package sensors

import (
	"encoding/json"
	"log/slog"
	"math/rand"
	"nats-app/internal/broker"
	"sync"
	"time"
)

type Simulator struct {
	*broker.NATS
	stopChannels map[string]chan bool
	mu           sync.Mutex
}

func Start(nats *broker.NATS) *Simulator {
	return &Simulator{
		NATS:         nats,
		stopChannels: make(map[string]chan bool),
	}
}

func (s *Simulator) SimulateSensor(sensor Sensor) {
	s.mu.Lock()
	stopChan := make(chan bool)
	s.stopChannels[sensor.SensorID] = stopChan
	s.mu.Unlock()

	ticker := time.NewTicker(*sensor.SamplingInterval * time.Second)
	defer ticker.Stop()

	for {
		select {
		case <-stopChan:
			slog.Info("stopping simulator for sensor", "sensor_id", sensor.SensorID)
			return
		case <-ticker.C:
			data := s.generateData(sensor)

			if data.SensorID == "" {
				slog.Warn("sensor data generation failed", "sensor_id", sensor.SensorID)
				continue
			}

			payload, err := json.Marshal(data)
			if err != nil {
				slog.Error("failed to marshal sensor data", "error", err, "sensor_id", sensor.SensorID)
				continue
			}

			subject := subjectSensorsData + sensor.SensorID
			if err := s.Publish(subject, payload); err != nil {
				slog.Error("failed to publish sensor data", "error", err, "subject", subject)
			} else {
				slog.Debug("sensor data published", "sensor_id", sensor.SensorID, "value", data.Value)
			}
		}
	}
}

func (s *Simulator) UpdateSensor(sensor Sensor) {
	s.mu.Lock()
	stopChan, exists := s.stopChannels[sensor.SensorID]
	s.mu.Unlock()

	if exists {
		stopChan <- true

		s.mu.Lock()
		delete(s.stopChannels, sensor.SensorID)
		s.mu.Unlock()
	}

	go s.SimulateSensor(sensor)
	slog.Info("simulator updated for sensor", "sensor_id", sensor.SensorID, "new_interval", sensor.SamplingInterval)
}

func (s *Simulator) generateData(sensor Sensor) SensorData {
	now := time.Now()
	data := SensorData{
		SensorID:  sensor.SensorID,
		Timestamp: &now,
	}

	if rand.Float64() < 0.05 {
		return SensorData{}
	}

	var value float64
	switch sensor.SensorType {
	case Temperature:
		value = -20 + rand.Float64()*100
	case Humidity:
		value = 10 + rand.Float64()*90
	case CarbonDioxide:
		value = 980 + rand.Float64()*60
	case Pressure:
		value = 950 + rand.Float64()*100
	case Proximity:
		value = rand.Float64() * 400
	case Light:
		value = rand.Float64() * 10000
	default:
		value = rand.Float64() * 100
	}
	data.Value = &value

	return data
}