first commit

internal/messages/messages.go

@@ -0,0 +1,52 @@
+package messages
+
+import (
+	"errors"
+	"fmt"
+	"log/slog"
+	"os"
+
+	"gopkg.in/yaml.v3"
+)
+
+var ErrUnknownEvent = errors.New("unknown event type")
+
+type Templates struct {
+	templates map[string]string
+}
+
+func Load(path string) (*Templates, error) {
+	t := &Templates{templates: defaultTemplates()}
+
+	b, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			slog.Warn("messages file not found, using embedded defaults", "path", path)
+			return t, nil
+		}
+		return nil, fmt.Errorf("read messages file: %w", err)
+	}
+
+	parsed := map[string]string{}
+	if err := yaml.Unmarshal(b, &parsed); err != nil {
+		return nil, fmt.Errorf("parse messages file: %w", err)
+	}
+
+	for k, v := range parsed {
+		t.templates[k] = v
+	}
+	return t, nil
+}
+
+func (t *Templates) Get(eventType string) (string, error) {
+	tmpl, ok := t.templates[eventType]
+	if !ok {
+		return "", fmt.Errorf("%w: %s", ErrUnknownEvent, eventType)
+	}
+	return tmpl, nil
+}
+
+func (t *Templates) Has(eventType string) bool {
+	_, ok := t.templates[eventType]
+	return ok
+}