package logger

import (
	"fmt"
	"log"
	"os"
	"time"

	"gorm.io/gorm"
	"rhemawavetech.com/rhemawave/internal/db"
)

type Level int

const (
	LevelDebug Level = iota
	LevelInfo
	LevelWarning
	LevelError
	LevelFatal
)

func (l Level) String() string {
	return [...]string{"DEBUG", "INFO", "WARNING", "ERROR", "FATAL"}[l]
}

var (
	DB      *gorm.DB
	file    *os.File
	console = log.New(os.Stderr, "", 0)
)

// AddFile attaches or replaces the file backend
func AddFile(path string) error {
	if file != nil {
		file.Close()
	}

	_, err := os.OpenFile(path, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if err != nil {
		return err
	}

	return nil
}

// AddDatabase attaches or replaces the database backend
func AddDatabase(d *gorm.DB) {
	console.Println("Adding database to logger")
	DB = d
}

// Close shuts down the file backend.
func Close() error {
	if file != nil {
		err := file.Close()
		file = nil
		return err
	}
	return nil
}

func logMsg(level Level, format string, args ...any) {
	message := fmt.Sprintf(format, args...)
	now := time.Now()
	timestamp := now.Format("2006-01-02 15:04:05.000")
	line := fmt.Sprintf("%s [%s] %s", timestamp, level, message)

	// 1. The standard log package is internally thread-safe
	console.Println(line)

	// 2. Write to file
	if file != nil {
		fmt.Fprintln(file, line)
	}

	// 3. Write to DB using GORM. It handles its own connection pooling and locking.
	if DB != nil {
		var entry db.Log
		entry.Timestamp = now.UnixMilli()
		entry.Level = level.String()
		entry.Message = message

		// Use Save() to insert the new record.
		result := DB.Save(&entry)
		if result.Error != nil {
			console.Printf("Failed to write log to database: %v\n", result.Error)
		}
	}
}

func Debug(format string, args ...any)   { logMsg(LevelDebug, format, args...) }
func Info(format string, args ...any)    { logMsg(LevelInfo, format, args...) }
func Warning(format string, args ...any) { logMsg(LevelWarning, format, args...) }
func Error(format string, args ...any)   { logMsg(LevelError, format, args...) }

func Fatal(format string, args ...any) {
	logMsg(LevelFatal, format, args...)
	time.Sleep(100 * time.Millisecond)
	os.Exit(1)
}