Simplify function definitions

Signed-off-by: Knut Ahlers <knut@ahlers.me>

action_ban.go

@@ -8,7 +8,7 @@ import (
 )
 
 func init() {
-	registerAction(func(c *irc.Client, m *irc.Message, r *ruleAction) error {
+	registerAction(func(c *irc.Client, m *irc.Message, ruleDef *rule, r *ruleAction) error {
 		if r.Ban == nil {
 			return nil
 		}

action_counter.go

@@ -6,7 +6,7 @@ import (
 )
 
 func init() {
-	registerAction(func(c *irc.Client, m *irc.Message, r *ruleAction) error {
+	registerAction(func(c *irc.Client, m *irc.Message, ruleDef *rule, r *ruleAction) error {
 		if r.Counter == nil {
 			return nil
 		}

action_respond.go

@@ -6,12 +6,12 @@ import (
 )
 
 func init() {
-	registerAction(func(c *irc.Client, m *irc.Message, r *ruleAction) error {
+	registerAction(func(c *irc.Client, m *irc.Message, ruleDef *rule, r *ruleAction) error {
 		if r.Respond == nil {
 			return nil
 		}
 
-		msg, err := formatMessage(*r.Respond, m, nil)
+		msg, err := formatMessage(*r.Respond, m, ruleDef, nil)
 		if err != nil {
 			return errors.Wrap(err, "preparing response")
 		}

action_timeout.go

@@ -9,7 +9,7 @@ import (
 )
 
 func init() {
-	registerAction(func(c *irc.Client, m *irc.Message, r *ruleAction) error {
+	registerAction(func(c *irc.Client, m *irc.Message, ruleDef *rule, r *ruleAction) error {
 		if r.Timeout == nil {
 			return nil
 		}

actions.go

@@ -13,7 +13,7 @@ var (
 	availableActionsLock = new(sync.RWMutex)
 )
 
-type actionFunc func(*irc.Client, *irc.Message, *ruleAction) error
+type actionFunc func(*irc.Client, *irc.Message, *rule, *ruleAction) error
 
 func registerAction(af actionFunc) {
 	availableActionsLock.Lock()
@@ -22,12 +22,12 @@ func registerAction(af actionFunc) {
 	availableActions = append(availableActions, af)
 }
 
-func triggerActions(c *irc.Client, m *irc.Message, ra *ruleAction) error {
+func triggerActions(c *irc.Client, m *irc.Message, rule *rule, ra *ruleAction) error {
 	availableActionsLock.RLock()
 	defer availableActionsLock.RUnlock()
 
 	for _, af := range availableActions {
-		if err := af(c, m, ra); err != nil {
+		if err := af(c, m, rule, ra); err != nil {
 			return errors.Wrap(err, "execute action")
 		}
 	}
@@ -38,7 +38,7 @@ func triggerActions(c *irc.Client, m *irc.Message, ra *ruleAction) error {
 func handleMessage(c *irc.Client, m *irc.Message, event *string) {
 	for _, r := range config.GetMatchingRules(m, event) {
 		for _, a := range r.Actions {
-			if err := triggerActions(c, m, a); err != nil {
+			if err := triggerActions(c, m, r, a); err != nil {
 				log.WithError(err).Error("Unable to trigger action")
 			}
 		}

msgformatter.go

@@ -12,9 +12,48 @@ import (
 	"github.com/pkg/errors"
 )
 
-var messageFunctions = korvike.GetFunctionMap()
+func formatMessage(tplString string, m *irc.Message, r *rule, fields map[string]interface{}) (string, error) {
+	// Create anonymous functions in current context in order to access function variables
+	messageFunctions := korvike.GetFunctionMap()
+	messageFunctions["fixUsername"] = func(username string) string { return strings.TrimLeft(username, "@") }
 
-func formatMessage(tplString string, m *irc.Message, fields map[string]interface{}) (string, error) {
+	messageFunctions["getArg"] = func(arg int) (string, error) {
+		msgParts := strings.Split(m.Trailing(), " ")
+		if len(msgParts) <= arg {
+			return "", errors.New("argument not found")
+		}
+
+		return msgParts[arg], nil
+	}
+
+	messageFunctions["getCounterValue"] = func(name string, _ ...string) int64 {
+		return store.GetCounterValue(name)
+	}
+
+	messageFunctions["getTag"] = func(tag string) string {
+		s, _ := m.GetTag(tag)
+		return s
+	}
+
+	messageFunctions["group"] = func(idx int) (string, error) {
+		fields := r.matchMessage.FindStringSubmatch(m.Trailing())
+		if len(fields) <= idx {
+			return "", errors.New("group not found")
+		}
+
+		return fields[idx], nil
+	}
+
+	messageFunctions["recentGame"] = func(username string, v ...string) (string, error) {
+		game, _, err := twitch.getRecentStreamInfo(username)
+		if err != nil && len(v) > 0 {
+			return v[0], nil
+		}
+
+		return game, err
+	}
+
+	// Parse and execute template
 	tpl, err := template.
 		New(tplString).
 		Funcs(messageFunctions).
@@ -36,34 +75,3 @@ func formatMessage(tplString string, m *irc.Message, fields map[string]interface
 
 	return buf.String(), errors.Wrap(err, "execute template")
 }
-
-func init() {
-	messageFunctions["fixUsername"] = func(username string) string { return strings.TrimLeft(username, "@") }
-
-	messageFunctions["getArg"] = func(m *irc.Message, params ...int) (string, error) {
-		msgParts := strings.Split(m.Trailing(), " ")
-		if len(msgParts) < params[0]+1 {
-			return "", errors.New("argument not found")
-		}
-
-		return msgParts[params[0]], nil
-	}
-
-	messageFunctions["getCounterValue"] = func(name string, _ ...string) int64 {
-		return store.GetCounterValue(name)
-	}
-
-	messageFunctions["getTag"] = func(m *irc.Message, params ...string) string {
-		s, _ := m.GetTag(params[0])
-		return s
-	}
-
-	messageFunctions["recentGame"] = func(username string, v ...string) (string, error) {
-		game, _, err := twitch.getRecentStreamInfo(username)
-		if err != nil && len(v) > 0 {
-			return v[0], nil
-		}
-
-		return game, err
-	}
-}