import 'package:flutter/foundation.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:mobile_monitoring/core/utils/cycle_phase_utils.dart';

/// Service untuk mengelola siklus tanam dengan fase pertumbuhan otomatis
class PlantingCyclesService {
  static const String collectionName = 'planting_cycles';

  CollectionReference<Map<String, dynamic>> get _collection =>
      FirebaseFirestore.instance.collection(collectionName);

  /// Stream siklus tanam yang sedang aktif (per user dengan fallback)
  Stream<Map<String, dynamic>?> getActiveCycleStream({required String userId}) {
    return _collection.snapshots().map((snapshot) {
      if (snapshot.docs.isEmpty) return null;

      if (userId.isNotEmpty) {
        final matches = snapshot.docs.where((d) => d.id == userId).toList();
        if (matches.isNotEmpty && matches.first.data().isNotEmpty) {
          return {...matches.first.data(), 'doc_id': matches.first.id};
        }
      }

      // Fallback ke dokumen siklus tanam pertama di database
      final firstDoc = snapshot.docs.first;
      return {...firstDoc.data(), 'doc_id': firstDoc.id};
    }).handleError((error) {
      debugPrint('[PlantingCyclesService] Stream error: $error');
      return null;
    });
  }

  /// Tambah siklus tanam baru (gunakan userId sebagai doc ID)
  Future<String> addCycle({
    required String userId,
    required DateTime startDate,
  }) async {
    if (userId.isEmpty) throw Exception('User tidak terautentikasi');

    await _collection.doc(userId).set({
      'user_id': userId,
      'start_date': Timestamp.fromDate(startDate),
      'days_since_planting': 0,
      'growth_phase': 'Semai',
      'created_at': FieldValue.serverTimestamp(),
      'updated_at': FieldValue.serverTimestamp(),
    });

    return userId;
  }

  /// Update hari dan fase tanam berdasarkan start_date
  Future<void> updateCycleProgress({
    required String userId,
    required DateTime startDate,
  }) async {
    final now = DateTime.now();
    final daysSincePlanting = now.difference(startDate).inDays;
    final growthPhase = CyclePhaseUtils.calculateCyclePhase(daysSincePlanting);

    await _collection.doc(userId).set({
      'days_since_planting': daysSincePlanting,
      'growth_phase': growthPhase,
      'updated_at': FieldValue.serverTimestamp(),
    }, SetOptions(merge: true));
  }

  /// Hitung hari total siklus untuk panen
  Future<int> calculateCycleDaysBeforeDelete({required String userId}) async {
    if (userId.isEmpty) throw Exception('User tidak terautentikasi');

    final doc = await _collection.doc(userId).get();
    if (!doc.exists || doc.data() == null) {
      throw Exception('Siklus tanam aktif tidak ditemukan');
    }

    final data = doc.data()!;
    final startValue = data['start_date'];
    DateTime? startDate;

    if (startValue is Timestamp) {
      startDate = startValue.toDate();
    } else if (startValue is DateTime) {
      startDate = startValue;
    }

    final daysSincePlanting = startDate == null
        ? (data['days_since_planting'] as num?)?.toInt() ?? 0
        : DateTime.now().difference(startDate).inDays;

    return daysSincePlanting;
  }

  /// Hapus siklus tanam (gunakan userId)
  Future<void> deleteCycle({required String userId}) async {
    await _collection.doc(userId).delete();
  }

  /// Get detail siklus berdasarkan userId dengan update otomatis
  Future<Map<String, dynamic>?> getCycleByUserId({
    required String userId,
  }) async {
    final doc = await _collection.doc(userId).get();
    if (!doc.exists || doc.data() == null) return null;

    final data = doc.data()!;
    final startDate = (data['start_date'] as Timestamp).toDate();

    // Update progress sebelum return
    await updateCycleProgress(userId: userId, startDate: startDate);

    // Get data terbaru
    final updatedDoc = await _collection.doc(userId).get();
    if (!updatedDoc.exists) return null;
    return {...updatedDoc.data()!, 'doc_id': updatedDoc.id};
  }

  /// Get siklus aktif dengan info fase terkini
  Future<Map<String, dynamic>?> getActiveCycle({required String userId}) async {
    if (userId.isEmpty) throw Exception('User tidak terautentikasi');

    final doc = await _collection.doc(userId).get();
    if (!doc.exists || doc.data() == null) return null;

    final data = doc.data()!;
    final startDate = (data['start_date'] as Timestamp).toDate();

    // Hitung days_since_planting dan growth_phase terkini
    final now = DateTime.now();
    final daysSincePlanting = now.difference(startDate).inDays;
    final growthPhase = CyclePhaseUtils.calculateCyclePhase(daysSincePlanting);

    return {
      ...data,
      'doc_id': doc.id,
      'days_since_planting': daysSincePlanting,
      'growth_phase': growthPhase,
    };
  }
}