// Programmatic POSITIONING test for the win7 context menu.
//
//   bun scripts/menu-probe.ts
//
// Why this exists: 7.css declares `position: relative` on ul[role=menu] (it
// needs it for the gutter stripe and submenus), and the `skin` layer outranks
// `utilities` — so Tailwind's `.fixed` on the app's own menu lost, its
// [style.left/top.px] became FLOW offsets, and every right-click menu rendered
// below the viewport of the h-screen frame. Nothing about the idle window
// changes when that breaks, so the screenshot harness (scripts/shot.ts) cannot
// see it, and hover-probe.ts tests a different axis. This script renders the
// menu markup at declared coordinates and pixel-scans whether it actually
// landed there.
//
// It carries its own control: a second menu WITHOUT the `w7-ctx` marker class,
// i.e. the bug verbatim. That one must stay invisible — if it ever shows up,
// 7.css stopped forcing `relative` and this probe's premise is stale.
//
// Inherits shot.ts's constraints: dedicated Firefox profile (a running Firefox
// holds the default profile's lock), and the page must be written INTO the
// dist folder or strict_origin_policy silently unstyles it.
import { existsSync, mkdirSync, readdirSync, rmSync } from "node:fs";
import path from "node:path";

const ROOT = path.join(import.meta.dir, "..");
const DIST = path.join(ROOT, "ui", "dist", "ui", "browser");
const WORK = path.join(ROOT, ".shot");

function fail(message: string): never {
	console.error(`[menu-probe] ERROR: ${message}`);
	process.exit(1);
}

if (!existsSync(DIST)) fail(`no build output at ${DIST} — run: bun run build:ui`);
const styles = readdirSync(DIST).find((f) => f.startsWith("styles-") && f.endsWith(".css"));
if (!styles) fail(`no styles-*.css in ${DIST} — run: bun run build:ui`);

// ---- the probe page ----

// Geometry (CSS px = image px; headless Firefox applies no DPR scaling).
const MENU_X = 200;
const MENU_Y = 100;
const CONTROL_X = 560;
const MENU_W = 200;

// Mirrors ui/src/app/skins/7like/context-menu.ts EXACTLY where it matters:
// ul[role=menu] > li[role=menuitem] > button, the `w7-ctx fixed` class pair,
// and left/top as inline pixel styles. `w7-ctx` is what the skinfix rule in
// 7like.css keys on; the control deliberately omits it.
const menu = (x: number, marker: boolean) => `
  <ul role="menu" tabindex="-1"
      class="${marker ? "w7-ctx " : ""}fixed z-50 outline-none"
      style="left: ${x}px; top: ${MENU_Y}px; width: ${MENU_W}px">
    <li role="menuitem"><button type="button">Send to Other Panel</button></li>
    <li role="menuitem" class="has-divider"><button type="button">Rename</button></li>
    <li role="menuitem"><button type="button">Copy Path</button></li>
    <li role="menuitem" aria-disabled="true"><button type="button">Delete</button></li>
  </ul>`;

// The frame reproduces the app's: .window.w7-frame is a 100vh flex column and
// <app-context-menu> is one of its LAST children, so a menu that falls back to
// static flow lands past the bottom edge — which is the whole bug.
// The body gets an explicit white background (inline, so no layer can touch
// it) purely so "is anything drawn here?" is an unambiguous question.
const page = `<!doctype html>
<html class="win7" lang="en">
<head><meta charset="utf-8"><link rel="stylesheet" href="${styles}">
</head>
<body>
  <div class="window glass w7-frame active" style="display: flex; flex-direction: column; height: 100vh">
    <div class="title-bar">
      <div class="title-bar-text">miniSCP</div>
      <div class="title-bar-controls"><button aria-label="Close"></button></div>
    </div>
    <div class="window-body" style="flex: 1; min-height: 0; background: #fff"></div>
    ${menu(MENU_X, true)}
    ${menu(CONTROL_X, false)}
  </div>
</body></html>`;

const pagePath = path.join(DIST, "_menu-probe.html");
await Bun.write(pagePath, page);

// ---- shoot ----

mkdirSync(WORK, { recursive: true });
const profile = path.join(WORK, "profile");
mkdirSync(profile, { recursive: true });
rmSync(path.join(profile, "parent.lock"), { force: true });

const out = path.join(WORK, "menu-probe.png");
const proc = Bun.spawnSync(
	["firefox", "--headless", "--profile", profile, "--screenshot", out, "--window-size", "800,400", `file://${pagePath}`],
	{ cwd: ROOT, stdout: "pipe", stderr: "pipe" },
);
if (!existsSync(out)) {
	console.error(proc.stderr.toString().trim());
	fail("firefox produced no image");
}

// ---- pixel scan ----

/**
 * Count pixels that are visibly NOT the white window body: the menu's border
 * (#0006 over white ≈ #999), its shadow and its black item text all qualify.
 * A menu that rendered where it was told fills this with hundreds of them; an
 * empty white region scores 0.
 */
async function inkCount(img: string, x: number, y: number, w: number, h: number): Promise<number> {
	const p = Bun.spawnSync(["magick", img, "-crop", `${w}x${h}+${x}+${y}`, "+repage", "txt:"], {
		stdout: "pipe",
		stderr: "pipe",
	});
	let count = 0;
	for (const line of p.stdout.toString().split("\n").slice(1)) {
		const m = /\((\d+),(\d+),(\d+)/.exec(line);
		if (!m) continue;
		const [r, g, b] = [Number(m[1]), Number(m[2]), Number(m[3])];
		if (Math.max(r, g, b) < 200) count++;
	}
	return count;
}

// Inset by 2px so the scan cannot straddle the region's own edge.
const BOX = { w: MENU_W - 4, h: 60 };
const placed = await inkCount(out, MENU_X + 2, MENU_Y + 2, BOX.w, BOX.h);
const control = await inkCount(out, CONTROL_X + 2, MENU_Y + 2, BOX.w, BOX.h);

console.log("[menu-probe] ink at the declared coordinates:\n");
console.log("  menu                        px  verdict");
console.log(
	`  w7-ctx (position: fixed)${String(placed).padStart(6)}  ${placed > 0 ? "placed" : "MISSING: menu did not render where it was told"}`,
);
console.log(
	`  control (no marker)     ${String(control).padStart(6)}  ${control > 0 ? "NOTE: 7.css no longer forces relative — premise stale" : "off-viewport, as expected"}`,
);
console.log(`\n[menu-probe] image: ${out}`);

if (placed === 0) {
	console.log("[menu-probe] the context menu is positioned in FLOW again — see 7like.css .w7-ctx");
	process.exit(2);
}
console.log("[menu-probe] clean");