Add github compatible tarball download API endpoints (#32572)

Fix #29654 
Fix #32481

routers/api/v1/repo/download.go

@@ -0,0 +1,53 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package repo
+
+import (
+	"fmt"
+	"net/http"
+
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/gitrepo"
+	"code.gitea.io/gitea/services/context"
+	archiver_service "code.gitea.io/gitea/services/repository/archiver"
+)
+
+func DownloadArchive(ctx *context.APIContext) {
+	var tp git.ArchiveType
+	switch ballType := ctx.PathParam("ball_type"); ballType {
+	case "tarball":
+		tp = git.TARGZ
+	case "zipball":
+		tp = git.ZIP
+	case "bundle":
+		tp = git.BUNDLE
+	default:
+		ctx.Error(http.StatusBadRequest, "", fmt.Sprintf("Unknown archive type: %s", ballType))
+		return
+	}
+
+	if ctx.Repo.GitRepo == nil {
+		gitRepo, err := gitrepo.OpenRepository(ctx, ctx.Repo.Repository)
+		if err != nil {
+			ctx.Error(http.StatusInternalServerError, "OpenRepository", err)
+			return
+		}
+		ctx.Repo.GitRepo = gitRepo
+		defer gitRepo.Close()
+	}
+
+	r, err := archiver_service.NewRequest(ctx.Repo.Repository.ID, ctx.Repo.GitRepo, ctx.PathParam("*"), tp)
+	if err != nil {
+		ctx.ServerError("NewRequest", err)
+		return
+	}
+
+	archive, err := r.Await(ctx)
+	if err != nil {
+		ctx.ServerError("archive.Await", err)
+		return
+	}
+
+	download(ctx, r.GetArchiveName(), archive)
+}