package sensor

import (
	"context"
	"fmt"
	"sync"

	"github.com/go-flucky/flucky/pkg/internal/collect"
	"github.com/go-flucky/flucky/pkg/internal/prittyprint"
	"github.com/go-flucky/flucky/pkg/types"
)

// ReadHumidities returns a list of measured humidities by humidity sensors
func ReadHumidities(humiditySensors []HumiditySensor, round float64) ([]*types.Humidity, error) {
	humidityChannel := make(chan *types.Humidity, len(humiditySensors))
	errorChannel := make(chan error, len(humiditySensors))

	wg := new(sync.WaitGroup)
	wg.Add(len(humiditySensors))

	for _, humiditySensor := range humiditySensors {
		go humiditySensor.ReadHumidityWriteIntoChannel(round, humidityChannel, errorChannel, wg)
	}

	wg.Wait()

	errors := collect.Errors(errorChannel)
	if len(errors) > 0 {
		return nil, prittyprint.FormatErrors(errors)
	}

	humidities := collect.Humidities(humidityChannel)

	return humidities, nil
}

// ReadHumiditiesWriteIntoChannel reads the humidity values of humidity sensors and writes them into a channel
func ReadHumiditiesWriteIntoChannel(ctx context.Context, humiditySensors []HumiditySensor, round float64, humidityChannel chan<- *types.Humidity, errorChannel chan<- error, wg *sync.WaitGroup) {
	for _, humiditySensor := range humiditySensors {
		humiditySensor.ReadHumidityWriteIntoChannel(round, humidityChannel, errorChannel, wg)
	}
}

// ReadHumiditiesContinuously reads the humidity values of humidity sensors continuously and writes them into a channel
func ReadHumiditiesContinuously(ctx context.Context, humiditySensors []HumiditySensor, round float64, humidityChannel chan<- *types.Humidity, errorChannel chan<- error) {
	for {
		select {
		case <-ctx.Done():
			errorChannel <- fmt.Errorf("Context closed: %v", ctx.Err())
			return
		default:
			ReadHumiditiesWriteIntoChannel(ctx, humiditySensors, round, humidityChannel, errorChannel, nil)
		}
	}
}

// ReadTemperatures returns a list of measured temperatures by temperature sensors
func ReadTemperatures(temperatureSensors []TemperatureSensor, degree types.TemperatureUnit, round float64) ([]*types.Temperature, error) {
	temperatureChannel := make(chan *types.Temperature, len(temperatureSensors))
	errorChannel := make(chan error, len(temperatureSensors))

	wg := new(sync.WaitGroup)
	wg.Add(len(temperatureSensors))

	for _, temperatureSensor := range temperatureSensors {
		go temperatureSensor.ReadTemperatureWriteIntoChannel(degree, round, temperatureChannel, errorChannel, wg)
	}

	wg.Wait()

	errors := collect.Errors(errorChannel)
	if len(errors) > 0 {
		return nil, prittyprint.FormatErrors(errors)
	}

	temperatures := collect.Temperatures(temperatureChannel)

	return temperatures, nil
}

// ReadTemperaturesWriteIntoChannel reads the temperature values of temperature sensors and writes them into a channel
func ReadTemperaturesWriteIntoChannel(ctx context.Context, temperatureSensors []TemperatureSensor, degree types.TemperatureUnit, round float64, temperatureChannel chan<- *types.Temperature, errorChannel chan<- error, wg *sync.WaitGroup) {
	for _, temperatureSensor := range temperatureSensors {
		temperatureSensor.ReadTemperatureWriteIntoChannel(degree, round, temperatureChannel, errorChannel, wg)
	}
}

// ReadTemperaturesContinuously reads the temperature values of temperature sensors continuously and writes them into a chann
func ReadTemperaturesContinuously(ctx context.Context, temperatureSensors []TemperatureSensor, degree types.TemperatureUnit, round float64, temperatureChannel chan<- *types.Temperature, errorChannel chan<- error) {
	for {
		select {
		case <-ctx.Done():
			errorChannel <- fmt.Errorf("Context closed: %v", ctx.Err())
			return
		default:
			ReadTemperaturesWriteIntoChannel(ctx, temperatureSensors, degree, round, temperatureChannel, errorChannel, nil)
		}
	}
}

func convertTemperatureMeasurementUnit(value float64, fromDegree types.TemperatureUnit, toDegree types.TemperatureUnit) float64 {

	switch fromDegree {
	// Celsius
	case types.TemperatureUnitCelsius:
		switch toDegree {
		// Celsius -> Celsius
		case types.TemperatureUnitCelsius:
			return value
		// Celsius -> Fahrenheit
		case types.TemperatureUnitFahrenheit:
			return (value * 9 / 5) + 32
		// Celsius -> Kelvin
		case types.TemperatureUnitKelvin:
			return value + 273.15
		}

		// Fahrenheit
	case types.TemperatureUnitFahrenheit:
		switch toDegree {
		// Fahrenheit -> Celsius
		case types.TemperatureUnitCelsius:
			return (value - 32) * 5 / 9
		// Fahrenheit -> Fahrenheit
		case types.TemperatureUnitFahrenheit:
			return value
		// Fahrenheit -> Kelvin
		case types.TemperatureUnitKelvin:
			return (value-32)*5/9 + 273.15
		}

	case types.TemperatureUnitKelvin:
		switch toDegree {
		// Kelvin -> Celsius
		case types.TemperatureUnitCelsius:
			return value - 273.15
		// Kelvin -> Fahrenheit
		case types.TemperatureUnitFahrenheit:
			return (value-273.15)*9/5 + 32
		// Kevin -> Kelvin
		case types.TemperatureUnitKelvin:
			return value
		}
	}

	return value
}

func SelectTemperatureMeasurementUnit(unit string) (types.TemperatureUnit, error) {
	switch unit {
	case "celsius":
		return types.TemperatureUnitCelsius, nil
	case "fahrenheit":
		return types.TemperatureUnitFahrenheit, nil
	case "kelvin":
		return types.TemperatureUnitKelvin, nil
	default:
		return "", fmt.Errorf("Can not determine temperature measurement unit")
	}
}