feat(federation): validate like activities (#3494)

First step on the way to #1680

The PR will

* accept like request on the api
* validate activity in a first level

You can find

* architecture at: https://codeberg.org/meissa/forgejo/src/branch/forgejo-federated-star/docs/unsure-where-to-put/federation-architecture.md

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/3494
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Co-authored-by: Michael Jerger <michael.jerger@meissa-gmbh.de>
Co-committed-by: Michael Jerger <michael.jerger@meissa-gmbh.de>

routers/api/v1/activitypub/repository.go

@@ -0,0 +1,83 @@
+// Copyright 2023, 2024 The Forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package activitypub
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+
+	"code.gitea.io/gitea/modules/forgefed"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/web"
+	"code.gitea.io/gitea/services/context"
+	"code.gitea.io/gitea/services/federation"
+
+	ap "github.com/go-ap/activitypub"
+)
+
+// Repository function returns the Repository actor for a repo
+func Repository(ctx *context.APIContext) {
+	// swagger:operation GET /activitypub/repository-id/{repository-id} activitypub activitypubRepository
+	// ---
+	// summary: Returns the Repository actor for a repo
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: repository-id
+	//   in: path
+	//   description: repository ID of the repo
+	//   type: integer
+	//   required: true
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/ActivityPub"
+
+	link := fmt.Sprintf("%s/api/v1/activitypub/repository-id/%d", strings.TrimSuffix(setting.AppURL, "/"), ctx.Repo.Repository.ID)
+	repo := forgefed.RepositoryNew(ap.IRI(link))
+
+	repo.Name = ap.NaturalLanguageValuesNew()
+	err := repo.Name.Set("en", ap.Content(ctx.Repo.Repository.Name))
+	if err != nil {
+		ctx.Error(http.StatusInternalServerError, "Set Name", err)
+		return
+	}
+	response(ctx, repo)
+}
+
+// PersonInbox function handles the incoming data for a repository inbox
+func RepositoryInbox(ctx *context.APIContext) {
+	// swagger:operation POST /activitypub/repository-id/{repository-id}/inbox activitypub activitypubRepositoryInbox
+	// ---
+	// summary: Send to the inbox
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: repository-id
+	//   in: path
+	//   description: repository ID of the repo
+	//   type: integer
+	//   required: true
+	// - name: body
+	//   in: body
+	//   schema:
+	//     "$ref": "#/definitions/ForgeLike"
+	// responses:
+	//   "204":
+	//     "$ref": "#/responses/empty"
+
+	repository := ctx.Repo.Repository
+	log.Info("RepositoryInbox: repo: %v", repository)
+
+	form := web.GetForm(ctx)
+	httpStatus, title, err := federation.ProcessLikeActivity(ctx, form, repository.ID)
+	if err != nil {
+		log.Error("Status: %v", httpStatus)
+		log.Error("Title: %v", title)
+		log.Error("Error: %v", err)
+		ctx.Error(httpStatus, title, err)
+	}
+	ctx.Status(http.StatusNoContent)
+}