4 files changed, 37 insertions, 10 deletions
diff --git a/internal/util/regexes.go b/internal/util/regexes.go
index a59bd678a..adab8c87f 100644
--- a/internal/util/regexes.go
+++ b/internal/util/regexes.go
@@ -35,6 +35,11 @@ const (
 )
 
 var (
+	mentionNameRegexString = `^@([a-zA-Z0-9_]+)(?:@([a-zA-Z0-9_\-\.]+)?)$`
+	// mention name regex captures the username and domain part from a mention string
+	// such as @whatever_user@example.org, returning whatever_user and example.org (without the @ symbols)
+	mentionNameRegex = regexp.MustCompile(mentionNameRegexString)
+
 	// mention regex can be played around with here: https://regex101.com/r/qwM9D3/1
 	mentionFinderRegexString = `(?: |^|\W)(@[a-zA-Z0-9_]+(?:@[a-zA-Z0-9_\-\.]+)?)(?: |\n)`
 	mentionFinderRegex       = regexp.MustCompile(mentionFinderRegexString)
diff --git a/internal/util/statustools.go b/internal/util/statustools.go
index 5591f185a..2c74749e5 100644
--- a/internal/util/statustools.go
+++ b/internal/util/statustools.go
@@ -19,17 +19,18 @@
 package util
 
 import (
+	"fmt"
 	"strings"
 )
 
-// DeriveMentions takes a plaintext (ie., not html-formatted) status,
+// DeriveMentionsFromStatus takes a plaintext (ie., not html-formatted) status,
 // and applies a regex to it to return a deduplicated list of accounts
 // mentioned in that status.
 //
 // It will look for fully-qualified account names in the form "@user@example.org".
 // or the form "@username" for local users.
 // The case of the returned mentions will be lowered, for consistency.
-func DeriveMentions(status string) []string {
+func DeriveMentionsFromStatus(status string) []string {
 	mentionedAccounts := []string{}
 	for _, m := range mentionFinderRegex.FindAllStringSubmatch(status, -1) {
 		mentionedAccounts = append(mentionedAccounts, m[1])
@@ -37,11 +38,11 @@ func DeriveMentions(status string) []string {
 	return lower(unique(mentionedAccounts))
 }
 
-// DeriveHashtags takes a plaintext (ie., not html-formatted) status,
+// DeriveHashtagsFromStatus takes a plaintext (ie., not html-formatted) status,
 // and applies a regex to it to return a deduplicated list of hashtags
 // used in that status, without the leading #. The case of the returned
 // tags will be lowered, for consistency.
-func DeriveHashtags(status string) []string {
+func DeriveHashtagsFromStatus(status string) []string {
 	tags := []string{}
 	for _, m := range hashtagFinderRegex.FindAllStringSubmatch(status, -1) {
 		tags = append(tags, m[1])
@@ -49,11 +50,11 @@ func DeriveHashtags(status string) []string {
 	return lower(unique(tags))
 }
 
-// DeriveEmojis takes a plaintext (ie., not html-formatted) status,
+// DeriveEmojisFromStatus takes a plaintext (ie., not html-formatted) status,
 // and applies a regex to it to return a deduplicated list of emojis
 // used in that status, without the surround ::. The case of the returned
 // emojis will be lowered, for consistency.
-func DeriveEmojis(status string) []string {
+func DeriveEmojisFromStatus(status string) []string {
 	emojis := []string{}
 	for _, m := range emojiFinderRegex.FindAllStringSubmatch(status, -1) {
 		emojis = append(emojis, m[1])
@@ -61,6 +62,21 @@ func DeriveEmojis(status string) []string {
 	return lower(unique(emojis))
 }
 
+// ExtractMentionParts extracts the username test_user and the domain example.org
+// from a mention string like @test_user@example.org.
+//
+// If nothing is matched, it will return an error.
+func ExtractMentionParts(mention string) (username, domain string, err error) {
+	matches := mentionNameRegex.FindStringSubmatch(mention)
+	if matches == nil || len(matches) != 3 {
+		err = fmt.Errorf("could't match mention %s", mention)
+		return
+	}
+	username = matches[1]
+	domain = matches[2]
+	return
+}
+
 // unique returns a deduplicated version of a given string slice.
 func unique(s []string) []string {
 	keys := make(map[string]bool)
diff --git a/internal/util/statustools_test.go b/internal/util/statustools_test.go
index 7c9af2cbd..2a12c7690 100644
--- a/internal/util/statustools_test.go
+++ b/internal/util/statustools_test.go
@@ -42,7 +42,7 @@ func (suite *StatusTestSuite) TestDeriveMentionsOK() {
 	here is a duplicate mention: @hello@test.lgbt
 	`
 
-	menchies := util.DeriveMentions(statusText)
+	menchies := util.DeriveMentionsFromStatus(statusText)
 	assert.Len(suite.T(), menchies, 4)
 	assert.Equal(suite.T(), "@dumpsterqueer@example.org", menchies[0])
 	assert.Equal(suite.T(), "@someone_else@testing.best-horse.com", menchies[1])
@@ -52,7 +52,7 @@ func (suite *StatusTestSuite) TestDeriveMentionsOK() {
 
 func (suite *StatusTestSuite) TestDeriveMentionsEmpty() {
 	statusText := ``
-	menchies := util.DeriveMentions(statusText)
+	menchies := util.DeriveMentionsFromStatus(statusText)
 	assert.Len(suite.T(), menchies, 0)
 }
 
@@ -67,7 +67,7 @@ func (suite *StatusTestSuite) TestDeriveHashtagsOK() {
 
 #111111 thisalsoshouldn'twork#### ##`
 
-	tags := util.DeriveHashtags(statusText)
+	tags := util.DeriveHashtagsFromStatus(statusText)
 	assert.Len(suite.T(), tags, 5)
 	assert.Equal(suite.T(), "testing123", tags[0])
 	assert.Equal(suite.T(), "also", tags[1])
@@ -90,7 +90,7 @@ Here's some normal text with an :emoji: at the end
 :underscores_ok_too:
 `
 
-	tags := util.DeriveEmojis(statusText)
+	tags := util.DeriveEmojisFromStatus(statusText)
 	assert.Len(suite.T(), tags, 7)
 	assert.Equal(suite.T(), "test", tags[0])
 	assert.Equal(suite.T(), "another", tags[1])
diff --git a/internal/util/uri.go b/internal/util/uri.go
index 538df9210..edcfc5c02 100644
--- a/internal/util/uri.go
+++ b/internal/util/uri.go
@@ -58,9 +58,15 @@ const (
 	// APAccount can be used the set and retrieve the account being interacted with
 	APAccount APContextKey = "account"
 	// APRequestingAccount can be used to set and retrieve the account of an incoming federation request.
+	// This will often be the actor of the instance that's posting the request.
 	APRequestingAccount APContextKey = "requestingAccount"
+	// APRequestingActorIRI can be used to set and retrieve the actor of an incoming federation request.
+	// This will usually be the owner of whatever activity is being posted.
+	APRequestingActorIRI APContextKey = "requestingActorIRI"
 	// APRequestingPublicKeyID can be used to set and retrieve the public key ID of an incoming federation request.
 	APRequestingPublicKeyID APContextKey = "requestingPublicKeyID"
+	// APFromFederatorChanKey can be used to pass a pointer to the fromFederator channel into the federator for use in callbacks.
+	APFromFederatorChanKey APContextKey = "fromFederatorChan"
 )
 
 type ginContextKey struct{}