package logger

import (
	"log"
	"os"
	"fmt"
	"path/filepath"
	"time"
)

type Logger interface {
	Printf(format string, v ...any)
	Fatalf(format string, v ...any)
}

type stdLogger struct {
	l *log.Logger
}

func (s *stdLogger) Printf(format string, v ...any) { s.l.Printf(format, v...) }
func (s *stdLogger) Fatalf(format string, v ...any) { s.l.Fatalf(format, v...) }

var defaultLogger Logger = &stdLogger{
	l: log.New(os.Stdout, "[app] ", log.LstdFlags|log.Lshortfile),
}

func L() Logger {
	return defaultLogger
}

func SetLogger(l Logger) {
	if l != nil {
		defaultLogger = l
	}
}

type prefLogger struct {
	prefix string
}

func (p *prefLogger) Printf(format string, v ...any) {
	defaultLogger.Printf("%s %s", p.prefix, fmt.Sprintf(format, v...))
}
func (p *prefLogger) Fatalf(format string, v ...any) {
	defaultLogger.Fatalf("%s %s", p.prefix, fmt.Sprintf(format, v...))
}

func WithPrefix(prefix string) Logger {
	return &prefLogger{prefix: prefix}
}

func SetupFile(path string) error {
	if path == "" {
		return fmt.Errorf("log file path empty")
	}
	if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
		return err
	}
	f, err := os.OpenFile(path, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)
	if err != nil {
		return err
	}
	defaultLogger = &stdLogger{
		l: log.New(f, "[app] ", log.LstdFlags|log.Lshortfile),
	}
	return nil
}

func SetupTimezone(tz string) error {
	if tz == "" {
		return fmt.Errorf("timezone empty")
	}
	loc, err := time.LoadLocation(tz)
	if err != nil {
		return err
	}
	time.Local = loc
	return nil
}