1 files changed, 255 insertions, 0 deletions
diff --git a/teleirc/matterbridge/bridge/slack/helpers.go b/teleirc/matterbridge/bridge/slack/helpers.go
new file mode 100644
index 0000000..e46e272
--- /dev/null
+++ b/teleirc/matterbridge/bridge/slack/helpers.go
@@ -0,0 +1,255 @@
+package bslack
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+	"time"
+
+	"github.com/42wim/matterbridge/bridge/config"
+	"github.com/sirupsen/logrus"
+	"github.com/slack-go/slack"
+)
+
+// populateReceivedMessage shapes the initial Matterbridge message that we will forward to the
+// router before we apply message-dependent modifications.
+func (b *Bslack) populateReceivedMessage(ev *slack.MessageEvent) (*config.Message, error) {
+	// Use our own func because rtm.GetChannelInfo doesn't work for private channels.
+	channel, err := b.channels.getChannelByID(ev.Channel)
+	if err != nil {
+		return nil, err
+	}
+
+	rmsg := &config.Message{
+		Text:     ev.Text,
+		Channel:  channel.Name,
+		Account:  b.Account,
+		ID:       ev.Timestamp,
+		Extra:    make(map[string][]interface{}),
+		ParentID: ev.ThreadTimestamp,
+		Protocol: b.Protocol,
+	}
+	if b.useChannelID {
+		rmsg.Channel = "ID:" + channel.ID
+	}
+
+	// Handle 'edit' messages.
+	if ev.SubMessage != nil && !b.GetBool(editDisableConfig) {
+		rmsg.ID = ev.SubMessage.Timestamp
+		if ev.SubMessage.ThreadTimestamp != ev.SubMessage.Timestamp {
+			b.Log.Debugf("SubMessage %#v", ev.SubMessage)
+			rmsg.Text = ev.SubMessage.Text + b.GetString(editSuffixConfig)
+		}
+	}
+
+	// For edits, only submessage has thread ts.
+	// Ensures edits to threaded messages maintain their prefix hint on the
+	// unthreaded end.
+	if ev.SubMessage != nil {
+		rmsg.ParentID = ev.SubMessage.ThreadTimestamp
+	}
+
+	if err = b.populateMessageWithUserInfo(ev, rmsg); err != nil {
+		return nil, err
+	}
+	return rmsg, err
+}
+
+func (b *Bslack) populateMessageWithUserInfo(ev *slack.MessageEvent, rmsg *config.Message) error {
+	if ev.SubType == sMessageDeleted || ev.SubType == sFileComment {
+		return nil
+	}
+
+	// First, deal with bot-originating messages but only do so when not using webhooks: we
+	// would not be able to distinguish which bot would be sending them.
+	if err := b.populateMessageWithBotInfo(ev, rmsg); err != nil {
+		return err
+	}
+
+	// Second, deal with "real" users if we have the necessary information.
+	var userID string
+	switch {
+	case ev.User != "":
+		userID = ev.User
+	case ev.SubMessage != nil && ev.SubMessage.User != "":
+		userID = ev.SubMessage.User
+	default:
+		return nil
+	}
+
+	user := b.users.getUser(userID)
+	if user == nil {
+		return fmt.Errorf("could not find information for user with id %s", ev.User)
+	}
+
+	rmsg.UserID = user.ID
+	rmsg.Username = user.Name
+	if user.Profile.DisplayName != "" {
+		rmsg.Username = user.Profile.DisplayName
+	}
+	if b.GetBool("UseFullName") && user.Profile.RealName != "" {
+		rmsg.Username = user.Profile.RealName
+	}
+	return nil
+}
+
+func (b *Bslack) populateMessageWithBotInfo(ev *slack.MessageEvent, rmsg *config.Message) error {
+	if ev.BotID == "" || b.GetString(outgoingWebhookConfig) != "" {
+		return nil
+	}
+
+	var err error
+	var bot *slack.Bot
+	for {
+		bot, err = b.rtm.GetBotInfo(ev.BotID)
+		if err == nil {
+			break
+		}
+
+		if err = handleRateLimit(b.Log, err); err != nil {
+			b.Log.Errorf("Could not retrieve bot information: %#v", err)
+			return err
+		}
+	}
+	b.Log.Debugf("Found bot %#v", bot)
+
+	if bot.Name != "" {
+		rmsg.Username = bot.Name
+		if ev.Username != "" {
+			rmsg.Username = ev.Username
+		}
+		rmsg.UserID = bot.ID
+	}
+	return nil
+}
+
+var (
+	mentionRE        = regexp.MustCompile(`<@([a-zA-Z0-9]+)>`)
+	channelRE        = regexp.MustCompile(`<#[a-zA-Z0-9]+\|(.+?)>`)
+	variableRE       = regexp.MustCompile(`<!((?:subteam\^)?[a-zA-Z0-9]+)(?:\|@?(.+?))?>`)
+	urlRE            = regexp.MustCompile(`<([^<\|]+)\|([^>]+)>`)
+	codeFenceRE      = regexp.MustCompile(`(?m)^` + "```" + `\w+$`)
+	topicOrPurposeRE = regexp.MustCompile(`(?s)(@.+) (cleared|set)(?: the)? channel (topic|purpose)(?:: (.*))?`)
+)
+
+func (b *Bslack) extractTopicOrPurpose(text string) (string, string) {
+	r := topicOrPurposeRE.FindStringSubmatch(text)
+	if len(r) == 5 {
+		action, updateType, extracted := r[2], r[3], r[4]
+		switch action {
+		case "set":
+			return updateType, extracted
+		case "cleared":
+			return updateType, ""
+		}
+	}
+	b.Log.Warnf("Encountered channel topic or purpose change message with unexpected format: %s", text)
+	return "unknown", ""
+}
+
+// @see https://api.slack.com/docs/message-formatting#linking_to_channels_and_users
+func (b *Bslack) replaceMention(text string) string {
+	replaceFunc := func(match string) string {
+		userID := strings.Trim(match, "@<>")
+		if username := b.users.getUsername(userID); userID != "" {
+			return "@" + username
+		}
+		return match
+	}
+	return mentionRE.ReplaceAllStringFunc(text, replaceFunc)
+}
+
+// @see https://api.slack.com/docs/message-formatting#linking_to_channels_and_users
+func (b *Bslack) replaceChannel(text string) string {
+	for _, r := range channelRE.FindAllStringSubmatch(text, -1) {
+		text = strings.Replace(text, r[0], "#"+r[1], 1)
+	}
+	return text
+}
+
+// @see https://api.slack.com/docs/message-formatting#variables
+func (b *Bslack) replaceVariable(text string) string {
+	for _, r := range variableRE.FindAllStringSubmatch(text, -1) {
+		if r[2] != "" {
+			text = strings.Replace(text, r[0], "@"+r[2], 1)
+		} else {
+			text = strings.Replace(text, r[0], "@"+r[1], 1)
+		}
+	}
+	return text
+}
+
+// @see https://api.slack.com/docs/message-formatting#linking_to_urls
+func (b *Bslack) replaceURL(text string) string {
+	return urlRE.ReplaceAllString(text, "[${2}](${1})")
+}
+
+func (b *Bslack) replaceb0rkedMarkDown(text string) string {
+	// taken from https://github.com/mattermost/mattermost-server/blob/master/app/slackimport.go
+	//
+	regexReplaceAllString := []struct {
+		regex *regexp.Regexp
+		rpl   string
+	}{
+		// bold
+		{
+			regexp.MustCompile(`(^|[\s.;,])\*(\S[^*\n]+)\*`),
+			"$1**$2**",
+		},
+		// strikethrough
+		{
+			regexp.MustCompile(`(^|[\s.;,])\~(\S[^~\n]+)\~`),
+			"$1~~$2~~",
+		},
+		// single paragraph blockquote
+		// Slack converts > character to &gt;
+		{
+			regexp.MustCompile(`(?sm)^&gt;`),
+			">",
+		},
+	}
+	for _, rule := range regexReplaceAllString {
+		text = rule.regex.ReplaceAllString(text, rule.rpl)
+	}
+	return text
+}
+
+func (b *Bslack) replaceCodeFence(text string) string {
+	return codeFenceRE.ReplaceAllString(text, "```")
+}
+
+// getUsersInConversation returns an array of userIDs that are members of channelID
+func (b *Bslack) getUsersInConversation(channelID string) ([]string, error) {
+	channelMembers := []string{}
+	for {
+		queryParams := &slack.GetUsersInConversationParameters{
+			ChannelID: channelID,
+		}
+
+		members, nextCursor, err := b.sc.GetUsersInConversation(queryParams)
+		if err != nil {
+			if err = handleRateLimit(b.Log, err); err != nil {
+				return channelMembers, fmt.Errorf("Could not retrieve users in channels: %#v", err)
+			}
+			continue
+		}
+
+		channelMembers = append(channelMembers, members...)
+
+		if nextCursor == "" {
+			break
+		}
+		queryParams.Cursor = nextCursor
+	}
+	return channelMembers, nil
+}
+
+func handleRateLimit(log *logrus.Entry, err error) error {
+	rateLimit, ok := err.(*slack.RateLimitedError)
+	if !ok {
+		return err
+	}
+	log.Infof("Rate-limited by Slack. Sleeping for %v", rateLimit.RetryAfter)
+	time.Sleep(rateLimit.RetryAfter)
+	return nil
+}