package logs

import (
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"os"
	"path/filepath"
	"text/tabwriter"

	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"
)

// AppendTemperature write a given array of temperatures to a logfile
func AppendTemperature(temperatures []*stypes.Temperature, cnf *types.Config) error {

	tLog, err := ReadTemperatures(cnf)
	if err != nil {
		return err
	}

	tLog = append(tLog, temperatures...)

	err = WriteTemperatures(tLog, cnf)
	if err != nil {
		return err
	}

	return nil
}

// FlushTemperatures ...
func FlushTemperatures(cnf *types.Config) error {
	if err := ioutil.WriteFile(cnf.TemperatureLogfile, []byte(""), 0644); err != nil {
		return err
	}
	return nil
}

// ListTemperatures ...
func ListTemperatures(configDir string, w io.Writer) error {

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

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

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

	sensors := []*stypes.Sensor{}

	// find all sensors which matched with one of the configuration file
	for _, temperature := range temperatures {
		for _, cnfSensor := range cnf.Sensors {
			if temperature.SensorID == cnfSensor.SensorID {
				var found bool
				for _, sensor := range sensors {
					if temperature.SensorID == sensor.SensorID {
						found = true
					}
				}

				if !found {
					sensors = append(sensors, cnfSensor)
				}
			}
		}
	}

	// sort temperature values to every sensor
	orderedTemperatures := make(map[string][]*stypes.Temperature)
	for _, temperature := range temperatures {
		orderedTemperatures[temperature.SensorID] = append(orderedTemperatures[temperature.SensorID], temperature)
	}

	// print headline
	fmt.Fprint(tw, "\t")
	for _, sensor := range sensors {
		fmt.Fprintf(tw, "%v\t", sensor.ReadableSensorName())
	}
	if len(sensors) > 0 {
		fmt.Fprint(tw, "\n")
	}

	// find max length
	maxLength := 0
	for _, orderedTemperature := range orderedTemperatures {
		if len(orderedTemperature) > maxLength {
			maxLength = len(orderedTemperature)
		}
	}

	// print body
	for i := 0; i < maxLength; i++ {
		fmt.Fprintf(tw, "%v\t", i)
		for _, sensor := range sensors {
			if len(orderedTemperatures[sensor.SensorID]) > i {
				fmt.Fprintf(tw, "%3.3f (%v)\t", orderedTemperatures[sensor.SensorID][i].TemperatureValue, orderedTemperatures[sensor.SensorID][i].TemperatureDate.Format("2006-01-02 15:04:05"))
			} else {
				fmt.Fprint(tw, "\t")
			}
		}
		fmt.Fprint(tw, "\n")
	}

	tw.Flush()

	return nil
}

// ReadTemperatures ...
func ReadTemperatures(cnf *types.Config) ([]*stypes.Temperature, error) {

	logPath := filepath.Dir(cnf.TemperatureLogfile)

	// create log dir if not exist
	if _, err := os.Stat(cnf.TemperatureLogfile); os.IsNotExist(err) {
		if _, err := os.Stat(logPath); os.IsNotExist(err) {
			err := os.MkdirAll(logPath, os.ModePerm)
			if err != nil {
				return nil, fmt.Errorf("Can not create directory: %v", err)
			}
		}
		if err := FlushTemperatures(cnf); err != nil {
			return nil, err
		}

	}

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

	bytes, err := ioutil.ReadAll(jsonFile)
	if err != nil {
		return nil, fmt.Errorf("Can not read jsonfile %v: %v", cnf.TemperatureLogfile, err)
	}

	temperatures := []*stypes.Temperature{}
	json.Unmarshal(bytes, &temperatures)

	return temperatures, nil
}

// WriteTemperatures ...
func WriteTemperatures(temperatures []*stypes.Temperature, cnf *types.Config) error {

	bytes, err := json.Marshal(temperatures)
	if err != nil {
		return err
	}

	if err := ioutil.WriteFile(cnf.TemperatureLogfile, bytes, 0644); err != nil {
		return err
	}

	return nil
}