import { z } from "zod";

/**
 * Todo item status
 */
export const TodoStatusSchema = z.enum(["pending", "in_progress", "completed", "cancelled"]);
export type TodoStatus = z.infer<typeof TodoStatusSchema>;

/**
 * Single todo item in a plan
 * Matches deepagents TodoListMiddleware output: { content, status }
 * id is auto-generated if not provided
 */
export const PlanTodoSchema = z.object({
	id: z.string().optional(),
	content: z.string(),
	status: TodoStatusSchema,
});

export type PlanTodo = z.infer<typeof PlanTodoSchema>;

/**
 * Serializable plan schema for tool results
 * Matches deepagents TodoListMiddleware output format
 * id/title are auto-generated if not provided
 */
export const SerializablePlanSchema = z.object({
	id: z.string().optional(),
	title: z.string().optional(),
	todos: z.array(PlanTodoSchema).min(1),
	maxVisibleTodos: z.number().optional(),
	showProgress: z.boolean().optional(),
});

export type SerializablePlan = z.infer<typeof SerializablePlanSchema>;

/**
 * Normalized plan with required fields (after auto-generation)
 */
export interface NormalizedPlan {
	id: string;
	title: string;
	todos: Array<{ id: string; content: string; status: TodoStatus }>;
	maxVisibleTodos?: number;
	showProgress?: boolean;
}

/**
 * Parse and normalize a plan from tool result
 * Auto-generates id/title if not provided (for deepagents compatibility)
 */
export function parseSerializablePlan(data: unknown): NormalizedPlan {
	const result = SerializablePlanSchema.safeParse(data);

	if (!result.success) {
		console.warn("Invalid plan data:", result.error.issues);

		// Try to extract basic info for fallback
		const obj = (data && typeof data === "object" ? data : {}) as Record<string, unknown>;

		return {
			id: typeof obj.id === "string" ? obj.id : `plan-${Date.now()}`,
			title: typeof obj.title === "string" ? obj.title : "Plan",
			todos: Array.isArray(obj.todos)
				? obj.todos.map((t: unknown, i: number) => {
						const todo = t as Record<string, unknown>;
						return {
							id: typeof todo?.id === "string" ? todo.id : `todo-${i}`,
							content: typeof todo?.content === "string" ? todo.content : "Task",
							status: TodoStatusSchema.safeParse(todo?.status).success
								? (todo.status as TodoStatus)
								: ("pending" as const),
						};
					})
				: [{ id: "1", content: "No tasks", status: "pending" as const }],
		};
	}

	// Normalize: add id/title if missing
	return {
		id: result.data.id || `plan-${Date.now()}`,
		title: result.data.title || "Plan",
		todos: result.data.todos.map((t, i) => ({
			id: t.id || `todo-${i}`,
			content: t.content,
			status: t.status,
		})),
		maxVisibleTodos: result.data.maxVisibleTodos,
		showProgress: result.data.showProgress,
	};
}