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/app/slashcommands/auto_channels.go

@@ -0,0 +1,79 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package slashcommands
+
+import (
+	"github.com/mattermost/mattermost-server/v6/model"
+	"github.com/mattermost/mattermost-server/v6/server/channels/app"
+	"github.com/mattermost/mattermost-server/v6/server/channels/app/request"
+	"github.com/mattermost/mattermost-server/v6/server/channels/utils"
+)
+
+type AutoChannelCreator struct {
+	a                  *app.App
+	userID             string
+	team               *model.Team
+	Fuzzy              bool
+	DisplayNameLen     utils.Range
+	DisplayNameCharset string
+	NameLen            utils.Range
+	NameCharset        string
+	ChannelType        model.ChannelType
+	CreateTime         int64
+}
+
+func NewAutoChannelCreator(a *app.App, team *model.Team, userID string) *AutoChannelCreator {
+	return &AutoChannelCreator{
+		a:                  a,
+		team:               team,
+		userID:             userID,
+		Fuzzy:              false,
+		DisplayNameLen:     ChannelDisplayNameLen,
+		DisplayNameCharset: utils.ALPHANUMERIC,
+		NameLen:            ChannelNameLen,
+		NameCharset:        utils.LOWERCASE,
+		ChannelType:        ChannelType,
+		CreateTime:         0,
+	}
+}
+
+func (cfg *AutoChannelCreator) createRandomChannel(c request.CTX) (*model.Channel, error) {
+	var displayName string
+	if cfg.Fuzzy {
+		displayName = utils.FuzzName()
+	} else {
+		displayName = utils.RandomName(cfg.NameLen, cfg.NameCharset)
+	}
+	name := utils.RandomName(cfg.NameLen, cfg.NameCharset)
+
+	channel := &model.Channel{
+		TeamId:      cfg.team.Id,
+		DisplayName: displayName,
+		Name:        name,
+		Type:        cfg.ChannelType,
+		CreatorId:   cfg.userID,
+		CreateAt:    cfg.CreateTime,
+	}
+
+	channel, err := cfg.a.CreateChannel(c, channel, true)
+	if err != nil {
+		return nil, err
+	}
+	return channel, nil
+}
+
+func (cfg *AutoChannelCreator) CreateTestChannels(c request.CTX, num utils.Range) ([]*model.Channel, error) {
+	numChannels := utils.RandIntFromRange(num)
+	channels := make([]*model.Channel, numChannels)
+
+	for i := 0; i < numChannels; i++ {
+		var err error
+		channels[i], err = cfg.createRandomChannel(c)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return channels, nil
+}