From ef0ff2512b2deab5c7e5b43b972ceb6c765039cf Mon Sep 17 00:00:00 2001
From: Ken Hibino <ken.hibino7@gmail.com>
Date: Sun, 6 Dec 2020 08:46:14 -0800
Subject: [PATCH] Add API endpoints to delete scheduled, retry, and dead task

---
 main.go          | 44 ++++++++++++++++++++------------------------
 task_handlers.go | 13 +++++++++++++
 2 files changed, 33 insertions(+), 24 deletions(-)

diff --git a/main.go b/main.go
index fdf2717..d5272cb 100644
--- a/main.go
+++ b/main.go
@@ -67,30 +67,26 @@ func main() {
 	router := mux.NewRouter()
 
 	api := router.PathPrefix("/api").Subrouter()
-	api.HandleFunc("/queues",
-		newListQueuesHandlerFunc(inspector)).Methods("GET")
-	api.HandleFunc("/queues/{qname}",
-		newGetQueueHandlerFunc(inspector)).Methods("GET")
-	api.HandleFunc("/queues/{qname}",
-		newDeleteQueueHandlerFunc(inspector)).Methods("DELETE")
-	api.HandleFunc("/queues/{qname}/pause",
-		newPauseQueueHandlerFunc(inspector)).Methods("POST")
-	api.HandleFunc("/queues/{qname}/resume",
-		newResumeQueueHandlerFunc(inspector)).Methods("POST")
-	api.HandleFunc("/queues/{qname}/active_tasks",
-		newListActiveTasksHandlerFunc(inspector)).Methods("GET")
-	api.HandleFunc("/queues/{qname}/active_tasks/{task_id}/cancel",
-		newCancelActiveTaskHandlerFunc(inspector)).Methods("POST")
-	api.HandleFunc("/queues/{qname}/pending_tasks",
-		newListPendingTasksHandlerFunc(inspector)).Methods("GET")
-	api.HandleFunc("/queues/{qname}/scheduled_tasks",
-		newListScheduledTasksHandlerFunc(inspector)).Methods("GET")
-	api.HandleFunc("/queues/{qname}/retry_tasks",
-		newListRetryTasksHandlerFunc(inspector)).Methods("GET")
-	api.HandleFunc("/queues/{qname}/dead_tasks",
-		newListDeadTasksHandlerFunc(inspector)).Methods("GET")
-	api.HandleFunc("/scheduler_entries",
-		newListSchedulerEntriesHandlerFunc(inspector)).Methods("GET")
+	// Queue endpoints.
+	api.HandleFunc("/queues", newListQueuesHandlerFunc(inspector)).Methods("GET")
+	api.HandleFunc("/queues/{qname}", newGetQueueHandlerFunc(inspector)).Methods("GET")
+	api.HandleFunc("/queues/{qname}", newDeleteQueueHandlerFunc(inspector)).Methods("DELETE")
+	api.HandleFunc("/queues/{qname}/pause", newPauseQueueHandlerFunc(inspector)).Methods("POST")
+	api.HandleFunc("/queues/{qname}/resume", newResumeQueueHandlerFunc(inspector)).Methods("POST")
+
+	// Task endpoints.
+	api.HandleFunc("/queues/{qname}/active_tasks", newListActiveTasksHandlerFunc(inspector)).Methods("GET")
+	api.HandleFunc("/queues/{qname}/active_tasks/{task_id}/cancel", newCancelActiveTaskHandlerFunc(inspector)).Methods("POST")
+	api.HandleFunc("/queues/{qname}/pending_tasks", newListPendingTasksHandlerFunc(inspector)).Methods("GET")
+	api.HandleFunc("/queues/{qname}/scheduled_tasks", newListScheduledTasksHandlerFunc(inspector)).Methods("GET")
+	api.HandleFunc("/queues/{qname}/scheduled_tasks/{task_key}", newDeleteTaskHandlerFunc(inspector)).Methods("DELETE")
+	api.HandleFunc("/queues/{qname}/retry_tasks", newListRetryTasksHandlerFunc(inspector)).Methods("GET")
+	api.HandleFunc("/queues/{qname}/retry_tasks/{task_key}", newDeleteTaskHandlerFunc(inspector)).Methods("DELETE")
+	api.HandleFunc("/queues/{qname}/dead_tasks", newListDeadTasksHandlerFunc(inspector)).Methods("GET")
+	api.HandleFunc("/queues/{qname}/dead_tasks/{task_key}", newDeleteTaskHandlerFunc(inspector)).Methods("DELETE")
+
+	// Scheduler Entry endpoints.
+	api.HandleFunc("/scheduler_entries", newListSchedulerEntriesHandlerFunc(inspector)).Methods("GET")
 
 	fs := &staticFileServer{staticPath: "ui/build", indexPath: "index.html"}
 	router.PathPrefix("/").Handler(fs)
diff --git a/task_handlers.go b/task_handlers.go
index 4921d3d..a371bfa 100644
--- a/task_handlers.go
+++ b/task_handlers.go
@@ -165,6 +165,19 @@ func newListDeadTasksHandlerFunc(inspector *asynq.Inspector) http.HandlerFunc {
 	}
 }
 
+func newDeleteTaskHandlerFunc(inspector *asynq.Inspector) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		vars := mux.Vars(r)
+		qname, key := vars["qname"], vars["task_key"]
+		if err := inspector.DeleteTaskByKey(qname, key); err != nil {
+			// TODO: Handle task not found error and return 404
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		w.WriteHeader(http.StatusNoContent)
+	}
+}
+
 // getPageOptions read page size and number from the request url if set,
 // otherwise it returns the default value.
 func getPageOptions(r *http.Request) (pageSize, pageNum int) {