package logging

import (
	"fmt"
	"os"
	"time"

	log "github.com/sirupsen/logrus"
)

// setupLogging ensures log directory, opens log file, and configures logrus.
// Returns the *os.File so caller can defer its Close().
func SetupLogging(logDir, serviceName, buildVersion string) (*os.File, error) {
	fileName := logDir + serviceName + ".log"
	f, err := os.OpenFile(fileName, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0666)
	if err != nil {
		return nil, fmt.Errorf("open log file: %w", err)
	}

	log.SetOutput(f)
	log.SetFormatter(&log.JSONFormatter{
		TimestampFormat: time.RFC3339,
	})
	log.SetLevel(log.InfoLevel)

	log.WithFields(log.Fields{
		"buildVersion": buildVersion,
	}).Info("Logging initialized")

	return f, nil
}