Merge loaders package into git_commands package

pkg/commands/git_commands/commit_loader.go

@@ -0,0 +1,459 @@
+package git_commands
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"github.com/fsmiamoto/git-todo-parser/todo"
+	"github.com/jesseduffield/generics/slices"
+	"github.com/jesseduffield/lazygit/pkg/commands/models"
+	"github.com/jesseduffield/lazygit/pkg/commands/oscommands"
+	"github.com/jesseduffield/lazygit/pkg/commands/types/enums"
+	"github.com/jesseduffield/lazygit/pkg/common"
+	"github.com/jesseduffield/lazygit/pkg/gui/style"
+)
+
+// context:
+// here we get the commits from git log but format them to show whether they're
+// unpushed/pushed/merged into the base branch or not, or if they're yet to
+// be processed as part of a rebase (these won't appear in git log but we
+// grab them from the rebase-related files in the .git directory to show them
+
+// CommitLoader returns a list of Commit objects for the current repo
+type CommitLoader struct {
+	*common.Common
+	cmd oscommands.ICmdObjBuilder
+
+	getCurrentBranchName func() (string, string, error)
+	getRebaseMode        func() (enums.RebaseMode, error)
+	readFile             func(filename string) ([]byte, error)
+	walkFiles            func(root string, fn filepath.WalkFunc) error
+	dotGitDir            string
+}
+
+// making our dependencies explicit for the sake of easier testing
+func NewCommitLoader(
+	cmn *common.Common,
+	cmd oscommands.ICmdObjBuilder,
+	dotGitDir string,
+	getCurrentBranchName func() (string, string, error),
+	getRebaseMode func() (enums.RebaseMode, error),
+) *CommitLoader {
+	return &CommitLoader{
+		Common:               cmn,
+		cmd:                  cmd,
+		getCurrentBranchName: getCurrentBranchName,
+		getRebaseMode:        getRebaseMode,
+		readFile:             os.ReadFile,
+		walkFiles:            filepath.Walk,
+		dotGitDir:            dotGitDir,
+	}
+}
+
+type GetCommitsOptions struct {
+	Limit                bool
+	FilterPath           string
+	IncludeRebaseCommits bool
+	RefName              string // e.g. "HEAD" or "my_branch"
+	// determines if we show the whole git graph i.e. pass the '--all' flag
+	All bool
+}
+
+// GetCommits obtains the commits of the current branch
+func (self *CommitLoader) GetCommits(opts GetCommitsOptions) ([]*models.Commit, error) {
+	commits := []*models.Commit{}
+	var rebasingCommits []*models.Commit
+	rebaseMode, err := self.getRebaseMode()
+	if err != nil {
+		return nil, err
+	}
+
+	if opts.IncludeRebaseCommits && opts.FilterPath == "" {
+		var err error
+		rebasingCommits, err = self.MergeRebasingCommits(commits)
+		if err != nil {
+			return nil, err
+		}
+		commits = append(commits, rebasingCommits...)
+	}
+
+	passedFirstPushedCommit := false
+	firstPushedCommit, err := self.getFirstPushedCommit(opts.RefName)
+	if err != nil {
+		// must have no upstream branch so we'll consider everything as pushed
+		passedFirstPushedCommit = true
+	}
+
+	err = self.getLogCmd(opts).RunAndProcessLines(func(line string) (bool, error) {
+		commit := self.extractCommitFromLine(line)
+		if commit.Sha == firstPushedCommit {
+			passedFirstPushedCommit = true
+		}
+		commit.Status = map[bool]string{true: "unpushed", false: "pushed"}[!passedFirstPushedCommit]
+		commits = append(commits, commit)
+		return false, nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	if len(commits) == 0 {
+		return commits, nil
+	}
+
+	if rebaseMode != enums.REBASE_MODE_NONE {
+		currentCommit := commits[len(rebasingCommits)]
+		youAreHere := style.FgYellow.Sprintf("<-- %s ---", self.Tr.YouAreHere)
+		currentCommit.Name = fmt.Sprintf("%s %s", youAreHere, currentCommit.Name)
+	}
+
+	commits, err = self.setCommitMergedStatuses(opts.RefName, commits)
+	if err != nil {
+		return nil, err
+	}
+
+	return commits, nil
+}
+
+func (self *CommitLoader) MergeRebasingCommits(commits []*models.Commit) ([]*models.Commit, error) {
+	// chances are we have as many commits as last time so we'll set the capacity to be the old length
+	result := make([]*models.Commit, 0, len(commits))
+	for i, commit := range commits {
+		if commit.Status != "rebasing" { // removing the existing rebase commits so we can add the refreshed ones
+			result = append(result, commits[i:]...)
+			break
+		}
+	}
+
+	rebaseMode, err := self.getRebaseMode()
+	if err != nil {
+		return nil, err
+	}
+
+	if rebaseMode == enums.REBASE_MODE_NONE {
+		// not in rebase mode so return original commits
+		return result, nil
+	}
+
+	rebasingCommits, err := self.getHydratedRebasingCommits(rebaseMode)
+	if err != nil {
+		return nil, err
+	}
+	if len(rebasingCommits) > 0 {
+		result = append(rebasingCommits, result...)
+	}
+
+	return result, nil
+}
+
+// extractCommitFromLine takes a line from a git log and extracts the sha, message, date, and tag if present
+// then puts them into a commit object
+// example input:
+// 8ad01fe32fcc20f07bc6693f87aa4977c327f1e1|10 hours ago|Jesse Duffield| (HEAD -> master, tag: v0.15.2)|refresh commits when adding a tag
+func (self *CommitLoader) extractCommitFromLine(line string) *models.Commit {
+	split := strings.SplitN(line, "\x00", 7)
+
+	sha := split[0]
+	unixTimestamp := split[1]
+	authorName := split[2]
+	authorEmail := split[3]
+	extraInfo := strings.TrimSpace(split[4])
+	parentHashes := split[5]
+	message := split[6]
+
+	tags := []string{}
+
+	if extraInfo != "" {
+		re := regexp.MustCompile(`tag: ([^,\)]+)`)
+		tagMatch := re.FindStringSubmatch(extraInfo)
+		if len(tagMatch) > 1 {
+			tags = append(tags, tagMatch[1])
+		}
+	}
+
+	unitTimestampInt, _ := strconv.Atoi(unixTimestamp)
+
+	parents := []string{}
+	if len(parentHashes) > 0 {
+		parents = strings.Split(parentHashes, " ")
+	}
+
+	return &models.Commit{
+		Sha:           sha,
+		Name:          message,
+		Tags:          tags,
+		ExtraInfo:     extraInfo,
+		UnixTimestamp: int64(unitTimestampInt),
+		AuthorName:    authorName,
+		AuthorEmail:   authorEmail,
+		Parents:       parents,
+	}
+}
+
+func (self *CommitLoader) getHydratedRebasingCommits(rebaseMode enums.RebaseMode) ([]*models.Commit, error) {
+	commits, err := self.getRebasingCommits(rebaseMode)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(commits) == 0 {
+		return nil, nil
+	}
+
+	commitShas := slices.Map(commits, func(commit *models.Commit) string {
+		return commit.Sha
+	})
+
+	// note that we're not filtering these as we do non-rebasing commits just because
+	// I suspect that will cause some damage
+	cmdObj := self.cmd.New(
+		fmt.Sprintf(
+			"git -c log.showSignature=false show %s --no-patch --oneline %s --abbrev=%d",
+			strings.Join(commitShas, " "),
+			prettyFormat,
+			20,
+		),
+	).DontLog()
+
+	hydratedCommits := make([]*models.Commit, 0, len(commits))
+	i := 0
+	err = cmdObj.RunAndProcessLines(func(line string) (bool, error) {
+		commit := self.extractCommitFromLine(line)
+		matchingCommit := commits[i]
+		commit.Action = matchingCommit.Action
+		commit.Status = matchingCommit.Status
+		hydratedCommits = append(hydratedCommits, commit)
+		i++
+		return false, nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	return hydratedCommits, nil
+}
+
+// getRebasingCommits obtains the commits that we're in the process of rebasing
+func (self *CommitLoader) getRebasingCommits(rebaseMode enums.RebaseMode) ([]*models.Commit, error) {
+	switch rebaseMode {
+	case enums.REBASE_MODE_MERGING:
+		return self.getNormalRebasingCommits()
+	case enums.REBASE_MODE_INTERACTIVE:
+		return self.getInteractiveRebasingCommits()
+	default:
+		return nil, nil
+	}
+}
+
+func (self *CommitLoader) getNormalRebasingCommits() ([]*models.Commit, error) {
+	rewrittenCount := 0
+	bytesContent, err := self.readFile(filepath.Join(self.dotGitDir, "rebase-apply/rewritten"))
+	if err == nil {
+		content := string(bytesContent)
+		rewrittenCount = len(strings.Split(content, "\n"))
+	}
+
+	// we know we're rebasing, so lets get all the files whose names have numbers
+	commits := []*models.Commit{}
+	err = self.walkFiles(filepath.Join(self.dotGitDir, "rebase-apply"), func(path string, f os.FileInfo, err error) error {
+		if rewrittenCount > 0 {
+			rewrittenCount--
+			return nil
+		}
+		if err != nil {
+			return err
+		}
+		re := regexp.MustCompile(`^\d+$`)
+		if !re.MatchString(f.Name()) {
+			return nil
+		}
+		bytesContent, err := self.readFile(path)
+		if err != nil {
+			return err
+		}
+		content := string(bytesContent)
+		commit := self.commitFromPatch(content)
+		commits = append([]*models.Commit{commit}, commits...)
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return commits, nil
+}
+
+// git-rebase-todo example:
+// pick ac446ae94ee560bdb8d1d057278657b251aaef17 ac446ae
+// pick afb893148791a2fbd8091aeb81deba4930c73031 afb8931
+
+// git-rebase-todo.backup example:
+// pick 49cbba374296938ea86bbd4bf4fee2f6ba5cccf6 third commit on master
+// pick ac446ae94ee560bdb8d1d057278657b251aaef17 blah  commit on master
+// pick afb893148791a2fbd8091aeb81deba4930c73031 fourth commit on master
+
+// getInteractiveRebasingCommits takes our git-rebase-todo and our git-rebase-todo.backup files
+// and extracts out the sha and names of commits that we still have to go
+// in the rebase:
+func (self *CommitLoader) getInteractiveRebasingCommits() ([]*models.Commit, error) {
+	bytesContent, err := self.readFile(filepath.Join(self.dotGitDir, "rebase-merge/git-rebase-todo"))
+	if err != nil {
+		self.Log.Error(fmt.Sprintf("error occurred reading git-rebase-todo: %s", err.Error()))
+		// we assume an error means the file doesn't exist so we just return
+		return nil, nil
+	}
+
+	commits := []*models.Commit{}
+
+	todos, err := todo.Parse(bytes.NewBuffer(bytesContent))
+	if err != nil {
+		self.Log.Error(fmt.Sprintf("error occurred while parsing git-rebase-todo file: %s", err.Error()))
+		return nil, nil
+	}
+
+	for _, t := range todos {
+		if t.Commit == "" {
+			// Command does not have a commit associated, skip
+			continue
+		}
+		commits = slices.Prepend(commits, &models.Commit{
+			Sha:    t.Commit,
+			Name:   t.Msg,
+			Status: "rebasing",
+			Action: t.Command.String(),
+		})
+	}
+
+	return commits, nil
+}
+
+// assuming the file starts like this:
+// From e93d4193e6dd45ca9cf3a5a273d7ba6cd8b8fb20 Mon Sep 17 00:00:00 2001
+// From: Lazygit Tester <test@example.com>
+// Date: Wed, 5 Dec 2018 21:03:23 +1100
+// Subject: second commit on master
+func (self *CommitLoader) commitFromPatch(content string) *models.Commit {
+	lines := strings.Split(content, "\n")
+	sha := strings.Split(lines[0], " ")[1]
+	name := strings.TrimPrefix(lines[3], "Subject: ")
+	return &models.Commit{
+		Sha:    sha,
+		Name:   name,
+		Status: "rebasing",
+	}
+}
+
+func (self *CommitLoader) setCommitMergedStatuses(refName string, commits []*models.Commit) ([]*models.Commit, error) {
+	ancestor, err := self.getMergeBase(refName)
+	if err != nil {
+		return nil, err
+	}
+	if ancestor == "" {
+		return commits, nil
+	}
+	passedAncestor := false
+	for i, commit := range commits {
+		if strings.HasPrefix(ancestor, commit.Sha) {
+			passedAncestor = true
+		}
+		if commit.Status != "pushed" {
+			continue
+		}
+		if passedAncestor {
+			commits[i].Status = "merged"
+		}
+	}
+	return commits, nil
+}
+
+func (self *CommitLoader) getMergeBase(refName string) (string, error) {
+	currentBranch, _, err := self.getCurrentBranchName()
+	if err != nil {
+		return "", err
+	}
+
+	baseBranch := "master"
+	if strings.HasPrefix(currentBranch, "feature/") {
+		baseBranch = "develop"
+	}
+
+	// swallowing error because it's not a big deal; probably because there are no commits yet
+	output, _ := self.cmd.New(fmt.Sprintf("git merge-base %s %s", self.cmd.Quote(refName), self.cmd.Quote(baseBranch))).DontLog().RunWithOutput()
+	return ignoringWarnings(output), nil
+}
+
+func ignoringWarnings(commandOutput string) string {
+	trimmedOutput := strings.TrimSpace(commandOutput)
+	split := strings.Split(trimmedOutput, "\n")
+	// need to get last line in case the first line is a warning about how the error is ambiguous.
+	// At some point we should find a way to make it unambiguous
+	lastLine := split[len(split)-1]
+
+	return lastLine
+}
+
+// getFirstPushedCommit returns the first commit SHA which has been pushed to the ref's upstream.
+// all commits above this are deemed unpushed and marked as such.
+func (self *CommitLoader) getFirstPushedCommit(refName string) (string, error) {
+	output, err := self.cmd.
+		New(
+			fmt.Sprintf("git merge-base %s %s@{u}", self.cmd.Quote(refName), self.cmd.Quote(refName)),
+		).
+		DontLog().
+		RunWithOutput()
+	if err != nil {
+		return "", err
+	}
+
+	return ignoringWarnings(output), nil
+}
+
+// getLog gets the git log.
+func (self *CommitLoader) getLogCmd(opts GetCommitsOptions) oscommands.ICmdObj {
+	limitFlag := ""
+	if opts.Limit {
+		limitFlag = " -300"
+	}
+
+	filterFlag := ""
+	if opts.FilterPath != "" {
+		filterFlag = fmt.Sprintf(" --follow -- %s", self.cmd.Quote(opts.FilterPath))
+	}
+
+	config := self.UserConfig.Git.Log
+
+	orderFlag := "--" + config.Order
+	allFlag := ""
+	if opts.All {
+		allFlag = " --all"
+	}
+
+	return self.cmd.New(
+		fmt.Sprintf(
+			"git -c log.showSignature=false log %s %s %s --oneline %s%s --abbrev=%d%s",
+			self.cmd.Quote(opts.RefName),
+			orderFlag,
+			allFlag,
+			prettyFormat,
+			limitFlag,
+			40,
+			filterFlag,
+		),
+	).DontLog()
+}
+
+var prettyFormat = fmt.Sprintf(
+	"--pretty=format:\"%%H%s%%at%s%%aN%s%%ae%s%%d%s%%p%s%%s\"",
+	NULL_CODE,
+	NULL_CODE,
+	NULL_CODE,
+	NULL_CODE,
+	NULL_CODE,
+	NULL_CODE,
+)
+
+const NULL_CODE = "%x00"