/**
 * Núcleo de structured-output para pandi-dynamic-workflows.
 *
 * El builder de system-prompt de structured-output, un helper genérico appendSystemPrompt,
 * y validación de schema respaldada por TypeBox (validateStructuredData) + formato de retry-prompt
 * usado cuando un subagente debe devolver JSON. formatSchemaValidationErrors
 * queda privado del módulo; index.ts importa de vuelta las 4 funciones que llama dentro de runSubagent.
 *
 * Dependencia runtime unidireccional: index.ts -> structured-output. La arista de vuelta hacia
 * index.ts es solo de tipos (AgentOptions vía import type, borrado); Value viene del paquete externo
 * typebox/value y safeJson del sibling format.ts (sin ciclo).
 * Extraído byte-idéntico desde index.ts.
 */
import { Value } from "typebox/value";
import { safeJson } from "../lib/format.js";
import type { AgentOptions } from "../types.js";

export function makeStructuredOutputSystemPrompt(schema: unknown): string {
	return [
		"You must respond with ONLY one valid JSON value that matches the JSON Schema below.",
		"Do not include Markdown fences, prose, comments, or any text outside the JSON value.",
		"If evidence is insufficient, still return a JSON value matching the schema and encode uncertainty inside the fields.",
		"JSON Schema:",
		safeJson(schema),
	].join("\n");
}

export function appendSystemPromptOption(options: AgentOptions, addition: string): AgentOptions {
	return {
		...options,
		appendSystemPrompt: options.appendSystemPrompt ? `${options.appendSystemPrompt}\n\n${addition}` : addition,
	};
}

function formatSchemaValidationErrors(schema: unknown, data: unknown): string[] {
	try {
		const valueApi = Value as unknown as {
			Errors(schema: unknown, value: unknown): Iterable<unknown>;
		};
		const errors = [...valueApi.Errors(schema, data)].slice(0, 8);
		return errors.map((error) => {
			if (!error || typeof error !== "object") return String(error);
			const record = error as Record<string, unknown>;
			const location =
				typeof record.path === "string"
					? record.path
					: typeof record.instancePath === "string"
						? record.instancePath
						: typeof record.schemaPath === "string"
							? record.schemaPath
							: "";
			const message = typeof record.message === "string" ? record.message : safeJson(record, 0);
			return `${location ? `${location}: ` : ""}${message}`;
		});
	} catch (err) {
		return [`schema validation failed: ${err instanceof Error ? err.message : String(err)}`];
	}
}

export function validateStructuredData(schema: unknown, data: unknown): { ok: true } | { ok: false; errors: string[] } {
	try {
		const valueApi = Value as unknown as { Check(schema: unknown, value: unknown): boolean };
		if (valueApi.Check(schema, data)) return { ok: true };
		return { ok: false, errors: formatSchemaValidationErrors(schema, data) };
	} catch (err) {
		return {
			ok: false,
			errors: [`schema validation failed: ${err instanceof Error ? err.message : String(err)}`],
		};
	}
}

export function formatSchemaRetryPrompt(prompt: string, error: string): string {
	return `${prompt}\n\nThe previous response did not match the required JSON schema. Return ONLY a corrected JSON value, with no Markdown or prose. Validation errors:\n${error}`;
}