package logfile

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

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

type jsonLogfile struct {
	logfile string
}

func (jl *jsonLogfile) Read() ([]*types.MeasuredValue, error) {

	if _, err := os.Stat(jl.logfile); os.IsNotExist(err) {
		return nil, fmt.Errorf("%v: %v", errorLogfileNotFound, jl.logfile)
	}

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

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

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

	return measuredValues, nil
}

func (jl *jsonLogfile) Write(measuredValues []*types.MeasuredValue) error {

	if _, err := os.Stat(filepath.Dir(jl.logfile)); os.IsNotExist(err) {
		if err := os.MkdirAll(filepath.Dir(jl.logfile), 755); err != nil {
			return fmt.Errorf("Directory for the logfile can not be created: %v", err)
		}
	}

	writeCreationDate(measuredValues)

	f, err := os.Create(jl.logfile)
	if err != nil {
		return fmt.Errorf("%v %v: %v", errorLogfileCreate, jl.logfile, err)
	}

	jsonEncoder := json.NewEncoder(f)
	jsonEncoder.SetIndent("", "  ")
	err = jsonEncoder.Encode(measuredValues)
	if err != nil {
		return fmt.Errorf("%v %v: %v", errorLogfileEncode, jl.logfile, err)
	}

	return nil

}