package logger

import (
	"encoding/json"
	"fmt"
	"io"
	"os"
	"time"

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

type FileLogger struct {
	LogFiles map[LogValue][]string `json:"logfiles"`
	writer   io.Writer
}

func (fl *FileLogger) AddLogFile(logfile string, logValue LogValue) error {
	for _, logfiles := range fl.LogFiles {
		for _, lf := range logfiles {
			if lf == logfile {
				return fmt.Errorf("Logfile %v already configured", logfile)
			}
		}
	}
	fl.LogFiles[logValue] = append(fl.LogFiles[logValue], logfile)
	return nil
}

func (fl *FileLogger) GetHumidities(fromDate *time.Time, tillDate *time.Time, sensorNameOrUUID *[]string) ([]*types.Humidity, error) {
	return nil, nil
}

func (fl *FileLogger) GetTemperatures(from *time.Time, till *time.Time, sensorIDs []string) ([]*types.Temperature, error) {
	cachedTemperatures := []*types.Temperature{}

	// iterate over all configured temperature logfiles
	for _, logfile := range fl.LogFiles[LogTemperature] {

		// skip logfile if not exists
		if _, err := os.Stat(logfile); os.IsNotExist(err) {
			return nil, fmt.Errorf("Logfile %v not exists", logfile)
		}

		loggedTemperatures := []*types.Temperature{}

		f, err := os.Open(logfile)
		if err != nil {
			return nil, fmt.Errorf("Can not open %v: %v", logfile, err)
		}
		defer f.Close()

		decoder := json.NewDecoder(f)
		err = decoder.Decode(&loggedTemperatures)
		if err != nil {
			return nil, fmt.Errorf("Can not decode temperatures from logfile %v: %v", logfile, err)
		}

		cachedTemperatures = append(cachedTemperatures, loggedTemperatures...)

		// // sort all redundant values out
		// for _, loggedTemperature := range loggedTemperatures {
		// 	found := false
		// 	for _, cachedTemperature := range cachedTemperatures {
		// 		if cachedTemperature.TemperatureID == loggedTemperature.TemperatureID {
		// 			found = true
		// 			break
		// 		}
		// 	}
		// 	if !found {
		// 		cachedTemperatures = append(cachedTemperatures, loggedTemperature)
		// 	}
		// }
	}

	// // sort out all temperatures which are not mesured by sensor id
	// for i, cachedTemperature := range cachedTemperatures {
	// 	found := false
	// 	for _, sensorID := range sensorIDs {
	// 		if cachedTemperature.SensorID == sensorID {
	// 			found = true
	// 			break
	// 		}
	// 	}
	// 	if !found {
	// 		cachedTemperatures = append(cachedTemperatures[:i], cachedTemperatures[i+1:]...)
	// 	}
	// }

	// // sort out all temperatures which are before from date
	// if from != nil {
	// 	for i, cachedTemperature := range cachedTemperatures {
	// 		if cachedTemperature.TemperatureDate.Before(*from) {
	// 			cachedTemperatures = append(cachedTemperatures[:i], cachedTemperatures[i+1:]...)
	// 		}
	// 	}
	// }

	// // sort out all temperatures which are after till date
	// if till != nil {
	// 	for i, cachedTemperature := range cachedTemperatures {
	// 		if cachedTemperature.TemperatureDate.After(*till) {
	// 			cachedTemperatures = append(cachedTemperatures[:i], cachedTemperatures[i+1:]...)
	// 		}
	// 	}
	// }

	return cachedTemperatures, nil
}

// LogHumidities write humidities to all configured humidity logfiles
func (fl *FileLogger) LogHumidities(humidities []*types.Humidity) error {
	for _, logfile := range fl.LogFiles[LogHumidity] {
		logHumidities := []*types.Humidity{}
		// if logfile already exists, read humidities from logfile
		if _, err := os.Stat(logfile); err == nil {
			f, err := os.Open(logfile)
			if err != nil {
				return fmt.Errorf("Can not open file %v: %v", logfile, err)
			}

			decoder := json.NewDecoder(f)
			err = decoder.Decode(&logHumidities)
			if err != nil {
				return fmt.Errorf("Can not decode humidities from reader")
			}

			f.Close()
		}

		// append new humidities with existing humidities from logfile
		logHumidities = append(logHumidities, humidities...)

		// overwrite lofgile with new entries
		f, err := os.Create(logfile)
		if err != nil {
			return fmt.Errorf("Can not open file %v: %v", logfile, err)
		}
		defer f.Close()

		// encode humidities
		encoder := json.NewEncoder(f)
		encoder.SetIndent("", " ")
		err = encoder.Encode(logHumidities)
		if err != nil {
			return fmt.Errorf("Can not encode humidities for the writer")
		}
	}

	return nil
}

// LogTemperatures write temperatures to all configured temperature logfiles
func (fl *FileLogger) LogTemperatures(temperatures []*types.Temperature) error {
	for _, logfile := range fl.LogFiles[LogTemperature] {
		logTemperatures := []*types.Temperature{}
		// if logfile already exists, read temperatures from logfile
		if _, err := os.Stat(logfile); err == nil {
			f, err := os.Open(logfile)
			if err != nil {
				return fmt.Errorf("Can not open file %v: %v", logfile, err)
			}

			decoder := json.NewDecoder(f)
			err = decoder.Decode(&logTemperatures)
			if err != nil {
				return fmt.Errorf("Can not decode temperatures from reader")
			}

			f.Close()
		}

		// append new temperatures with existing temperatures from logfile
		logTemperatures = append(logTemperatures, temperatures...)

		// overwrite lofgile with new entries
		f, err := os.Create(logfile)
		if err != nil {
			return fmt.Errorf("Can not open file %v: %v", logfile, err)
		}
		defer f.Close()

		// encode temperatures
		encoder := json.NewEncoder(f)
		encoder.SetIndent("", " ")
		err = encoder.Encode(logTemperatures)
		if err != nil {
			return fmt.Errorf("Can not encode temperatures for the writer")
		}
	}

	return nil
}

func (fl *FileLogger) RemoveLogFile(logfile string) error {

	for i, logfiles := range fl.LogFiles {
		cachedLogfiles := []string{}
		for _, lf := range logfiles {
			if lf == logfile {
				continue
			}
			cachedLogfiles = append(cachedLogfiles, lf)
		}
		fl.LogFiles[i] = cachedLogfiles
	}

	if _, err := os.Stat(logfile); err == nil {
		err := os.Remove(logfile)
		if err != nil {
			return fmt.Errorf("Can not remote file %v: %v", logfile, err)
		}
	}

	return nil
}

func NewFileLogger(w io.Writer) *FileLogger {
	return &FileLogger{
		writer: w,
	}
}