From 4c278def930dbe21b6e4194c28ed09489c582bae Mon Sep 17 00:00:00 2001
From: Ayman Bagabas <ayman.bagabas@gmail.com>
Date: Tue, 15 Jul 2025 14:01:57 -0400
Subject: [PATCH] fix(tui): permissions: default to diff split mode when dialog
 is wide enough

This makes the diff view more readable in wider dialogs by default,
while still allowing users to toggle between split and unified modes.
If the user has previously set a preference, that will be respected.
Otherwise, the dialog will start in split mode when wide enough.
---
 .../dialogs/permissions/permissions.go        | 29 +++++++++++++++----
 1 file changed, 23 insertions(+), 6 deletions(-)

diff --git a/internal/tui/components/dialogs/permissions/permissions.go b/internal/tui/components/dialogs/permissions/permissions.go
index 0bbaa034ed2357cc4643ad92c0a680bb01cf61ff..4370d99e3fbf5490beb67422c9f102195482948c 100644
--- a/internal/tui/components/dialogs/permissions/permissions.go
+++ b/internal/tui/components/dialogs/permissions/permissions.go
@@ -52,9 +52,10 @@ type permissionDialogCmp struct {
 	selectedOption  int // 0: Allow, 1: Allow for session, 2: Deny
 
 	// Diff view state
-	diffSplitMode bool // true for split, false for unified
-	diffXOffset   int  // horizontal scroll offset
-	diffYOffset   int  // vertical scroll offset
+	defaultDiffSplitMode bool  // true for split, false for unified
+	diffSplitMode        *bool // nil means use defaultDiffSplitMode
+	diffXOffset          int   // horizontal scroll offset
+	diffYOffset          int   // vertical scroll offset
 
 	// Caching
 	cachedContent string
@@ -122,7 +123,12 @@ func (p *permissionDialogCmp) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			)
 		case key.Matches(msg, p.keyMap.ToggleDiffMode):
 			if p.supportsDiffView() {
-				p.diffSplitMode = !p.diffSplitMode
+				if p.diffSplitMode == nil {
+					diffSplitMode := !p.defaultDiffSplitMode
+					p.diffSplitMode = &diffSplitMode
+				} else {
+					*p.diffSplitMode = !*p.diffSplitMode
+				}
 				p.contentDirty = true // Mark content as dirty when diff mode changes
 				return p, nil
 			}
@@ -354,7 +360,7 @@ func (p *permissionDialogCmp) generateEditContent() string {
 			Width(p.contentViewPort.Width()).
 			XOffset(p.diffXOffset).
 			YOffset(p.diffYOffset)
-		if p.diffSplitMode {
+		if p.useDiffSplitMode() {
 			formatter = formatter.Split()
 		} else {
 			formatter = formatter.Unified()
@@ -376,7 +382,7 @@ func (p *permissionDialogCmp) generateWriteContent() string {
 			Width(p.contentViewPort.Width()).
 			XOffset(p.diffXOffset).
 			YOffset(p.diffYOffset)
-		if p.diffSplitMode {
+		if p.useDiffSplitMode() {
 			formatter = formatter.Split()
 		} else {
 			formatter = formatter.Unified()
@@ -425,6 +431,14 @@ func (p *permissionDialogCmp) generateDefaultContent() string {
 	return finalContent
 }
 
+func (p *permissionDialogCmp) useDiffSplitMode() bool {
+	if p.diffSplitMode != nil {
+		return *p.diffSplitMode
+	} else {
+		return p.defaultDiffSplitMode
+	}
+}
+
 func (p *permissionDialogCmp) styleViewport() string {
 	t := styles.CurrentTheme()
 	return t.S().Base.Render(p.contentViewPort.View())
@@ -512,6 +526,9 @@ func (p *permissionDialogCmp) SetSize() tea.Cmd {
 		p.height = int(float64(p.wHeight) * 0.5)
 	}
 
+	// Default to diff split mode when dialog is wide enough.
+	p.defaultDiffSplitMode = p.width >= 140
+
 	// Mark content as dirty if size changed
 	if oldWidth != p.width || oldHeight != p.height {
 		p.contentDirty = true