feat: finish project basic structure and core functions

handler/user.go

@@ -0,0 +1,124 @@
+package handler
+
+import (
+	"encoding/json"
+	"net/http"
+
+	db "nukumizu-backend/database"
+	"nukumizu-backend/postLog"
+	"nukumizu-backend/utils"
+)
+
+// UserLoginRequest represents the login request body.
+type UserLoginRequest struct {
+	Username string `json:"username"`
+	Password string `json:"password"`
+}
+
+// UserLoginHandler handles POST /api/user/login.
+func UserLoginHandler(w http.ResponseWriter, r *http.Request) {
+	if !utils.Auth(w, r, "POST", "None") {
+		return
+	}
+
+	var req UserLoginRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		utils.SendErrorResponse(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+
+	if req.Username == "" || req.Password == "" {
+		utils.SendErrorResponse(w, http.StatusBadRequest, "username and password are required")
+		return
+	}
+
+	userID, username, level, registerDate, err := db.GetUserByUsername(req.Username, req.Password)
+	if err != nil {
+		postLog.Warning("Login failed for user " + req.Username + ": " + err.Error())
+		utils.SendErrorResponse(w, http.StatusUnauthorized, "invalid username or password")
+		return
+	}
+
+	token, err := utils.GenerateToken()
+	if err != nil {
+		postLog.Error("Failed to generate token: " + err.Error())
+		utils.SendErrorResponse(w, http.StatusInternalServerError, "failed to generate token")
+		return
+	}
+
+	utils.AddToken(token, userID, level, username)
+	postLog.Info("User logged in: " + username)
+
+	utils.SendSuccessResponse(w, "login successful", map[string]interface{}{
+		"token":        token,
+		"userID":       userID,
+		"username":     username,
+		"level":        level,
+		"registerDate": registerDate,
+	})
+}
+
+// UserRegisterHandler handles POST /api/user/register.
+// Only allowed when there are no existing users in the database.
+func UserRegisterHandler(w http.ResponseWriter, r *http.Request) {
+	if !utils.Auth(w, r, "POST", "None") {
+		return
+	}
+
+	// Check if any user already exists.
+	count, err := db.GetUserCount()
+	if err != nil {
+		postLog.Error("Failed to check user count: " + err.Error())
+		utils.SendErrorResponse(w, http.StatusInternalServerError, "database error")
+		return
+	}
+	if count > 0 {
+		utils.SendErrorResponse(w, http.StatusForbidden, "registration is closed: users already exist")
+		return
+	}
+
+	var req UserLoginRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		utils.SendErrorResponse(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+
+	if req.Username == "" || req.Password == "" {
+		utils.SendErrorResponse(w, http.StatusBadRequest, "username and password are required")
+		return
+	}
+
+	if len(req.Username) > 50 {
+		utils.SendErrorResponse(w, http.StatusBadRequest, "username too long (max 50 characters)")
+		return
+	}
+
+	if len(req.Password) < 6 || len(req.Password) > 100 {
+		utils.SendErrorResponse(w, http.StatusBadRequest, "password must be between 6 and 100 characters")
+		return
+	}
+
+	userID, err := db.CreateUser(req.Username, req.Password, "admin")
+	if err != nil {
+		postLog.Error("Failed to register user: " + err.Error())
+		utils.SendErrorResponse(w, http.StatusInternalServerError, "failed to register user, username may already exist")
+		return
+	}
+
+	token, err := utils.GenerateToken()
+	if err != nil {
+		postLog.Error("Failed to generate token: " + err.Error())
+		utils.SendErrorResponse(w, http.StatusInternalServerError, "failed to generate token")
+		return
+	}
+
+	utils.AddToken(token, userID, "admin", req.Username)
+	postLog.Info("User registered: " + req.Username)
+
+	utils.SendSuccessResponse(w, "user registered successfully", map[string]interface{}{
+		"token":    token,
+		"userID":   userID,
+		"username": req.Username,
+		"level":    "admin",
+	})
+}