/**
 * pi-stop-notify
 *
 * Fires when the pi agent stops (event: `agent_end`) and emits:
 *   - terminal OSC notification (OSC 777 / OSC 99 / Windows toast)
 *   - macOS sound via `afplay` (configurable, off on non-macOS)
 *   - optional native macOS notification via `osascript`
 *
 * Heuristic: if the last assistant text ends with "?", title becomes
 * "Pi has a question" — otherwise "Pi finished".
 *
 * Env vars:
 *   PI_STOP_NOTIFY_SOUND   path to .aiff/.wav (default: /System/Library/Sounds/Glass.aiff)
 *                          set to "off" to disable sound
 *   PI_STOP_NOTIFY_NATIVE  "0" to disable osascript native popup (macOS only, default on)
 *   PI_STOP_NOTIFY_OSC     "off" to disable terminal OSC notification
 *   PI_STOP_NOTIFY_NAME    explicit name prefix (defaults to basename of session cwd)
 */

import type { AgentEndEvent, ExtensionAPI } from "@earendil-works/pi-coding-agent";
import { execFile } from "node:child_process";
import { platform } from "node:os";
import { basename } from "node:path";

const DEFAULT_SOUND = "/System/Library/Sounds/Glass.aiff";

function osc777(title: string, body: string): void {
	process.stdout.write(`\x1b]777;notify;${escapeOsc(title)};${escapeOsc(body)}\x07`);
}

function osc99(title: string, body: string): void {
	process.stdout.write(`\x1b]99;i=1:d=0;${escapeOsc(title)}\x1b\\`);
	process.stdout.write(`\x1b]99;i=1:p=body;${escapeOsc(body)}\x1b\\`);
}

function windowsToast(title: string, body: string): void {
	const t = "Windows.UI.Notifications";
	const mgr = `[${t}.ToastNotificationManager, ${t}, ContentType = WindowsRuntime]`;
	const template = `[${t}.ToastTemplateType]::ToastText02`;
	const script = [
		`${mgr} > $null`,
		`$xml = [${t}.ToastNotificationManager]::GetTemplateContent(${template})`,
		`$nodes = $xml.GetElementsByTagName('text')`,
		`$nodes[0].AppendChild($xml.CreateTextNode('${escapePosh(title)}')) > $null`,
		`$nodes[1].AppendChild($xml.CreateTextNode('${escapePosh(body)}')) > $null`,
		`[${t}.ToastNotificationManager]::CreateToastNotifier('pi').Show([${t}.ToastNotification]::new($xml))`,
	].join("; ");
	execFile("powershell.exe", ["-NoProfile", "-Command", script], () => {});
}

function escapeOsc(s: string): string {
	// strip BEL / ESC so we don't break the escape sequence
	return s.replace(/[\x07\x1b]/g, "");
}

function escapePosh(s: string): string {
	return s.replace(/'/g, "''");
}

function emitOsc(title: string, body: string): void {
	if (process.env.PI_STOP_NOTIFY_OSC === "off") return;
	if (process.env.WT_SESSION) return windowsToast(title, body);
	if (process.env.KITTY_WINDOW_ID) return osc99(title, body);
	osc777(title, body);
}

function playSound(): void {
	const sound = process.env.PI_STOP_NOTIFY_SOUND ?? DEFAULT_SOUND;
	if (sound === "off") return;
	if (platform() !== "darwin") return;
	execFile("afplay", [sound], () => {});
}

function nativeMacNotify(title: string, body: string): void {
	if (process.env.PI_STOP_NOTIFY_NATIVE === "0") return;
	if (platform() !== "darwin") return;
	const t = title.replace(/"/g, '\\"');
	const b = body.replace(/"/g, '\\"');
	execFile("osascript", ["-e", `display notification "${b}" with title "${t}"`], () => {});
}

function sessionName(cwd: string): string {
	const override = process.env.PI_STOP_NOTIFY_NAME;
	if (override && override.trim()) return override.trim();
	const name = basename(cwd || "").trim();
	return name || "Pi";
}

function classify(event: AgentEndEvent, cwd: string): { title: string; body: string } {
	const lastText = extractLastAssistantText(event);
	const trimmed = lastText.trim();
	const isQuestion = /\?\s*$/.test(trimmed);
	const preview = trimmed.length > 120 ? `${trimmed.slice(0, 117)}...` : trimmed;
	const name = sessionName(cwd);
	return {
		title: isQuestion ? `${name} has a question` : `${name} finished`,
		body: preview || (isQuestion ? "Awaiting your input" : "Task complete"),
	};
}

function extractLastAssistantText(event: AgentEndEvent): string {
	const messages = event.messages ?? [];
	for (let i = messages.length - 1; i >= 0; i--) {
		const msg = messages[i] as unknown as { role?: string; content?: unknown };
		if (msg?.role !== "assistant") continue;
		const text = stringifyContent(msg.content);
		if (text) return text;
	}
	return "";
}

function stringifyContent(content: unknown): string {
	if (typeof content === "string") return content;
	if (!Array.isArray(content)) return "";
	const parts: string[] = [];
	for (const block of content) {
		if (!block || typeof block !== "object") continue;
		const b = block as { type?: string; text?: string };
		if (b.type === "text" && typeof b.text === "string") parts.push(b.text);
	}
	return parts.join("\n");
}

export default function (pi: ExtensionAPI) {
	pi.on("agent_end", async (event, ctx) => {
		const { title, body } = classify(event, ctx.cwd);
		emitOsc(title, body);
		playSound();
		nativeMacNotify(title, body);
	});
}