Split commit message panel into commit summary and commit description panel

When we use the one panel for the entire commit message, its tricky to have a keybinding both for adding a newline and submitting.
By having two panels: one for the summary line and one for the description, we allow for 'enter' to submit the message when done from the summary panel,
and 'enter' to add a newline when done from the description panel. Alt-enter, for those who can use that key combo, also works for submitting the message
from the description panel. For those who can't use that key combo, and don't want to remap the keybinding, they can hit tab to go back to the summary panel
and then 'enter' to submit the message.

We have some awkwardness in that both contexts (i.e. panels) need to appear and disappear in tandem and we don't have a great way of handling that concept,
so we just push both contexts one after the other, and likewise remove both contexts when we escape.

3 files changed, 222 insertions, 39 deletions

diff --git a/pkg/gui/controllers/helpers/commits_helper.go b/pkg/gui/controllers/helpers/commits_helper.go
new file mode 100644
index 000000000..2b8c4688b
--- /dev/null
+++ b/pkg/gui/controllers/helpers/commits_helper.go
@@ -0,0 +1,163 @@
+package helpers
+
+import (
+	"strings"
+
+	"github.com/jesseduffield/lazygit/pkg/gui/context"
+	"github.com/jesseduffield/lazygit/pkg/gui/types"
+)
+
+type ICommitsHelper interface {
+	UpdateCommitPanelView(message string)
+}
+
+type CommitsHelper struct {
+	c *types.HelperCommon
+
+	model                *types.Model
+	contexts             *context.ContextTree
+	getCommitSummary     func() string
+	setCommitSummary     func(string)
+	getCommitDescription func() string
+	setCommitDescription func(string)
+	renderCommitLength   func()
+}
+
+var _ ICommitsHelper = &CommitsHelper{}
+
+func NewCommitsHelper(
+	c *types.HelperCommon,
+	model *types.Model,
+	contexts *context.ContextTree,
+	getCommitSummary func() string,
+	setCommitSummary func(string),
+	getCommitDescription func() string,
+	setCommitDescription func(string),
+	renderCommitLength func(),
+) *CommitsHelper {
+	return &CommitsHelper{
+		c:                    c,
+		model:                model,
+		contexts:             contexts,
+		getCommitSummary:     getCommitSummary,
+		setCommitSummary:     setCommitSummary,
+		getCommitDescription: getCommitDescription,
+		setCommitDescription: setCommitDescription,
+		renderCommitLength:   renderCommitLength,
+	}
+}
+
+func (self *CommitsHelper) SplitCommitMessageAndDescription(message string) (string, string) {
+	for _, separator := range []string{"\n\n", "\n\r\n\r", "\n", "\n\r"} {
+		msg, description, found := strings.Cut(message, separator)
+		if found {
+			return msg, description
+		}
+	}
+	return message, ""
+}
+
+func (self *CommitsHelper) SetMessageAndDescriptionInView(message string) {
+	summary, description := self.SplitCommitMessageAndDescription(message)
+
+	self.setCommitSummary(summary)
+	self.setCommitDescription(description)
+	self.renderCommitLength()
+}
+
+func (self *CommitsHelper) joinCommitMessageAndDescription() string {
+	if len(self.getCommitDescription()) == 0 {
+		return self.getCommitSummary()
+	}
+	return self.getCommitSummary() + "\n" + self.getCommitDescription()
+}
+
+func (self *CommitsHelper) UpdateCommitPanelView(message string) {
+	// first try the passed in message, if not fallback to context -> view in that order
+	if message != "" {
+		self.SetMessageAndDescriptionInView(message)
+		return
+	}
+	message = self.contexts.CommitMessage.GetPreservedMessage()
+	if message != "" {
+		self.SetMessageAndDescriptionInView(message)
+	} else {
+		self.SetMessageAndDescriptionInView(self.getCommitSummary())
+	}
+}
+
+type OpenCommitMessagePanelOpts struct {
+	CommitIndex     int
+	Title           string
+	PreserveMessage bool
+	OnConfirm       func(string) error
+	InitialMessage  string
+}
+
+func (self *CommitsHelper) OpenCommitMessagePanel(opts *OpenCommitMessagePanelOpts) error {
+	self.contexts.CommitMessage.SetPanelState(
+		opts.CommitIndex,
+		opts.Title,
+		opts.PreserveMessage,
+		opts.OnConfirm,
+	)
+
+	self.UpdateCommitPanelView(opts.InitialMessage)
+
+	return self.pushCommitMessageContexts()
+}
+
+func (self *CommitsHelper) OnCommitSuccess() {
+	// if we have a preserved message we want to clear it on success
+	if self.contexts.CommitMessage.GetPreserveMessage() {
+		self.contexts.CommitMessage.SetPreservedMessage("")
+	}
+	self.SetMessageAndDescriptionInView("")
+}
+
+func (self *CommitsHelper) HandleCommitConfirm() error {
+	fullMessage := self.joinCommitMessageAndDescription()
+
+	if fullMessage == "" {
+		return self.c.ErrorMsg(self.c.Tr.CommitWithoutMessageErr)
+	}
+
+	err := self.contexts.CommitMessage.OnConfirm(fullMessage)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (self *CommitsHelper) CloseCommitMessagePanel() error {
+	if self.contexts.CommitMessage.GetPreserveMessage() {
+		message := self.joinCommitMessageAndDescription()
+
+		self.contexts.CommitMessage.SetPreservedMessage(message)
+	} else {
+		self.SetMessageAndDescriptionInView("")
+	}
+	return self.EscapeCommitsPanel()
+}
+
+func (self *CommitsHelper) EscapeCommitsPanel() error {
+	return self.c.RemoveContexts(self.commitMessageContexts())
+}
+
+func (self *CommitsHelper) pushCommitMessageContexts() error {
+	for _, context := range self.commitMessageContexts() {
+		if err := self.c.PushContext(context); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (self *CommitsHelper) commitMessageContexts() []types.Context {
+	return []types.Context{
+		self.contexts.CommitDescription,
+		self.contexts.CommitMessage,
+	}
+}
diff --git a/pkg/gui/controllers/helpers/helpers.go b/pkg/gui/controllers/helpers/helpers.go
index a66d013bd..471e8a03a 100644
--- a/pkg/gui/controllers/helpers/helpers.go
+++ b/pkg/gui/controllers/helpers/helpers.go
@@ -15,6 +15,7 @@ type Helpers struct {
 	GPG            *GpgHelper
 	Upstream       *UpstreamHelper
 	AmendHelper    *AmendHelper
+	Commits        *CommitsHelper
 }
 
 func NewStubHelpers() *Helpers {
@@ -33,5 +34,6 @@ func NewStubHelpers() *Helpers {
 		GPG:            &GpgHelper{},
 		Upstream:       &UpstreamHelper{},
 		AmendHelper:    &AmendHelper{},
+		Commits:        &CommitsHelper{},
 	}
 }
diff --git a/pkg/gui/controllers/helpers/working_tree_helper.go b/pkg/gui/controllers/helpers/working_tree_helper.go
index 17850b994..d205a98dc 100644
--- a/pkg/gui/controllers/helpers/working_tree_helper.go
+++ b/pkg/gui/controllers/helpers/working_tree_helper.go
@@ -20,13 +20,14 @@ type IWorkingTreeHelper interface {
 }
 
 type WorkingTreeHelper struct {
-	c                     *types.HelperCommon
-	git                   *commands.GitCommand
-	contexts              *context.ContextTree
-	refHelper             *RefsHelper
-	model                 *types.Model
-	setCommitMessage      func(message string)
-	getSavedCommitMessage func() string
+	c                *types.HelperCommon
+	git              *commands.GitCommand
+	contexts         *context.ContextTree
+	refHelper        *RefsHelper
+	model            *types.Model
+	setCommitMessage func(message string)
+	commitsHelper    *CommitsHelper
+	gpgHelper        *GpgHelper
 }
 
 func NewWorkingTreeHelper(
@@ -36,16 +37,18 @@ func NewWorkingTreeHelper(
 	refHelper *RefsHelper,
 	model *types.Model,
 	setCommitMessage func(message string),
-	getSavedCommitMessage func() string,
+	commitsHelper *CommitsHelper,
+	gpgHelper *GpgHelper,
 ) *WorkingTreeHelper {
 	return &WorkingTreeHelper{
-		c:                     c,
-		git:                   git,
-		contexts:              contexts,
-		refHelper:             refHelper,
-		model:                 model,
-		setCommitMessage:      setCommitMessage,
-		getSavedCommitMessage: getSavedCommitMessage,
+		c:                c,
+		git:              git,
+		contexts:         contexts,
+		refHelper:        refHelper,
+		model:            model,
+		setCommitMessage: setCommitMessage,
+		commitsHelper:    commitsHelper,
+		gpgHelper:        gpgHelper,
 	}
 }
 
@@ -94,7 +97,7 @@ func (self *WorkingTreeHelper) OpenMergeTool() error {
 	})
 }
 
-func (self *WorkingTreeHelper) HandleCommitPress() error {
+func (self *WorkingTreeHelper) HandleCommitPressWithMessage(initialMessage string) error {
 	if err := self.prepareFilesForCommit(); err != nil {
 		return self.c.Error(err)
 	}
@@ -107,28 +110,25 @@ func (self *WorkingTreeHelper) HandleCommitPress() error {
 		return self.PromptToStageAllAndRetry(self.HandleCommitPress)
 	}
 
-	savedCommitMessage := self.getSavedCommitMessage()
-	if len(savedCommitMessage) > 0 {
-		self.setCommitMessage(savedCommitMessage)
-	} else {
-		commitPrefixConfig := self.commitPrefixConfigForRepo()
-		if commitPrefixConfig != nil {
-			prefixPattern := commitPrefixConfig.Pattern
-			prefixReplace := commitPrefixConfig.Replace
-			rgx, err := regexp.Compile(prefixPattern)
-			if err != nil {
-				return self.c.ErrorMsg(fmt.Sprintf("%s: %s", self.c.Tr.LcCommitPrefixPatternError, err.Error()))
-			}
-			prefix := rgx.ReplaceAllString(self.refHelper.GetCheckedOutRef().Name, prefixReplace)
-			self.setCommitMessage(prefix)
-		}
-	}
-
-	if err := self.c.PushContext(self.contexts.CommitMessage); err != nil {
-		return err
-	}
+	return self.commitsHelper.OpenCommitMessagePanel(
+		&OpenCommitMessagePanelOpts{
+			CommitIndex:     context.NoCommitIndex,
+			InitialMessage:  initialMessage,
+			Title:           self.c.Tr.CommitSummary,
+			PreserveMessage: true,
+			OnConfirm:       self.handleCommit,
+		},
+	)
+}
 
-	return nil
+func (self *WorkingTreeHelper) handleCommit(message string) error {
+	cmdObj := self.git.Commit.CommitCmdObj(message)
+	self.c.LogAction(self.c.Tr.Actions.Commit)
+	_ = self.commitsHelper.EscapeCommitsPanel()
+	return self.gpgHelper.WithGpgHandling(cmdObj, self.c.Tr.CommittingStatus, func() error {
+		self.commitsHelper.OnCommitSuccess()
+		return nil
+	})
 }
 
 // HandleCommitEditorPress - handle when the user wants to commit changes via
@@ -154,9 +154,27 @@ func (self *WorkingTreeHelper) HandleWIPCommitPress() error {
 		return self.c.ErrorMsg(self.c.Tr.SkipHookPrefixNotConfigured)
 	}
 
-	self.setCommitMessage(skipHookPrefix)
+	return self.HandleCommitPressWithMessage(skipHookPrefix)
+}
+
+func (self *WorkingTreeHelper) HandleCommitPress() error {
+	message := self.contexts.CommitMessage.GetPreservedMessage()
+
+	if message != "" {
+		commitPrefixConfig := self.commitPrefixConfigForRepo()
+		if commitPrefixConfig != nil {
+			prefixPattern := commitPrefixConfig.Pattern
+			prefixReplace := commitPrefixConfig.Replace
+			rgx, err := regexp.Compile(prefixPattern)
+			if err != nil {
+				return self.c.ErrorMsg(fmt.Sprintf("%s: %s", self.c.Tr.LcCommitPrefixPatternError, err.Error()))
+			}
+			prefix := rgx.ReplaceAllString(self.refHelper.GetCheckedOutRef().Name, prefixReplace)
+			message = prefix
+		}
+	}
 
-	return self.HandleCommitPress()
+	return self.HandleCommitPressWithMessage(message)
 }
 
 func (self *WorkingTreeHelper) PromptToStageAllAndRetry(retry func() error) error {