Give user a link to create PR after push (#4716)

* Give user a link to create PR after push

* Forks now create PR in the base repository + make sure PR creation is allowed

* fix code style

cmd/hook.go

@@ -8,6 +8,7 @@ import (
 	"bufio"
 	"bytes"
 	"fmt"
+	"net/url"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -174,6 +175,7 @@ func runHookPostReceive(c *cli.Context) error {
 	hookSetup("hooks/post-receive.log")
 
 	// the environment setted on serv command
+	repoID, _ := strconv.ParseInt(os.Getenv(models.ProtectedBranchRepoID), 10, 64)
 	repoUser := os.Getenv(models.EnvRepoUsername)
 	isWiki := (os.Getenv(models.EnvRepoIsWiki) == "true")
 	repoName := os.Getenv(models.EnvRepoName)
@@ -211,6 +213,47 @@ func runHookPostReceive(c *cli.Context) error {
 		}); err != nil {
 			log.GitLogger.Error(2, "Update: %v", err)
 		}
+
+		if strings.HasPrefix(refFullName, git.BranchPrefix) {
+			branch := strings.TrimPrefix(refFullName, git.BranchPrefix)
+			repo, pullRequestAllowed, err := private.GetRepository(repoID)
+			if err != nil {
+				log.GitLogger.Error(2, "get repo: %v", err)
+				break
+			}
+			if !pullRequestAllowed {
+				break
+			}
+
+			baseRepo := repo
+			if repo.IsFork {
+				baseRepo = repo.BaseRepo
+			}
+
+			if !repo.IsFork && branch == baseRepo.DefaultBranch {
+				break
+			}
+
+			pr, err := private.ActivePullRequest(baseRepo.ID, repo.ID, baseRepo.DefaultBranch, branch)
+			if err != nil {
+				log.GitLogger.Error(2, "get active pr: %v", err)
+				break
+			}
+
+			fmt.Fprintln(os.Stderr, "")
+			if pr == nil {
+				if repo.IsFork {
+					branch = fmt.Sprintf("%s:%s", repo.OwnerName, branch)
+				}
+				fmt.Fprintf(os.Stderr, "Create a new pull request for '%s':\n", branch)
+				fmt.Fprintf(os.Stderr, "  %s/compare/%s...%s\n", baseRepo.HTMLURL(), url.QueryEscape(baseRepo.DefaultBranch), url.QueryEscape(branch))
+			} else {
+				fmt.Fprint(os.Stderr, "Visit the existing pull request:\n")
+				fmt.Fprintf(os.Stderr, "  %s/pulls/%d\n", baseRepo.HTMLURL(), pr.Index)
+			}
+			fmt.Fprintln(os.Stderr, "")
+		}
+
 	}
 
 	return nil

modules/private/repository.go

@@ -0,0 +1,68 @@
+// 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 private
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/url"
+
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+// GetRepository return the repository by its ID and a bool about if it's allowed to have PR
+func GetRepository(repoID int64) (*models.Repository, bool, error) {
+	reqURL := setting.LocalURL + fmt.Sprintf("api/internal/repository/%d", repoID)
+	log.GitLogger.Trace("GetRepository: %s", reqURL)
+
+	resp, err := newInternalRequest(reqURL, "GET").Response()
+	if err != nil {
+		return nil, false, err
+	}
+
+	var repoInfo struct {
+		Repository       *models.Repository
+		AllowPullRequest bool
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&repoInfo); err != nil {
+		return nil, false, err
+	}
+
+	defer resp.Body.Close()
+
+	// All 2XX status codes are accepted and others will return an error
+	if resp.StatusCode/100 != 2 {
+		return nil, false, fmt.Errorf("failed to retrieve repository: %s", decodeJSONError(resp).Err)
+	}
+
+	return repoInfo.Repository, repoInfo.AllowPullRequest, nil
+}
+
+// ActivePullRequest returns an active pull request if it exists
+func ActivePullRequest(baseRepoID int64, headRepoID int64, baseBranch, headBranch string) (*models.PullRequest, error) {
+	reqURL := setting.LocalURL + fmt.Sprintf("api/internal/active-pull-request?baseRepoID=%d&headRepoID=%d&baseBranch=%s&headBranch=%s", baseRepoID, headRepoID, url.QueryEscape(baseBranch), url.QueryEscape(headBranch))
+	log.GitLogger.Trace("ActivePullRequest: %s", reqURL)
+
+	resp, err := newInternalRequest(reqURL, "GET").Response()
+	if err != nil {
+		return nil, err
+	}
+
+	var pr *models.PullRequest
+	if err := json.NewDecoder(resp.Body).Decode(&pr); err != nil {
+		return nil, err
+	}
+
+	defer resp.Body.Close()
+
+	// All 2XX status codes are accepted and others will return an error
+	if resp.StatusCode/100 != 2 {
+		return nil, fmt.Errorf("failed to retrieve pull request: %s", decodeJSONError(resp).Err)
+	}
+
+	return pr, nil
+}

routers/private/internal.go

@@ -44,5 +44,7 @@ func RegisterRoutes(m *macaron.Macaron) {
 		m.Post("/push/update", PushUpdate)
 		m.Get("/protectedbranch/:pbid/:userid", CanUserPush)
 		m.Get("/branch/:id/*", GetProtectedBranchBy)
+		m.Get("/repository/:rid", GetRepository)
+		m.Get("/active-pull-request", GetActivePullRequest)
 	}, CheckInternalToken)
 }

routers/private/repository.go

@@ -0,0 +1,84 @@
+// 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 private
+
+import (
+	"net/http"
+	"net/url"
+
+	"code.gitea.io/gitea/models"
+
+	macaron "gopkg.in/macaron.v1"
+)
+
+// GetRepository return the default branch of a repository
+func GetRepository(ctx *macaron.Context) {
+	repoID := ctx.ParamsInt64(":rid")
+	repository, err := models.GetRepositoryByID(repoID)
+	repository.MustOwnerName()
+	allowPulls := repository.AllowsPulls()
+	// put it back to nil because json unmarshal can't unmarshal it
+	repository.Units = nil
+
+	if err != nil {
+		ctx.JSON(http.StatusInternalServerError, map[string]interface{}{
+			"err": err.Error(),
+		})
+		return
+	}
+
+	if repository.IsFork {
+		repository.GetBaseRepo()
+		if err != nil {
+			ctx.JSON(http.StatusInternalServerError, map[string]interface{}{
+				"err": err.Error(),
+			})
+			return
+		}
+		repository.BaseRepo.MustOwnerName()
+		allowPulls = repository.BaseRepo.AllowsPulls()
+		// put it back to nil because json unmarshal can't unmarshal it
+		repository.BaseRepo.Units = nil
+	}
+
+	ctx.JSON(http.StatusOK, struct {
+		Repository       *models.Repository
+		AllowPullRequest bool
+	}{
+		Repository:       repository,
+		AllowPullRequest: allowPulls,
+	})
+}
+
+// GetActivePullRequest return an active pull request when it exists or an empty object
+func GetActivePullRequest(ctx *macaron.Context) {
+	baseRepoID := ctx.QueryInt64("baseRepoID")
+	headRepoID := ctx.QueryInt64("headRepoID")
+	baseBranch, err := url.QueryUnescape(ctx.QueryTrim("baseBranch"))
+	if err != nil {
+		ctx.JSON(http.StatusInternalServerError, map[string]interface{}{
+			"err": err.Error(),
+		})
+		return
+	}
+
+	headBranch, err := url.QueryUnescape(ctx.QueryTrim("headBranch"))
+	if err != nil {
+		ctx.JSON(http.StatusInternalServerError, map[string]interface{}{
+			"err": err.Error(),
+		})
+		return
+	}
+
+	pr, err := models.GetUnmergedPullRequest(headRepoID, baseRepoID, headBranch, baseBranch)
+	if err != nil && !models.IsErrPullRequestNotExist(err) {
+		ctx.JSON(http.StatusInternalServerError, map[string]interface{}{
+			"err": err.Error(),
+		})
+		return
+	}
+
+	ctx.JSON(http.StatusOK, pr)
+}