feat: add Custom prompt action (p) with editor integration; shared editor helper in internal/editor; hexai CLI opens editor when no args

5 files changed, 98 insertions, 6 deletions

diff --git a/internal/editor/editor.go b/internal/editor/editor.go
new file mode 100644
index 0000000..44aa1d4
--- /dev/null
+++ b/internal/editor/editor.go
@@ -0,0 +1,70 @@
+package editor
+
+import (
+    "errors"
+    "os"
+    "os/exec"
+    "path/filepath"
+    "strings"
+)
+
+// Resolve returns the editor command from HEXAI_EDITOR or EDITOR.
+func Resolve() (string, error) {
+    ed := strings.TrimSpace(os.Getenv("HEXAI_EDITOR"))
+    if ed == "" {
+        ed = strings.TrimSpace(os.Getenv("EDITOR"))
+    }
+    if ed == "" {
+        return "", errors.New("no editor configured (set HEXAI_EDITOR or EDITOR)")
+    }
+    return ed, nil
+}
+
+// RunEditor is the seam that invokes the editor on the given file path.
+// Override in tests to avoid launching a real editor.
+var RunEditor = func(editor, path string) error {
+    cmd := exec.Command(editor, path)
+    cmd.Stdin = os.Stdin
+    cmd.Stdout = os.Stdout
+    cmd.Stderr = os.Stderr
+    return cmd.Run()
+}
+
+// OpenTempAndEdit creates a temporary .md file, writes initial content if provided,
+// opens it in the resolved editor, then reads the final content and removes the file.
+// Returns the trimmed content.
+func OpenTempAndEdit(initial []byte) (string, error) {
+    ed, err := Resolve()
+    if err != nil {
+        return "", err
+    }
+    // Create temp file under system temp dir; ensure .md suffix
+    dir := os.TempDir()
+    f, err := os.CreateTemp(dir, "hexai-*.md")
+    if err != nil {
+        return "", err
+    }
+    path := f.Name()
+    defer func() { _ = os.Remove(path) }()
+    if len(initial) > 0 {
+        if _, err := f.Write(initial); err != nil {
+            _ = f.Close()
+            return "", err
+        }
+    }
+    if err := f.Sync(); err != nil {
+        _ = f.Close()
+        return "", err
+    }
+    if err := f.Close(); err != nil {
+        return "", err
+    }
+    if err := RunEditor(ed, path); err != nil {
+        return "", err
+    }
+    b, err := os.ReadFile(filepath.Clean(path))
+    if err != nil {
+        return "", err
+    }
+    return strings.TrimSpace(string(b)), nil
+}
diff --git a/internal/hexaiaction/run.go b/internal/hexaiaction/run.go
index 5417d3f..1325e9d 100644
--- a/internal/hexaiaction/run.go
+++ b/internal/hexaiaction/run.go
@@ -8,6 +8,7 @@ import (
     "strings"
 
     "codeberg.org/snonux/hexai/internal/appconfig"
+    "codeberg.org/snonux/hexai/internal/editor"
     "codeberg.org/snonux/hexai/internal/logging"
     "codeberg.org/snonux/hexai/internal/llmutils"
 )
@@ -74,6 +75,16 @@ func executeAction(ctx context.Context, kind ActionKind, parts InputParts, cfg a
         cctx, cancel := timeout10s(ctx)
         defer cancel()
         return runSimplify(cctx, cfg, client, parts.Selection)
+    case ActionCustom:
+        cctx, cancel := timeout10s(ctx)
+        defer cancel()
+        // Open editor for free-form instruction
+        prompt, err := editor.OpenTempAndEdit([]byte("# Enter your instruction below\n\n"))
+        if err != nil || strings.TrimSpace(prompt) == "" {
+            fmt.Fprintln(stderr, logging.AnsiBase+"hexai-tmux-action: custom prompt canceled or empty; echoing input"+logging.AnsiReset)
+            return parts.Selection, nil
+        }
+        return runRewrite(cctx, cfg, client, prompt, parts.Selection)
     default:
         return parts.Selection, nil
     }
diff --git a/internal/hexaiaction/tui.go b/internal/hexaiaction/tui.go
index 80b1fee..317a991 100644
--- a/internal/hexaiaction/tui.go
+++ b/internal/hexaiaction/tui.go
@@ -31,6 +31,7 @@ func newModel() model {
         item{title: "Simplify and improve", desc: "", kind: ActionSimplify, hotkey: 'i'},
         item{title: "Document code", desc: "", kind: ActionDocument, hotkey: 'c'},
         item{title: "Generate Go unit test(s)", desc: "", kind: ActionGoTest, hotkey: 't'},
+        item{title: "Custom prompt", desc: "", kind: ActionCustom, hotkey: 'p'},
         item{title: "Skip", desc: "", kind: ActionSkip, hotkey: 's'},
     }
     l := list.New(items, oneLineDelegate{}, 0, 0)
@@ -78,7 +79,7 @@ func handleKey(m model, msg tea.KeyMsg) (tea.Model, tea.Cmd) {
         m.list.Select(0)
     case "end":
         if n := len(m.list.Items()); n > 0 { m.list.Select(n - 1) }
-    case "s", "r", "c", "t", "i":
+    case "s", "r", "c", "t", "i", "p":
         items := m.list.Items()
         for i := 0; i < len(items); i++ {
             if it, ok := items[i].(item); ok && strings.ToLower(string(it.hotkey)) == low {
diff --git a/internal/hexaiaction/types.go b/internal/hexaiaction/types.go
index 708c433..7bc292e 100644
--- a/internal/hexaiaction/types.go
+++ b/internal/hexaiaction/types.go
@@ -11,6 +11,7 @@ const (
     ActionDocument    ActionKind = "document"
     ActionGoTest      ActionKind = "gotest"
     ActionSimplify    ActionKind = "simplify"
+    ActionCustom      ActionKind = "custom"
 )
 
 // InputParts represents parsed stdin input for actions.
diff --git a/internal/hexaicli/run.go b/internal/hexaicli/run.go
index f10850b..98e4c40 100644
--- a/internal/hexaicli/run.go
+++ b/internal/hexaicli/run.go
@@ -13,6 +13,7 @@ import (
     "time"
 
     "codeberg.org/snonux/hexai/internal/appconfig"
+    "codeberg.org/snonux/hexai/internal/editor"
     "codeberg.org/snonux/hexai/internal/logging"
     "codeberg.org/snonux/hexai/internal/llm"
     "codeberg.org/snonux/hexai/internal/llmutils"
@@ -21,16 +22,24 @@ import (
 // Run executes the Hexai CLI behavior given arguments and I/O streams.
 // It assumes flags have already been parsed by the caller.
 func Run(ctx context.Context, args []string, stdin io.Reader, stdout, stderr io.Writer) error {
-	// Load configuration with a logger so file-based config is respected.
-	logger := log.New(stderr, "hexai ", log.LstdFlags|log.Lmsgprefix)
-	cfg := appconfig.Load(logger)
+    // Load configuration with a logger so file-based config is respected.
+    logger := log.New(stderr, "hexai ", log.LstdFlags|log.Lmsgprefix)
+    cfg := appconfig.Load(logger)
     client, err := llmutils.NewClientFromApp(cfg)
 	if err != nil {
 		fmt.Fprintf(stderr, logging.AnsiBase+"hexai: LLM disabled: %v"+logging.AnsiReset+"\n", err)
 		return err
 	}
-	// Inline the flow here to use configured CLI prompts.
-	input, rerr := readInput(stdin, args)
+    // No args: open editor to capture a prompt, then combine with stdin as usual.
+    if len(args) == 0 {
+        if prompt, eerr := editor.OpenTempAndEdit([]byte("# Enter your prompt below\n\n")); eerr == nil && strings.TrimSpace(prompt) != "" {
+            args = []string{prompt}
+        } else {
+            // If editor fails or empty, continue; readInput will likely error if no stdin either.
+        }
+    }
+    // Inline the flow here to use configured CLI prompts.
+    input, rerr := readInput(stdin, args)
 	if rerr != nil {
 		fmt.Fprintln(stderr, logging.AnsiBase+rerr.Error()+logging.AnsiReset)
 		return rerr