package logfile

import (
	"encoding/csv"
	"fmt"
	"os"
	"strconv"
	"time"

	"github.com/go-flucky/flucky/pkg/types"
)

type csvLogfile struct {
	logfile string
}

func (cl *csvLogfile) Read() ([]types.MeasuredValue, error) {
	if _, err := os.Stat(cl.logfile); os.IsNotExist(err) {
		return nil, fmt.Errorf("%v: %v", errorLogfileNotFound, cl.logfile)
	}

	f, err := os.Open(cl.logfile)
	if err != nil {
		return nil, fmt.Errorf("%v: %v", errorLogfileOpen, cl.logfile)
	}
	defer f.Close()

	r := csv.NewReader(f)
	records, err := r.ReadAll()
	if err != nil {
		return nil, fmt.Errorf("%v %v: %v", errorLogfileDecode, cl.logfile, err)
	}

	measuredValues := make([]types.MeasuredValue, 0)

	for _, record := range records {

		// Value
		value, err := strconv.ParseFloat(record[2], 64)
		if err != nil {
			return nil, fmt.Errorf("%v %v: %v", errorParseFloat, record[2], err)
		}

		// Times
		times := make([]time.Time, 0)
		for _, i := range []int{3, 4} {
			time, err := time.Parse(timeFormat, record[i])
			if err != nil {
				return nil, fmt.Errorf("%v %v: %v", errorParseTime, record[i], err)
			}
			times = append(times, time)
		}

		switch record[1] {
		case fmt.Sprint(types.MeasuredValueTypeHumidity):
			measuredValue := &types.Humidity{
				HumidityID: record[0], // 0
				// 1 - MeasuredValue
				HumidityValue:    value,     // 2
				HumidityFromDate: times[0],  // 3
				HumidityTillDate: times[1],  // 4
				SensorID:         record[5], // 5
			}

			// CreationDate
			creationDate, err := time.Parse(timeFormat, record[6])
			if err != nil {
				return nil, fmt.Errorf("%v %v: %v", errorParseTime, record[6], err)
			}
			measuredValue.CreationDate = &creationDate

			// UpdateDate
			if record[7] != "null" {
				updateDate, err := time.Parse(timeFormat, record[7])
				if err != nil {
					return nil, fmt.Errorf("%v %v: %v", errorParseTime, record[7], err)
				}
				measuredValue.UpdateDate = &updateDate
			}

			measuredValues = append(measuredValues, measuredValue)

		case fmt.Sprint(types.MeasuredValueTypePressure):
			measuredValue := &types.Pressure{
				PressureID: record[0], // 0
				// 1 - MeasuredValue
				PressureValue:    value,     // 2
				PressureFromDate: times[0],  // 3
				PressureTillDate: times[1],  // 4
				SensorID:         record[5], // 5
			}

			// CreationDate
			creationDate, err := time.Parse(timeFormat, record[6])
			if err != nil {
				return nil, fmt.Errorf("%v %v: %v", errorParseTime, record[6], err)
			}
			measuredValue.CreationDate = &creationDate

			// UpdateDate
			if record[7] != "null" {
				updateDate, err := time.Parse(timeFormat, record[7])
				if err != nil {
					return nil, fmt.Errorf("%v %v: %v", errorParseTime, record[7], err)
				}
				measuredValue.UpdateDate = &updateDate
			}

			measuredValues = append(measuredValues, measuredValue)

		case fmt.Sprint(types.MeasuredValueTypeTemperature):
			measuredValue := &types.Temperature{
				TemperatureID: record[0], // 0
				// 1 - MeasuredValue
				TemperatureValue:    value,     // 2
				TemperatureFromDate: times[0],  // 3
				TemperatureTillDate: times[1],  // 4
				SensorID:            record[5], // 5
			}

			// CreationDate
			creationDate, err := time.Parse(timeFormat, record[6])
			if err != nil {
				return nil, fmt.Errorf("%v %v: %v", errorParseTime, record[6], err)
			}
			measuredValue.CreationDate = &creationDate

			// UpdateDate
			if record[7] != "null" {
				updateDate, err := time.Parse(timeFormat, record[7])
				if err != nil {
					return nil, fmt.Errorf("%v %v: %v", errorParseTime, record[7], err)
				}
				measuredValue.UpdateDate = &updateDate
			}

			measuredValues = append(measuredValues, measuredValue)
		default:
			continue
		}

	}

	return measuredValues, nil

}

func (cl *csvLogfile) Write(measuredValues []types.MeasuredValue) error {
	f, err := os.Create(cl.logfile)
	if err != nil {
		return fmt.Errorf("%v: %v", errorLogfileCreate, cl.logfile)
	}
	defer f.Close()

	writeCreationDate(measuredValues)

	w := csv.NewWriter(f)

	for _, measuredValue := range measuredValues {

		record := []string{
			measuredValue.GetID(),
			fmt.Sprintf("%v", measuredValue.GetMeasuredValueType()),
			fmt.Sprintf("%v", measuredValue.GetValue()),
			measuredValue.GetFromDate().Format(timeFormat),
			measuredValue.GetTillDate().Format(timeFormat),
			measuredValue.GetSensorID(),
		}

		if measuredValue.GetCreationDate() != nil {
			record = append(record, measuredValue.GetCreationDate().Format(timeFormat))
		} else {
			record = append(record, "null")
		}

		if measuredValue.GetUpdateDate() != nil {
			record = append(record, measuredValue.GetUpdateDate().Format(timeFormat))
		} else {
			record = append(record, "null")
		}

		w.Write(record)
	}

	w.Flush()

	return nil
}