Add interactive mode for tea pr create (#279)

refactor pull create into task & interact module

avoid creation of invalid PRs

refactor task.CreatePull

to make functionality reusable in interact module

implement interactive.CreatePull

Co-authored-by: Norwin Roosen <git@nroo.de>
Reviewed-on: https://gitea.com/gitea/tea/pulls/279
Reviewed-by: 6543 <6543@obermui.de>
Reviewed-by: techknowlogick <techknowlogick@gitea.io>
Co-Authored-By: Norwin <noerw@noreply.gitea.io>
Co-Committed-By: Norwin <noerw@noreply.gitea.io>

modules/task/pull_create.go

@@ -0,0 +1,151 @@
+// Copyright 2020 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 task
+
+import (
+	"fmt"
+	"log"
+	"strings"
+
+	"code.gitea.io/sdk/gitea"
+	"code.gitea.io/tea/modules/config"
+	local_git "code.gitea.io/tea/modules/git"
+	"code.gitea.io/tea/modules/print"
+	"code.gitea.io/tea/modules/utils"
+
+	"github.com/go-git/go-git/v5"
+)
+
+// CreatePull creates a PR in the given repo and prints the result
+func CreatePull(login *config.Login, repoOwner, repoName, base, head, title, description string) error {
+
+	// open local git repo
+	localRepo, err := local_git.RepoForWorkdir()
+	if err != nil {
+		log.Fatal("could not open local repo: ", err)
+	}
+
+	// push if possible
+	log.Println("git push")
+	err = localRepo.Push(&git.PushOptions{})
+	if err != nil && err != git.NoErrAlreadyUpToDate {
+		log.Printf("Error occurred during 'git push':\n%s\n", err.Error())
+	}
+
+	// default is default branch
+	if len(base) == 0 {
+		base, err = GetDefaultPRBase(login, repoOwner, repoName)
+		if err != nil {
+			return err
+		}
+	}
+
+	// default is current one
+	if len(head) == 0 {
+		headOwner, headBranch, err := GetDefaultPRHead(localRepo)
+		if err != nil {
+			return err
+		}
+
+		head = GetHeadSpec(headOwner, headBranch, repoOwner)
+	}
+
+	// head & base may not be the same
+	if head == base {
+		return fmt.Errorf("can't create PR from %s to %s", head, base)
+	}
+
+	// default is head branch name
+	if len(title) == 0 {
+		title = GetDefaultPRTitle(head)
+	}
+	// title is required
+	if len(title) == 0 {
+		return fmt.Errorf("Title is required")
+	}
+
+	pr, _, err := login.Client().CreatePullRequest(repoOwner, repoName, gitea.CreatePullRequestOption{
+		Head:  head,
+		Base:  base,
+		Title: title,
+		Body:  description,
+	})
+
+	if err != nil {
+		log.Fatalf("could not create PR from %s to %s:%s: %s", head, repoOwner, base, err)
+	}
+
+	print.PullDetails(pr, nil)
+
+	fmt.Println(pr.HTMLURL)
+
+	return err
+}
+
+// GetDefaultPRBase retrieves the default base branch for the given repo
+func GetDefaultPRBase(login *config.Login, owner, repo string) (string, error) {
+	meta, _, err := login.Client().GetRepo(owner, repo)
+	if err != nil {
+		return "", fmt.Errorf("could not fetch repo meta: %s", err)
+	}
+	return meta.DefaultBranch, nil
+}
+
+// GetDefaultPRHead uses the currently checked out branch, checks if
+// a remote currently holds the commit it points to, extracts the owner
+// from its URL, and assembles the result to a valid head spec for gitea.
+func GetDefaultPRHead(localRepo *local_git.TeaRepo) (owner, branch string, err error) {
+	headBranch, err := localRepo.Head()
+	if err != nil {
+		return
+	}
+	sha := headBranch.Hash().String()
+
+	remote, err := localRepo.TeaFindBranchRemote("", sha)
+	if err != nil {
+		err = fmt.Errorf("could not determine remote for current branch: %s", err)
+		return
+	}
+
+	if remote == nil {
+		// if no remote branch is found for the local hash, we abort:
+		// user has probably not configured a remote for the local branch,
+		// or local branch does not represent remote state.
+		err = fmt.Errorf("no matching remote found for this branch. try git push -u <remote> <branch>")
+		return
+	}
+
+	branch, err = localRepo.TeaGetCurrentBranchName()
+	if err != nil {
+		return
+	}
+
+	url, err := local_git.ParseURL(remote.Config().URLs[0])
+	if err != nil {
+		return
+	}
+	owner, _ = utils.GetOwnerAndRepo(strings.TrimLeft(url.Path, "/"), "")
+	return
+}
+
+// GetHeadSpec creates a head string as expected by gitea API
+func GetHeadSpec(owner, branch, baseOwner string) string {
+	if len(owner) != 0 && owner != baseOwner {
+		return fmt.Sprintf("%s:%s", owner, branch)
+	}
+	return branch
+}
+
+// GetDefaultPRTitle transforms a string like a branchname to a readable text
+func GetDefaultPRTitle(head string) string {
+	title := head
+	if strings.Contains(title, ":") {
+		title = strings.SplitN(title, ":", 2)[1]
+	}
+	title = strings.Replace(title, "-", " ", -1)
+	title = strings.Replace(title, "_", " ", -1)
+	title = strings.Title(strings.ToLower(title))
+	return title
+}