/**
 * Model-facing registration for the `send_wechat` tool.
 *
 * The bridge replies to inbound messages automatically; this tool is for the
 * agent to message the owner proactively. It is deliberately owner-only: the
 * model cannot choose a recipient, so untrusted generated text cannot be aimed at
 * an arbitrary WeChat account. It carries one text or one local image, and an
 * image arrives as a picture rather than a document.
 */

import { basename } from "node:path";
import type { JsonValue } from "@earendil-works/pi-ai";
import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
import { Type, type Static } from "typebox";
import { reuseText, toolDetails } from "../../lib/tui/chrome.ts";
import { failedResult, textResult } from "../../lib/tool-result.ts";
import { callLine, errorLine, rejectionLine } from "../../lib/tui/tool.ts";
import { paint } from "../../lib/tui/tokens.ts";
import type { Bridge } from "./bridge.ts";

export const TOOL_NAME = "send_wechat";

const WechatSendParams = Type.Object({
	text: Type.Optional(
		Type.String({
			minLength: 1,
			maxLength: 4000,
			description: "The message to send to the WeChat owner. Plain text.",
		}),
	),
	image: Type.Optional(
		Type.String({
			minLength: 1,
			maxLength: 4096,
			description: "Path to a local image to send instead, as a picture. One of text or image.",
		}),
	),
});
type WechatSendArgs = Static<typeof WechatSendParams>;

const WechatSendResult = Type.Object({
	sent: Type.Boolean({ description: "Whether the message was delivered to the WeChat backend." }),
	error: Type.Optional(Type.String({ description: "Why the send failed, when sent is false." })),
});

export interface ToolDeps {
	getBridge: () => Bridge | undefined;
}

function sendResult(sent: boolean, error?: string) {
	const details = error === undefined ? { sent } : { sent, error };
	const structuredContent: Record<string, JsonValue> = { sent };
	if (error !== undefined) structuredContent.error = error;
	const text = sent ? "Sent to the WeChat owner." : `WeChat send failed: ${error ?? "unknown error"}`;
	return sent ? textResult(text, details, structuredContent) : failedResult(text, details, structuredContent);
}

export function registerTools(pi: ExtensionAPI, deps: ToolDeps): void {
	pi.registerTool({
		name: TOOL_NAME,
		label: "WeChat send",
		description: [
			"Send a WeChat message — plain text, or one local image as a picture — to the account owner from the running bridge (start it with /wechat login).",
			"The recipient is always the owner and cannot be chosen.",
		].join(" "),
		promptSnippet: "Send a WeChat text or image to the account owner.",
		promptGuidelines: [
			"Use send_wechat only to message the owner proactively, not to answer an inbound WeChat message (the bridge replies automatically).",
			"Give one of text or image: a plot or screenshot goes as a path, not described in words.",
			"Keep messages concise and do not include secrets unless the user asked for them.",
		],
		parameters: WechatSendParams,
		outputSchema: WechatSendResult,
		annotations: { readOnlyHint: false, destructiveHint: false, idempotentHint: false, openWorldHint: true },
		executionMode: "sequential",

		async execute(_toolCallId, params) {
			const args = params as WechatSendArgs;
			if ((args.text === undefined) === (args.image === undefined)) {
				return sendResult(false, "Give exactly one of text or image.");
			}
			const bridge = deps.getBridge();
			if (!bridge) {
				return sendResult(false, "WeChat bridge is not started. Run /wechat login first.");
			}
			const outcome = await bridge.sendToOwner(args.text, args.image);
			return sendResult(outcome.ok, outcome.error);
		},

		renderCall(args, theme, context) {
			const { text, image } = args as { text?: unknown; image?: unknown };
			// An image is named by its file, so a call line never carries a whole path.
			const body = typeof image === "string" ? basename(image) : text;
			const label = context.argsComplete && typeof body === "string" ? body : "…";
			return callLine(theme, context.lastComponent, TOOL_NAME, label);
		},

		renderResult(result, options, theme, context) {
			const text = reuseText(context.lastComponent);
			const details = toolDetails<{ sent?: boolean; error?: string }>(result.details);
			if (details?.sent) {
				text.setText(paint(theme, "ok", "sent to WeChat owner"));
				return text;
			}
			if (details?.error) {
				text.setText(errorLine(theme, details.error));
				return text;
			}
			// Pi's rejection result carries `{}`; show its sanitized message.
			text.setText(rejectionLine(theme, result, options.expanded));
			return text;
		},
	});
}