Mono repo -> Master (#22553)

Combines the following repositories into one:

https://github.com/mattermost/mattermost-server
https://github.com/mattermost/mattermost-webapp
https://github.com/mattermost/focalboard
https://github.com/mattermost/mattermost-plugin-playbooks

server/channels/jobs/base_schedulers.go

@@ -0,0 +1,84 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package jobs
+
+import (
+	"crypto/rand"
+	"math/big"
+	"time"
+
+	"github.com/mattermost/mattermost-server/v6/model"
+)
+
+type PeriodicScheduler struct {
+	jobs        *JobServer
+	period      time.Duration
+	jobType     string
+	enabledFunc func(cfg *model.Config) bool
+}
+
+func NewPeriodicScheduler(jobs *JobServer, jobType string, period time.Duration, enabledFunc func(cfg *model.Config) bool) *PeriodicScheduler {
+	return &PeriodicScheduler{
+		period:      period,
+		jobType:     jobType,
+		enabledFunc: enabledFunc,
+		jobs:        jobs,
+	}
+}
+
+func (scheduler *PeriodicScheduler) Enabled(cfg *model.Config) bool {
+	return scheduler.enabledFunc(cfg)
+}
+
+func (scheduler *PeriodicScheduler) NextScheduleTime(_ *model.Config, _ time.Time /* pendingJobs */, _ bool /* lastSuccessfulJob */, _ *model.Job) *time.Time {
+	nextTime := time.Now().Add(getRandomDelay(jitterRange)).Add(scheduler.period)
+	return &nextTime
+}
+
+func (scheduler *PeriodicScheduler) ScheduleJob(_ *model.Config /* pendingJobs */, _ bool /* lastSuccessfulJob */, _ *model.Job) (*model.Job, *model.AppError) {
+	return scheduler.jobs.CreateJob(scheduler.jobType, nil)
+}
+
+type DailyScheduler struct {
+	jobs          *JobServer
+	startTimeFunc func(cfg *model.Config) *time.Time
+	jobType       string
+	enabledFunc   func(cfg *model.Config) bool
+}
+
+func NewDailyScheduler(jobs *JobServer, jobType string, startTimeFunc func(cfg *model.Config) *time.Time, enabledFunc func(cfg *model.Config) bool) *DailyScheduler {
+	return &DailyScheduler{
+		startTimeFunc: startTimeFunc,
+		jobType:       jobType,
+		enabledFunc:   enabledFunc,
+		jobs:          jobs,
+	}
+}
+
+func (scheduler *DailyScheduler) Enabled(cfg *model.Config) bool {
+	return scheduler.enabledFunc(cfg)
+}
+
+func (scheduler *DailyScheduler) NextScheduleTime(cfg *model.Config, now time.Time /* pendingJobs */, _ bool /* lastSuccessfulJob */, _ *model.Job) *time.Time {
+	scheduledTime := scheduler.startTimeFunc(cfg)
+	if scheduledTime == nil {
+		return nil
+	}
+
+	return GenerateNextStartDateTime(now, *scheduledTime)
+}
+
+func (scheduler *DailyScheduler) ScheduleJob(_ *model.Config /* pendingJobs */, _ bool /* lastSuccessfulJob */, _ *model.Job) (*model.Job, *model.AppError) {
+	return scheduler.jobs.CreateJob(scheduler.jobType, nil)
+}
+
+const jitterRange = 2000 // milliseconds
+
+func getRandomDelay(limit int64) time.Duration {
+	num, err := rand.Int(rand.Reader, big.NewInt(limit))
+	if err != nil {
+		return time.Millisecond
+	}
+	return time.Millisecond * time.Duration(num.Int64())
+}