instagram: new extraction method

new extraction method first tries to fetch content directly from instagram graphql API, fallback to html embed page. in case every method fail, rely on 3rd party

ext/instagram/main.go

@@ -10,24 +10,7 @@ import (
 	"regexp"
 )
 
-// as a public service, we can't use the official API
-// so we use igram.world API, a third-party service
-// that provides a similar functionality
-// feel free to open PR, if you want to
-// add support for the official Instagram API
-
-const (
-	apiHostname  = "api.igram.world"
-	apiKey       = "aaeaf2805cea6abef3f9d2b6a666fce62fd9d612a43ab772bb50ce81455112e0"
-	apiTimestamp = "1742201548873"
-
-	// todo: Implement a proper way
-	// to get the API key and timestamp
-)
-
-var instagramHost = []string{
-	"instagram.com",
-}
+var instagramHost = []string{"instagram.com"}
 
 var Extractor = &models.Extractor{
 	Name:       "Instagram",
@@ -39,10 +22,28 @@ var Extractor = &models.Extractor{
 	IsRedirect: false,
 
 	Run: func(ctx *models.DownloadContext) (*models.ExtractorResponse, error) {
-		mediaList, err := MediaListFromAPI(ctx, false)
-		return &models.ExtractorResponse{
-			MediaList: mediaList,
-		}, err
+		// method 1: get media from GQL web API
+		mediaList, err := GetGQLMediaList(ctx)
+		if err == nil && len(mediaList) > 0 {
+			return &models.ExtractorResponse{
+				MediaList: mediaList,
+			}, nil
+		}
+		// method 2: get media from embed page
+		mediaList, err = GetEmbedMediaList(ctx)
+		if err == nil && len(mediaList) > 0 {
+			return &models.ExtractorResponse{
+				MediaList: mediaList,
+			}, nil
+		}
+		// method 3: get media from 3rd party service (unlikely)
+		mediaList, err = GetIGramMediaList(ctx)
+		if err == nil && len(mediaList) > 0 {
+			return &models.ExtractorResponse{
+				MediaList: mediaList,
+			}, nil
+		}
+		return nil, fmt.Errorf("failed to extract media: all methods failed")
 	},
 }
 
@@ -56,7 +57,7 @@ var StoriesExtractor = &models.Extractor{
 	IsRedirect: false,
 
 	Run: func(ctx *models.DownloadContext) (*models.ExtractorResponse, error) {
-		mediaList, err := MediaListFromAPI(ctx, true)
+		mediaList, err := GetIGramMediaList(ctx)
 		return &models.ExtractorResponse{
 			MediaList: mediaList,
 		}, err
@@ -88,31 +89,63 @@ var ShareURLExtractor = &models.Extractor{
 	},
 }
 
-func MediaListFromAPI(
+func GetGQLMediaList(
 	ctx *models.DownloadContext,
-	stories bool,
 ) ([]*models.Media, error) {
-	client := util.GetHTTPClient(ctx.Extractor.CodeName)
+	graphData, err := GetGQLData(ctx, ctx.MatchedContentID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get graph data: %w", err)
+	}
+	return ParseGQLMedia(ctx, graphData.ShortcodeMedia)
+}
 
+func GetEmbedMediaList(
+	ctx *models.DownloadContext,
+) ([]*models.Media, error) {
+	session := util.GetHTTPClient(ctx.Extractor.CodeName)
+	embedURL := fmt.Sprintf("https://www.instagram.com/p/%s/embed/captioned", ctx.MatchedContentID)
+	req, err := http.NewRequest(
+		http.MethodGet,
+		embedURL,
+		nil,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+	for key, value := range igHeaders {
+		req.Header.Set(key, value)
+	}
+	resp, err := session.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to send request: %w", err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("failed to get embed page: %s", resp.Status)
+	}
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read response body: %w", err)
+	}
+	graphData, err := ParseEmbedGQL(body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse embed page: %w", err)
+	}
+	return ParseGQLMedia(ctx, graphData)
+}
+
+func GetIGramMediaList(ctx *models.DownloadContext) ([]*models.Media, error) {
 	var mediaList []*models.Media
 	postURL := ctx.MatchedContentURL
-	details, err := GetVideoAPI(client, postURL)
+	details, err := GetFromIGram(ctx, postURL)
 	if err != nil {
 		return nil, fmt.Errorf("failed to get post: %w", err)
 	}
-	var caption string
-	if !stories {
-		caption, err = GetPostCaption(client, postURL)
-		if err != nil {
-			return nil, fmt.Errorf("failed to get caption: %w", err)
-		}
-	}
 	for _, item := range details.Items {
 		media := ctx.Extractor.NewMedia(
 			ctx.MatchedContentID,
 			ctx.MatchedContentURL,
 		)
-		media.SetCaption(caption)
 		urlObj := item.URL[0]
 		contentURL, err := GetCDNURL(urlObj.URL)
 		if err != nil {
@@ -150,26 +183,27 @@ func MediaListFromAPI(
 	return mediaList, nil
 }
 
-func GetVideoAPI(
-	client models.HTTPClient,
+func GetFromIGram(
+	ctx *models.DownloadContext,
 	contentURL string,
 ) (*IGramResponse, error) {
+	session := util.GetHTTPClient(ctx.Extractor.CodeName)
 	apiURL := fmt.Sprintf(
 		"https://%s/api/convert",
-		apiHostname,
+		igramHostname,
 	)
-	payload, err := BuildSignedPayload(contentURL)
+	payload, err := BuildIGramPayload(contentURL)
 	if err != nil {
 		return nil, fmt.Errorf("failed to build signed payload: %w", err)
 	}
-	req, err := http.NewRequest(http.MethodPost, apiURL, payload)
+	req, err := http.NewRequest("POST", apiURL, payload)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create request: %w", err)
 	}
 	req.Header.Set("Content-Type", "application/json")
 	req.Header.Set("User-Agent", util.ChromeUA)
 
-	resp, err := client.Do(req)
+	resp, err := session.Do(req)
 	if err != nil {
 		return nil, fmt.Errorf("failed to send request: %w", err)
 	}