package config

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"text/tabwriter"

	"github.com/satori/go.uuid"

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

// FluckyConfig dasd
type FluckyConfig struct {
	Device  *types.Device   `json:"device"`
	Sensors []*types.Sensor `json:"sensors"`
	Remotes []*Remote       `json:"remotes"`
}

// AddSensor add a new sensor
func (fc *FluckyConfig) AddSensor(sensor *types.Sensor) error {

	// check if sensorID is a valid UUID string
	if !validUUID.MatchString(sensor.SensorID) {
		sensor.SensorID = uuid.NewV4().String()
	}

	// check if sensor name and sensor uuid already exists
	for _, s := range fc.Sensors {
		if s.SensorName == sensor.SensorName {
			return fmt.Errorf("Sensor %v already exists", s.SensorName)
		}

		if s.SensorID == sensor.SensorID {
			return fmt.Errorf("Sensor %v with UUID %v already exists", s.SensorName, s.SensorID)
		}

		if sensor.WireID != nil &&
			s.WireID == sensor.WireID {
			return fmt.Errorf("Sensor with 1wire-id %v already exists as %v", s.WireID, s.SensorName)
		}
	}

	fc.Sensors = append(fc.Sensors, sensor)

	return nil
}

// AddRemote add a new remote address
func (fc *FluckyConfig) AddRemote(remote *Remote) error {

	// check if remoteID is a valid UUID string
	if !validUUID.MatchString(remote.RemoteID) {
		remote.RemoteID = uuid.NewV4().String()
	}

	// check if remote name or remiteid already exists
	for _, r := range fc.Remotes {
		if r.Name == remote.Name {
			return fmt.Errorf("Remote %v -> %v already exists", r.Name, r.Address)
		}

		if r.RemoteID == remote.RemoteID {
			return fmt.Errorf("Remote %v with UUID %v already exists", r.Name, r.RemoteID)
		}
	}

	fc.Remotes = append(fc.Remotes, remote)

	return nil
}

// DisableRemote disables a remote address by its name or its unique UUID
func (fc *FluckyConfig) DisableRemote(nameOrUUID string) error {
	found := false

	for _, remote := range fc.Remotes {

		// disable sensor matched after name
		if !validUUID.MatchString(nameOrUUID) &&
			remote.Name == nameOrUUID {
			remote.Enabled = false
			found = true
			break
		}

		// remove machted uuid
		if validUUID.MatchString(nameOrUUID) &&
			remote.RemoteID == nameOrUUID {
			remote.Enabled = false
			found = true
			break
		}
	}

	if !found {
		return fmt.Errorf("Can not found remote name %v", nameOrUUID)
	}

	return nil
}

// DisableSensor disables a sensor by its name or its unique UUID
func (fc *FluckyConfig) DisableSensor(nameOrUUID string) error {
	found := false

	for _, sensor := range fc.Sensors {

		// disable sensor matched after name
		if !validUUID.MatchString(nameOrUUID) &&
			*sensor.SensorName == nameOrUUID {
			*sensor.SensorEnabled = false
			found = true
			break
		}

		// remove machted uuid
		if validUUID.MatchString(nameOrUUID) &&
			sensor.SensorID == nameOrUUID {
			*sensor.SensorEnabled = false
			found = true
			break
		}
	}

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

	return nil
}

// EnableRemote enable a remote address by its name or its unique UUID
func (fc *FluckyConfig) EnableRemote(nameOrUUID string) error {
	found := false

	for _, remote := range fc.Remotes {

		// disable sensor matched after name
		if !validUUID.MatchString(nameOrUUID) &&
			remote.Name == nameOrUUID {
			remote.Enabled = true
			found = true
			break
		}

		// remove machted uuid
		if validUUID.MatchString(nameOrUUID) &&
			remote.RemoteID == nameOrUUID {
			remote.Enabled = true
			found = true
			break
		}
	}

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

	return nil
}

// EnableSensor enables a sensor by its name or its unique UUID
func (fc *FluckyConfig) EnableSensor(nameOrUUID string) error {
	found := false

	for _, sensor := range fc.Sensors {

		// disable sensor matched after name
		if !validUUID.MatchString(nameOrUUID) &&
			*sensor.SensorName == nameOrUUID {
			*sensor.SensorEnabled = true
			found = true
			break
		}

		// remove machted uuid
		if validUUID.MatchString(nameOrUUID) &&
			sensor.SensorID == nameOrUUID {
			*sensor.SensorEnabled = true
			found = true
			break
		}
	}

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

	return nil
}

// JSONDecoder decode a JSON string from a reader into a struct
func (fc *FluckyConfig) JSONDecoder(r io.Reader) error {
	jsonDecoder := json.NewDecoder(r)
	if err := jsonDecoder.Decode(&fc); err != nil {
		return fmt.Errorf("Can not unmarshal JSON: %v", err)
	}
	return nil
}

// JSONWriter needs a writer to write the struct into JSON string
func (fc *FluckyConfig) JSONWriter(w io.Writer) error {
	encoder := json.NewEncoder(w)
	encoder.SetIndent("", "  ")
	err := encoder.Encode(&fc)
	if err != nil {
		return fmt.Errorf("Error in encoding struct to json: %v", err)
	}
	return nil
}

// PrintRemotes displays a list with all configured remote addresses
func (fc *FluckyConfig) PrintRemotes(w io.Writer) error {

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

	fmt.Fprint(tw, "name\taddress\tenabled\tregistered\n")

	for _, remote := range fc.Remotes {
		fmt.Fprintf(tw, "%v\t%v\t%v\t%v\n", remote.Name, remote.Address, remote.Enabled, remote.Registered)
	}

	tw.Flush()

	return nil
}

// PrintSensors displays a list with all configured sensors
func (fc *FluckyConfig) PrintSensors(w io.Writer) error {

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

	fmt.Fprint(tw, "id\tname\tlocation\ttype\twire-id\tgpio\tenabled\n")

	for _, sensor := range fc.Sensors {
		fmt.Fprintf(tw, "%v\t%v\t%v\t%v\t%v\t%v\t%v\n", sensor.SensorID, *sensor.SensorName, *sensor.SensorLocation, *sensor.SensorType, *sensor.WireID, *sensor.GPIONumber, *sensor.SensorEnabled)
	}

	tw.Flush()

	return nil
}

// RemoveSensor deletes a sensor by its name or its unique UUID
func (fc *FluckyConfig) RemoveSensor(nameOrUUID string) error {
	found := false

	for i, sensor := range fc.Sensors {

		// remove machted name
		if !validUUID.MatchString(nameOrUUID) &&
			*sensor.SensorName == nameOrUUID {
			fc.Sensors = append(fc.Sensors[:i], fc.Sensors[i+1:]...)
			found = true
			break
		}

		// remove machted uuid
		if validUUID.MatchString(nameOrUUID) &&
			sensor.SensorID == nameOrUUID {
			fc.Sensors = append(fc.Sensors[:i], fc.Sensors[i+1:]...)
			found = true
			break
		}
	}

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

	return nil
}

// RemoveRemote deletes a remote address by its name or its unique UUID
func (fc *FluckyConfig) RemoveRemote(nameOrUUID string) error {
	found := false

	for i, remote := range fc.Remotes {

		// remove machted name
		if !validUUID.MatchString(nameOrUUID) &&
			remote.Name == nameOrUUID {
			fc.Remotes = append(fc.Remotes[:i], fc.Remotes[i+1:]...)
			found = true
		}

		// remove machted uuid
		if validUUID.MatchString(nameOrUUID) &&
			remote.RemoteID == nameOrUUID {
			fc.Remotes = append(fc.Remotes[:i], fc.Remotes[i+1:]...)
			found = true
		}
	}

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

	return nil
}

// ToJSON returns the struct as JSON string
func (fc *FluckyConfig) ToJSON() (string, error) {
	var b bytes.Buffer
	err := fc.JSONWriter(&b)
	if err != nil {
		return "", err
	}

	return b.String(), nil
}