Initial 423down proxy service

server.go

@@ -0,0 +1,80 @@
+package main
+
+import (
+	"errors"
+	"net/http"
+	"strings"
+
+	"github.com/duke-git/lancet/v2/validator"
+	"github.com/gin-gonic/gin"
+	"resty.dev/v3"
+)
+
+// newServer 创建并配置 HTTP 服务。
+func newServer(db *DB, client *resty.Client) *gin.Engine {
+	gin.SetMode(gin.ReleaseMode)
+	server := gin.Default()
+	server.Use(corsMiddleware())
+	registerRoutes(server, db, client)
+	return server
+}
+
+// corsMiddleware 允许浏览器跨域访问接口。
+func corsMiddleware() gin.HandlerFunc {
+	return func(ctx *gin.Context) {
+		ctx.Header("Access-Control-Allow-Origin", "*")
+		ctx.Header("Access-Control-Allow-Methods", "GET, OPTIONS")
+		ctx.Header("Access-Control-Allow-Headers", "Origin, Content-Type, Accept, Authorization")
+
+		if ctx.Request.Method == http.MethodOptions {
+			ctx.AbortWithStatus(http.StatusNoContent)
+			return
+		}
+
+		ctx.Next()
+	}
+}
+
+// registerRoutes 注册当前服务公开的 HTTP 路由。
+func registerRoutes(server *gin.Engine, db *DB, client *resty.Client) {
+	server.GET("/", handleArticleRequest(db, client))
+}
+
+// handleArticleRequest 处理文章查询请求：校验参数，读取缓存或抓取源站。
+func handleArticleRequest(db *DB, client *resty.Client) gin.HandlerFunc {
+	return func(ctx *gin.Context) {
+		articleID := strings.TrimSpace(ctx.Query("article_id"))
+		if articleID == "" {
+			ctx.JSON(http.StatusNotFound, response{Ok: false})
+			return
+		}
+
+		if !validator.IsNumberStr(articleID) {
+			ctx.JSON(http.StatusBadRequest, response{
+				Ok:    false,
+				Error: "article_id 应为数字",
+			})
+			return
+		}
+
+		html, err := getArticleHTML(db, client, articleID)
+		if err != nil {
+			ctx.JSON(articleErrorStatusCode(err), createErr(err))
+			return
+		}
+
+		ctx.JSON(http.StatusOK, response{
+			Ok:   true,
+			Html: html,
+		})
+	}
+}
+
+// articleErrorStatusCode 将文章抓取错误映射为合适的 HTTP 状态码。
+func articleErrorStatusCode(err error) int {
+	if errors.Is(err, errArticleContentNotFound) || errors.Is(err, errArticleContentParseFailed) {
+		return http.StatusNotFound
+	}
+
+	return http.StatusInternalServerError
+}