feat: 初始化 ChatGPT Team 管理后端项目

- 添加用户认证模块 (JWT + 密码管理)
- 添加 ChatGPT 账户管理功能
- 添加卡密管理功能 (创建、批量生成、查询)
- 添加邀请功能
- 配置数据库迁移和路由系统

internal/handler/auth_handler.go

@@ -0,0 +1,138 @@
+package handler
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"gpt-manager-go/internal/auth"
+	"gpt-manager-go/internal/repository"
+)
+
+// AuthHandler 认证处理器
+type AuthHandler struct {
+	adminRepo *repository.AdminRepository
+}
+
+// NewAuthHandler 创建认证处理器
+func NewAuthHandler(adminRepo *repository.AdminRepository) *AuthHandler {
+	return &AuthHandler{adminRepo: adminRepo}
+}
+
+// LoginRequest 登录请求
+type LoginRequest struct {
+	Username string `json:"username"`
+	Password string `json:"password"`
+}
+
+// LoginResponse 登录响应
+type LoginResponse struct {
+	Success bool      `json:"success"`
+	Message string    `json:"message"`
+	Token   string    `json:"token,omitempty"`
+	User    *UserInfo `json:"user,omitempty"`
+}
+
+// UserInfo 用户信息
+type UserInfo struct {
+	ID           int    `json:"id"`
+	Username     string `json:"username"`
+	Email        string `json:"email"`
+	IsSuperAdmin bool   `json:"is_super_admin"`
+}
+
+// Login 登录接口
+func (h *AuthHandler) Login(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		respondJSON(w, http.StatusMethodNotAllowed, LoginResponse{
+			Success: false,
+			Message: "Method not allowed",
+		})
+		return
+	}
+
+	var req LoginRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		respondJSON(w, http.StatusBadRequest, LoginResponse{
+			Success: false,
+			Message: "Invalid request body",
+		})
+		return
+	}
+
+	// 验证必填字段
+	if req.Username == "" || req.Password == "" {
+		respondJSON(w, http.StatusBadRequest, LoginResponse{
+			Success: false,
+			Message: "Username and password are required",
+		})
+		return
+	}
+
+	// 查找用户
+	admin, err := h.adminRepo.FindByUsername(req.Username)
+	if err != nil {
+		respondJSON(w, http.StatusInternalServerError, LoginResponse{
+			Success: false,
+			Message: "Internal server error",
+		})
+		return
+	}
+
+	if admin == nil {
+		respondJSON(w, http.StatusUnauthorized, LoginResponse{
+			Success: false,
+			Message: "Invalid username or password",
+		})
+		return
+	}
+
+	// 检查账号是否激活
+	if !admin.IsActive {
+		respondJSON(w, http.StatusForbidden, LoginResponse{
+			Success: false,
+			Message: "Account is disabled",
+		})
+		return
+	}
+
+	// 验证密码
+	if !auth.CheckPassword(req.Password, admin.PasswordHash) {
+		respondJSON(w, http.StatusUnauthorized, LoginResponse{
+			Success: false,
+			Message: "Invalid username or password",
+		})
+		return
+	}
+
+	// 生成 Token
+	token, err := auth.GenerateToken(admin.ID, admin.Username, admin.IsSuperAdmin)
+	if err != nil {
+		respondJSON(w, http.StatusInternalServerError, LoginResponse{
+			Success: false,
+			Message: "Failed to generate token",
+		})
+		return
+	}
+
+	// 更新最后登录时间
+	_ = h.adminRepo.UpdateLastLogin(admin.ID)
+
+	respondJSON(w, http.StatusOK, LoginResponse{
+		Success: true,
+		Message: "Login successful",
+		Token:   token,
+		User: &UserInfo{
+			ID:           admin.ID,
+			Username:     admin.Username,
+			Email:        admin.Email,
+			IsSuperAdmin: admin.IsSuperAdmin,
+		},
+	})
+}
+
+// respondJSON 返回 JSON 响应
+func respondJSON(w http.ResponseWriter, status int, data interface{}) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	json.NewEncoder(w).Encode(data)
+}