feat: add Gin HTTP API with SSE streaming chat

internal/api/handler_index.go

@@ -0,0 +1,27 @@
+package api
+
+import (
+	"net/http"
+
+	"eino-test/config"
+	"eino-test/internal/rag"
+
+	"github.com/gin-gonic/gin"
+)
+
+type IndexHandler struct {
+	pipeline *rag.RAGPipeline
+	cfg      *config.Config
+}
+
+func NewIndexHandler(pipeline *rag.RAGPipeline, cfg *config.Config) *IndexHandler {
+	return &IndexHandler{pipeline: pipeline, cfg: cfg}
+}
+
+func (h *IndexHandler) RebuildIndex(c *gin.Context) {
+	if err := h.pipeline.IndexAllFromDir(c.Request.Context(), h.cfg.DataDir); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"message": "index rebuilt"})
+}