import 'dart:io';
import 'package:flutter/foundation.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:image/image.dart' as img;
import 'package:path_provider/path_provider.dart';

/// Service untuk mengelola data user (profile, foto, password)
class UsersService {
  final FirebaseAuth _auth = FirebaseAuth.instance;
  final FirebaseFirestore _firestore = FirebaseFirestore.instance;
  static const String collectionName = 'users';

  User? get currentUser => _auth.currentUser;
  String get userId => currentUser?.uid ?? '';

  /// Inisiasi profil saat pertama kali register
  Future<void> createUserDocument(String uid, String name, String email) async {
    try {
      await _firestore.collection(collectionName).doc(uid).set({
        'user_id': uid,
        'display_name': name.trim(),
        'email': email.trim(),
        'created_at': FieldValue.serverTimestamp(),
        'updated_at': FieldValue.serverTimestamp(),
      });
    } catch (e) {
      throw Exception('Gagal inisiasi dokumen user: $e');
    }
  }

  /// Update nama user di Firebase Auth dan Firestore
  Future<void> updateName(String name) async {
    try {
      await currentUser?.updateDisplayName(name.trim());
      await _firestore.collection(collectionName).doc(userId).set(
        {
          'user_id': userId,
          'display_name': name.trim(),
          'updated_at': FieldValue.serverTimestamp(),
        },
        SetOptions(merge: true),
      );
      await currentUser?.reload();
    } catch (e) {
      throw Exception('Gagal update nama: $e');
    }
  }

  /// Kompresi gambar ke 800x800px dengan quality 75%
  Future<File> _compressImage(File imageFile) async {
    try {
      final bytes = await imageFile.readAsBytes();
      final image = img.decodeImage(bytes);
      if (image == null) throw Exception('Gagal decode gambar');

      final resized = img.copyResize(image, width: 800, height: 800, maintainAspect: true);
      final compressed = img.encodeJpg(resized, quality: 75);

      final dir = await getApplicationDocumentsDirectory();
      final compressedFile = File('${dir.path}/profile_compressed.jpg');
      await compressedFile.writeAsBytes(compressed);
      return compressedFile;
    } catch (e) {
      throw Exception('Gagal kompresi foto: $e');
    }
  }

  /// Simpan foto profil ke lokal storage dengan kompresi
  Future<String> saveProfilePhotoLocal(File imageFile) async {
    try {
      if (userId.isEmpty) throw Exception('User tidak terautentikasi');
      if (!await imageFile.exists()) throw Exception('File gambar tidak ditemukan');

      final compressedFile = await _compressImage(imageFile);
      final appDocDir = await getApplicationDocumentsDirectory();
      final photosDir = Directory('${appDocDir.path}/HydroNutrify/photos');

      if (!await photosDir.exists()) {
        await photosDir.create(recursive: true);
      }

      final fileName = 'profile_${DateTime.now().millisecondsSinceEpoch}.jpg';
      final localPath = '${photosDir.path}/$fileName';
      await compressedFile.copy(localPath);

      await _firestore.collection(collectionName).doc(userId).set({
        'user_id': userId,
        'profile_photo_filename': fileName,
        'profile_photo_path': localPath,
        'updated_at': FieldValue.serverTimestamp(),
      }, SetOptions(merge: true));

      return localPath;
    } catch (e) {
      throw Exception('Gagal simpan foto lokal: $e');
    }
  }

  /// Get path foto profil dari lokal storage
  Future<String?> getProfilePhotoPath() async {
    try {
      final profile = await getUserProfile();
      if (profile != null) {
        final filePath = profile['profile_photo_path'] as String?;
        if (filePath != null && await File(filePath).exists()) {
          return filePath;
        }
      }
      return null;
    } catch (e) {
      return null;
    }
  }

  /// Update password dengan re-authentication
  Future<void> reauthenticateAndUpdatePassword(String oldPassword, String newPassword) async {
    try {
      if (currentUser == null) throw Exception('User tidak ditemukan');
      final email = currentUser!.email;
      if (email == null) throw Exception('Email tidak ditemukan');

      final credential = EmailAuthProvider.credential(email: email, password: oldPassword);
      await currentUser!.reauthenticateWithCredential(credential);
      await currentUser!.updatePassword(newPassword);
    } on FirebaseAuthException catch (e) {
      if (e.code == 'wrong-password') {
        throw Exception('Password lama salah');
      } else if (e.code == 'weak-password') {
        throw Exception('Password baru terlalu lemah');
      }
      throw Exception('Gagal update password: ${e.message}');
    }
  }

  /// Get data profile user dari Firestore
  Future<Map<String, dynamic>?> getUserProfile() async {
    try {
      if (userId.isEmpty) return null;
      final doc = await _firestore.collection(collectionName).doc(userId).get();
      return doc.data();
    } catch (e) {
      return null;
    }
  }

  /// Stream perubahan profile user real-time
  Stream<DocumentSnapshot?> getUserProfileStream() {
    if (userId.isEmpty) return Stream.value(null);
    return _firestore.collection(collectionName).doc(userId).snapshots().handleError((e) {
      debugPrint('[UsersService] Stream error: $e');
      return null;
    });
  }
}