package sensor

import (
	"fmt"
	"sync"

	"github.com/go-flucky/go-dht"
	uuid "github.com/satori/go.uuid"
	"github.com/volker-raschek/flucky/pkg/internal/format"
	"github.com/volker-raschek/flucky/pkg/types"
)

// DHT22 is a sensor to measure humidity and temperature.
type DHT22 struct {
	*types.Sensor
	mutex *sync.Mutex
}

// Read measured values
func (dht22 *DHT22) Read() ([]*types.MeasuredValue, error) {

	// Lock multiple access
	dht22.mutex.Lock()
	defer dht22.mutex.Unlock()

	err := dht.HostInit()
	if err != nil {
		return nil, fmt.Errorf("Failed to initialize periph: %v", err)
	}

	dht, err := dht.NewDHT(dht22.GPIONumber, dht.Celsius, "")
	if err != nil {
		return nil, fmt.Errorf("Failed to initialize new DHT22 sensor: %v", err)
	}

	humidityValue, temperatureValue, err := dht.Read()
	if err != nil {
		return nil, fmt.Errorf("Read error: %v", err)
	}

	measuredValues := []*types.MeasuredValue{
		{
			ID:        uuid.NewV4().String(),
			Value:     float64(humidityValue),
			ValueType: "humidity",
			FromDate:  format.FormatedTime(),
			TillDate:  format.FormatedTime(),
			SensorID:  dht22.ID,
		},
		{
			ID:        uuid.NewV4().String(),
			Value:     float64(temperatureValue),
			ValueType: "temperature",
			FromDate:  format.FormatedTime(),
			TillDate:  format.FormatedTime(),
			SensorID:  dht22.ID,
		},
	}

	return measuredValues, nil
}