[msgformat] Add module to retrieve filled template through API

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

internal/apimodules/msgformat/msgformat.go

@@ -0,0 +1,51 @@
+package msgformat
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/pkg/errors"
+
+	"github.com/Luzifer/twitch-bot/plugins"
+)
+
+var formatMessage plugins.MsgFormatter
+
+func Register(args plugins.RegistrationArguments) error {
+	formatMessage = args.FormatMessage
+
+	args.RegisterAPIRoute(plugins.HTTPRouteRegistrationArgs{
+		HandlerFunc: handleFormattedMessage,
+		Method:      http.MethodGet,
+		Module:      "msgformat",
+		Path:        "/format",
+		QueryParams: []plugins.HTTPRouteParamDocumentation{
+			{
+				Description: "The template to execute",
+				Name:        "template",
+				Required:    true,
+				Type:        "string",
+			},
+		},
+		RequiresWriteAuth: true, // This module can potentially be used to harvest data / read internal variables so it is handled as a write-module
+		ResponseType:      plugins.HTTPRouteResponseTypeTextPlain,
+	})
+
+	return nil
+}
+
+func handleFormattedMessage(w http.ResponseWriter, r *http.Request) {
+	tpl := r.FormValue("template")
+	if tpl == "" {
+		w.WriteHeader(http.StatusNoContent)
+		return
+	}
+
+	msg, err := formatMessage(tpl, nil, nil, nil)
+	if err != nil {
+		http.Error(w, errors.Wrap(err, "executing template").Error(), http.StatusInternalServerError)
+		return
+	}
+
+	fmt.Fprint(w, msg)
+}

plugins_core.go

@@ -21,6 +21,7 @@ import (
 	"github.com/Luzifer/twitch-bot/internal/actors/respond"
 	"github.com/Luzifer/twitch-bot/internal/actors/timeout"
 	"github.com/Luzifer/twitch-bot/internal/actors/whisper"
+	"github.com/Luzifer/twitch-bot/internal/apimodules/msgformat"
 	"github.com/Luzifer/twitch-bot/internal/template/numeric"
 	"github.com/Luzifer/twitch-bot/internal/template/random"
 	"github.com/Luzifer/twitch-bot/plugins"
@@ -47,6 +48,9 @@ var (
 		// Template functions
 		numeric.Register,
 		random.Register,
+
+		// API-only modules
+		msgformat.Register,
 	}
 	knownModules []string
 )