1 files changed, 204 insertions, 0 deletions
diff --git a/pkg/commands/git_commands/branch_loader.go b/pkg/commands/git_commands/branch_loader.go
new file mode 100644
index 000000000..08811374d
--- /dev/null
+++ b/pkg/commands/git_commands/branch_loader.go
@@ -0,0 +1,204 @@
+package git_commands
+
+import (
+	"regexp"
+	"strings"
+
+	"github.com/jesseduffield/generics/set"
+	"github.com/jesseduffield/generics/slices"
+	"github.com/jesseduffield/go-git/v5/config"
+	"github.com/jesseduffield/lazygit/pkg/commands/models"
+	"github.com/jesseduffield/lazygit/pkg/common"
+	"github.com/jesseduffield/lazygit/pkg/utils"
+)
+
+// context:
+// we want to only show 'safe' branches (ones that haven't e.g. been deleted)
+// which `git branch -a` gives us, but we also want the recency data that
+// git reflog gives us.
+// So we get the HEAD, then append get the reflog branches that intersect with
+// our safe branches, then add the remaining safe branches, ensuring uniqueness
+// along the way
+
+// if we find out we need to use one of these functions in the git.go file, we
+// can just pull them out of here and put them there and then call them from in here
+
+type BranchLoaderConfigCommands interface {
+	Branches() (map[string]*config.Branch, error)
+}
+
+// BranchLoader returns a list of Branch objects for the current repo
+type BranchLoader struct {
+	*common.Common
+	getRawBranches       func() (string, error)
+	getCurrentBranchName func() (string, string, error)
+	config               BranchLoaderConfigCommands
+}
+
+func NewBranchLoader(
+	cmn *common.Common,
+	getRawBranches func() (string, error),
+	getCurrentBranchName func() (string, string, error),
+	config BranchLoaderConfigCommands,
+) *BranchLoader {
+	return &BranchLoader{
+		Common:               cmn,
+		getRawBranches:       getRawBranches,
+		getCurrentBranchName: getCurrentBranchName,
+		config:               config,
+	}
+}
+
+// Load the list of branches for the current repo
+func (self *BranchLoader) Load(reflogCommits []*models.Commit) ([]*models.Branch, error) {
+	branches := self.obtainBranches()
+
+	reflogBranches := self.obtainReflogBranches(reflogCommits)
+
+	// loop through reflog branches. If there is a match, merge them, then remove it from the branches and keep it in the reflog branches
+	branchesWithRecency := make([]*models.Branch, 0)
+outer:
+	for _, reflogBranch := range reflogBranches {
+		for j, branch := range branches {
+			if branch.Head {
+				continue
+			}
+			if strings.EqualFold(reflogBranch.Name, branch.Name) {
+				branch.Recency = reflogBranch.Recency
+				branchesWithRecency = append(branchesWithRecency, branch)
+				branches = slices.Remove(branches, j)
+				continue outer
+			}
+		}
+	}
+
+	branches = slices.Prepend(branches, branchesWithRecency...)
+
+	foundHead := false
+	for i, branch := range branches {
+		if branch.Head {
+			foundHead = true
+			branch.Recency = "  *"
+			branches = slices.Move(branches, i, 0)
+			break
+		}
+	}
+	if !foundHead {
+		currentBranchName, currentBranchDisplayName, err := self.getCurrentBranchName()
+		if err != nil {
+			return nil, err
+		}
+		branches = slices.Prepend(branches, &models.Branch{Name: currentBranchName, DisplayName: currentBranchDisplayName, Head: true, Recency: "  *"})
+	}
+
+	configBranches, err := self.config.Branches()
+	if err != nil {
+		return nil, err
+	}
+
+	for _, branch := range branches {
+		match := configBranches[branch.Name]
+		if match != nil {
+			branch.UpstreamRemote = match.Remote
+			branch.UpstreamBranch = match.Merge.Short()
+		}
+	}
+
+	return branches, nil
+}
+
+func (self *BranchLoader) obtainBranches() []*models.Branch {
+	output, err := self.getRawBranches()
+	if err != nil {
+		panic(err)
+	}
+
+	trimmedOutput := strings.TrimSpace(output)
+	outputLines := strings.Split(trimmedOutput, "\n")
+
+	return slices.FilterMap(outputLines, func(line string) (*models.Branch, bool) {
+		if line == "" {
+			return nil, false
+		}
+
+		split := strings.Split(line, "\x00")
+		if len(split) != 4 {
+			// Ignore line if it isn't separated into 4 parts
+			// This is probably a warning message, for more info see:
+			// https://github.com/jesseduffield/lazygit/issues/1385#issuecomment-885580439
+			return nil, false
+		}
+
+		return obtainBranch(split), true
+	})
+}
+
+// Obtain branch information from parsed line output of getRawBranches()
+// split contains the '|' separated tokens in the line of output
+func obtainBranch(split []string) *models.Branch {
+	name := strings.TrimPrefix(split[1], "heads/")
+	branch := &models.Branch{
+		Name:      name,
+		Pullables: "?",
+		Pushables: "?",
+		Head:      split[0] == "*",
+	}
+
+	upstreamName := split[2]
+	if upstreamName == "" {
+		// if we're here then it means we do not have a local version of the remote.
+		// The branch might still be tracking a remote though, we just don't know
+		// how many commits ahead/behind it is
+		return branch
+	}
+
+	track := split[3]
+	if track == "[gone]" {
+		branch.UpstreamGone = true
+	} else {
+		re := regexp.MustCompile(`ahead (\d+)`)
+		match := re.FindStringSubmatch(track)
+		if len(match) > 1 {
+			branch.Pushables = match[1]
+		} else {
+			branch.Pushables = "0"
+		}
+
+		re = regexp.MustCompile(`behind (\d+)`)
+		match = re.FindStringSubmatch(track)
+		if len(match) > 1 {
+			branch.Pullables = match[1]
+		} else {
+			branch.Pullables = "0"
+		}
+	}
+
+	return branch
+}
+
+// TODO: only look at the new reflog commits, and otherwise store the recencies in
+// int form against the branch to recalculate the time ago
+func (self *BranchLoader) obtainReflogBranches(reflogCommits []*models.Commit) []*models.Branch {
+	foundBranches := set.New[string]()
+	re := regexp.MustCompile(`checkout: moving from ([\S]+) to ([\S]+)`)
+	reflogBranches := make([]*models.Branch, 0, len(reflogCommits))
+
+	for _, commit := range reflogCommits {
+		match := re.FindStringSubmatch(commit.Name)
+		if len(match) != 3 {
+			continue
+		}
+
+		recency := utils.UnixToTimeAgo(commit.UnixTimestamp)
+		for _, branchName := range match[1:] {
+			if !foundBranches.Includes(branchName) {
+				foundBranches.Add(branchName)
+				reflogBranches = append(reflogBranches, &models.Branch{
+					Recency: recency,
+					Name:    branchName,
+				})
+			}
+		}
+	}
+	return reflogBranches
+}