package config

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"

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

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

var configFilename = "config.json"
var humiditiesLogfileName = "humidities.log"
var temperatureLogfileName = "temperature.log"

func Create(configDir, logDir string, force bool) error {

	configPath := filepath.Join(configDir, configFilename)
	humiditiesLogfile := filepath.Join(logDir, humiditiesLogfileName)
	temperaturLogfile := filepath.Join(logDir, temperatureLogfileName)

	config := &types.Config{
		DeviceID:           uuid.NewV4().String(),
		HumidityLogfile:    humiditiesLogfile,
		TemperatureLogfile: temperaturLogfile,
	}

	// If no config file exists, create a new one on the location
	if !force {
		if _, err := os.Stat(configPath); !os.IsNotExist(err) {
			return fmt.Errorf("%v already exists. Use -f to overwrite", configPath)
		}
	}

	if _, err := os.Stat(configPath); os.IsNotExist(err) {
		err := os.MkdirAll(configDir, os.ModePerm)
		if err != nil {
			return fmt.Errorf("Can not create directory: %v", err)
		}
	}

	f, err := os.Create(configPath)
	if err != nil {
		return fmt.Errorf("Can not create config: %v", err)
	}
	defer f.Close()

	config.JSONWriter(f)

	return nil

}

func DeviceName(deviceName, configDir string) error {
	cnf, err := Read(configDir)
	if err != nil {
		return err
	}

	cnf.DeviceName = deviceName

	err = Write(cnf, configDir)
	if err != nil {
		return err
	}

	return nil
}

func DeviceLocation(deviceLocation, configDir string) error {
	cnf, err := Read(configDir)
	if err != nil {
		return err
	}

	cnf.DeviceLocation = deviceLocation

	err = Write(cnf, configDir)
	if err != nil {
		return err
	}

	return nil
}

func Read(configDir string) (*types.Config, error) {

	configPath := filepath.Join(configDir, configFilename)

	var config types.Config

	// If no config file exists, return an error
	if _, err := os.Stat(configPath); os.IsNotExist(err) {
		return nil, fmt.Errorf("Can not find config %v: %v", configPath, err)
	}

	// open config file
	jsonFile, err := os.Open(configPath)
	if err != nil {
		return nil, fmt.Errorf("Can not open file %v: %v", configPath, err)
	}
	defer jsonFile.Close()

	jsonParser := json.NewDecoder(jsonFile)
	if err := jsonParser.Decode(&config); err != nil {
		return nil, err
	}

	return &config, nil
}

func Write(config *types.Config, configDir string) error {

	configPath := filepath.Join(configDir, configFilename)

	// If no config file exists, return an error
	if _, err := os.Stat(configPath); os.IsNotExist(err) {
		return fmt.Errorf("Can not find config %v: %v", configPath, err)
	}

	// open config file
	jsonFile, err := os.Create(configPath)
	if err != nil {
		return fmt.Errorf("Can not open file %v: %v", configPath, err)
	}
	defer jsonFile.Close()

	err = config.JSONWriter(jsonFile)
	if err != nil {
		return err
	}

	return nil
}