refactor: migrate backend main function

backend/main.go

@@ -2,14 +2,15 @@
 package main
 
 import (
-	"log"
-	"net/http"
-
-	"github.com/gin-gonic/gin"
+	"fmt"
+	"os"
 
 	"github.com/yyc12345/coconut-leaf/backend/cli"
 	"github.com/yyc12345/coconut-leaf/backend/config"
+	"github.com/yyc12345/coconut-leaf/backend/database"
 	"github.com/yyc12345/coconut-leaf/backend/logger"
+	"github.com/yyc12345/coconut-leaf/backend/server"
+	"github.com/yyc12345/coconut-leaf/backend/utils"
 )
 
 func main() {
@@ -17,29 +18,62 @@ func main() {
 
 	cfg, err := config.Load(args.Config)
 	if err != nil {
-		log.Fatal(err)
+		fmt.Fprintln(os.Stderr, "error loading config file:", err)
+		os.Exit(1)
 	}
 
-	var loggerLevel logger.LoggerLevel
+	// Splash is printed directly; the logger is not built yet.
+	fmt.Println("Coconut-leaf")
+	fmt.Println("A light, self-host and multi-account calendar system")
+	fmt.Println("Project: https://github.com/yyc12345/coconut-leaf")
+	fmt.Println("===================")
+
+	// Build the logger from the loaded config.
+	loggerLevel := logger.Production
 	if cfg.Others.Debug {
 		loggerLevel = logger.Development
-	} else {
-		loggerLevel = logger.Production
 	}
-	logger := logger.New(loggerLevel)
+	log := logger.New(loggerLevel)
 
-	_ = logger
+	// Create the database backend selected by the config.
+	deps := database.Deps{Cfg: cfg, Logger: log}
+	var db database.Database
+	switch cfg.Database.Driver {
+	case config.DatabaseDriverSqlite:
+		db, err = database.NewSqlite3Database(deps)
+	case config.DatabaseDriverMysql:
+		db, err = database.NewMysqlDatabase(deps)
+	default:
+		log.Error("unknown database driver", "driver", cfg.Database.Driver)
+		os.Exit(1)
+	}
+	if err != nil {
+		log.Error("failed to open database", "error", err)
+		os.Exit(1)
+	}
 
-	// 创建默认的 Gin 引擎(包含 Logger 和 Recovery 中间件)
-	r := gin.Default()
+	// Initialize the schema and first admin user when requested.
+	if args.Init {
+		if !utils.IsValidUsername(args.Username) {
+			log.Error("invalid init username")
+			os.Exit(1)
+		}
+		if !utils.IsValidPassword(args.Password) {
+			log.Error("invalid init password")
+			os.Exit(1)
+		}
+		if err := db.Init(args.Username, args.Password); err != nil {
+			log.Error("failed to initialize database", "error", err)
+			os.Exit(1)
+		}
+	}
 
-	// 定义路由
-	r.GET("/", func(c *gin.Context) {
-		c.JSON(http.StatusOK, gin.H{
-			"message": "Hello, Gin!",
-		})
-	})
-
-	//启动服务器（默认端口8088）
-	r.Run(":8080")
+	// Serve.
+	defer db.Close()
+	log.Info("Starting server...")
+	handler := &server.Handler{DB: db, Logger: log, Cfg: cfg}
+	if err := server.Run(handler); err != nil {
+		log.Error("server stopped with error", "error", err)
+		os.Exit(1)
+	}
 }