Use mattermost v5 module (#1192)

vendor/github.com/mattermost/mattermost-server/v5/model/scheduled_task.go

@@ -0,0 +1,77 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package model
+
+import (
+	"fmt"
+	"time"
+)
+
+type TaskFunc func()
+
+type ScheduledTask struct {
+	Name      string        `json:"name"`
+	Interval  time.Duration `json:"interval"`
+	Recurring bool          `json:"recurring"`
+	function  func()
+	cancel    chan struct{}
+	cancelled chan struct{}
+}
+
+func CreateTask(name string, function TaskFunc, timeToExecution time.Duration) *ScheduledTask {
+	return createTask(name, function, timeToExecution, false)
+}
+
+func CreateRecurringTask(name string, function TaskFunc, interval time.Duration) *ScheduledTask {
+	return createTask(name, function, interval, true)
+}
+
+func createTask(name string, function TaskFunc, interval time.Duration, recurring bool) *ScheduledTask {
+	task := &ScheduledTask{
+		Name:      name,
+		Interval:  interval,
+		Recurring: recurring,
+		function:  function,
+		cancel:    make(chan struct{}),
+		cancelled: make(chan struct{}),
+	}
+
+	go func() {
+		defer close(task.cancelled)
+
+		ticker := time.NewTicker(interval)
+		defer func() {
+			ticker.Stop()
+		}()
+
+		for {
+			select {
+			case <-ticker.C:
+				function()
+			case <-task.cancel:
+				return
+			}
+
+			if !task.Recurring {
+				break
+			}
+		}
+	}()
+
+	return task
+}
+
+func (task *ScheduledTask) Cancel() {
+	close(task.cancel)
+	<-task.cancelled
+}
+
+func (task *ScheduledTask) String() string {
+	return fmt.Sprintf(
+		"%s\nInterval: %s\nRecurring: %t\n",
+		task.Name,
+		task.Interval.String(),
+		task.Recurring,
+	)
+}