package temperature

import (
	"fmt"
	"io"
	"os"
	"os/signal"
	"syscall"
	"text/tabwriter"
	"time"

	stypes "git.cryptic.systems/fh-trier/go-flucky-server/pkg/types"
	"git.cryptic.systems/fh-trier/go-flucky/pkg/httpcall"
	"git.cryptic.systems/fh-trier/go-flucky/pkg/logs"

	"git.cryptic.systems/fh-trier/go-flucky/pkg/config"

	uuid "github.com/satori/go.uuid"
	"github.com/yryz/ds18b20"
)

var temperatureLog = "temperature.log"

// Get ...
func Get(sensorNames []string, push bool, configDir string, w io.Writer) error {

	// get cnf
	cnf, err := config.Read(configDir)
	if err != nil {
		return err
	}

	tw := tabwriter.NewWriter(w, 0, 0, 5, ' ', 0)

	// filter sensors
	var sensors []*stypes.Sensor
	if len(sensorNames) > 0 {
		for _, sensorName := range sensorNames {
			for _, sensor := range cnf.Sensors {
				if sensorName == *sensor.SensorName && *sensor.SensorEnabled ||
					sensorName == sensor.SensorID && *sensor.SensorEnabled ||
					sensorName == *sensor.WireID && *sensor.SensorEnabled {
					sensors = append(sensors, sensor)
				}
			}
		}
	} else {
		for _, sensor := range cnf.Sensors {
			if *sensor.SensorEnabled {
				sensors = append(sensors, sensor)
			}
		}

	}

	// check if sensor exists in cnf and has a wire id
	for _, filterdSensor := range sensors {
		if filterdSensor.WireID == nil || *filterdSensor.WireID == "" {
			return fmt.Errorf("Sensor %v has no wire id", filterdSensor.SensorID)
		}

		var found bool
		for _, cnfSensor := range cnf.Sensors {
			if filterdSensor.SensorID == cnfSensor.SensorID {
				found = true
			}
		}
		if !found {
			return fmt.Errorf("Can not found sensor %v in config", filterdSensor.SensorID)
		}
	}

	// headlines
	for _, sensor := range sensors {
		if sensor.SensorName != nil && *sensor.SensorName != "" {
			fmt.Fprintf(tw, "%v\t", *sensor.SensorName)
		} else {
			fmt.Fprintf(tw, "%v\t", sensor.SensorID)
		}
	}
	fmt.Fprint(tw, "\n")

	// body
	temperatures, err := getTemperatures(sensors)
	if err != nil {
		return err
	}
	for _, temperature := range temperatures {
		fmt.Fprintf(tw, "%v\t", temperature.TemperatureValue)
	}
	fmt.Fprint(tw, "\n")

	tw.Flush()

	// write logfiles or push
	if !push {
		if err := logs.AppendTemperature(temperatures, cnf); err != nil {
			return err
		}
	} else {
		if err := httpcall.SendTemperatures(temperatures, configDir); err != nil {
			return err
		}
	}

	return nil

}

func Follow(sensorNames []string, push bool, configDir string, w io.Writer) error {

	// get cnf
	cnf, err := config.Read(configDir)
	if err != nil {
		return err
	}

	var temperatures []*stypes.Temperature

	// tabwriter
	tw := tabwriter.NewWriter(w, 0, 0, 5, ' ', 0)

	// headlines
	var sensors []*stypes.Sensor

	numOfSensors := len(cnf.Sensors)
	for _, sensor := range cnf.Sensors {
		switch {
		case sensor.SensorName != nil && numOfSensors <= 1:
			sensors = append(sensors, sensor)
		case sensor.SensorName == nil && numOfSensors <= 1:
			sensors = append(sensors, sensor)
		case sensor.SensorName != nil && numOfSensors > 1:
			fmt.Fprintf(tw, "%v\t", *sensor.SensorName)
			sensors = append(sensors, sensor)
			break
		case sensor.SensorName == nil && numOfSensors > 1:
			fmt.Fprintf(tw, "%v\t", sensor.SensorID)
			sensors = append(sensors, sensor)
			break
		}
	}

	if numOfSensors > 1 {
		fmt.Fprint(tw, "\n")
	}

	// body
	ticker := time.NewTicker(1 * time.Second)

	go func() {
		for {
			select {
			case _, more := <-ticker.C:
				if !more {
					return
				}

				// get temperatures from sensors and write them into writer
				temperatures, err = getTemperatures(sensors)
				for _, temperature := range temperatures {
					fmt.Fprintf(tw, "%3.3f\t", temperature.TemperatureValue)
				}

				fmt.Fprint(tw, "\n")

				// flush writer
				tw.Flush()

			}
		}
	}()

	signalChannel := make(chan os.Signal)
	signal.Notify(signalChannel, syscall.SIGINT, syscall.SIGTERM)

	sig := <-signalChannel
	fmt.Printf("Got signal %s, initiating shutdown\n", sig)
	ticker.Stop()

	// write logfiles or push
	if !push {
		if err := logs.AppendTemperature(temperatures, cnf); err != nil {
			return err
		}
	} else {
		if err := httpcall.SendTemperatures(temperatures, configDir); err != nil {
			return err
		}
	}

	return nil
}

// Push ...
func Push(configDir string) error {

	// get cnf
	cnf, err := config.Read(configDir)
	if err != nil {
		return err
	}

	temperatures, err := logs.ReadTemperatures(cnf.TemperatureLogfile)
	if err != nil {
		return err
	}

	if err := httpcall.SendTemperatures(temperatures, configDir); err != nil {
		return err
	}

	if err := logs.FlushTemperatures(cnf.TemperatureLogfile); err != nil {
		return err
	}

	return nil

}

func getTemperatures(sensors []*stypes.Sensor) ([]*stypes.Temperature, error) {

	temperatures := []*stypes.Temperature{}

	for _, sensor := range sensors {
		t, err := ds18b20.Temperature(*sensor.WireID)
		if err != nil {
			return []*stypes.Temperature{}, fmt.Errorf("Can not read temperature from sensor %v: %v", sensor.SensorID, err)
		}

		temperature := &stypes.Temperature{
			TemperatureID:    uuid.NewV4().String(),
			TemperatureValue: t,
			TemperatureDate:  time.Now(),
			SensorID:         sensor.SensorID,
			CreationDate:     time.Now(),
		}

		temperatures = append(temperatures, temperature)
	}

	return temperatures, nil
}