Feature: Support downloading collections and individual episodes

README.md

@@ -22,7 +22,7 @@
 <!-- ABOUT THE PROJECT -->
 ## About The Project
 
-`audiotheker` allows downloading all episodes of a program in the [ARD Audiothek](https://www.ardaudiothek.de/). It queries the official [GraphQL API](https://api.ardaudiothek.de/docs/#/GraphQL) to gather the download URLs.
+`audiotheker` allows downloading all episodes of a program/collection or an individual episode in the [ARD Audiothek](https://www.ardaudiothek.de/). It queries the official [GraphQL API](https://api.ardaudiothek.de/docs/#/GraphQL) to gather the download URLs.
 
 <p align="right">(<a href="#top">back to top</a>)</p>
 
@@ -77,7 +77,10 @@
 <!-- USAGE EXAMPLES -->
 ## Usage
 
+Copy the URL to a program, collection, or an individual episode from your browser and provide the URL and a target directory to the binary or a Docker container.
+
 ### Built binary
+
 ```sh
 $ ./audiotheker download \
    "https://www.ardaudiothek.de/sendung/j-r-r-tolkien-der-herr-der-ringe-fantasy-hoerspiel-klassiker/12197351/" \

cmd/download.go

@@ -16,6 +16,17 @@ import (
 	"github.com/spf13/cobra"
 )
 
+var GRAPHQL_ENDPOINT = "https://api.ardaudiothek.de/graphql"
+
+type QueryType int64
+
+const (
+	Episode QueryType = iota
+	Collection
+	Program
+	Unknown
+)
+
 func init() {
 	rootCmd.AddCommand(downloadCmd)
 }
@@ -58,7 +69,7 @@ func downloadFile(url string, targetDirectory string) (err error) {
 	return nil
 }
 
-func extractDownloadUrls(response *Response) []string {
+func extractDownloadUrls(response *ItemsResponse) []string {
 	var urls []string
 
 	for _, nodes := range response.Result.Items.Nodes {
@@ -72,13 +83,37 @@ func extractDownloadUrls(response *Response) []string {
 	return urls
 }
 
-func extractProgramId(url string) string {
+func extractQueryId(url string) (string, QueryType) {
 	normalizedUrl := strings.TrimSuffix(url, "/")
-	pattern := regexp.MustCompile(`^https:\/\/www\.ardaudiothek\.de\/sendung\/.*\/(\d*)$`)
-	return pattern.FindStringSubmatch(normalizedUrl)[1]
+
+	// Program
+	programPattern := regexp.MustCompile(`^https:\/\/www\.ardaudiothek\.de\/sendung\/.*\/(\d*)$`)
+	matches := programPattern.FindStringSubmatch(normalizedUrl)
+
+	if matches != nil {
+		return matches[1], Program
+	}
+
+	// Collection
+	collectionPattern := regexp.MustCompile(`^https:\/\/www\.ardaudiothek\.de\/sammlung\/.*\/(\d*)$`)
+	matches = collectionPattern.FindStringSubmatch(normalizedUrl)
+
+	if matches != nil {
+		return matches[1], Collection
+	}
+
+	// Episode
+	episodePattern := regexp.MustCompile(`^https:\/\/www\.ardaudiothek\.de\/episode\/.*\/(\d*)$`)
+	matches = episodePattern.FindStringSubmatch(normalizedUrl)
+
+	if matches != nil {
+		return matches[1], Episode
+	}
+
+	return "", Unknown
 }
 
-type Response struct {
+type ItemsResponse struct {
 	Result struct {
 		Items struct {
 			Nodes []struct {
@@ -90,11 +125,22 @@ type Response struct {
 	}
 }
 
-func run(url string, targetDirectory string) {
-	programId := extractProgramId(url)
+func sendGraphQlQuery(query string, variables map[string]interface{}, response interface{}) error {
+	client := graphql.NewClient(GRAPHQL_ENDPOINT, nil)
 
-	client := graphql.NewClient("https://api.ardaudiothek.de/graphql", nil)
+	rawGraphqlResponse, graphQlErr := client.ExecRaw(context.Background(), query, variables)
+	if graphQlErr != nil {
+		return graphQlErr
+	}
 
+	if jsonError := json.Unmarshal(rawGraphqlResponse, &response); jsonError != nil {
+		return jsonError
+	}
+
+	return nil
+}
+
+func getProgramUrls(queryId string) ([]string, error) {
 	query := `query ProgramSetEpisodesQuery($id: ID!, $offset: Int!, $count: Int!) {
 		result: programSet(id: $id) {
 			items(
@@ -111,30 +157,126 @@ func run(url string, targetDirectory string) {
 			}
 		}
   	}`
-
 	variables := map[string]interface{}{
-		"id":     programId,
+		"id":     queryId,
 		"offset": 0,
 		"count":  100,
 	}
 
-	rawGraphqlResponse, graphQlErr := client.ExecRaw(context.Background(), query, variables)
-	if graphQlErr != nil {
-		panic(graphQlErr)
+	var response ItemsResponse
+	graphQlError := sendGraphQlQuery(query, variables, &response)
+
+	if graphQlError != nil {
+		return nil, graphQlError
 	}
 
-	var response Response
-	if jsonError := json.Unmarshal(rawGraphqlResponse, &response); jsonError != nil {
-		panic(jsonError)
+	urls := extractDownloadUrls(&response)
+
+	return urls, nil
+}
+
+func getCollectionUrls(queryId string) ([]string, error) {
+	query := `query EpisodesQuery($id: ID!, $offset: Int!, $limit: Int!) {
+		result: editorialCollection(id: $id, offset: $offset, limit: $limit) {
+			items {
+				nodes {
+			  		id
+			  		audios {
+						url
+						downloadUrl
+						allowDownload
+			  		}
+				}
+		  	}
+		}
+	}`
+	variables := map[string]interface{}{
+		"id":     queryId,
+		"offset": 0,
+		"limit":  100,
+	}
+
+	var response ItemsResponse
+	graphQlError := sendGraphQlQuery(query, variables, &response)
+
+	if graphQlError != nil {
+		return nil, graphQlError
 	}
 
 	urls := extractDownloadUrls(&response)
 
+	return urls, nil
+}
+
+type ItemResponse struct {
+	Result struct {
+		Audios []struct {
+			DownloadUrl *string
+		}
+	}
+}
+
+func getEpisodeUrls(queryId string) ([]string, error) {
+	query := `query EpisodeQuery($id: ID!) {
+		result: item(id: $id) {
+		  	audios {
+				downloadUrl
+		  	}
+		}
+	}`
+	variables := map[string]interface{}{
+		"id": queryId,
+	}
+
+	var response ItemResponse
+	graphQlError := sendGraphQlQuery(query, variables, &response)
+
+	if graphQlError != nil {
+		return nil, graphQlError
+	}
+
+	var urls []string
+	for _, audios := range response.Result.Audios {
+		if audios.DownloadUrl != nil {
+			if *audios.DownloadUrl != "" {
+				urls = append(urls, *audios.DownloadUrl)
+			}
+		}
+	}
+
+	return urls, nil
+}
+
+func getDownloadUrls(url string) ([]string, error) {
+	queryId, queryType := extractQueryId(url)
+
+	switch queryType {
+	case Episode:
+		return getEpisodeUrls(queryId)
+
+	case Collection:
+		return getCollectionUrls(queryId)
+
+	case Program:
+		return getProgramUrls(queryId)
+
+	default:
+		return nil, fmt.Errorf("URL is not supported: %s", url)
+	}
+}
+
+func run(url string, targetDirectory string) {
+	urls, err := getDownloadUrls(url)
+
+	if err != nil {
+		panic(err)
+	}
+
 	for _, url := range urls {
 		downloadErr := downloadFile(url, targetDirectory)
 
 		if downloadErr != nil {
-			fmt.Printf("Downloading URL %s failed with error: %v\n", url, downloadErr)
+			fmt.Printf("Downloading file %s failed with error: %v\n", url, downloadErr)
 		}
 	}
 }