MM-45317: global drafts endpoints and ws events (#20614)

* MM-23881: global drafts endpoints and ws events

Adds endpoints:
- create/update drafts
- delete draft
- get drafts

Adds WS events:
- draft_updated
- draft_created
- draft_deleted

* Ordering and WS event name fixes

* Adds PostID to the drafts table

In the future the drafts will include edited posts, this commit adds the
post id in the combined pkey of the table.

* Fixes route for deleting a thread draft

* Fixes failed checks

* Fixes migrations

* Fixes migration

* Extract translation strings

* Removes PostID since we won't sync editing posts

* Fixes tests

* Fixes i18n

* Update migrations for global drafts

* update branch with latest master changes

* Add feature flag for global drafts

* Set global drafts feature flag default to true

* Added support for files in drafts

* Fix failing i18n check

* Added support for deleting files in drafts

* Revert "Added support for deleting files in drafts"

This reverts commit 45dfd04a760359de2e8814d652c9ef46daf994f6.

* Triggering new test server

* Add config setting 'AllowSyncedDrafts' for syncing drafts with server

* Triggering new test server

* Triggering new test server

* Add guard for config setting and add initial tests

* Fix i18n and lint errors

* Triggering new test server

* Add tests for drafts

* fix lint issues

* Add tests for model/draft

* Triggering new test server

* Triggering new test server

* Trigger new test server

* Address PR comments

* Change left join to regular join in GetDraftsForUser

* Fix broken test

Maybe consider adding an inclDeleted field if we want to get deleted drafts in the future

* fix translations

* Add store tests for drafts

* fix test naming

* remove comment

* update migrations

* set feature flag default to false

* update migrations

Co-authored-by: Mylon Suren <mylonsuren@gmail.com>
Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

model/draft.go

@@ -0,0 +1,101 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package model
+
+import (
+	"net/http"
+	"sync"
+	"unicode/utf8"
+)
+
+type Draft struct {
+	CreateAt  int64  `json:"create_at"`
+	UpdateAt  int64  `json:"update_at"`
+	DeleteAt  int64  `json:"delete_at"`
+	UserId    string `json:"user_id"`
+	ChannelId string `json:"channel_id"`
+	RootId    string `json:"root_id"`
+
+	Message string `json:"message"`
+
+	propsMu  sync.RWMutex    `db:"-"`       // Unexported mutex used to guard Draft.Props.
+	Props    StringInterface `json:"props"` // Deprecated: use GetProps()
+	FileIds  StringArray     `json:"file_ids,omitempty"`
+	Metadata *PostMetadata   `json:"metadata,omitempty"`
+}
+
+func (o *Draft) IsValid(maxDraftSize int) *AppError {
+	if o.CreateAt == 0 {
+		return NewAppError("Drafts.IsValid", "model.draft.is_valid.create_at.app_error", nil, "channelid="+o.ChannelId, http.StatusBadRequest)
+	}
+
+	if o.UpdateAt == 0 {
+		return NewAppError("Drafts.IsValid", "model.draft.is_valid.update_at.app_error", nil, "channelid="+o.ChannelId, http.StatusBadRequest)
+	}
+
+	if !IsValidId(o.UserId) {
+		return NewAppError("Drafts.IsValid", "model.draft.is_valid.user_id.app_error", nil, "", http.StatusBadRequest)
+	}
+
+	if !IsValidId(o.ChannelId) {
+		return NewAppError("Drafts.IsValid", "model.draft.is_valid.channel_id.app_error", nil, "", http.StatusBadRequest)
+	}
+
+	if !(IsValidId(o.RootId) || o.RootId == "") {
+		return NewAppError("Drafts.IsValid", "model.draft.is_valid.root_id.app_error", nil, "", http.StatusBadRequest)
+	}
+
+	if utf8.RuneCountInString(o.Message) > maxDraftSize {
+		return NewAppError("Drafts.IsValid", "model.draft.is_valid.msg.app_error", nil, "channelid="+o.ChannelId, http.StatusBadRequest)
+	}
+
+	if utf8.RuneCountInString(ArrayToJSON(o.FileIds)) > PostFileidsMaxRunes {
+		return NewAppError("Drafts.IsValid", "model.draft.is_valid.file_ids.app_error", nil, "channelid="+o.ChannelId, http.StatusBadRequest)
+	}
+
+	if utf8.RuneCountInString(StringInterfaceToJSON(o.GetProps())) > PostPropsMaxRunes {
+		return NewAppError("Drafts.IsValid", "model.draft.is_valid.props.app_error", nil, "channelid="+o.ChannelId, http.StatusBadRequest)
+	}
+
+	return nil
+}
+
+func (o *Draft) SetProps(props StringInterface) {
+	o.propsMu.Lock()
+	defer o.propsMu.Unlock()
+	o.Props = props
+}
+
+func (o *Draft) GetProps() StringInterface {
+	o.propsMu.RLock()
+	defer o.propsMu.RUnlock()
+	return o.Props
+}
+
+func (o *Draft) PreSave() {
+	if o.CreateAt == 0 {
+		o.CreateAt = GetMillis()
+	}
+
+	o.UpdateAt = o.CreateAt
+	o.PreCommit()
+}
+
+func (o *Draft) PreCommit() {
+	if o.GetProps() == nil {
+		o.SetProps(make(map[string]interface{}))
+	}
+
+	if o.FileIds == nil {
+		o.FileIds = []string{}
+	}
+
+	// There's a rare bug where the client sends up duplicate FileIds so protect against that
+	o.FileIds = RemoveDuplicateStrings(o.FileIds)
+}
+
+func (o *Draft) PreUpdate() {
+	o.UpdateAt = GetMillis()
+	o.PreCommit()
+}