import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:kettlebell_tracker/models/training_session.dart';
import 'package:kettlebell_tracker/services/api_service.dart';
import 'package:kettlebell_tracker/services/database_helper.dart';
import 'dart:async';

// Training State
class TrainingState {
  final bool isTrainingRunning;
  final int remainingSeconds;
  final int initialDurationSeconds;
  final int setsDone;
  final int goalSets;
  final int repsPerSet;
  final List<DateTime> setTimes;
  final double progress;
  final int secondsSinceLastSet;
  final DateTime? lastSetTimestamp;
  final String currentProgram;
  final int currentBlockDay;
  final int currentReps;
  final int totalTrainingDays;

  TrainingState({
    this.isTrainingRunning = false,
    this.remainingSeconds = 0,
    this.initialDurationSeconds = 0,
    this.setsDone = 0,
    this.goalSets = 5,
    this.repsPerSet = 5,
    this.setTimes = const [],
    this.progress = 0.0,
    this.secondsSinceLastSet = 0,
    this.lastSetTimestamp,
    this.currentProgram = 'giant_1.0',
    this.currentBlockDay = 1,
    this.currentReps = 5,
    this.totalTrainingDays = 0,
  });

  TrainingState copyWith({
    bool? isTrainingRunning,
    int? remainingSeconds,
    int? initialDurationSeconds,
    int? setsDone,
    int? goalSets,
    int? repsPerSet,
    List<DateTime>? setTimes,
    double? progress,
    int? secondsSinceLastSet,
    DateTime? lastSetTimestamp,
    bool clearLastSetTimestamp = false,
    String? currentProgram,
    int? currentBlockDay,
    int? currentReps,
    int? totalTrainingDays,
  }) {
    return TrainingState(
      isTrainingRunning: isTrainingRunning ?? this.isTrainingRunning,
      remainingSeconds: remainingSeconds ?? this.remainingSeconds,
      initialDurationSeconds:
          initialDurationSeconds ?? this.initialDurationSeconds,
      setsDone: setsDone ?? this.setsDone,
      goalSets: goalSets ?? this.goalSets,
      repsPerSet: repsPerSet ?? this.repsPerSet,
      setTimes: setTimes ?? this.setTimes,
      progress: progress ?? this.progress,
      secondsSinceLastSet: secondsSinceLastSet ?? this.secondsSinceLastSet,
      lastSetTimestamp: clearLastSetTimestamp
          ? null
          : lastSetTimestamp ?? this.lastSetTimestamp,
      currentProgram: currentProgram ?? this.currentProgram,
      currentBlockDay: currentBlockDay ?? this.currentBlockDay,
      currentReps: currentReps ?? this.currentReps,
      totalTrainingDays: totalTrainingDays ?? this.totalTrainingDays,
    );
  }
}

class TrainingNotifier extends StateNotifier<TrainingState> {
  final Ref ref;
  TrainingNotifier(this.ref) : super(TrainingState());

  void _updateProgram() {
    int newTotalDays = state.totalTrainingDays + 1;
    String newProgram = state.currentProgram;
    int newDay = (state.currentBlockDay % 3) + 1;
    int newReps = state.currentReps;

    if (newTotalDays > 0 && newTotalDays % 12 == 0) {
      switch (state.currentProgram) {
        case 'giant_1.0':
          newProgram = 'giant_1.1';
          break;
        case 'giant_1.1':
          newProgram = 'giant_1.2';
          break;
        case 'giant_1.2':
          newProgram = 'ksk_1.0';
          break;
        case 'ksk_1.0':
          newProgram = 'ksk_1.1';
          break;
        case 'ksk_1.1':
          newProgram = 'ksk_1.2';
          break;
        case 'ksk_1.2':
          newProgram = 'giant_1.0';
          break;
        default:
          newProgram = 'giant_1.0';
      }
      newDay = 1;
    }

    if (newProgram == 'giant_1.0') {
      newReps = [5, 6, 4][newDay - 1];
    } else if (newProgram == 'giant_1.1') {
      newReps = [6, 8, 7][newDay - 1];
    } else if (newProgram == 'giant_1.2') {
      newReps = [7, 9, 8][newDay - 1];
    } else if (newProgram == 'ksk_1.0') {
      newReps = [5, 6, 4][newDay - 1];
    } else if (newProgram == 'ksk_1.1') {
      newReps = [6, 8, 7][newDay - 1];
    } else if (newProgram == 'ksk_1.2') {
      newReps = [7, 9, 8][newDay - 1];
    } else {
      newReps = 5;
    }

    state = state.copyWith(
      currentProgram: newProgram,
      currentBlockDay: newDay,
      currentReps: newReps,
      totalTrainingDays: newTotalDays,
    );
  }

  void startTraining(int minutes, int goal) {
    _updateProgram();
    final duration = minutes * 60;
    state = state.copyWith(
      isTrainingRunning: true,
      initialDurationSeconds: duration,
      remainingSeconds: duration,
      goalSets: goal,
      repsPerSet: state.currentReps,
    );
  }

  void tick() {
    if (state.remainingSeconds > 0) {
      state = state.copyWith(remainingSeconds: state.remainingSeconds - 1);
    }
  }

  void tickLastSetTimer() {
    if (state.isTrainingRunning && state.lastSetTimestamp != null) {
      state = state.copyWith(
        secondsSinceLastSet:
            DateTime.now().difference(state.lastSetTimestamp!).inSeconds,
      );
    }
  }

  void completeSet() {
    final newSetsDone = state.setsDone + 1;
    final newSetTimes = List<DateTime>.from(state.setTimes)
      ..add(DateTime.now());
    final newProgress = state.goalSets > 0 ? newSetsDone / state.goalSets : 0.0;

    state = state.copyWith(
      setsDone: newSetsDone,
      setTimes: newSetTimes,
      progress: newProgress > 1.0 ? 1.0 : newProgress,
      lastSetTimestamp: DateTime.now(),
      secondsSinceLastSet: 0,
    );
  }

  Future<void> finishTraining(TrainingSession session) async {
    final updatedSession = session.copyWith(
      program: state.currentProgram,
      blockDay: state.currentBlockDay,
    );
    await DatabaseHelper().saveTraining(updatedSession);
    try {
      await sendTrainingToBackend(
          reps: session.repsPerSet,
          rest: session.duration / session.sets,
          sets: session.sets);
    } catch (e) {
      print("Error sending information to backend");
    }
    ref.refresh(historyProvider);
    resetTraining();
  }

  void resetTraining() {
    state = TrainingState();
  }
}

final historyProvider = FutureProvider<List<TrainingSession>>((ref) async {
  return DatabaseHelper().getHistory();
});

final trainingProvider = StateNotifierProvider<TrainingNotifier, TrainingState>(
  (ref) {
    return TrainingNotifier(ref);
  },
);