add feature of display diff between specific commits #397

11 files changed, 131 insertions, 24 deletions

diff --git a/docs/keybindings/Keybindings_en.md b/docs/keybindings/Keybindings_en.md
index 9d9d1471e..3f393610d 100644
--- a/docs/keybindings/Keybindings_en.md
+++ b/docs/keybindings/Keybindings_en.md
@@ -25,16 +25,15 @@
   <kbd>A</kbd>: amend last commit
   <kbd>C</kbd>: commit changes using git editor
   <kbd>space</kbd>: toggle staged
-  <kbd>d</kbd>: delete if untracked / checkout if tracked
+  <kbd>d</kbd>: view 'discard changes' options
   <kbd>e</kbd>: edit file
   <kbd>o</kbd>: open file
   <kbd>i</kbd>: add to .gitignore
   <kbd>r</kbd>: refresh files
   <kbd>S</kbd>: stash files
-  <kbd>s</kbd>: soft reset to last commit
   <kbd>a</kbd>: stage/unstage all
   <kbd>t</kbd>: add patch
-  <kbd>D</kbd>: reset hard and remove untracked files
+  <kbd>D</kbd>: view reset options
   <kbd>enter</kbd>: stage individual hunks/lines
   <kbd>f</kbd>: fetch
 </pre>
@@ -72,6 +71,7 @@
   <kbd>C</kbd>: copy commit range (cherry-pick)
   <kbd>v</kbd>: paste commits (cherry-pick)
   <kbd>enter</kbd>: view commit's files
+  <kbd>space</kbd>: diff specific commits
 </pre>
 
 ## Stash
@@ -91,19 +91,6 @@
   <kbd>o</kbd>: open file
 </pre>
 
-## Main (Merging)
-
-<pre>
-  <kbd>esc</kbd>: return to files panel
-  <kbd>space</kbd>: pick hunk
-  <kbd>b</kbd>: pick both hunks
-  <kbd>◄</kbd>: select previous conflict
-  <kbd>►</kbd>: select next conflict
-  <kbd>▲</kbd>: select top hunk
-  <kbd>▼</kbd>: select bottom hunk
-  <kbd>z</kbd>: undo
-</pre>
-
 ## Main (Normal)
 
 <pre>
@@ -122,3 +109,16 @@
   <kbd>space</kbd>: stage line
   <kbd>a</kbd>: stage hunk
 </pre>
+
+## Main (Merging)
+
+<pre>
+  <kbd>esc</kbd>: return to files panel
+  <kbd>space</kbd>: pick hunk
+  <kbd>b</kbd>: pick both hunks
+  <kbd>◄</kbd>: select previous conflict
+  <kbd>►</kbd>: select next conflict
+  <kbd>▲</kbd>: select top hunk
+  <kbd>▼</kbd>: select bottom hunk
+  <kbd>z</kbd>: undo
+</pre>
diff --git a/docs/keybindings/Keybindings_nl.md b/docs/keybindings/Keybindings_nl.md
index dfa45df2c..3b5f250ec 100644
--- a/docs/keybindings/Keybindings_nl.md
+++ b/docs/keybindings/Keybindings_nl.md
@@ -25,16 +25,15 @@
   <kbd>A</kbd>: wijzig laatste commit
   <kbd>C</kbd>: commit veranderingen met de git editor
   <kbd>space</kbd>: toggle staged
-  <kbd>d</kbd>: Verwijder als untracked / uitchecken wordt gevolgd (ga weg)
+  <kbd>d</kbd>: view 'discard changes' options
   <kbd>e</kbd>: verander bestand
   <kbd>o</kbd>: open bestand
   <kbd>i</kbd>: voeg toe aan .gitignore
   <kbd>r</kbd>: refresh bestanden
   <kbd>S</kbd>: stash-bestanden
-  <kbd>s</kbd>: soft reset to last commit
   <kbd>a</kbd>: toggle staged alle
   <kbd>t</kbd>: bewerkingen toevoegen
-  <kbd>D</kbd>: harde reset and verwijderen ongevolgde bestanden
+  <kbd>D</kbd>: view reset options
   <kbd>enter</kbd>: stage individuele hunks/lijnen
   <kbd>f</kbd>: fetch
 </pre>
@@ -72,6 +71,7 @@
   <kbd>C</kbd>: copy commit range (cherry-pick)
   <kbd>v</kbd>: paste commits (cherry-pick)
   <kbd>enter</kbd>: view commit's files
+  <kbd>space</kbd>: diff specific commits
 </pre>
 
 ## Stash
diff --git a/docs/keybindings/Keybindings_pl.md b/docs/keybindings/Keybindings_pl.md
index 9e60e9657..f4394af58 100644
--- a/docs/keybindings/Keybindings_pl.md
+++ b/docs/keybindings/Keybindings_pl.md
@@ -25,16 +25,15 @@
   <kbd>A</kbd>: zmień ostatnie zatwierdzenie
   <kbd>C</kbd>: commituj zmiany używając edytora z gita
   <kbd>space</kbd>: przełącz zatwierdzenie
-  <kbd>d</kbd>: usuń jeśli nie śledzony / przełącz jeśli śledzony
+  <kbd>d</kbd>: view 'discard changes' options
   <kbd>e</kbd>: edytuj plik
   <kbd>o</kbd>: otwórz plik
   <kbd>i</kbd>: dodaj do .gitignore
   <kbd>r</kbd>: odśwież pliki
   <kbd>S</kbd>: przechowaj pliki
-  <kbd>s</kbd>: soft reset to last commit
   <kbd>a</kbd>: przełącz wszystkie zatwierdzenia
   <kbd>t</kbd>: dodaj łatkę
-  <kbd>D</kbd>: zresetuj twardo i usuń niepotwierdzone pliki
+  <kbd>D</kbd>: view reset options
   <kbd>enter</kbd>: zatwierdź pojedyncze linie
   <kbd>f</kbd>: fetch
 </pre>
@@ -72,6 +71,7 @@
   <kbd>C</kbd>: copy commit range (cherry-pick)
   <kbd>v</kbd>: paste commits (cherry-pick)
   <kbd>enter</kbd>: view commit's files
+  <kbd>space</kbd>: diff specific commits
 </pre>
 
 ## Schowek
diff --git a/pkg/commands/commit.go b/pkg/commands/commit.go
index 4253a5495..8f23ca001 100644
--- a/pkg/commands/commit.go
+++ b/pkg/commands/commit.go
@@ -13,6 +13,7 @@ type Commit struct {
 	DisplayString string
 	Action        string // one of "", "pick", "edit", "squash", "reword", "drop", "fixup"
 	Copied        bool   // to know if this commit is ready to be cherry-picked somewhere
+	Selected      bool
 }
 
 // GetDisplayStrings is a function.
@@ -52,5 +53,12 @@ func (c *Commit) GetDisplayStrings(isFocused bool) []string {
 		actionString = cyan.Sprint(utils.WithPadding(c.Action, 7)) + " "
 	}
 
-	return []string{shaColor.Sprint(c.Sha), actionString + white.Sprint(c.Name)}
+	name := ""
+	if c.Selected {
+		name = color.New(color.FgMagenta).Sprint(c.Name)
+	} else {
+		name = white.Sprint(c.Name)
+	}
+
+	return []string{shaColor.Sprint(c.Sha), actionString + name}
 }
diff --git a/pkg/commands/git.go b/pkg/commands/git.go
index 1b798990c..afd18dee7 100644
--- a/pkg/commands/git.go
+++ b/pkg/commands/git.go
@@ -910,3 +910,9 @@ func (c *GitCommand) ResetHardHead() error {
 func (c *GitCommand) ResetSoftHead() error {
 	return c.OSCommand.RunCommand("git reset --soft HEAD")
 }
+
+// DiffCommits show diff between commits
+func (c *GitCommand) DiffCommits(sha1, sha2 string) (string, error) {
+	cmd := fmt.Sprintf("git diff --color %s %s", sha1, sha2)
+	return c.OSCommand.RunCommandWithOutput(cmd)
+}
diff --git a/pkg/gui/commits_panel.go b/pkg/gui/commits_panel.go
index 1bd8be4a1..0d3dd6e84 100644
--- a/pkg/gui/commits_panel.go
+++ b/pkg/gui/commits_panel.go
@@ -39,6 +39,12 @@ func (gui *Gui) handleCommitSelect(g *gocui.Gui, v *gocui.View) error {
 	if err := gui.focusPoint(0, gui.State.Panels.Commits.SelectedLine, len(gui.State.Commits), v); err != nil {
 		return err
 	}
+
+	// if specific diff mode is on, don't show diff
+	if gui.State.Panels.Commits.SpecificDiffMode {
+		return nil
+	}
+
 	commitText, err := gui.GitCommand.Show(commit.Sha)
 	if err != nil {
 		return err
@@ -56,6 +62,13 @@ func (gui *Gui) refreshCommits(g *gocui.Gui) error {
 		if err != nil {
 			return err
 		}
+
+		for _, commit := range commits {
+			if _, has := gui.State.DiffEntries[commit.Sha]; has {
+				commit.Selected = true
+			}
+		}
+
 		gui.State.Commits = commits
 
 		gui.refreshSelectedLine(&gui.State.Panels.Commits.SelectedLine, len(gui.State.Commits))
@@ -448,3 +461,56 @@ func (gui *Gui) handleSwitchToCommitFilesPanel(g *gocui.Gui, v *gocui.View) erro
 
 	return gui.switchFocus(g, v, gui.getCommitFilesView())
 }
+
+func (gui *Gui) handleToggleDiffCommit(g *gocui.Gui, v *gocui.View) error {
+	selectLimit := 2
+
+	// get selected commit
+	commit := gui.getSelectedCommit(g)
+	if commit == nil {
+		return gui.renderString(g, "main", gui.Tr.SLocalize("NoCommitsThisBranch"))
+	}
+
+	// if already selected commit delete
+	if _, has := gui.State.DiffEntries[commit.Sha]; has {
+		delete(gui.State.DiffEntries, commit.Sha)
+		gui.setDiffMode()
+	} else {
+		if len(gui.State.DiffEntries) == selectLimit {
+			return gui.createErrorPanel(gui.g, "you have already selected two commit, please deselect one of two")
+		}
+		gui.State.DiffEntries[commit.Sha] = commit
+		gui.setDiffMode()
+	}
+
+	// if selected tow commits, display diff between
+	if len(gui.State.DiffEntries) == selectLimit {
+		var entries []string
+		for _, entry := range gui.State.DiffEntries {
+			entries = append(entries, entry.Sha)
+		}
+
+		commitText, err := gui.GitCommand.DiffCommits(entries[0], entries[1])
+
+		if err != nil {
+			return gui.createErrorPanel(gui.g, err.Error())
+		}
+
+		return gui.renderString(g, "main", commitText)
+	}
+
+	return nil
+}
+
+func (gui *Gui) setDiffMode() {
+	v := gui.getCommitsView()
+	if len(gui.State.DiffEntries) != 0 {
+		gui.State.Panels.Commits.SpecificDiffMode = true
+		v.Title = gui.Tr.SLocalize("CommitsDiffTitle")
+	} else {
+		gui.State.Panels.Commits.SpecificDiffMode = false
+		v.Title = gui.Tr.SLocalize("CommitsTitle")
+	}
+
+	gui.refreshCommits(gui.g)
+}
diff --git a/pkg/gui/gui.go b/pkg/gui/gui.go
index 07d51e2bc..f6cdd093d 100644
--- a/pkg/gui/gui.go
+++ b/pkg/gui/gui.go
@@ -103,7 +103,8 @@ type branchPanelState struct {
 }
 
 type commitPanelState struct {
-	SelectedLine int
+	SelectedLine     int
+	SpecificDiffMode bool
 }
 
 type stashPanelState struct {
@@ -135,6 +136,7 @@ type guiState struct {
 	Commits             []*commands.Commit
 	StashEntries        []*commands.StashEntry
 	CommitFiles         []*commands.CommitFile
+	DiffEntries         map[string]*commands.Commit
 	MenuItemCount       int // can't store the actual list because it's of interface{} type
 	PreviousView        string
 	Platform            commands.Platform
@@ -154,6 +156,7 @@ func NewGui(log *logrus.Entry, gitCommand *commands.GitCommand, oSCommand *comma
 		Commits:             make([]*commands.Commit, 0),
 		CherryPickedCommits: make([]*commands.Commit, 0),
 		StashEntries:        make([]*commands.StashEntry, 0),
+		DiffEntries:         make(map[string]*commands.Commit),
 		Platform:            *oSCommand.Platform,
 		Panels: &panelStates{
 			Files:       &filePanelState{SelectedLine: -1},
diff --git a/pkg/gui/keybindings.go b/pkg/gui/keybindings.go
index 518575550..28a60d473 100644
--- a/pkg/gui/keybindings.go
+++ b/pkg/gui/keybindings.go
@@ -389,6 +389,12 @@ func (gui *Gui) GetInitialKeybindings() []*Binding {
 			Handler:     gui.handleSwitchToCommitFilesPanel,
 			Description: gui.Tr.SLocalize("viewCommitFiles"),
 		}, {
+			ViewName:    "commits",
+			Key:         gocui.KeySpace,
+			Modifier:    gocui.ModNone,
+			Handler:     gui.handleToggleDiffCommit,
+			Description: gui.Tr.SLocalize("CommitsDiff"),
+		}, {
 			ViewName:    "stash",
 			Key:         gocui.KeySpace,
 			Modifier:    gocui.ModNone,
diff --git a/pkg/i18n/dutch.go b/pkg/i18n/dutch.go
index 8e0f6ce3b..c87f93c9b 100644
--- a/pkg/i18n/dutch.go
+++ b/pkg/i18n/dutch.go
@@ -29,6 +29,12 @@ func addDutch(i18nObject *i18n.Bundle) error {
 			ID:    "CommitsTitle",
 			Other: "Commits",
 		}, &i18n.Message{
+			ID:    "CommitsDiffTitle",
+			Other: "Commits(specific diff mode)",
+		}, &i18n.Message{
+			ID:    "CommitsDiff",
+			Other: "diff specific commits",
+		}, &i18n.Message{
 			ID:    "StashTitle",
 			Other: "Stash",
 		}, &i18n.Message{
diff --git a/pkg/i18n/english.go b/pkg/i18n/english.go
index 397c262a2..c5fd61924 100644
--- a/pkg/i18n/english.go
+++ b/pkg/i18n/english.go
@@ -37,6 +37,12 @@ func addEnglish(i18nObject *i18n.Bundle) error {
 			ID:    "CommitsTitle",
 			Other: "Commits",
 		}, &i18n.Message{
+			ID:    "CommitsDiffTitle",
+			Other: "Commits(specific diff mode)",
+		}, &i18n.Message{
+			ID:    "CommitsDiff",
+			Other: "diff specific commits",
+		}, &i18n.Message{
 			ID:    "StashTitle",
 			Other: "Stash",
 		}, &i18n.Message{
diff --git a/pkg/i18n/polish.go b/pkg/i18n/polish.go
index e6d09eafb..cf9d7abf5 100644
--- a/pkg/i18n/polish.go
+++ b/pkg/i18n/polish.go
@@ -27,6 +27,12 @@ func addPolish(i18nObject *i18n.Bundle) error {
 			ID:    "CommitsTitle",
 			Other: "Commity",
 		}, &i18n.Message{
+			ID:    "CommitsDiffTitle",
+			Other: "Commits(specific diff mode)",
+		}, &i18n.Message{
+			ID:    "CommitsDiff",
+			Other: "diff specific commits",
+		}, &i18n.Message{
 			ID:    "StashTitle",
 			Other: "Schowek",
 		}, &i18n.Message{