feat(agent): support btw side questions (#2532)

pkg/commands/builtin.go

@@ -11,6 +11,7 @@ func BuiltinDefinitions() []Definition {
 		showCommand(),
 		listCommand(),
 		useCommand(),
+		btwCommand(),
 		switchCommand(),
 		checkCommand(),
 		clearCommand(),

pkg/commands/builtin_test.go

@@ -188,3 +188,79 @@ func TestBuiltinUseCommand_PassthroughsToAgentLogic(t *testing.T) {
 		t.Fatalf("/use command=%q, want=%q", res.Command, "use")
 	}
 }
+
+func TestBuiltinBtwCommand_UsesSideQuestionRuntime(t *testing.T) {
+	rt := &Runtime{
+		AskSideQuestion: func(ctx context.Context, question string) (string, error) {
+			if question != "what is 2+2?" {
+				t.Fatalf("question=%q, want %q", question, "what is 2+2?")
+			}
+			return "4", nil
+		},
+	}
+	defs := BuiltinDefinitions()
+	ex := NewExecutor(NewRegistry(defs), rt)
+
+	var reply string
+	res := ex.Execute(context.Background(), Request{
+		Text: "/btw what is 2+2?",
+		Reply: func(text string) error {
+			reply = text
+			return nil
+		},
+	})
+	if res.Outcome != OutcomeHandled {
+		t.Fatalf("/btw outcome=%v, want=%v", res.Outcome, OutcomeHandled)
+	}
+	if reply != "4" {
+		t.Fatalf("/btw reply=%q, want=%q", reply, "4")
+	}
+}
+
+func TestBuiltinBtwCommand_MissingQuestion(t *testing.T) {
+	defs := BuiltinDefinitions()
+	ex := NewExecutor(NewRegistry(defs), &Runtime{
+		AskSideQuestion: func(context.Context, string) (string, error) {
+			return "", nil
+		},
+	})
+
+	var reply string
+	res := ex.Execute(context.Background(), Request{
+		Text: "/btw",
+		Reply: func(text string) error {
+			reply = text
+			return nil
+		},
+	})
+	if res.Outcome != OutcomeHandled {
+		t.Fatalf("/btw outcome=%v, want=%v", res.Outcome, OutcomeHandled)
+	}
+	if reply != "Usage: /btw <question>" {
+		t.Fatalf("/btw reply=%q, want usage message", reply)
+	}
+}
+
+func TestBuiltinBtwCommand_PreservesQuestionWhitespace(t *testing.T) {
+	const want = "explain:\n    fmt.Println(\"hi\")"
+	rt := &Runtime{
+		AskSideQuestion: func(ctx context.Context, question string) (string, error) {
+			if question != want {
+				t.Fatalf("question=%q, want %q", question, want)
+			}
+			return "ok", nil
+		},
+	}
+	defs := BuiltinDefinitions()
+	ex := NewExecutor(NewRegistry(defs), rt)
+
+	res := ex.Execute(context.Background(), Request{
+		Text: "/btw " + want,
+		Reply: func(text string) error {
+			return nil
+		},
+	})
+	if res.Outcome != OutcomeHandled {
+		t.Fatalf("/btw outcome=%v, want=%v", res.Outcome, OutcomeHandled)
+	}
+}

pkg/commands/cmd_btw.go

@@ -0,0 +1,51 @@
+package commands
+
+import (
+	"context"
+	"strings"
+)
+
+func btwCommand() Definition {
+	return Definition{
+		Name:        "btw",
+		Description: "Ask a side question without changing session history",
+		Usage:       "/btw <question>",
+		Handler: func(ctx context.Context, req Request, rt *Runtime) error {
+			const emptyAnswerMsg = "The model returned an empty response. This may indicate a provider error or token limit."
+
+			if rt == nil || rt.AskSideQuestion == nil {
+				return req.Reply(unavailableMsg)
+			}
+
+			question := sideQuestionText(req.Text)
+			if question == "" {
+				return req.Reply("Usage: /btw <question>")
+			}
+
+			answer, err := rt.AskSideQuestion(ctx, question)
+			if err != nil {
+				return req.Reply(err.Error())
+			}
+			if strings.TrimSpace(answer) == "" {
+				return req.Reply(emptyAnswerMsg)
+			}
+
+			return req.Reply(answer)
+		},
+	}
+}
+
+func sideQuestionText(input string) string {
+	input = strings.TrimSpace(input)
+	if input == "" {
+		return ""
+	}
+	parts := strings.Fields(input)
+	if len(parts) < 2 {
+		return ""
+	}
+	if !strings.HasPrefix(input, parts[0]) {
+		return ""
+	}
+	return strings.TrimSpace(input[len(parts[0]):])
+}

pkg/commands/runtime.go

@@ -1,6 +1,10 @@
 package commands
 
-import "github.com/sipeed/picoclaw/pkg/config"
+import (
+	"context"
+
+	"github.com/sipeed/picoclaw/pkg/config"
+)
 
 // Runtime provides runtime dependencies to command handlers. It is constructed
 // per-request by the agent loop so that per-request state (like session scope)
@@ -8,6 +12,7 @@ import "github.com/sipeed/picoclaw/pkg/config"
 type Runtime struct {
 	Config             *config.Config
 	GetModelInfo       func() (name, provider string)
+	AskSideQuestion    func(ctx context.Context, question string) (string, error)
 	ListAgentIDs       func() []string
 	ListDefinitions    func() []Definition
 	ListSkillNames     func() []string