package logfile

import (
	"encoding/xml"
	"fmt"
	"os"

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

type xmlLogfile struct {
	logfile string
}

func (xl *xmlLogfile) GetLogfile() string {
	return xl.logfile
}

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

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

	measuredValues := new(MeasuredValues)

	if err := xml.NewDecoder(f).Decode(&measuredValues); err != nil {
		return nil, fmt.Errorf("%v: %v", errorLogfileDecode, err)
	}

	cachedMeasuredValues := make([]*types.MeasuredValue, 0)
	for _, measuredValue := range measuredValues.MeasuredValues {
		cachedMeasuredValues = append(cachedMeasuredValues, measuredValue.MeasuredValue)
	}

	return cachedMeasuredValues, nil
}

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

	writeCreationDate(measuredValues)

	cachedMeasuredValues := new(MeasuredValues)

	for _, measuredValue := range measuredValues {
		cachedMeasuredValue := &MeasuredValue{
			MeasuredValue: measuredValue,
		}

		cachedMeasuredValues.MeasuredValues = append(cachedMeasuredValues.MeasuredValues, cachedMeasuredValue)
	}

	bytes, err := xml.MarshalIndent(cachedMeasuredValues, "", "  ")
	if err != nil {
		return fmt.Errorf("%v: %v", errorLogfileMarshal, err)
	}

	_, err = f.Write(bytes)
	if err != nil {
		return fmt.Errorf("%v: %v", errorLogfileWrite, err)
	}

	return nil
}