Correctly encode url in fallback embed && better error handling

Author: ItsOnlyBinary

fallback-embed/fallback-embed-provider.go

@@ -6,6 +6,7 @@ import (
 	"io"
 	"io/ioutil"
 	"net/http"
+	"net/url"
 	"regexp"
 	"strconv"
 	"strings"
@@ -57,13 +58,13 @@ func (f *FallbackEmbed) ParseProviders(buf io.Reader) error {
 }
 
 // Get returns html string
-func (f *FallbackEmbed) Get(url string, width int, height int) (html string, err error) {
-	if !f.ValidURL(url) {
+func (f *FallbackEmbed) Get(wantedURL string, width int, height int) (html string, err error) {
+	if !f.ValidURL(wantedURL) {
 		return
 	}
 
 	// Do replacements
-	reqURL := strings.Replace(f.providerURL, "{url}", url, 1)
+	reqURL := strings.Replace(f.providerURL, "{url}", url.QueryEscape(wantedURL), 1)
 	reqURL = strings.Replace(reqURL, "{width}", strconv.Itoa(width), 1)
 	reqURL = strings.Replace(reqURL, "{height}", strconv.Itoa(height), 1)
 
@@ -96,7 +97,16 @@ func (f *FallbackEmbed) Get(url string, width int, height int) (html string, err
 		}
 	}
 
-	err = errors.New("Failed to get target json key")
+	// Check for error key in json response
+	if jsonVal, ok := resp["error"]; ok {
+		// Check error is string
+		if errorString, ok := jsonVal.(string); ok {
+			err = errors.New(errorString)
+			return
+		}
+	}
+
+	err = errors.New(`Fallback embed provider did not include a JSON property of "` + f.targetKey + `"`)
 	return
 }
 

server/web-preview.go

@@ -7,6 +7,7 @@ import (
 	"encoding/hex"
 	"errors"
 	"io/ioutil"
+	"log"
 	"net/http"
 	"net/url"
 	"os"
@@ -233,6 +234,7 @@ func (serv *UploadServer) handleImageCache(c *gin.Context) {
 
 func (serv *UploadServer) handleWebPreview(c *gin.Context) {
 	queryURL := c.Query("url")
+	log.Printf("queryURL: " + queryURL)
 	if !isValidURL(queryURL) {
 		c.AbortWithStatus(http.StatusBadRequest)
 		return
@@ -319,13 +321,13 @@ func (serv *UploadServer) handleWebPreview(c *gin.Context) {
 
 		// No embedable html, time to try our fallback provider
 		if item.html == "" && !fallbackEmbedDisabled {
-			noEmbedResp, err := fallbackEmbed.Get(queryURL, width, height)
+			fallbackEmbedResp, err := fallbackEmbed.Get(queryURL, width, height)
 			if err != nil {
 				serv.log.Error().
 					Err(err).
-					Msg("Unexpected error in noEmbed")
+					Msg("Unexpected error in fallback embed")
 			} else {
-				item.html = noEmbedResp
+				item.html = fallbackEmbedResp
 			}
 		}