ticketmaster: Support retrieving more than 1k events

pkg/ticketmaster/api.go

@@ -39,26 +39,48 @@ func NewReader(apiKey string) *Reader {
 
 func (r *Reader) GetEvents(params map[string]string) ([]*Event, error) {
 	// Construct the URL from the params
-	url := fmt.Sprintf(getEventsURL, r.apiKey)
+	rootURL := fmt.Sprintf(getEventsURL, r.apiKey)
 	for key, value := range params {
-		url += fmt.Sprintf("&%s=%s", key, value)
+		rootURL += fmt.Sprintf("&%s=%s", key, value)
 	}
 
-	// TODO: Offset by startDate=events[-1].date to avoid the 1k results limit.
+	url := rootURL
 	var events []*Event
 	for {
-		resp := &getEventsResponse{}
-		err := query(url, resp)
-		if err != nil {
-			return nil, err
+		// The ticketmaster API only lets us paginate until we hit 1000 results. To circumvent this
+		// we will make use of the startDate of the last event we found to start a new search.
+		var eventsFromPagination int
+		for {
+			resp := &getEventsResponse{}
+			err := query(url, resp)
+			if err != nil {
+				return nil, err
+			}
+			if len(resp.Embedded.Events) == 0 {
+				break
+			}
+			events = append(events, resp.Embedded.Events...)
+			eventsFromPagination += len(resp.Embedded.Events)
+
+			next, ok := resp.Links["next"]
+			if !ok {
+				break
+			}
+
+			// If we continue to query after we've retrieved 1000 results we'll hit an error.
+			if eventsFromPagination >= 1000 {
+				break
+			}
+			url = fmt.Sprintf("%s%s&apikey=%s", apiURL, next.URL, r.apiKey)
 		}
-		events = append(events, resp.Embedded.Events...)
 
-		next, ok := resp.Links["next"]
-		if !ok {
+		// If we haven't found a multiple of 1000 then we weren't limited by ticketmaster and
+		// instead simply ran out of events.
+		if len(events)%1000 != 0 {
 			break
 		}
-		url = fmt.Sprintf("%s%s&apikey=%s", apiURL, next.URL, r.apiKey)
+
+		url = fmt.Sprintf("%s&startDateTime=%s", rootURL, events[len(events)-1].Dates.Start.DateTime)
 	}
 
 	return events, nil
@@ -72,6 +94,10 @@ func query[T any](url string, target T) error {
 	}
 	defer resp.Body.Close()
 
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("%q returned %q", url, resp.Status)
+	}
+
 	if err := json.NewDecoder(resp.Body).Decode(&target); err != nil {
 		return err
 	}

pkg/ticketmaster/events.go

@@ -16,6 +16,7 @@ type Venue struct {
 type Date struct {
 	LocalDate string `json:"localDate"`
 	LocalTime string `json:"localTime"`
+	DateTime  string `json:"dateTime"`
 }
 
 type Event struct {