refactor(repo): conform structure to AGENTS.md (web->frontend, internal/api->cmd/webui/{api,handlers}, docs/README+CHANGELOGs, module .gitignores, drop stray library/ and committed debug bins)

backend/cmd/webui/handlers/handlers.go

@@ -0,0 +1,83 @@
+package handlers
+
+import (
+	"errors"
+	"io"
+	"log"
+	"net"
+	"net/http"
+	"strings"
+	"syscall"
+
+	"github.com/gin-gonic/gin"
+	"github.com/jackc/pgx/v5/pgconn"
+	"github.com/jackc/puddle/v2"
+
+	"booklib/internal/auth"
+	"booklib/internal/config"
+	"booklib/internal/redispkg"
+	"booklib/internal/scanner"
+	"booklib/internal/store"
+)
+
+type H struct {
+	cfg *config.Config
+	st  *store.Store
+	rdb *redispkg.R
+	sc  *scanner.Scanner
+}
+
+func New(cfg *config.Config, st *store.Store, rdb *redispkg.R, sc *scanner.Scanner) *H {
+	return &H{cfg: cfg, st: st, rdb: rdb, sc: sc}
+}
+
+func err(c *gin.Context, status int, code, msg string) {
+	c.AbortWithStatusJSON(status, gin.H{"error": gin.H{"code": code, "message": msg}})
+}
+
+// dbErr 统一处理 store 层失败:记日志;连接类错误 503(Service Unavailable),其余 500
+// 注:brief 里的 pgxpool.ErrClosedPool 在 pgx v5 不存在,实际由 puddle 原样透出,用它替代;
+// PG 停机时池内连接先收到 SQLSTATE 57P01(administrator shutdown),故把 08xx/57Pxx 也归为 503
+func dbErr(c *gin.Context, e error) {
+	log.Printf("db: %v", e)
+	status, code := http.StatusInternalServerError, "internal"
+	var pgErr *pgconn.PgError
+	connClass := errors.As(e, &pgErr) && (strings.HasPrefix(pgErr.Code, "08") || strings.HasPrefix(pgErr.Code, "57P"))
+	if connClass || errors.Is(e, syscall.ECONNREFUSED) || errors.Is(e, io.ErrUnexpectedEOF) ||
+		errors.Is(e, net.ErrClosed) || errors.Is(e, puddle.ErrClosedPool) {
+		status, code = http.StatusServiceUnavailable, "unavailable"
+	}
+	err(c, status, code, "db error")
+}
+
+func (h *H) AuthMw() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		hdr := c.GetHeader("Authorization")
+		tok, ok := strings.CutPrefix(hdr, "Bearer ")
+		if !ok {
+			err(c, http.StatusUnauthorized, "unauthorized", "missing bearer token")
+			return
+		}
+		cl, perr := auth.Parse(h.cfg.JWTSecret, tok)
+		if perr != nil {
+			err(c, http.StatusUnauthorized, "unauthorized", "invalid token")
+			return
+		}
+		c.Set("uid", cl.UID)
+		c.Set("role", cl.Role)
+		c.Next()
+	}
+}
+
+func (h *H) AdminOnly() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		if c.GetString("role") != "admin" {
+			err(c, http.StatusForbidden, "forbidden", "admin only")
+			return
+		}
+		c.Next()
+	}
+}
+
+func uid(c *gin.Context) int64    { return c.GetInt64("uid") }
+func isAdmin(c *gin.Context) bool { return c.GetString("role") == "admin" }