implmented download file

internal/s3Broswer.go

@@ -2,8 +2,11 @@ package s3browser
 
 import (
 	"context"
+	"fmt"
+	"io"
 	"log"
 	"net/http"
+	"path/filepath"
 
 	"github.com/graph-gophers/dataloader"
 	"github.com/graphql-go/graphql"
@@ -56,6 +59,30 @@ func initHttp(schema graphql.Schema, s3Client *minio.Client, loaderMap map[strin
 		h.ContextHandler(resolveContext, rw, r)
 	})
 
+	http.HandleFunc("/api/file", func(rw http.ResponseWriter, r *http.Request) {
+		id := r.URL.Query().Get("id")
+		objInfo, err := s3Client.StatObject(context.Background(), bucketName, id, minio.GetObjectOptions{})
+
+		if err != nil {
+			rw.WriteHeader(500)
+			return
+		}
+
+		obj, err := s3Client.GetObject(context.Background(), bucketName, id, minio.GetObjectOptions{})
+
+		if err != nil {
+			rw.WriteHeader(500)
+			return
+		}
+
+		rw.Header().Set("Cache-Control", "no-store")
+		rw.Header().Set("Content-Disposition", fmt.Sprintf("attachment; filename=\"%s\"", filepath.Base((objInfo.Key))))
+		rw.Header().Set("Content-Type", objInfo.ContentType)
+		rw.Header().Set("ETag", objInfo.ETag)
+
+		io.Copy(rw, obj)
+	})
+
 	http.ListenAndServe(":8080", nil)
 }