package sensor

import (
	"fmt"
	"io"
	"os"
	"path/filepath"
	"text/tabwriter"
	"time"

	"github.com/satori/go.uuid"

	stypes "git.cryptic.systems/fh-trier/go-flucky-server/pkg/types"
	"git.cryptic.systems/fh-trier/go-flucky/pkg/config"
	"git.cryptic.systems/fh-trier/go-flucky/pkg/types"
)

// Add ...
func Add(sensorName, sensorLocation, sensorType, wireID, gpioNumber *string, wirePath, configDir string, enabled bool) error {

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

	s := &types.Sensor{
		Enabled: enabled,
		RemoteSensor: &stypes.Sensor{
			SensorID:       uuid.NewV4().String(),
			SensorName:     sensorName,
			SensorLocation: sensorLocation,
			GPIONumber:     gpioNumber,
			SensorType:     sensorType,
			DeviceID:       cnf.DeviceID,
			CreationDate:   time.Now(),
		},
	}

	// If the new sensor is a wire sensor
	if wireID != nil {

		// check if sensor exists
		if !exists(wirePath, *wireID) {
			return fmt.Errorf("Can not find sensor: %v", filepath.Join(wirePath, *wireID))
		}

		// check if sensor is redundant
		if isWireIDRedundant(*wireID, cnf.Sensors) {
			return fmt.Errorf("Sensor %v already exists", *wireID)
		}

		s.RemoteSensor.WireID = wireID
	}

	// check if sensor is redundant
	if isSensorNameRedundant(*sensorName, cnf.Sensors) {
		return fmt.Errorf("Sensor %v already exists", *sensorName)
	}

	// append sensor to list
	cnf.Sensors = append(cnf.Sensors, s)

	// write cnf file
	if err := config.Write(cnf, configDir); err != nil {
		return err
	}

	return nil
}

// Enable a remote link
func Enable(sensorName string, configDir string) error {

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

	// search after duplicate remote_names
	var found bool
	for _, sensor := range cnf.Sensors {
		if *sensor.RemoteSensor.SensorName == sensorName ||
			sensor.RemoteSensor.SensorID == sensorName {
			sensor.Enabled = true
			found = true
			break
		}
	}

	if !found {
		return fmt.Errorf("Can not find sensor %v", sensorName)
	}

	if err := config.Write(cnf, configDir); err != nil {
		return err
	}

	return nil
}

// Disable a remote link
func Disable(sensorName string, configDir string) error {

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

	// search after duplicate remote_names
	var found bool
	for _, sensor := range cnf.Sensors {
		if *sensor.RemoteSensor.SensorName == sensorName ||
			sensor.RemoteSensor.SensorID == sensorName {
			sensor.Enabled = false
			found = true
			break
		}
	}

	if !found {
		return fmt.Errorf("Can not find sensor %v", sensorName)
	}

	if err := config.Write(cnf, configDir); err != nil {
		return err
	}

	return nil
}

// Print a list with the given writer w over all temperature sensors
func Print(w io.Writer, configDir string, quiet bool) error {

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

	// declar tabwriter
	tw := tabwriter.NewWriter(w, 0, 0, 3, ' ', 0)

	// headline
	if !quiet {
		fmt.Fprint(tw, "id\tname\tlocation\ttype\twire-id\tgpio\tenabled\n")
	}

	for _, sensor := range cnf.Sensors {
		if quiet {
			fmt.Fprintf(tw, "%v\n", sensor.RemoteSensor.SensorID)
		} else {
			fmt.Fprintf(tw, "%v\t%v\t%v\t%v\t%v\t%v\t%v\n", sensor.RemoteSensor.SensorID, *sensor.RemoteSensor.SensorName, *sensor.RemoteSensor.SensorLocation, *sensor.RemoteSensor.SensorType, *sensor.RemoteSensor.WireID, *sensor.RemoteSensor.GPIONumber, sensor.Enabled)
		}
	}

	tw.Flush()

	return nil
}

// Remove a sensor
func Remove(sensorName, configDir string) error {

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

	var j int
	for _, sensor := range cnf.Sensors {
		if *sensor.RemoteSensor.SensorName == sensorName ||
			sensor.RemoteSensor.SensorID == sensorName {
			cnf.Sensors = append(cnf.Sensors[:j], cnf.Sensors[j+1:]...)

			if j > 0 {
				j = j - 1
			}
			continue
		}
		j++
	}

	if err := config.Write(cnf, configDir); err != nil {
		return err
	}

	return nil
}

func exists(wirePath, sensorID string) bool {
	sensorPath := filepath.Join(wirePath, sensorID)
	if _, err := os.Stat(sensorPath); os.IsNotExist(err) {
		return false
	}
	return true
}

// isWireIDRedundant returns a boolean if the sensor id redundant
func isWireIDRedundant(wireID string, sensors []*types.Sensor) bool {
	for _, sensor := range sensors {
		if *sensor.RemoteSensor.WireID == wireID {
			return true
		}
	}

	return false
}

// isSensorNameRedundant returns a boolean if the sensor name redundant
func isSensorNameRedundant(sensorName string, sensors []*types.Sensor) bool {
	for _, sensor := range sensors {
		if *sensor.RemoteSensor.SensorName == sensorName {
			return true
		}
	}

	return false
}