/**
 * Minimal browser / environment detection used by the floating-ui-react port.
 *
 * Mirrors `@base-ui/utils/detectBrowser` — only the subset the port actually
 * consumes is inlined here so we don't have to vendor a separate dependency.
 * Each flag matches the React source so behavior is 1:1.
 */

interface NavigatorUAData {
	brands: Array<{ brand: string; version: string }>;
	mobile: boolean;
	platform: string;
}

const hasNavigator = typeof navigator !== "undefined";

function getNavigatorData(): { platform: string; maxTouchPoints: number } {
	if (!hasNavigator) {
		return { platform: "", maxTouchPoints: -1 };
	}
	const uaData = (navigator as { userAgentData?: NavigatorUAData })
		.userAgentData;
	if (uaData?.platform) {
		return {
			platform: uaData.platform,
			maxTouchPoints: navigator.maxTouchPoints,
		};
	}
	return {
		platform: navigator.platform ?? "",
		maxTouchPoints: navigator.maxTouchPoints ?? -1,
	};
}

function getUserAgent(): string {
	if (!hasNavigator) {
		return "";
	}
	const uaData = (navigator as { userAgentData?: NavigatorUAData })
		.userAgentData;
	if (uaData && Array.isArray(uaData.brands)) {
		return uaData.brands
			.map(({ brand, version }) => `${brand}/${version}`)
			.join(" ");
	}
	// `navigator` can exist with an absent `userAgent` on non-browser runtimes
	// (Node ≥21, Deno, edge workers expose a partial Navigator), so the
	// `hasNavigator` guard alone isn't enough — coalesce to avoid a
	// module-load crash on `userAgent.includes(...)` below.
	return navigator.userAgent ?? "";
}

function getPlatform(): string {
	if (!hasNavigator) {
		return "";
	}
	const uaData = (navigator as { userAgentData?: NavigatorUAData })
		.userAgentData;
	if (uaData?.platform) {
		return uaData.platform;
	}
	return navigator.platform ?? "";
}

const nav = getNavigatorData();
const platform = getPlatform();
const userAgent = getUserAgent();

export const isAndroid =
	(hasNavigator && /android/i.test(platform)) || /android/i.test(userAgent);

export const isJSDOM = userAgent.includes("jsdom/");

/**
 * happy-dom sets a user-agent beginning with "Mozilla/5.0 (X11; Linux x64) ..."
 * and does NOT include "jsdom/". We also treat happy-dom as JSDOM-ish because
 * it shares the same limitations (no real focus-visible, no real layout).
 */
const isHappyDOM = userAgent.includes("HappyDOM");

/**
 * Umbrella flag: true in either jsdom or happy-dom. Code that guards on
 * test-env limitations (e.g. `matches(':focus-visible')` throwing) should
 * use this.
 */
export const isTestEnv = isJSDOM || isHappyDOM;

export const isIOS =
	nav.platform === "MacIntel" && nav.maxTouchPoints > 1
		? true
		: /iP(hone|ad|od)|iOS/.test(nav.platform);

export const isMac =
	hasNavigator &&
	platform.toLowerCase().startsWith("mac") &&
	!navigator.maxTouchPoints;

/**
 * Safari detection — mirrors `@base-ui/utils/detectBrowser`'s `isSafari`.
 * Uses `navigator.vendor` which is "Apple Computer, Inc." in Safari and
 * empty / different in Chrome/Firefox/Edge.
 */
export const isSafari =
	hasNavigator && /apple/i.test((navigator as Navigator).vendor ?? "");

/**
 * WebKit engine detection — mirrors `@base-ui/utils/detectBrowser`'s
 * `isWebKit`. Matches Safari AND other WebKit-shell browsers (WKWebView,
 * standalone iOS PWAs) without matching Chromium-based browsers (which
 * keep "AppleWebKit" in their UA for historical compat).
 */
export const isWebKit =
	hasNavigator &&
	/AppleWebKit/.test(userAgent) &&
	!/Edg|Chrome|Chromium|Firefox/.test(userAgent);