Implement git refs API for listing references (branches, tags and other) (#5354)

* Inital routes to git refs api

* Git refs API implementation

* Update swagger

* Fix copyright

* Make swagger happy add basic test

* Fix test

* Fix test again :)

routers/api/v1/repo/git_ref.go

@@ -0,0 +1,115 @@
+// Copyright 2018 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package repo
+
+import (
+	"code.gitea.io/gitea/modules/context"
+
+	"code.gitea.io/git"
+	api "code.gitea.io/sdk/gitea"
+)
+
+// GetGitAllRefs get ref or an list all the refs of a repository
+func GetGitAllRefs(ctx *context.APIContext) {
+	// swagger:operation GET /repos/{owner}/{repo}/git/refs repository repoListAllGitRefs
+	// ---
+	// summary: Get specified ref or filtered repository's refs
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: owner
+	//   in: path
+	//   description: owner of the repo
+	//   type: string
+	//   required: true
+	// - name: repo
+	//   in: path
+	//   description: name of the repo
+	//   type: string
+	//   required: true
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/Reference"
+	//     "$ref": "#/responses/ReferenceList"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+
+	getGitRefsInternal(ctx, "")
+}
+
+// GetGitRefs get ref or an filteresd list of refs of a repository
+func GetGitRefs(ctx *context.APIContext) {
+	// swagger:operation GET /repos/{owner}/{repo}/git/refs/{ref} repository repoListGitRefs
+	// ---
+	// summary: Get specified ref or filtered repository's refs
+	// produces:
+	// - application/json
+	// parameters:
+	// - name: owner
+	//   in: path
+	//   description: owner of the repo
+	//   type: string
+	//   required: true
+	// - name: repo
+	//   in: path
+	//   description: name of the repo
+	//   type: string
+	//   required: true
+	// - name: ref
+	//   in: path
+	//   description: part or full name of the ref
+	//   type: string
+	//   required: true
+	// responses:
+	//   "200":
+	//     "$ref": "#/responses/Reference"
+	//     "$ref": "#/responses/ReferenceList"
+	//   "404":
+	//     "$ref": "#/responses/notFound"
+
+	getGitRefsInternal(ctx, ctx.Params("*"))
+}
+
+func getGitRefsInternal(ctx *context.APIContext, filter string) {
+	gitRepo, err := git.OpenRepository(ctx.Repo.Repository.RepoPath())
+	if err != nil {
+		ctx.Error(500, "OpenRepository", err)
+		return
+	}
+	if len(filter) > 0 {
+		filter = "refs/" + filter
+	}
+
+	refs, err := gitRepo.GetRefsFiltered(filter)
+	if err != nil {
+		ctx.Error(500, "GetRefsFiltered", err)
+		return
+	}
+
+	if len(refs) == 0 {
+		ctx.Status(404)
+		return
+	}
+
+	apiRefs := make([]*api.Reference, len(refs))
+	for i := range refs {
+		apiRefs[i] = &api.Reference{
+			Ref: refs[i].Name,
+			URL: ctx.Repo.Repository.APIURL() + "/git/" + refs[i].Name,
+			Object: &api.GitObject{
+				SHA:  refs[i].Object.String(),
+				Type: refs[i].Type,
+				// TODO: Add commit/tag info URL
+				//URL:  ctx.Repo.Repository.APIURL() + "/git/" + refs[i].Type + "s/" + refs[i].Object.String(),
+			},
+		}
+	}
+	// If single reference is found and it matches filter exactly return it as object
+	if len(apiRefs) == 1 && apiRefs[0].Ref == filter {
+		ctx.JSON(200, &apiRefs[0])
+		return
+	}
+	ctx.JSON(200, &apiRefs)
+}