feat: v2重定向链路（按Host解析域名、修复多域名code冲突、缓存与访问日志）

Author: nodesire7

internal/app/app.go

@@ -100,9 +100,6 @@ func Run() error {
 		})
 	})
 
-	// 重定向路由（不需要认证）
-	router.GET("/:code", linkHandler.RedirectLink)
-
 	// Web UI 路由
 	router.GET("/login", func(c *gin.Context) {
 		c.HTML(200, "login.html", gin.H{"title": "登录 - 短链接管理系统"})
@@ -157,11 +154,19 @@ func Run() error {
 	}
 
 	// 挂载重写版 v2 路由（增量迁移，不影响 v1）
+	v2Enabled := false
 	if v2, err := httpv2.New(); err != nil {
 		utils.LogWarn("v2模块初始化失败（已忽略，不影响v1）: %v", err)
 	} else {
 		defer v2.Close()
 		httpv2.RegisterRoutes(router, v2)
+		v2Enabled = true
+	}
+
+	// 重定向路由（不需要认证）
+	// 优先使用重写版（已修复多域名 code 冲突风险），否则回退 legacy
+	if !v2Enabled {
+		router.GET("/:code", linkHandler.RedirectLink)
 	}
 
 	// 启动服务器

internal/httpv2/handlers/redirect_handler.go

@@ -0,0 +1,55 @@
+/**
+ * v2 Redirect Handler（重写版）
+ * - GET /:code
+ * 使用 pgxpool 解析 code（按 Host 匹配 domain），并写入点击/访问日志
+ */
+package handlers
+
+import (
+	"context"
+	"net/http"
+	"time"
+
+	"short-link/internal/repo"
+	"short-link/internal/service"
+
+	"github.com/gin-gonic/gin"
+)
+
+// RedirectHandler v2 重定向处理器
+type RedirectHandler struct {
+	linkService *service.LinkService
+}
+
+// NewRedirectHandler 创建 RedirectHandler
+func NewRedirectHandler(linkService *service.LinkService) *RedirectHandler {
+	return &RedirectHandler{linkService: linkService}
+}
+
+// Redirect 执行 302 跳转
+func (h *RedirectHandler) Redirect(c *gin.Context) {
+	code := c.Param("code")
+
+	ctx, cancel := context.WithTimeout(c.Request.Context(), 5*time.Second)
+	defer cancel()
+
+	url, err := h.linkService.RedirectLink(
+		ctx,
+		c.Request.Host,
+		code,
+		c.ClientIP(),
+		c.GetHeader("User-Agent"),
+		c.GetHeader("Referer"),
+	)
+	if err != nil {
+		if err == repo.ErrNotFound {
+			c.JSON(http.StatusNotFound, gin.H{"error": "链接不存在"})
+			return
+		}
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "重定向失败: " + err.Error()})
+		return
+	}
+	c.Redirect(http.StatusFound, url)
+}
+
+

internal/httpv2/router.go

@@ -29,10 +29,12 @@ type Module struct {
 	DomainRepo  *repo.DomainRepo
 	SettingsRepo *repo.SettingsRepo
 	LinkRepo    *repo.LinkRepo
+	AccessLogRepo *repo.AccessLogRepo
 	UserService *service.UserService
 	LinkService *service.LinkService
 	AuthHandler *handlers.AuthHandler
 	LinkHandler *handlers.LinkHandler
+	RedirectHandler *handlers.RedirectHandler
 }
 
 // New 创建 v2 模块
@@ -53,12 +55,14 @@ func New() (*Module, error) {
 	domainRepo := repo.NewDomainRepo(pool)
 	settingsRepo := repo.NewSettingsRepo(pool)
 	linkRepo := repo.NewLinkRepo(pool)
+	accessLogRepo := repo.NewAccessLogRepo(pool)
 
 	userService := service.NewUserService(userRepo)
-	linkService := service.NewLinkService(cfg.BaseURL, cfg.MinCodeLength, cfg.MaxCodeLength, linkRepo, domainRepo, settingsRepo, userRepo)
+	linkService := service.NewLinkService(cfg.BaseURL, cfg.MinCodeLength, cfg.MaxCodeLength, linkRepo, domainRepo, settingsRepo, userRepo, accessLogRepo)
 
 	authHandler := handlers.NewAuthHandler(cfg, userService)
 	linkHandler := handlers.NewLinkHandler(cfg, linkService, linkRepo, domainRepo)
+	redirectHandler := handlers.NewRedirectHandler(linkService)
 
 	return &Module{
 		Cfg:         cfg,
@@ -67,10 +71,12 @@ func New() (*Module, error) {
 		DomainRepo:  domainRepo,
 		SettingsRepo: settingsRepo,
 		LinkRepo:    linkRepo,
+		AccessLogRepo: accessLogRepo,
 		UserService: userService,
 		LinkService: linkService,
 		AuthHandler: authHandler,
 		LinkHandler: linkHandler,
+		RedirectHandler: redirectHandler,
 	}, nil
 }
 
@@ -85,6 +91,9 @@ func (m *Module) Close() {
 func RegisterRoutes(router *gin.Engine, m *Module) {
 	utils.LogInfo("挂载重写版路由：/api/v2")
 
+	// 重写版 redirect（替换 legacy 的任意域名查询，修复多域名 code 冲突风险）
+	router.GET("/:code", m.RedirectHandler.Redirect)
+
 	api := router.Group("/api/v2")
 	{
 		authGroup := api.Group("/auth")

internal/repo/access_log_repo.go

@@ -0,0 +1,33 @@
+/**
+ * AccessLog Repo（重写版）
+ * - 负责 access_logs 表写入（pgxpool）
+ */
+package repo
+
+import (
+	"context"
+	"fmt"
+	"short-link/internal/db"
+	"short-link/models"
+)
+
+// AccessLogRepo 访问日志仓储
+type AccessLogRepo struct {
+	pool *db.Pool
+}
+
+// NewAccessLogRepo 创建 AccessLogRepo
+func NewAccessLogRepo(pool *db.Pool) *AccessLogRepo {
+	return &AccessLogRepo{pool: pool}
+}
+
+// CreateAccessLog 写入访问日志
+func (r *AccessLogRepo) CreateAccessLog(ctx context.Context, log *models.AccessLog) error {
+	query := `INSERT INTO access_logs (link_id, ip, user_agent, referer, created_at) VALUES ($1, $2, $3, $4, $5) RETURNING id`
+	if err := r.pool.QueryRow(ctx, query, log.LinkID, log.IP, log.UserAgent, log.Referer, log.CreatedAt).Scan(&log.ID); err != nil {
+		return fmt.Errorf("create access log failed: %w", err)
+	}
+	return nil
+}
+
+

internal/repo/domain_repo.go

@@ -24,6 +24,26 @@ func NewDomainRepo(pool *db.Pool) *DomainRepo {
 	return &DomainRepo{pool: pool}
 }
 
+// FindActiveDomainsByName 按 domain 字段查找启用的域名（可能返回多条：代表配置冲突）
+func (r *DomainRepo) FindActiveDomainsByName(ctx context.Context, name string) ([]models.Domain, error) {
+	query := `SELECT id, user_id, domain, is_default, is_active, created_at, updated_at FROM domains WHERE domain = $1 AND is_active = true`
+	rows, err := r.pool.Query(ctx, query, name)
+	if err != nil {
+		return nil, fmt.Errorf("find domains failed: %w", err)
+	}
+	defer rows.Close()
+
+	var out []models.Domain
+	for rows.Next() {
+		var d models.Domain
+		if err := rows.Scan(&d.ID, &d.UserID, &d.Domain, &d.IsDefault, &d.IsActive, &d.CreatedAt, &d.UpdatedAt); err != nil {
+			return nil, fmt.Errorf("scan domain failed: %w", err)
+		}
+		out = append(out, d)
+	}
+	return out, nil
+}
+
 // GetDomainByID 根据ID获取域名
 func (r *DomainRepo) GetDomainByID(ctx context.Context, domainID int64) (*models.Domain, error) {
 	d := &models.Domain{}

internal/repo/link_repo.go

@@ -63,6 +63,77 @@ func (r *LinkRepo) CreateLink(ctx context.Context, link *models.Link) error {
 	return nil
 }
 
+// GetLinkByCode 根据 code + domain_id 获取链接
+func (r *LinkRepo) GetLinkByCode(ctx context.Context, code string, domainID int64) (*models.Link, error) {
+	l := &models.Link{}
+	query := `
+		SELECT id, user_id, domain_id, code, original_url, title, hash, qr_code, click_count, created_at, updated_at
+		FROM links
+		WHERE code = $1 AND domain_id = $2
+		LIMIT 1
+	`
+	err := r.pool.QueryRow(ctx, query, code, domainID).Scan(
+		&l.ID,
+		&l.UserID,
+		&l.DomainID,
+		&l.Code,
+		&l.OriginalURL,
+		&l.Title,
+		&l.Hash,
+		&l.QRCode,
+		&l.ClickCount,
+		&l.CreatedAt,
+		&l.UpdatedAt,
+	)
+	if errors.Is(err, pgx.ErrNoRows) {
+		return nil, ErrNotFound
+	}
+	if err != nil {
+		return nil, fmt.Errorf("get link by code failed: %w", err)
+	}
+	return l, nil
+}
+
+// GetLinkByCodeAnyDomain 兼容：按 code 查询任意域名（最多返回 limit 条，用于歧义判断）
+func (r *LinkRepo) GetLinkByCodeAnyDomain(ctx context.Context, code string, limit int) ([]models.Link, error) {
+	if limit <= 0 {
+		limit = 2
+	}
+	query := `
+		SELECT id, user_id, domain_id, code, original_url, title, hash, qr_code, click_count, created_at, updated_at
+		FROM links
+		WHERE code = $1
+		LIMIT $2
+	`
+	rows, err := r.pool.Query(ctx, query, code, limit)
+	if err != nil {
+		return nil, fmt.Errorf("get link by code any domain failed: %w", err)
+	}
+	defer rows.Close()
+
+	var out []models.Link
+	for rows.Next() {
+		var l models.Link
+		if err := rows.Scan(
+			&l.ID,
+			&l.UserID,
+			&l.DomainID,
+			&l.Code,
+			&l.OriginalURL,
+			&l.Title,
+			&l.Hash,
+			&l.QRCode,
+			&l.ClickCount,
+			&l.CreatedAt,
+			&l.UpdatedAt,
+		); err != nil {
+			return nil, fmt.Errorf("scan link failed: %w", err)
+		}
+		out = append(out, l)
+	}
+	return out, nil
+}
+
 // GetLinkByHashUserDomain 幂等检查：按 (hash, user_id, domain_id)
 func (r *LinkRepo) GetLinkByHashUserDomain(ctx context.Context, hash string, userID int64, domainID int64) (*models.Link, error) {
 	l := &models.Link{}