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/email/notification_email.go

@@ -0,0 +1,136 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package email
+
+import (
+	"html"
+	"html/template"
+	"net/url"
+	"path/filepath"
+	"strings"
+
+	"github.com/mattermost/mattermost-server/v6/model"
+	"github.com/mattermost/mattermost-server/v6/server/channels/utils"
+	"github.com/mattermost/mattermost-server/v6/server/platform/shared/i18n"
+	"github.com/mattermost/mattermost-server/v6/server/platform/shared/mlog"
+)
+
+type FieldRow struct {
+	Cells []*model.SlackAttachmentField
+}
+
+type EmailMessageAttachment struct {
+	model.SlackAttachment
+
+	Pretext   template.HTML
+	Text      template.HTML
+	FieldRows []FieldRow
+}
+
+func (es *Service) GetMessageForNotification(post *model.Post, translateFunc i18n.TranslateFunc) string {
+	if strings.TrimSpace(post.Message) != "" || len(post.FileIds) == 0 {
+		return post.Message
+	}
+
+	// extract the filenames from their paths and determine what type of files are attached
+	infos, err := es.store.FileInfo().GetForPost(post.Id, true, false, true)
+	if err != nil {
+		mlog.Warn("Encountered error when getting files for notification message", mlog.String("post_id", post.Id), mlog.Err(err))
+	}
+
+	filenames := make([]string, len(infos))
+	onlyImages := true
+	for i, info := range infos {
+		if escaped, err := url.QueryUnescape(filepath.Base(info.Name)); err != nil {
+			// this should never error since filepath was escaped using url.QueryEscape
+			filenames[i] = escaped
+		} else {
+			filenames[i] = info.Name
+		}
+
+		onlyImages = onlyImages && info.IsImage()
+	}
+
+	props := map[string]any{"Filenames": strings.Join(filenames, ", ")}
+
+	if onlyImages {
+		return translateFunc("api.post.get_message_for_notification.images_sent", len(filenames), props)
+	}
+	return translateFunc("api.post.get_message_for_notification.files_sent", len(filenames), props)
+}
+
+func ProcessMessageAttachments(post *model.Post, siteURL string) []*EmailMessageAttachment {
+	emailMessageAttachments := []*EmailMessageAttachment{}
+
+	for _, messageAttachment := range post.Attachments() {
+		emailMessageAttachment := &EmailMessageAttachment{
+			SlackAttachment: *messageAttachment,
+			Pretext:         prepareTextForEmail(messageAttachment.Pretext, siteURL),
+			Text:            prepareTextForEmail(messageAttachment.Text, siteURL),
+		}
+
+		stripedTitle, err := utils.StripMarkdown(emailMessageAttachment.Title)
+		if err != nil {
+			mlog.Warn("Failed parse to markdown from messageatatchment title", mlog.String("post_id", post.Id), mlog.Err(err))
+			stripedTitle = ""
+		}
+
+		emailMessageAttachment.Title = stripedTitle
+
+		shortFieldRow := FieldRow{}
+
+		for i := range messageAttachment.Fields {
+			// Create a new instance to avoid altering the original pointer reference
+			// We update field value to parse markdown.
+			// If we do that on the original pointer, the rendered text in mattermost
+			// becomes invalid as its no longer a markdown string, but rather an HTML string.
+			field := &model.SlackAttachmentField{
+				Title: messageAttachment.Fields[i].Title,
+				Value: messageAttachment.Fields[i].Value,
+				Short: messageAttachment.Fields[i].Short,
+			}
+
+			if stringValue, ok := field.Value.(string); ok {
+				field.Value = prepareTextForEmail(stringValue, siteURL)
+			}
+
+			if !field.Short {
+				if len(shortFieldRow.Cells) > 0 {
+					emailMessageAttachment.FieldRows = append(emailMessageAttachment.FieldRows, shortFieldRow)
+					shortFieldRow = FieldRow{}
+				}
+
+				emailMessageAttachment.FieldRows = append(emailMessageAttachment.FieldRows, FieldRow{[]*model.SlackAttachmentField{field}})
+			} else {
+				shortFieldRow.Cells = append(shortFieldRow.Cells, field)
+
+				if len(shortFieldRow.Cells) == 2 {
+					emailMessageAttachment.FieldRows = append(emailMessageAttachment.FieldRows, shortFieldRow)
+					shortFieldRow = FieldRow{}
+				}
+			}
+		}
+
+		// collect any leftover short fields
+		if len(shortFieldRow.Cells) > 0 {
+			emailMessageAttachment.FieldRows = append(emailMessageAttachment.FieldRows, shortFieldRow)
+			shortFieldRow = FieldRow{}
+		}
+
+		emailMessageAttachments = append(emailMessageAttachments, emailMessageAttachment)
+	}
+
+	return emailMessageAttachments
+}
+
+func prepareTextForEmail(text, siteURL string) template.HTML {
+	escapedText := html.EscapeString(text)
+	markdownText, err := utils.MarkdownToHTML(escapedText, siteURL)
+	if err != nil {
+		mlog.Warn("Encountered error while converting markdown to HTML", mlog.Err(err))
+		return template.HTML(text)
+	}
+
+	return template.HTML(markdownText)
+}