From daa903e6c840d8b96f0d0b3642fd93f4eb4b12c8 Mon Sep 17 00:00:00 2001
From: Tyler Hawkins <3319104+tyzbit@users.noreply.github.com>
Date: Tue, 24 Sep 2024 17:36:00 -0400
Subject: [PATCH] feat(history): add keyboard shortcuts to navigate history

---
 internal/model/history.go       | 98 +++++++++++++++++++++++----------
 internal/ui/key.go              | 12 ++--
 internal/view/actions.go        |  2 +-
 internal/view/alias.go          |  2 +-
 internal/view/app.go            | 83 ++++++++++++++--------------
 internal/view/command.go        | 32 ++++++-----
 internal/view/crd.go            |  2 +-
 internal/view/ns.go             |  2 +-
 internal/view/owner_extender.go |  3 +-
 internal/view/pulse.go          |  2 +-
 internal/view/reference.go      |  2 +-
 internal/view/sanitizer.go      |  2 +-
 internal/view/workload.go       |  2 +-
 internal/view/xray.go           |  2 +-
 14 files changed, 145 insertions(+), 101 deletions(-)

diff --git a/internal/model/history.go b/internal/model/history.go
index adb4df6c5a..37c4c5de12 100644
--- a/internal/model/history.go
+++ b/internal/model/history.go
@@ -12,8 +12,10 @@ const MaxHistory = 20
 
 // History represents a command history.
 type History struct {
-	commands []string
-	limit    int
+	commands             []string
+	limit                int
+	activeCommandIndex   int
+	previousCommandIndex int
 }
 
 // NewHistory returns a new instance.
@@ -23,31 +25,76 @@ func NewHistory(limit int) *History {
 	}
 }
 
-// Last returns the most recent history item
-func (h *History) Last() string {
+// Last switches the current and previous history index positions so the
+// new command referenced by the index is the previous command
+func (h *History) Last() bool {
 	if h.Empty() {
-		return ""
+		return false
 	}
 
-	return h.commands[0]
+	h.activeCommandIndex, h.previousCommandIndex = h.previousCommandIndex, h.activeCommandIndex
+	return true
 }
 
-// Pop removes the most recent history item and returns a bool if the list changed.
-// Optional argument specifies how many to remove from the history
-func (h *History) Pop(n ...int) bool {
-	if len(h.commands) == 0 {
+// Back moves the history position index back by one
+func (h *History) Back() bool {
+	if h.Empty() {
+		return false
+	}
+
+	// Return if there are no more commands left in the backward history
+	if h.activeCommandIndex == 0 {
+		return false
+	}
+
+	h.previousCommandIndex = h.activeCommandIndex
+	h.activeCommandIndex = h.activeCommandIndex - 1
+	return true
+}
+
+// Forward moves the history position index forward by one
+func (h *History) Forward() bool {
+	if h.Empty() {
+		return false
+	}
+
+	// Return if there are no more commands left in the forward history
+	if h.activeCommandIndex >= len(h.commands)-1 {
 		return false
 	}
 
-	count := 1
-	if len(n) > 1 {
-		// only one argument is expected
+	h.previousCommandIndex = h.activeCommandIndex
+	h.activeCommandIndex = h.activeCommandIndex + 1
+	return true
+}
+
+// CurrentIndex returns the current index of the active command in the history
+func (h *History) CurrentIndex() int {
+	return h.activeCommandIndex
+}
+
+// PreviousIndex returns the index of the command that was the most recent
+// active command in the history
+func (h *History) PreviousIndex() int {
+	return h.previousCommandIndex
+}
+
+// Pop removes the single most recent history item
+// and returns a bool if the list changed.
+func (h *History) Pop() bool {
+	return h.PopN(1)
+}
+
+// PopN removes the N most recent history item
+// and returns a bool if the list changed.
+// Argument specifies how many to remove from the history
+func (h *History) PopN(n int) bool {
+	cmdLength := len(h.commands)
+	if cmdLength == 0 {
 		return false
-	} else if len(n) == 1 {
-		count = n[0]
 	}
 
-	h.commands = h.commands[count:]
+	h.commands = h.commands[:cmdLength-n]
 	return true
 }
 
@@ -63,31 +110,22 @@ func (h *History) Push(c string) {
 	}
 
 	c = strings.ToLower(c)
-	if i := h.indexOf(c); i != -1 {
-		return
-	}
 	if len(h.commands) < h.limit {
-		h.commands = append([]string{c}, h.commands...)
+		h.commands = append(h.commands, c)
+		h.previousCommandIndex = h.activeCommandIndex
+		h.activeCommandIndex = len(h.commands) - 1
 		return
 	}
-	h.commands = append([]string{c}, h.commands[:len(h.commands)-1]...)
 }
 
 // Clear clears out the stack.
 func (h *History) Clear() {
 	h.commands = nil
+	h.activeCommandIndex = 0
+	h.previousCommandIndex = 0
 }
 
 // Empty returns true if no history.
 func (h *History) Empty() bool {
 	return len(h.commands) == 0
 }
-
-func (h *History) indexOf(s string) int {
-	for i, c := range h.commands {
-		if c == s {
-			return i
-		}
-	}
-	return -1
-}
diff --git a/internal/ui/key.go b/internal/ui/key.go
index 1f36b9d45a..d6a506d099 100644
--- a/internal/ui/key.go
+++ b/internal/ui/key.go
@@ -76,11 +76,13 @@ const (
 	KeyX
 	KeyY
 	KeyZ
-	KeyHelp  = 63
-	KeySlash = 47
-	KeyColon = 58
-	KeySpace = 32
-	KeyDash  = 45 //or minus for those searching in the code
+	KeyHelp         = 63
+	KeySlash        = 47
+	KeyColon        = 58
+	KeySpace        = 32
+	KeyDash         = 45 //or minus for those searching in the code
+	KeyLeftBracket  = 91
+	KeyRightBracket = 93
 )
 
 // Define Shift Keys.
diff --git a/internal/view/actions.go b/internal/view/actions.go
index d86d0098ad..fa4cf6ad0f 100644
--- a/internal/view/actions.go
+++ b/internal/view/actions.go
@@ -104,7 +104,7 @@ func hotKeyActions(r Runner, aa *ui.KeyActions) error {
 
 func gotoCmd(r Runner, cmd, path string, clearStack bool) ui.ActionHandler {
 	return func(evt *tcell.EventKey) *tcell.EventKey {
-		r.App().gotoResource(cmd, path, clearStack)
+		r.App().gotoResource(cmd, path, clearStack, true)
 		return nil
 	}
 }
diff --git a/internal/view/alias.go b/internal/view/alias.go
index 496f2e5c73..9ca8a79e61 100644
--- a/internal/view/alias.go
+++ b/internal/view/alias.go
@@ -67,7 +67,7 @@ func (a *Alias) gotoCmd(evt *tcell.EventKey) *tcell.EventKey {
 	if r != 0 {
 		s := ui.TrimCell(a.GetTable().SelectTable, r, 1)
 		tokens := strings.Split(s, ",")
-		a.App().gotoResource(tokens[0], "", true)
+		a.App().gotoResource(tokens[0], "", true, true)
 		return nil
 	}
 
diff --git a/internal/view/app.go b/internal/view/app.go
index 23d6248b45..80ffe4a454 100644
--- a/internal/view/app.go
+++ b/internal/view/app.go
@@ -240,15 +240,16 @@ func (a *App) keyboard(evt *tcell.EventKey) *tcell.EventKey {
 
 func (a *App) bindKeys() {
 	a.AddActions(ui.NewKeyActionsFromMap(ui.KeyMap{
-		ui.KeyShift9:   ui.NewSharedKeyAction("DumpGOR", a.dumpGOR, false),
-		tcell.KeyCtrlE: ui.NewSharedKeyAction("ToggleHeader", a.toggleHeaderCmd, false),
-		tcell.KeyCtrlG: ui.NewSharedKeyAction("toggleCrumbs", a.toggleCrumbsCmd, false),
-		ui.KeyHelp:     ui.NewSharedKeyAction("Help", a.helpCmd, false),
-		ui.KeyB:        ui.NewSharedKeyAction("Go Back", a.previousView, false),
-		ui.KeyDash:     ui.NewSharedKeyAction("Last View", a.lastView, false),
-		tcell.KeyCtrlA: ui.NewSharedKeyAction("Aliases", a.aliasCmd, false),
-		tcell.KeyEnter: ui.NewKeyAction("Goto", a.gotoCmd, false),
-		tcell.KeyCtrlC: ui.NewKeyAction("Quit", a.quitCmd, false),
+		ui.KeyShift9:       ui.NewSharedKeyAction("DumpGOR", a.dumpGOR, false),
+		tcell.KeyCtrlE:     ui.NewSharedKeyAction("ToggleHeader", a.toggleHeaderCmd, false),
+		tcell.KeyCtrlG:     ui.NewSharedKeyAction("toggleCrumbs", a.toggleCrumbsCmd, false),
+		ui.KeyHelp:         ui.NewSharedKeyAction("Help", a.helpCmd, false),
+		ui.KeyLeftBracket:  ui.NewSharedKeyAction("Go Back", a.previousCommand, false),
+		ui.KeyRightBracket: ui.NewSharedKeyAction("Go Forward", a.nextCommand, false),
+		ui.KeyDash:         ui.NewSharedKeyAction("Last View", a.lastCommand, false),
+		tcell.KeyCtrlA:     ui.NewSharedKeyAction("Aliases", a.aliasCmd, false),
+		tcell.KeyEnter:     ui.NewKeyAction("Goto", a.gotoCmd, false),
+		tcell.KeyCtrlC:     ui.NewKeyAction("Quit", a.quitCmd, false),
 	}))
 }
 
@@ -484,7 +485,7 @@ func (a *App) switchContext(ci *cmd.Interpreter, force bool) error {
 		log.Debug().Msgf("--> Switching Context %q -- %q -- %q", name, ns, a.Config.ActiveView())
 		a.Flash().Infof("Switching context to %q::%q", name, ns)
 		a.ReloadStyles()
-		a.gotoResource(a.Config.ActiveView(), "", true)
+		a.gotoResource(a.Config.ActiveView(), "", true, true)
 		a.clusterModel.Reset(a.factory)
 	}
 
@@ -632,7 +633,7 @@ func (a *App) toggleCrumbsCmd(evt *tcell.EventKey) *tcell.EventKey {
 
 func (a *App) gotoCmd(evt *tcell.EventKey) *tcell.EventKey {
 	if a.CmdBuff().IsActive() && !a.CmdBuff().Empty() {
-		a.gotoResource(a.GetCmd(), "", true)
+		a.gotoResource(a.GetCmd(), "", true, true)
 		a.ResetCmd()
 		return nil
 	}
@@ -693,51 +694,49 @@ func (a *App) helpCmd(evt *tcell.EventKey) *tcell.EventKey {
 	return nil
 }
 
-// previousView returns to the view prior to the current one in the history
-func (a *App) previousView(evt *tcell.EventKey) *tcell.EventKey {
-	if evt != nil && evt.Rune() == rune(ui.KeyB) && a.Prompt().InCmdMode() {
+// previousCommand returns to the command prior to the current one in the history
+func (a *App) previousCommand(evt *tcell.EventKey) *tcell.EventKey {
+	if evt != nil && evt.Rune() == rune(ui.KeyLeftBracket) && a.Prompt().InCmdMode() {
 		return evt
 	}
 	cmds := a.cmdHistory.List()
-	if !(len(cmds) > 1) {
-		dialog.ShowError(
-			a.Styles.Dialog(),
-			a.Content.Pages,
-			"Can't go back any further")
+	if !a.cmdHistory.Back() {
+		a.App.Flash().Warn("Can't go back any further")
 		return evt
-	} else {
-		previousCmd := cmds[1]
-		a.cmdHistory.Pop()
-		a.gotoResource(previousCmd, "", true)
-		a.ResetCmd()
 	}
+	a.gotoResource(cmds[a.cmdHistory.CurrentIndex()], "", true, false)
+	return nil
+}
 
+// nextCommand returns to the command subsequent to the current one in the history
+func (a *App) nextCommand(evt *tcell.EventKey) *tcell.EventKey {
+	if evt != nil && evt.Rune() == rune(ui.KeyRightBracket) && a.Prompt().InCmdMode() {
+		return evt
+	}
+	cmds := a.cmdHistory.List()
+	if !a.cmdHistory.Forward() {
+		a.App.Flash().Warn("Can't go forward any further")
+		return evt
+	}
+	// We go to the resource before updating the history so that
+	// gotoResource doesn't add this command to the history
+	a.gotoResource(cmds[a.cmdHistory.CurrentIndex()], "", true, false)
 	return nil
 }
 
-// lastView switches between the last view and this one a la `cd -`
-func (a *App) lastView(evt *tcell.EventKey) *tcell.EventKey {
+// lastCommand switches between the last command and the current one a la `cd -`
+func (a *App) lastCommand(evt *tcell.EventKey) *tcell.EventKey {
 	if evt != nil && evt.Rune() == ui.KeyDash && a.Prompt().InCmdMode() {
 		return evt
 	}
 	cmds := a.cmdHistory.List()
-	if !(len(cmds) > 1) {
-		dialog.ShowError(
-			a.Styles.Dialog(),
-			a.Content.Pages,
-			"No previous view to switch to")
+	if len(cmds) < 1 {
+		a.App.Flash().Warn("No previous view to switch to")
 		return evt
 	} else {
-		current := cmds[0]
-		last := cmds[1]
-		a.gotoResource(last, "", true)
-		// remove current page and last page
-		a.cmdHistory.Pop(2)
-		// re add in opposite order
-		a.cmdHistory.Push(current)
-		a.cmdHistory.Push(last)
+		a.cmdHistory.Last()
+		a.gotoResource(cmds[a.cmdHistory.CurrentIndex()], "", true, false)
 	}
-
 	return nil
 }
 
@@ -754,8 +753,8 @@ func (a *App) aliasCmd(evt *tcell.EventKey) *tcell.EventKey {
 	return nil
 }
 
-func (a *App) gotoResource(c, path string, clearStack bool) {
-	err := a.command.run(cmd.NewInterpreter(c), path, clearStack)
+func (a *App) gotoResource(c, path string, clearStack bool, pushCmd bool) {
+	err := a.command.run(cmd.NewInterpreter(c), path, clearStack, pushCmd)
 	if err != nil {
 		dialog.ShowError(a.Styles.Dialog(), a.Content.Pages, err.Error())
 	}
diff --git a/internal/view/command.go b/internal/view/command.go
index 22415a38bb..d92a7cb995 100644
--- a/internal/view/command.go
+++ b/internal/view/command.go
@@ -98,7 +98,7 @@ func (c *Command) contextCmd(p *cmd.Interpreter) error {
 		return err
 	}
 
-	return c.exec(p, gvr, c.componentFor(gvr, ct, v), true)
+	return c.exec(p, gvr, c.componentFor(gvr, ct, v), true, true)
 }
 
 func (c *Command) namespaceCmd(p *cmd.Interpreter) bool {
@@ -121,7 +121,7 @@ func (c *Command) aliasCmd(p *cmd.Interpreter) error {
 	v := NewAlias(gvr)
 	v.SetFilter(filter)
 
-	return c.exec(p, gvr, v, false)
+	return c.exec(p, gvr, v, false, true)
 }
 
 func (c *Command) xrayCmd(p *cmd.Interpreter) error {
@@ -147,11 +147,11 @@ func (c *Command) xrayCmd(p *cmd.Interpreter) error {
 		return err
 	}
 
-	return c.exec(p, client.NewGVR("xrays"), NewXray(gvr), true)
+	return c.exec(p, client.NewGVR("xrays"), NewXray(gvr), true, true)
 }
 
 // Run execs the command by showing associated display.
-func (c *Command) run(p *cmd.Interpreter, fqn string, clearStack bool) error {
+func (c *Command) run(p *cmd.Interpreter, fqn string, clearStack bool, pushCmd bool) error {
 	if c.specialCmd(p) {
 		return nil
 	}
@@ -206,22 +206,22 @@ func (c *Command) run(p *cmd.Interpreter, fqn string, clearStack bool) error {
 		co.SetLabelFilter(ll)
 	}
 
-	return c.exec(p, gvr, co, clearStack)
+	return c.exec(p, gvr, co, clearStack, pushCmd)
 }
 
 func (c *Command) defaultCmd() error {
 	if c.app.Conn() == nil || !c.app.Conn().ConnectionOK() {
-		return c.run(cmd.NewInterpreter("context"), "", true)
+		return c.run(cmd.NewInterpreter("context"), "", true, true)
 	}
 
 	p := cmd.NewInterpreter(c.app.Config.ActiveView())
 	if p.IsBlank() {
-		return c.run(p.Reset("pod"), "", true)
+		return c.run(p.Reset("pod"), "", true, true)
 	}
 
-	if err := c.run(p, "", true); err != nil {
+	if err := c.run(p, "", true, true); err != nil {
 		log.Error().Err(err).Msgf("Default run command failed %q", p.GetLine())
-		return c.run(p.Reset("pod"), "", true)
+		return c.run(p.Reset("pod"), "", true, true)
 	}
 
 	return nil
@@ -310,7 +310,7 @@ func (c *Command) componentFor(gvr client.GVR, fqn string, v *MetaViewer) Resour
 	return view
 }
 
-func (c *Command) exec(p *cmd.Interpreter, gvr client.GVR, comp model.Component, clearStack bool) (err error) {
+func (c *Command) exec(p *cmd.Interpreter, gvr client.GVR, comp model.Component, clearStack bool, pushCmd bool) (err error) {
 	defer func() {
 		if e := recover(); e != nil {
 			log.Error().Msgf("Something bad happened! %#v", e)
@@ -319,10 +319,12 @@ func (c *Command) exec(p *cmd.Interpreter, gvr client.GVR, comp model.Component,
 			log.Error().Msg(string(debug.Stack()))
 
 			p := cmd.NewInterpreter("pod")
-			if cmd := c.app.cmdHistory.Last(); cmd != "" {
-				p = p.Reset(cmd)
+			cmds := c.app.cmdHistory.List()
+			currentCommand := cmds[c.app.cmdHistory.CurrentIndex()]
+			if currentCommand != "pod" {
+				p = p.Reset(currentCommand)
 			}
-			err = c.run(p, "", true)
+			err = c.run(p, "", true, true)
 		}
 	}()
 
@@ -338,7 +340,9 @@ func (c *Command) exec(p *cmd.Interpreter, gvr client.GVR, comp model.Component,
 		return err
 	}
 
-	c.app.cmdHistory.Push(p.GetLine())
+	if pushCmd {
+		c.app.cmdHistory.Push(p.GetLine())
+	}
 
 	return
 }
diff --git a/internal/view/crd.go b/internal/view/crd.go
index 7ff1a1f969..1a70f5b650 100644
--- a/internal/view/crd.go
+++ b/internal/view/crd.go
@@ -34,5 +34,5 @@ func (s *CRD) bindKeys(aa *ui.KeyActions) {
 
 func (s *CRD) showCRD(app *App, _ ui.Tabular, _ client.GVR, path string) {
 	_, crd := client.Namespaced(path)
-	app.gotoResource(crd, "", false)
+	app.gotoResource(crd, "", false, true)
 }
diff --git a/internal/view/ns.go b/internal/view/ns.go
index 1eac09dbef..ffde8a42bf 100644
--- a/internal/view/ns.go
+++ b/internal/view/ns.go
@@ -41,7 +41,7 @@ func (n *Namespace) bindKeys(aa *ui.KeyActions) {
 
 func (n *Namespace) switchNs(app *App, _ ui.Tabular, _ client.GVR, path string) {
 	n.useNamespace(path)
-	app.gotoResource("pods", "", false)
+	app.gotoResource("pods", "", false, true)
 }
 
 func (n *Namespace) useNsCmd(evt *tcell.EventKey) *tcell.EventKey {
diff --git a/internal/view/owner_extender.go b/internal/view/owner_extender.go
index 89b42449ec..0095c52d0e 100644
--- a/internal/view/owner_extender.go
+++ b/internal/view/owner_extender.go
@@ -3,6 +3,7 @@ package view
 import (
 	"context"
 	"fmt"
+
 	"github.com/derailed/k9s/internal/ui/dialog"
 	"github.com/rs/zerolog/log"
 
@@ -105,7 +106,7 @@ func (v *OwnerExtender) jumpOwner(ns string, owner metav1.OwnerReference) error
 		ownerFQN = owner.Name
 	}
 
-	v.App().gotoResource(gvr.String(), ownerFQN, false)
+	v.App().gotoResource(gvr.String(), ownerFQN, false, true)
 	return nil
 }
 
diff --git a/internal/view/pulse.go b/internal/view/pulse.go
index 6d36e7a5fd..ac75714820 100644
--- a/internal/view/pulse.go
+++ b/internal/view/pulse.go
@@ -320,7 +320,7 @@ func (p *Pulse) enterCmd(evt *tcell.EventKey) *tcell.EventKey {
 	if res == "cpu" || res == "mem" {
 		res = "pod"
 	}
-	p.App().gotoResource(res+" all", "", false)
+	p.App().gotoResource(res+" all", "", false, true)
 
 	return nil
 }
diff --git a/internal/view/reference.go b/internal/view/reference.go
index 2f08cc7bba..4da57c6cf7 100644
--- a/internal/view/reference.go
+++ b/internal/view/reference.go
@@ -55,7 +55,7 @@ func (r *Reference) gotoCmd(evt *tcell.EventKey) *tcell.EventKey {
 
 	path := r.GetTable().GetSelectedItem()
 	gvr := ui.TrimCell(r.GetTable().SelectTable, row, 2)
-	r.App().gotoResource(client.NewGVR(gvr).R(), path, false)
+	r.App().gotoResource(client.NewGVR(gvr).R(), path, false, true)
 
 	return evt
 }
diff --git a/internal/view/sanitizer.go b/internal/view/sanitizer.go
index 9ec116d73e..100e3f8262 100644
--- a/internal/view/sanitizer.go
+++ b/internal/view/sanitizer.go
@@ -231,7 +231,7 @@ func (s *Sanitizer) gotoCmd(evt *tcell.EventKey) *tcell.EventKey {
 	if len(strings.Split(path, "/")) == 1 && spec.GVR() != "node" {
 		path = "-/" + path
 	}
-	s.app.gotoResource(client.NewGVR(spec.GVR()).R(), path, false)
+	s.app.gotoResource(client.NewGVR(spec.GVR()).R(), path, false, true)
 
 	return nil
 }
diff --git a/internal/view/workload.go b/internal/view/workload.go
index 4f0ba02fcd..b238b53d9b 100644
--- a/internal/view/workload.go
+++ b/internal/view/workload.go
@@ -82,7 +82,7 @@ func (w *Workload) showRes(app *App, _ ui.Tabular, _ client.GVR, path string) {
 		app.Flash().Err(fmt.Errorf("Unable to parse path: %q", path))
 		return
 	}
-	app.gotoResource(gvr.R(), fqn, false)
+	app.gotoResource(gvr.R(), fqn, false, true)
 }
 
 func (w *Workload) deleteCmd(evt *tcell.EventKey) *tcell.EventKey {
diff --git a/internal/view/xray.go b/internal/view/xray.go
index 34e9e0ccad..1c5429dd00 100644
--- a/internal/view/xray.go
+++ b/internal/view/xray.go
@@ -476,7 +476,7 @@ func (x *Xray) gotoCmd(evt *tcell.EventKey) *tcell.EventKey {
 	if len(strings.Split(spec.Path(), "/")) == 1 {
 		return nil
 	}
-	x.app.gotoResource(client.NewGVR(spec.GVR()).R(), spec.Path(), false)
+	x.app.gotoResource(client.NewGVR(spec.GVR()).R(), spec.Path(), false, true)
 
 	return nil
 }