import { existsSync } from "node:fs";
import { dirname, join, resolve } from "node:path";
import { fileURLToPath } from "node:url";
import {
	CONFIG_DIR_NAME,
	type ExtensionAPI,
} from "@earendil-works/pi-coding-agent";
import { Type } from "typebox";

const packageRoot = resolve(dirname(fileURLToPath(import.meta.url)), "..");
const workflowScript = join(packageRoot, "scripts", "parse_china_standard.py");

export default function (pi: ExtensionAPI) {
	pi.registerTool({
		name: "china_standard_parse",
		label: "解析中国国家标准",
		description:
			"按 GB、GB/T 或 GB/Z 标准编号从国家标准全文公开系统下载官方 PDF，使用 MinerU 解析，并返回工作区内 Markdown 文件的绝对路径。",
		promptSnippet: "下载并解析中国国家标准，返回 Markdown 文件路径",
		promptGuidelines: [
			"Use china_standard_parse when the user asks to retrieve or read a Chinese national standard by its GB, GB/T, or GB/Z number.",
			"After china_standard_parse returns a Markdown path, use the read tool to inspect only the sections needed for the user's request.",
		],
		parameters: Type.Object({
			standard_number: Type.String({
				description: '标准编号，例如 "GB/T 35697-2026"',
			}),
		}),

		async execute(_toolCallId, params, signal, onUpdate, ctx) {
			if (!existsSync(workflowScript)) {
				throw new Error(`国标解析脚本不存在：${workflowScript}`);
			}

			const outputRoot = resolve(ctx.cwd, "china-standard-output");
			const projectConfig = resolve(
				ctx.cwd,
				CONFIG_DIR_NAME,
				"china-standard",
				"mineru.json",
			);
			const command = [
				workflowScript,
				params.standard_number,
				"--output-root",
				outputRoot,
			];
			if (!process.env.MINERU_CONFIG && existsSync(projectConfig)) {
				command.push("--config", projectConfig);
			}

			onUpdate?.({
				content: [
					{ type: "text", text: `正在下载并解析 ${params.standard_number}` },
				],
				details: {},
			});

			const python =
				process.env.PYTHON ||
				(process.platform === "win32" ? "python" : "python3");
			const result = await pi.exec(python, command, { cwd: ctx.cwd, signal });
			if (result.code !== 0) {
				const detail =
					result.stderr.trim() ||
					result.stdout.trim() ||
					`退出码 ${result.code}`;
				throw new Error(`国标解析失败：${detail}`);
			}

			let payload: unknown;
			try {
				payload = JSON.parse(result.stdout);
			} catch {
				throw new Error("国标解析脚本没有返回有效 JSON");
			}
			if (
				typeof payload !== "object" ||
				payload === null ||
				!("markdown" in payload) ||
				typeof payload.markdown !== "string" ||
				!payload.markdown.endsWith(".md") ||
				!existsSync(payload.markdown)
			) {
				throw new Error("国标解析结果没有包含有效的 Markdown 文件");
			}

			return {
				content: [{ type: "text", text: payload.markdown }],
				details: {},
			};
		},
	});
}