[GH-47] [FIX] Agenda item number should get updated if the items of t…

…he agenda are deleted (#90)

server/command.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"regexp"
 	"strings"
 	"time"
 
@@ -16,6 +17,13 @@ const (
 	wsEventList = "list"
 )
 
+// ParsedMeetingMessage is meeting message after being parsed
+type ParsedMeetingMessage struct {
+	date        string
+	number      string
+	textMessage string
+}
+
 const helpCommandText = "###### Mattermost Agenda Plugin - Slash Command Help\n" +
 	"The Agenda plugin lets you queue up meeting topics for channel discussion at a later time.  When your meeting happens, you can click on the Hashtag to see all agenda items in the RHS. \n" +
 	"To configure the agenda for this channel, click on the Channel Name in Mattermost to access the channel options menu and select `Agenda Settings`" +
@@ -132,6 +140,11 @@ func (p *Plugin) executeCommandQueue(args *model.CommandArgs) *model.CommandResp
 		return responsef("Missing parameters for queue command")
 	}
 
+	meeting, err := p.GetMeeting(args.ChannelId)
+	if err != nil {
+		p.API.LogError("failed to get meeting for channel", "err", err.Error(), "channel_id", args.ChannelId)
+	}
+
 	nextWeek := false
 	weekday := -1
 	message := strings.Join(split[2:], " ")
@@ -147,25 +160,21 @@ func (p *Plugin) executeCommandQueue(args *model.CommandArgs) *model.CommandResp
 		message = strings.Join(split[3:], " ")
 	}
 
-	hashtag, error := p.GenerateHashtag(args.ChannelId, nextWeek, weekday)
-	if error != nil {
+	hashtag, err := p.GenerateHashtag(args.ChannelId, nextWeek, weekday)
+	if err != nil {
 		return responsef("Error calculating hashtags. Check the meeting settings for this channel.")
 	}
 
-	searchResults, appErr := p.API.SearchPostsInTeamForUser(args.TeamId, args.UserId, model.SearchParameter{Terms: &hashtag})
-
-	if appErr != nil {
-		return responsef("Error calculating list number")
+	numQueueItems, itemErr := p.calculateQueueItemNumberAndUpdateOldItems(meeting, args, hashtag)
+	if itemErr != nil {
+		return responsef(itemErr.Error())
 	}
 
-	postList := *searchResults.PostList
-	numQueueItems := len(postList.Posts)
-
-	_, appErr = p.API.CreatePost(&model.Post{
+	_, appErr := p.API.CreatePost(&model.Post{
 		UserId:    args.UserId,
 		ChannelId: args.ChannelId,
 		RootId:    args.RootId,
-		Message:   fmt.Sprintf("#### %v %v) %v", hashtag, numQueueItems+1, message),
+		Message:   fmt.Sprintf("#### %v %v) %v", hashtag, numQueueItems, message),
 	})
 	if appErr != nil {
 		return responsef("Error creating post: %s", appErr.Message)
@@ -174,6 +183,39 @@ func (p *Plugin) executeCommandQueue(args *model.CommandArgs) *model.CommandResp
 	return &model.CommandResponse{}
 }
 
+func parseMeetingPost(meeting *Meeting, post *model.Post) (string, ParsedMeetingMessage, error) {
+	var (
+		prefix            string
+		hashtagDateFormat string
+	)
+	if matchGroups := meetingDateFormatRegex.FindStringSubmatch(meeting.HashtagFormat); len(matchGroups) == 4 {
+		prefix = matchGroups[1]
+		hashtagDateFormat = strings.TrimSpace(matchGroups[2])
+	} else {
+		return "", ParsedMeetingMessage{}, errors.New("error Parsing meeting post")
+	}
+
+	var (
+		messageRegexFormat, err = regexp.Compile(fmt.Sprintf(`(?m)^#### #%s(?P<date>.*) ([0-9]+)\) (?P<message>.*)?$`, prefix))
+	)
+
+	if err != nil {
+		return "", ParsedMeetingMessage{}, err
+	}
+	matchGroups := messageRegexFormat.FindStringSubmatch(post.Message)
+	if len(matchGroups) == 4 {
+		parsedMeetingMessage := ParsedMeetingMessage{
+			date:        matchGroups[1],
+			number:      matchGroups[2],
+			textMessage: matchGroups[3],
+		}
+
+		return hashtagDateFormat, parsedMeetingMessage, nil
+	}
+
+	return hashtagDateFormat, ParsedMeetingMessage{}, errors.New("failed to parse meeting post's header")
+}
+
 func (p *Plugin) executeCommandHelp(args *model.CommandArgs) *model.CommandResponse {
 	return responsef(helpCommandText)
 }

server/meeting.go

@@ -4,8 +4,12 @@ import (
 	"encoding/json"
 	"fmt"
 	"regexp"
+	"sort"
 	"strings"
 	"time"
+
+	"github.com/mattermost/mattermost-server/v5/model"
+	"github.com/pkg/errors"
 )
 
 var (
@@ -61,6 +65,53 @@ func (p *Plugin) SaveMeeting(meeting *Meeting) error {
 	return nil
 }
 
+func (p *Plugin) calculateQueueItemNumberAndUpdateOldItems(meeting *Meeting, args *model.CommandArgs, hashtag string) (int, error) {
+	c, appErr := p.API.GetChannel(args.ChannelId)
+	if appErr != nil {
+		return 0, appErr
+	}
+	terms := fmt.Sprintf("in:%s %s", c.Name, hashtag)
+	searchResults, appErr := p.API.SearchPostsInTeamForUser(args.TeamId, args.UserId, model.SearchParameter{Terms: &terms})
+	if appErr != nil {
+		return 0, errors.Wrap(appErr, "Error searching posts to find hashtags")
+	}
+
+	counter := 1
+
+	var sortedPosts []*model.Post
+	// TODO we won't need to do this once we fix https://github.com/mattermost/mattermost-server/issues/11006
+	for _, post := range searchResults.PostList.Posts {
+		sortedPosts = append(sortedPosts, post)
+	}
+
+	sort.Slice(sortedPosts, func(i, j int) bool {
+		return sortedPosts[i].CreateAt < sortedPosts[j].CreateAt
+	})
+
+	for _, post := range sortedPosts {
+		_, parsedMessage, err := parseMeetingPost(meeting, post)
+		if err != nil {
+			p.API.LogDebug(err.Error())
+			return 0, errors.New(err.Error())
+		}
+
+		_, updateErr := p.API.UpdatePost(&model.Post{
+			Id:        post.Id,
+			UserId:    post.UserId,
+			ChannelId: post.ChannelId,
+			RootId:    post.RootId,
+			Message:   fmt.Sprintf("#### %v %v) %v", hashtag, counter, parsedMessage.textMessage),
+		})
+		if updateErr != nil {
+			return 0, errors.Wrap(updateErr, "Error updating post")
+		}
+
+		counter++
+	}
+
+	return counter, nil
+}
+
 // GenerateHashtag returns a meeting hashtag
 func (p *Plugin) GenerateHashtag(channelID string, nextWeek bool, weekday int) (string, error) {
 	meeting, err := p.GetMeeting(channelID)