @override
  Widget build(BuildContext context) {
    final stats = metrics.counterpartStats;
    if (stats.isEmpty) {
      return Center(
        child: Text('$label henüz yok.', style: const TextStyle(color: AppColors.textMuted)),
      );
    }
    final fmt = NumberFormat.currency(locale: 'tr_TR', symbol: metrics.currency, decimalDigits: 0);
    final maxJobs = stats.fold(0, (m, s) => s.jobCount > m ? s.jobCount : m);

    return _TabBody(children: [
      const _SectionHeader('Protez Türü Dağılımı'),
      _Card(
        child: Column(
          children: _buildTypeRows(metrics.byProstheticType),
        ),
      ),
      _SectionHeader('En Aktif $label'),
      _Card(
        child: Column(
          children: stats.asMap().entries.map((entry) {
            final i = entry.key;
            final s = entry.value;
            return Padding(
              padding: EdgeInsets.only(bottom: i < stats.length - 1 ? 12 : 0),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Row(
                    children: [
                      Container(
                        width: 22, height: 22,
                        decoration: BoxDecoration(
                          color: AppColors.inProgressBg,
                          shape: BoxShape.circle,
                        ),
                        child: Center(
                          child: Text('${i + 1}',
                              style: const TextStyle(fontSize: 11, fontWeight: FontWeight.w700, color: AppColors.inProgress)),
                        ),
                      ),
                      const SizedBox(width: 8),
                      Expanded(
                        child: Text(s.name,
                            style: const TextStyle(fontSize: 13, fontWeight: FontWeight.w600, color: AppColors.textPrimary),
                            maxLines: 1, overflow: TextOverflow.ellipsis),
                      ),
                      Text('${s.jobCount} iş',
                          style: const TextStyle(fontSize: 12, color: AppColors.textSecondary, fontWeight: FontWeight.w500)),
                    ],
                  ),
                  const SizedBox(height: 6),
                  ClipRRect(
                    borderRadius: BorderRadius.circular(4),
                    child: LinearProgressIndicator(
                      value: maxJobs > 0 ? s.jobCount / maxJobs : 0,
                      minHeight: 6,
                      backgroundColor: AppColors.surfaceVariant,
                      valueColor: const AlwaysStoppedAnimation<Color>(AppColors.accent),
                    ),
                  ),
                  if (s.totalRevenue > 0) Padding(
                    padding: const EdgeInsets.only(top: 4),
                    child: Text(
                      '${fmt.format(s.paidRevenue)} tahsil · ${fmt.format(s.pendingRevenue)} bekliyor',
                      style: const TextStyle(fontSize: 11, color: AppColors.textMuted),
                    ),
                  ),
                ],
              ),
            );
          }).toList(),
        ),
      ),
    ]);
  }

  List<Widget> _buildTypeRows(Map<String, int> byType) {
    if (byType.isEmpty) return [const Text('Veri yok', style: TextStyle(color: AppColors.textMuted))];
    final sorted = byType.entries.toList()..sort((a, b) => b.value.compareTo(a.value));
    final max = sorted.first.value;
    return sorted.map((e) => _HBarRow(
      label: _typeLabel(e.key),
      value: e.value,
      max: max,
      color: AppColors.accent,
    )).toList();
  }

  static String _typeLabel(String s) => switch (s) {
    'metal_porselen'        => 'Metal Porselen',
    'zirkonyum'             => 'Zirkonyum',
    'implant_ustu_zirkonyum'=> 'İmplant Üstü',
    'gecici'                => 'Geçici',
    'e_max'                 => 'E-Max',
    'tam_protez'            => 'Tam Protez',
    'parsiyel'              => 'Parsiyel',
    _                       => 'Diğer',
  };
}

// ── Chart widgets ─────────────────────────────────────────────────────────────

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

  @override
  Widget build(BuildContext context) {
    final fraction = max > 0 ? value / max : 0.0;
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 5),
      child: Row(
        children: [
          SizedBox(
            width: 100,
            child: Text(label,
                style: const TextStyle(fontSize: 12, color: AppColors.textSecondary),
                maxLines: 1, overflow: TextOverflow.ellipsis),
          ),
          Expanded(
            child: ClipRRect(
              borderRadius: BorderRadius.circular(4),
              child: Stack(
                children: [
                  Container(height: 22, color: AppColors.surfaceVariant),
                  FractionallySizedBox(
                    widthFactor: fraction,
                    child: Container(
                      height: 22,
                      decoration: BoxDecoration(
                        color: color.withValues(alpha: 0.8),
                        borderRadius: BorderRadius.circular(4),
                      ),
                    ),
                  ),
                ],
              ),
            ),
          ),
          const SizedBox(width: 8),
          SizedBox(
            width: 28,
            child: Text('$value',
                style: const TextStyle(fontSize: 12, fontWeight: FontWeight.w700, color: AppColors.textPrimary),
                textAlign: TextAlign.right),
          ),
        ],
      ),
    );
  }
}

class _VBarChart extends StatelessWidget {
  const _VBarChart({required this.data, required this.color, this.formatValue});
  final List<MonthlyCount> data;
  final Color color;
  final String Function(int)? formatValue;

  @override
  Widget build(BuildContext context) {
    if (data.isEmpty) return const SizedBox.shrink();
    final maxVal = data.fold(0, (m, e) => e.count > m ? e.count : m);
    final fmt = formatValue ?? (v) => '$v';

    return SizedBox(
      height: 140,
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.end,
        children: data.map((d) {
          final fraction = maxVal > 0 ? d.count / maxVal : 0.0;
          return Expanded(
            child: Padding(
              padding: const EdgeInsets.symmetric(horizontal: 2),
              child: Column(
                mainAxisAlignment: MainAxisAlignment.end,
                children: [
                  if (d.count > 0)
                    Text(fmt(d.count),
                        style: const TextStyle(fontSize: 9, color: AppColors.textMuted),
                        textAlign: TextAlign.center),
                  const SizedBox(height: 2),
                  AnimatedContainer(
                    duration: const Duration(milliseconds: 600),
                    curve: Curves.easeOut,
                    height: (fraction * 90).clamp(2, 90),
                    decoration: BoxDecoration(
                      color: color,
                      borderRadius: const BorderRadius.vertical(top: Radius.circular(4)),
                    ),
                  ),
                  const SizedBox(height: 4),
                  Text(d.label,
                      style: const TextStyle(fontSize: 10, color: AppColors.textMuted),
                      textAlign: TextAlign.center),
                ],
              ),
            ),
          );
        }).toList(),
      ),
    );
  }
}