package csv

import (
	"encoding/csv"
	"os"

	"go.uber.org/fx"
	"go.uber.org/zap"
)

type Helper struct {
	fx.In
	csvFile   *os.File
	csvWriter *csv.Writer
	logger    *zap.Logger
}

func NewHelper(lc fx.Lifecycle, logger *zap.Logger) *Helper {
	csvFile, err := os.OpenFile("mqtt-logs.csv", os.O_CREATE|os.O_RDWR|os.O_APPEND, 0644)
	if err != nil {
		logger.Fatal("error opening csv file", zap.Error(err))
	}

	csvWriter := csv.NewWriter(csvFile)

	return &Helper{
		csvFile:   csvFile,
		csvWriter: csvWriter,
		logger:    logger,
	}
}

func (h *Helper) AddEntry(date string, topic string, message string) error {
	record := []string{date, topic, message}
	if err := h.csvWriter.Write(record); err != nil {
		h.logger.Error("error writing to csv file", zap.Error(err))
		return err
	}

	h.csvWriter.Flush()

	return nil
}

func (h *Helper) Close() error {
	h.csvWriter.Flush()

	if err := h.csvFile.Close(); err != nil {
		h.logger.Error("error closing csv file", zap.Error(err))
		return err
	}

	return nil
}