import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/material.dart';
import 'package:firebase_database/firebase_database.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'wait_for_rfid_screen.dart';

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

  @override
  State<StartActivityScreen> createState() => _StartActivityScreenState();
}

class _StartActivityScreenState extends State<StartActivityScreen> {
  String? _selectedType;
  final _lapController = TextEditingController();  // Untuk input jumlah putaran
  final _calculatedDistanceController = TextEditingController();  // Untuk menampilkan jarak total
  String _unit = 'KM';

  // Variabel untuk menghitung waktu setiap lap
  DateTime lapStartTime = DateTime.now();
  DateTime lapEndTime = DateTime.now();
  double lapTimeInSeconds = 0;
  double speed = 0.0;  // Kecepatan dalam m/s

  void _showError(String message) {
    showDialog(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text("Error", style: TextStyle(color: Colors.red)),
        content: Text(message),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context),
            child: const Text("OK", style: TextStyle(color: Colors.blue)),
          )
        ],
      ),
    );
  }

  // Fungsi untuk memulai timer saat lap dimulai
  void startLapTimer() {
    lapStartTime = DateTime.now();  // Mulai timer dengan DateTime
  }

  // Fungsi untuk menghentikan timer saat lap selesai dan menghitung kecepatan
  void endLapTimer(double lapDistance, String uidTag) {
    lapEndTime = DateTime.now();  // Hentikan timer dengan DateTime
    lapTimeInSeconds = lapEndTime.difference(lapStartTime).inSeconds.toDouble();  // Hitung waktu dalam detik
    speed = lapDistance / lapTimeInSeconds;  // Hitung kecepatan dalam meter per detik

    // Simpan kecepatan per lap di Firebase
    saveSpeedToFirebase(uidTag, speed);
  }

  // Fungsi untuk menyimpan kecepatan per lap ke Firebase (RTDB)
  void saveSpeedToFirebase(String uidTag, double speed) {
    final user = FirebaseAuth.instance.currentUser;

    if (user == null) {
      print("User tidak ditemukan");
      return;
    }

    try {
      final db = FirebaseDatabase.instanceFor(
        app: Firebase.app(),
        databaseURL: "https://ta-running-default-rtdb.asia-southeast1.firebasedatabase.app",
      );
      final ref = db.ref("activities/$uidTag");

      // Simpan kecepatan per lap
      ref.child('kecepatan_lap').push().set({
        'speed': speed,
        'timestamp': DateTime.now().toIso8601String(),
      });

      print("Kecepatan lap $uidTag berhasil disimpan: $speed m/s");
    } catch (e) {
      print("❌ Gagal menyimpan kecepatan lap: $e");
    }
  }

  // Fungsi untuk mengupdate jarak dan kecepatan setiap lap
  void _updateDistance() {
    final laps = int.tryParse(_lapController.text);
    if (laps != null && laps >= 3) {
      final totalDistance = laps * 400;  // 400 meter per putaran
      _calculatedDistanceController.text = totalDistance.toString();
    } else if (laps != null && laps < 3) {
      _calculatedDistanceController.text = '';
      _showError("Jumlah putaran minimal adalah 3 (1200m).");
    } else {
      _calculatedDistanceController.text = '';
    }
  }

  // Fungsi untuk submit aktivitas ke Firebase
  void _submit() {
    if (_selectedType == 'Lintasan') {
      final laps = int.tryParse(_lapController.text);

      if (laps == null || laps < 3) {
        _showError("Masukkan jumlah putaran yang valid (minimal 3).");
        return;
      }

      final totalDistance = laps * 400;  // 400 meter per putaran

      _calculatedDistanceController.text = totalDistance.toString();

      submitToFirebase(
        jarak: totalDistance.toDouble(),
        jenisAktivitas: 'lintasan',
        satuan: 'M',
        putaran: laps,
      );
    } else if (_selectedType == 'Non-Lintasan') {
      final jarak = double.tryParse(_lapController.text);

      if (jarak == null || jarak <= 0) {
        _showError("Masukkan jarak yang valid.");
        return;
      }

      submitToFirebase(
        jarak: jarak,
        jenisAktivitas: 'non-lintasan',
        satuan: _unit,
      );
    } else {
      _showError("Pilih jenis aktivitas terlebih dahulu.");
    }
  }

  // Fungsi untuk submit data ke Firebase
  void submitToFirebase({
    required double jarak,
    required String jenisAktivitas,
    required String satuan,
    int? putaran,
  }) async {
    final user = FirebaseAuth.instance.currentUser;

    if (user == null) {
      print("User tidak ditemukan");
      return;
    }

    try {
      final userDoc = await FirebaseFirestore.instance
          .collection("users")
          .doc(user.uid)
          .get();

      final userData = userDoc.data();
      if (userData == null || !userData.containsKey("idGelang")) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text("Silakan daftarkan gelang RFID terlebih dahulu.")),
        );
        return;
      }

      final uidTag = userData["idGelang"];

      final db = FirebaseDatabase.instanceFor(
        app: Firebase.app(),
        databaseURL: "https://ta-running-default-rtdb.asia-southeast1.firebasedatabase.app",
      );
      final ref = db.ref("activities/$uidTag");

      await ref.set({
        'uid_apk': user.uid,
        'jarak': jarak,
        'satuan': satuan,
        'putaran': putaran,
        'type': jenisAktivitas,
        'status': 'waiting_for_rfid',
        'timestamp': DateTime.now().toIso8601String(),
      });

      print("✅ Data aktivitas dikirim ke Firebase dengan UID tag: $uidTag");

      Navigator.pushReplacement(
        context,
        MaterialPageRoute(
          builder: (_) => WaitForRfidScreen(uidTag: uidTag),
        ),
      );
    } catch (e) {
      print("❌ Gagal mengirim aktivitas: $e");
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text("Gagal mengirim aktivitas: $e")),
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.white,
      appBar: PreferredSize(
        preferredSize: const Size.fromHeight(80),
        child: Container(
          decoration: const BoxDecoration(
            color: Colors.blue,
            borderRadius: BorderRadius.only(
              bottomLeft: Radius.circular(20),
              bottomRight: Radius.circular(20),
            ),
          ),
          padding: const EdgeInsets.only(top: 40, left: 16, right: 16),
          child: Row(
            children: [
              if (_selectedType != null)
                IconButton(
                  icon: const Icon(Icons.arrow_back, color: Colors.white),
                  onPressed: () => setState(() => _selectedType = null),
                )
              else
                const SizedBox(width: 48),
              Expanded(
                child: Center(
                  child: Text(
                    "Start Activity",
                    style: const TextStyle(
                      color: Colors.white,
                      fontSize: 28,
                      fontWeight: FontWeight.bold,
                    ),
                  ),
                ),
              ),
              const SizedBox(width: 48),
            ],
          ),
        ),
      ),
      body: SingleChildScrollView(
        padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 32),
        child: _selectedType == null
            ? Column(
                children: [
                  const SizedBox(height: 70),
                  Image.asset(
                    'images/run.png',
                    width: 100,
                    height: 100,
                  ),
                  const SizedBox(height: 80),
                  const Text(
                    'Pilih Jenis Aktivitas',
                    style: TextStyle(fontSize: 28, fontWeight: FontWeight.w800),
                    textAlign: TextAlign.center,
                  ),
                  const SizedBox(height: 28),
                  Row(
                    children: [
                      Expanded(
                        child: ElevatedButton(
                          onPressed: () => setState(() => _selectedType = 'Lintasan'),
                          style: ElevatedButton.styleFrom(
                            backgroundColor: _selectedType == 'Lintasan' ? Colors.blueAccent : Colors.white,
                            side: const BorderSide(color: Colors.blueAccent),
                            foregroundColor: _selectedType == 'Lintasan' ? Colors.white : Colors.blueAccent,
                            shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10)),
                            padding: const EdgeInsets.symmetric(vertical: 14),
                          ),
                          child: const Text('LINTASAN'),
                        ),
                      ),
                      const SizedBox(width: 12),
                      Expanded(
                        child: ElevatedButton(
                          onPressed: () => setState(() => _selectedType = 'Non-Lintasan'),
                          style: ElevatedButton.styleFrom(
                            backgroundColor: _selectedType == 'Non-Lintasan' ? Colors.blueAccent : Colors.white,
                            side: const BorderSide(color: Colors.blueAccent),
                            foregroundColor: _selectedType == 'Non-Lintasan' ? Colors.white : Colors.blueAccent,
                            shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10)),
                            padding: const EdgeInsets.symmetric(vertical: 14),
                          ),
                          child: const Text('NON-LINTASAN'),
                        ),
                      ),
                    ],
                  ),
                ],
              )
            : Column(
                children: [
                  const SizedBox(height: 70),
                  Image.asset(
                    'images/run.png',
                    width: 100,
                    height: 100,
                    fit: BoxFit.contain,
                  ),
                  const SizedBox(height: 80),
                  Text(
                    _selectedType!,
                    style: const TextStyle(fontSize: 28, fontWeight: FontWeight.w800),
                  ),
                  const SizedBox(height: 20),
                  if (_selectedType == 'Lintasan') ...[
                    TextField(
                      controller: _lapController,
                      keyboardType: TextInputType.number,
                      decoration: const InputDecoration(
                        labelText: 'Jumlah Putaran (400M/Putaran)',
                        border: OutlineInputBorder(),
                      ),
                      onChanged: (text) {
                        _updateDistance();  // Update jarak total setiap kali jumlah putaran diubah
                      },
                    ),
                    const SizedBox(height: 12),
                    TextField(
                      controller: _calculatedDistanceController,
                      enabled: false,  // Disable editing
                      decoration: const InputDecoration(
                        labelText: 'Jarak Total (M)',
                        border: OutlineInputBorder(),
                      ),
                    ),
                  ] else ...[
                    Row(
                      children: [
                        Expanded(
                          child: TextField(
                            controller: _lapController,  // Menggunakan lapController untuk Non-Lintasan
                            keyboardType: TextInputType.number,
                            decoration: const InputDecoration(
                              labelText: 'Jarak',
                              border: OutlineInputBorder(),
                            ),
                          ),
                        ),
                        const SizedBox(width: 12),
                        DropdownButton<String>(
                          value: _unit,
                          items: const [
                            DropdownMenuItem(value: 'KM', child: Text('KM')),
                            DropdownMenuItem(value: 'M', child: Text('M')),
                          ],
                          onChanged: (value) => setState(() => _unit = value!),
                        ),
                      ],
                    ),
                  ],
                  const SizedBox(height: 20),
                  ElevatedButton(
                    onPressed: _submit,
                    style: ElevatedButton.styleFrom(
                      backgroundColor: Colors.blueAccent,
                      padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 12),
                      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
                    ),
                    child: const Text(
                      'Submit dan Scan RFID',
                      style: TextStyle(fontSize: 16, color: Colors.white),
                    ),
                  ),
                ],
              ),
      ),
    );
  }
}