feat: complete v0.3.1 agent workflow

internal/tools/todo.go

@@ -0,0 +1,173 @@
+package tools
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"strings"
+	"sync"
+
+	"agentu/pkg/llm"
+)
+
+// ────────────────────────────────────────────────────────────────────────────
+// TodoTool — in-memory task tracking
+// ────────────────────────────────────────────────────────────────────────────
+
+type todoItem struct {
+	Content string `json:"content"`
+	Status  string `json:"status"` // "pending", "in_progress", "completed"
+}
+
+type TodoTool struct {
+	mu    sync.Mutex
+	items []todoItem
+}
+
+func NewTodoTool() *TodoTool {
+	return &TodoTool{}
+}
+
+func (t *TodoTool) Definition() llm.Tool {
+	return llm.Tool{
+		Type: "function",
+		Function: llm.ToolFunction{
+			Name:        "todo",
+			Description: "Manage a task list for the current conversation. Create, update, and track multi-step work. Use this to plan complex tasks and show progress.",
+			Parameters: JSONSchema(`{
+  "type": "object",
+  "properties": {
+    "action": {"type": "string", "enum": ["list", "create", "update", "start", "complete", "clear"], "description": "Operation to perform."},
+    "items": {"type": "array", "items": {"type": "string"}, "description": "For 'create': list of task descriptions to add."},
+    "task": {"type": "string", "description": "For 'update'/'start'/'complete': the exact task content string to target."},
+    "status": {"type": "string", "enum": ["pending", "in_progress", "completed"], "description": "For 'update': new status for the task."}
+  },
+  "required": ["action"],
+  "additionalProperties": false
+}`),
+		},
+	}
+}
+
+type todoArgs struct {
+	Action string   `json:"action"`
+	Items  []string `json:"items"`
+	Task   string   `json:"task"`
+	Status string   `json:"status"`
+}
+
+func (t *TodoTool) Execute(ctx context.Context, raw json.RawMessage) (string, error) {
+	var args todoArgs
+	if err := json.Unmarshal(raw, &args); err != nil {
+		return "", fmt.Errorf("parse arguments: %w", err)
+	}
+
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if err := ctx.Err(); err != nil {
+		return "", err
+	}
+
+	switch args.Action {
+	case "list":
+		return t.listTasks(), nil
+	case "create":
+		return t.createTasks(args.Items)
+	case "start":
+		return t.startTask(args.Task)
+	case "complete":
+		return t.completeTask(args.Task)
+	case "update":
+		return t.updateTask(args.Task, args.Status)
+	case "clear":
+		t.items = nil
+		return "Tasks cleared.", nil
+	default:
+		return "", fmt.Errorf("unknown todo action: %s", args.Action)
+	}
+}
+
+func (t *TodoTool) listTasks() string {
+	if len(t.items) == 0 {
+		return "No tasks."
+	}
+
+	var b strings.Builder
+	b.WriteString("Tasks:\n")
+	for _, item := range t.items {
+		fmt.Fprintf(&b, "[%s] %s\n", item.Status, item.Content)
+	}
+	return b.String()
+}
+
+func (t *TodoTool) createTasks(items []string) (string, error) {
+	if len(items) == 0 {
+		return "", fmt.Errorf("items is required for create")
+	}
+	for _, content := range items {
+		content = strings.TrimSpace(content)
+		if content == "" {
+			return "", fmt.Errorf("task content must not be empty")
+		}
+		t.items = append(t.items, todoItem{
+			Content: content,
+			Status:  "pending",
+		})
+	}
+	return t.listTasks(), nil
+}
+
+func (t *TodoTool) startTask(task string) (string, error) {
+	idx := -1
+	for i, item := range t.items {
+		if item.Content == task {
+			idx = i
+			break
+		}
+	}
+	if idx < 0 {
+		return "", fmt.Errorf("task not found: %s", task)
+	}
+
+	// Set all in_progress items to pending, then mark the target as in_progress.
+	for i := range t.items {
+		if t.items[i].Status == "in_progress" {
+			t.items[i].Status = "pending"
+		}
+	}
+	t.items[idx].Status = "in_progress"
+	return t.listTasks(), nil
+}
+
+func (t *TodoTool) completeTask(task string) (string, error) {
+	idx := -1
+	for i, item := range t.items {
+		if item.Content == task {
+			idx = i
+			break
+		}
+	}
+	if idx < 0 {
+		return "", fmt.Errorf("task not found: %s", task)
+	}
+	t.items[idx].Status = "completed"
+	return t.listTasks(), nil
+}
+
+func (t *TodoTool) updateTask(task, status string) (string, error) {
+	if status != "pending" && status != "in_progress" && status != "completed" {
+		return "", fmt.Errorf("status must be one of: pending, in_progress, completed")
+	}
+	idx := -1
+	for i, item := range t.items {
+		if item.Content == task {
+			idx = i
+			break
+		}
+	}
+	if idx < 0 {
+		return "", fmt.Errorf("task not found: %s", task)
+	}
+	t.items[idx].Status = status
+	return t.listTasks(), nil
+}