From aa88b6c9895eb2b8178ec500388b14bb31cdc58a Mon Sep 17 00:00:00 2001
From: niboshi <niboshi000@gmail.com>
Date: Wed, 9 Dec 2020 15:26:42 +0000
Subject: [PATCH] push: Resolve from commit

---
 cmd/push.go           | 40 +++++++++++++++++++++++++++++++++++++++-
 pkg/ghost/git/repo.go | 26 ++++++++++++++++++++++++++
 2 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/cmd/push.go b/cmd/push.go
index 32ceab3..0f5542c 100644
--- a/cmd/push.go
+++ b/cmd/push.go
@@ -17,8 +17,10 @@ package cmd
 import (
 	"fmt"
 	"os"
+	"strings"
 
 	"github.com/pfnet-research/git-ghost/pkg/ghost"
+	"github.com/pfnet-research/git-ghost/pkg/ghost/git"
 	"github.com/pfnet-research/git-ghost/pkg/ghost/types"
 	"github.com/pfnet-research/git-ghost/pkg/util/errors"
 
@@ -43,7 +45,7 @@ func NewPushCommand() *cobra.Command {
 		Short: "push commits(hash1...hash2), diff(hash...current state) to your ghost repo",
 		Long:  "push commits or diff or all to your ghost repo.  If you didn't specify any subcommand, this commands works as an alias for 'push diff' command.",
 		Args:  cobra.RangeArgs(0, 1),
-		Run:   runPushDiffCommand(&flags),
+		Run:   runPushCommitsCommand(&flags),
 	}
 	command.AddCommand(&cobra.Command{
 		Use:   "commits [from-hash] [to-hash(default=HEAD)]",
@@ -73,6 +75,32 @@ func NewPushCommand() *cobra.Command {
 	return command
 }
 
+func getFirstRemoteAncestorCommit(commit string) (string, errors.GitGhostError) {
+	dir := globalOpts.srcDir
+	for {
+		branchNames, err := git.GetRemoteBranchesContainingCommit(dir, commit)
+		if err != nil {
+			return "", err
+		}
+		var originBranchNames []string
+		for _, branchName := range branchNames {
+			if strings.HasPrefix(branchName, fmt.Sprintf("refs/remotes/%s/", git.ORIGIN)) {
+				originBranchNames = append(originBranchNames, branchName)
+			}
+		}
+		if len(originBranchNames) > 0 {
+			// This commit is the first ancestor commit in the origin remote.
+			break
+		}
+		parentCommit, err := git.GetParentCommit(dir, commit)
+		if err != nil {
+			return "", err
+		}
+		commit = parentCommit
+	}
+	return commit, nil
+}
+
 type pushCommitsArg struct {
 	commitsFrom string
 	commitsTo   string
@@ -111,6 +139,16 @@ func (arg pushCommitsArg) validate() errors.GitGhostError {
 func runPushCommitsCommand(flags *pushFlags) func(cmd *cobra.Command, args []string) {
 	return func(cmd *cobra.Command, args []string) {
 		pushArg := newPushCommitsArg(args)
+
+		// If commitsFrom is not given, find the first ancestor commit that is included in the origin remote.
+		if pushArg.commitsFrom == "" {
+			commitsFrom, err := getFirstRemoteAncestorCommit(pushArg.commitsTo)
+			if err != nil {
+				errors.LogErrorWithStack(err)
+				os.Exit(1)
+			}
+			pushArg.commitsFrom = commitsFrom
+		}
 		if err := pushArg.validate(); err != nil {
 			errors.LogErrorWithStack(err)
 			os.Exit(1)
diff --git a/pkg/ghost/git/repo.go b/pkg/ghost/git/repo.go
index fff6a8b..ed14e44 100644
--- a/pkg/ghost/git/repo.go
+++ b/pkg/ghost/git/repo.go
@@ -15,6 +15,7 @@
 package git
 
 import (
+	"bytes"
 	"fmt"
 	"os/exec"
 	"strings"
@@ -146,3 +147,28 @@ func ResetHardToBranch(dir, branch string) errors.GitGhostError {
 		exec.Command("git", "-C", dir, "reset", "--hard", branch),
 	)
 }
+
+// GetParentCommit returns the parent commit of the given commit
+func GetParentCommit(dir, commit string) (string, errors.GitGhostError) {
+	resultBytes, err := util.JustOutputCmd(exec.Command("git", "-C", dir, "rev-parse", fmt.Sprintf("%s^", commit)))
+	if err != nil {
+		return "", errors.WithStack(gherrors.WithMessage(err, "failed to get the parent commit of a commit"))
+	}
+	return strings.TrimSuffix(string(resultBytes), "\n"), nil
+}
+
+// GetRemoteBranchesContainingCommit returns a slice of remote branch names each of which contain the given commit
+func GetRemoteBranchesContainingCommit(dir, commit string) ([]string, errors.GitGhostError) {
+	resultBytes, err := util.JustOutputCmd(exec.Command("git", "-C", dir, "branch", "--format", "%(refname)", "--remotes", "--contains", commit))
+	if err != nil {
+		return nil, errors.WithStack(gherrors.WithMessage(err, "failed to get remote branches containing a commit"))
+	}
+	var branchNames []string
+	for _, line := range bytes.Split(resultBytes, []byte("\n")) {
+		branchName := string(line)
+		if len(branchName) > 0 {
+			branchNames = append(branchNames, branchName)
+		}
+	}
+	return branchNames, nil
+}