import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:intl/intl.dart';
import 'package:supabase_flutter/supabase_flutter.dart';
import 'package:uuid/uuid.dart';
import '/core/auth_provider.dart';
import '/models/payment.dart';
import '/models/child.dart';
import '/models/profile.dart';

const _bg    = Color(0xFF0D1117);
const _card  = Color(0xFF161B22);
const _blue  = Color(0xFF4FC3F7);
const _green = Color(0xFF2ECC71);
const _amber = Color(0xFFFFB300);
const _red   = Color(0xFFE74C3C);

class PaymentsScreen extends ConsumerStatefulWidget {
  const PaymentsScreen({super.key});
  @override
  ConsumerState<PaymentsScreen> createState() => _State();
}

class _State extends ConsumerState<PaymentsScreen> {
  bool _isAdmin = false;

  @override
  void initState() {
    super.initState();
    _checkRole();
  }

  Future<void> _checkRole() async {
    final p = await ref.read(currentProfileProvider.future);
    if (mounted) setState(() => _isAdmin = p?.role == 'principal' || p?.role == 'admin');
  }

  @override
  Widget build(BuildContext context) {
    final sb = Supabase.instance.client;

    return Scaffold(
      backgroundColor: _bg,
      appBar: AppBar(
        backgroundColor: _card, elevation: 0,
        title: const Text('Mensalidades', style: TextStyle(color: _blue, fontWeight: FontWeight.bold)),
      ),
      body: StreamBuilder<List<Map<String, dynamic>>>(
        // Join com children para ter nomes
        stream: sb.from('payments').stream(primaryKey: ['id']).order('month', ascending: false),
        builder: (ctx, snap) {
          if (snap.hasError) return Center(child: Text('Erro: ${snap.error}', style: const TextStyle(color: _red)));
          if (!snap.hasData) return const Center(child: CircularProgressIndicator(color: _blue));

          final payments = snap.data!.map(Payment.fromMap).toList();

          final paid    = payments.where((p) => p.status == 'paid').length;
          final pending = payments.where((p) => p.status == 'pending').length;
          final overdue = payments.where((p) => p.status == 'overdue').length;
          final total   = payments.where((p) => p.status == 'paid')
              .fold<double>(0, (sum, p) => sum + p.amount);

          return Column(children: [
            // Resumo
            Container(
              color: _card,
              padding: const EdgeInsets.all(16),
              child: Column(children: [
                Row(children: [
                  _SummaryTile(label: 'Pagos', count: paid, color: _green),
                  const SizedBox(width: 8),
                  _SummaryTile(label: 'Pendentes', count: pending, color: _amber),
                  const SizedBox(width: 8),
                  _SummaryTile(label: 'Atrasados', count: overdue, color: _red),
                ]),
                const SizedBox(height: 10),
                Container(
                  width: double.infinity,
                  padding: const EdgeInsets.symmetric(vertical: 10),
                  decoration: BoxDecoration(color: _green.withOpacity(0.08), borderRadius: BorderRadius.circular(10),
                      border: Border.all(color: _green.withOpacity(0.2))),
                  child: Center(child: Text(
                    'Total recebido: Kz ${NumberFormat('#,###.##').format(total)}',
                    style: const TextStyle(color: _green, fontWeight: FontWeight.bold, fontSize: 14))),
                ),
              ]),
            ),
            // Lista
            Expanded(child: payments.isEmpty
              ? Center(child: Column(mainAxisAlignment: MainAxisAlignment.center, children: [
                  Icon(Icons.payment, size: 60, color: Colors.white.withOpacity(0.08)),
                  const SizedBox(height: 10),
                  const Text('Sem mensalidades registadas', style: TextStyle(color: Color(0xFF888888))),
                ]))
              : ListView.builder(
                padding: const EdgeInsets.all(14),
                itemCount: payments.length,
                itemBuilder: (_, i) => _PaymentCard(
                  payment: payments[i], isAdmin: _isAdmin,
                  onStatusChange: _isAdmin ? (p, status) => _updateStatus(p, status) : null,
                ),
              )),
          ]);
        },
      ),
      floatingActionButton: _isAdmin ? FloatingActionButton.extended(
        backgroundColor: _blue,
        icon: const Icon(Icons.add, color: Colors.white),
        label: const Text('Nova Mensalidade', style: TextStyle(color: Colors.white)),
        onPressed: () => _showAddDialog(context),
      ) : null,
    );
  }

  Future<void> _updateStatus(Payment p, String status) async {
    final sb = Supabase.instance.client;
    try {
      await sb.from('payments').update({'status': status, 'paid_at': status == 'paid' ? DateTime.now().toIso8601String() : null}).eq('id', p.id);
    } catch (e) {
      if (mounted) ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('Erro: $e'), backgroundColor: _red));
    }
  }

  void _showAddDialog(BuildContext ctx) {
    showModalBottomSheet(
      context: ctx, isScrollControlled: true, backgroundColor: _card,
      shape: const RoundedRectangleBorder(borderRadius: BorderRadius.vertical(top: Radius.circular(20))),
      builder: (_) => const _AddPaymentForm());
  }
}

class _PaymentCard extends StatelessWidget {
  final Payment payment;
  final bool isAdmin;
  final Function(Payment, String)? onStatusChange;
  const _PaymentCard({required this.payment, required this.isAdmin, this.onStatusChange});

  Color get _statusColor => switch (payment.status) {
    'paid'    => _green,
    'overdue' => _red,
    _         => _amber,
  };

  String get _statusLabel => switch (payment.status) {
    'paid'    => 'Pago ✓',
    'overdue' => 'Em Atraso',
    _         => 'Pendente',
  };

  @override
  Widget build(BuildContext context) {
    return FutureBuilder<String>(
      future: _getChildName(),
      builder: (ctx, snap) {
        final childName = snap.data ?? payment.childId.substring(0, 8) + '...';
        return Container(
          margin: const EdgeInsets.only(bottom: 10),
          padding: const EdgeInsets.all(14),
          decoration: BoxDecoration(
            color: _card, borderRadius: BorderRadius.circular(14),
            border: Border.all(color: _statusColor.withOpacity(0.25)),
          ),
          child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
            Row(children: [
              Container(
                padding: const EdgeInsets.all(8),
                decoration: BoxDecoration(color: _statusColor.withOpacity(0.1), shape: BoxShape.circle),
                child: Icon(Icons.receipt_long, color: _statusColor, size: 18),
              ),
              const SizedBox(width: 12),
              Expanded(child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
                Text(childName, style: const TextStyle(color: Colors.white, fontWeight: FontWeight.bold, fontSize: 14)),
                Text(DateFormat('MMMM yyyy', 'pt_PT').format(payment.month),
                    style: const TextStyle(color: Color(0xFF888888), fontSize: 12)),
              ])),
              Column(crossAxisAlignment: CrossAxisAlignment.end, children: [
                Text('Kz ${NumberFormat('#,###').format(payment.amount)}',
                    style: const TextStyle(color: Colors.white, fontWeight: FontWeight.bold, fontSize: 15)),
                Container(
                  margin: const EdgeInsets.only(top: 3),
                  padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
                  decoration: BoxDecoration(color: _statusColor.withOpacity(0.12), borderRadius: BorderRadius.circular(10)),
                  child: Text(_statusLabel, style: TextStyle(color: _statusColor, fontSize: 11)),
                ),
              ]),
            ]),
            if (isAdmin && payment.status != 'paid') ...[
              const SizedBox(height: 10),
              Row(children: [
                Expanded(child: _ActionBtn(
                  label: '✓ Marcar Pago', color: _green,
                  onTap: () => onStatusChange?.call(payment, 'paid'))),
                const SizedBox(width: 8),
                Expanded(child: _ActionBtn(
                  label: '⚠ Marcar Atraso', color: _red,
                  onTap: () => onStatusChange?.call(payment, 'overdue'))),
              ]),
            ],
          ]),
        );
      },
    );
  }

  Future<String> _getChildName() async {
    try {
      final sb = Supabase.instance.client;
      final data = await sb.from('children').select('first_name,last_name')
          .eq('id', payment.childId).maybeSingle();
      if (data == null) return 'Criança';
      return '${data['first_name']} ${data['last_name']}';
    } catch (_) { return 'Criança'; }
  }
}

class _ActionBtn extends StatelessWidget {
  final String label; final Color color; final VoidCallback onTap;
  const _ActionBtn({required this.label, required this.color, required this.onTap});
  @override
  Widget build(BuildContext context) => GestureDetector(
    onTap: onTap,
    child: Container(
      padding: const EdgeInsets.symmetric(vertical: 8),
      decoration: BoxDecoration(color: color.withOpacity(0.1), borderRadius: BorderRadius.circular(8),
          border: Border.all(color: color.withOpacity(0.3))),
      child: Center(child: Text(label, style: TextStyle(color: color, fontSize: 11, fontWeight: FontWeight.bold))),
    ),
  );
}

class _SummaryTile extends StatelessWidget {
  final String label; final int count; final Color color;
  const _SummaryTile({required this.label, required this.count, required this.color});
  @override
  Widget build(BuildContext context) => Expanded(child: Container(
    padding: const EdgeInsets.symmetric(vertical: 10),
    decoration: BoxDecoration(color: color.withOpacity(0.08), borderRadius: BorderRadius.circular(10),
        border: Border.all(color: color.withOpacity(0.25))),
    child: Column(children: [
      Text('$count', style: TextStyle(color: color, fontSize: 22, fontWeight: FontWeight.bold)),
      Text(label, style: const TextStyle(color: Color(0xFF888888), fontSize: 11)),
    ]),
  ));
}

class _AddPaymentForm extends ConsumerStatefulWidget {
  const _AddPaymentForm();
  @override
  ConsumerState<_AddPaymentForm> createState() => _AddState();
}

class _AddState extends ConsumerState<_AddPaymentForm> {
  final _amountCtrl = TextEditingController();
  String? _childId;
  DateTime _month = DateTime(DateTime.now().year, DateTime.now().month);
  List<Child> _children = [];
  bool _saving = false;

  @override
  void initState() { super.initState(); _loadChildren(); }
  @override
  void dispose() { _amountCtrl.dispose(); super.dispose(); }

  Future<void> _loadChildren() async {
    final sb = Supabase.instance.client;
    final data = await sb.from('children').select().order('first_name');
    if (mounted) setState(() => _children = data.map((d) => Child.fromMap(d)).toList());
  }

  Future<void> _save() async {
    if (_childId == null || _amountCtrl.text.trim().isEmpty) return;
    setState(() => _saving = true);
    try {
      final sb = Supabase.instance.client;
      await sb.from('payments').insert({
        'id':         const Uuid().v4(),
        'child_id':   _childId,
        'guardian_id': _childId, // placeholder — adjust if you have guardian FK
        'month':      DateFormat('yyyy-MM-01').format(_month),
        'amount':     double.tryParse(_amountCtrl.text.replaceAll(',', '.')) ?? 0,
        'status':     'pending',
      });
      if (mounted) Navigator.pop(context);
    } catch (e) {
      if (mounted) ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('Erro: $e'), backgroundColor: _red));
    } finally { if (mounted) setState(() => _saving = false); }
  }

  @override
  Widget build(BuildContext context) => Padding(
    padding: EdgeInsets.only(left: 20, right: 20, top: 20, bottom: MediaQuery.of(context).viewInsets.bottom + 20),
    child: Column(mainAxisSize: MainAxisSize.min, children: [
      const Text('Nova Mensalidade', style: TextStyle(color: Colors.white, fontSize: 16, fontWeight: FontWeight.bold)),
      const SizedBox(height: 16),
      DropdownButtonFormField<String>(
        value: _childId, dropdownColor: _card,
        style: const TextStyle(color: Colors.white),
        decoration: _dec('Seleccionar criança', Icons.child_care),
        items: _children.map((c) => DropdownMenuItem(value: c.id,
            child: Text(c.fullName, style: const TextStyle(color: Colors.white)))).toList(),
        onChanged: (v) => setState(() => _childId = v),
      ),
      const SizedBox(height: 12),
      GestureDetector(
        onTap: () async {
          final picked = await showDatePicker(context: context,
            initialDate: _month, firstDate: DateTime(2020), lastDate: DateTime(2030),
            builder: (ctx, child) => Theme(data: ThemeData.dark().copyWith(
                colorScheme: const ColorScheme.dark(primary: _blue)), child: child!));
          if (picked != null) setState(() => _month = DateTime(picked.year, picked.month));
        },
        child: Container(
          padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 14),
          decoration: BoxDecoration(color: Colors.white.withOpacity(0.04), borderRadius: BorderRadius.circular(12),
              border: Border.all(color: Colors.white.withOpacity(0.09))),
          child: Row(children: [
            const Icon(Icons.calendar_month, color: _blue, size: 18),
            const SizedBox(width: 10),
            Text(DateFormat('MMMM yyyy', 'pt_PT').format(_month),
                style: const TextStyle(color: Colors.white)),
          ]),
        ),
      ),
      const SizedBox(height: 12),
      TextField(controller: _amountCtrl, keyboardType: TextInputType.number,
        style: const TextStyle(color: Colors.white),
        decoration: _dec('Valor (Kz)', Icons.attach_money)),
      const SizedBox(height: 16),
      GestureDetector(onTap: _saving ? null : _save,
        child: Container(height: 48, width: double.infinity,
          decoration: BoxDecoration(gradient: const LinearGradient(colors: [_blue, Color(0xFF0288D1)]),
              borderRadius: BorderRadius.circular(12)),
          child: Center(child: _saving
            ? const SizedBox(width: 20, height: 20, child: CircularProgressIndicator(color: Colors.white, strokeWidth: 2))
            : const Text('Criar Mensalidade', style: TextStyle(color: Colors.white, fontWeight: FontWeight.bold))))),
    ]),
  );

  InputDecoration _dec(String hint, IconData icon) => InputDecoration(
    hintText: hint, hintStyle: const TextStyle(color: Color(0xFF555555), fontSize: 13),
    prefixIcon: Icon(icon, color: _blue.withOpacity(0.6), size: 18),
    filled: true, fillColor: Colors.white.withOpacity(0.04),
    enabledBorder: OutlineInputBorder(borderRadius: BorderRadius.circular(12),
        borderSide: BorderSide(color: Colors.white.withOpacity(0.09))),
    contentPadding: const EdgeInsets.symmetric(horizontal: 14, vertical: 12),
  );
}