/*!
 * PHASE 6M — Nuva -> IS60 handoff token delivery (outbound link only)
 *
 * WHAT THIS FILE DOES, AND ONLY THIS:
 *   NuvaProductCatalogAdmin.getProductUrl(product) is the single function
 *   every "View Product" link on the Quick Skin Match / Advanced Skin Scan
 *   results pages already goes through -- is60-bridge.js (Phase 6D) already
 *   wraps it once to swap in the real, live IS60 URL and to append its own
 *   non-identity utm_source/utm_medium/nuva_ref tag. This file wraps
 *   getProductUrl() a SECOND, independent time, on top of whatever it
 *   already returns, to additionally append the current, already-issued,
 *   still-valid Phase 6L handoff token as one query parameter:
 *   `is60_ho=<token>`. It creates no token, extends no token, and reads the
 *   token from exactly the same localStorage slot Phase 6L already writes
 *   (`nuva_quick_skin_match_handoff_token` / `nuva_advanced_skin_scan_
 *   handoff_token`) -- never a new mechanism.
 *
 *   Every resolved IS60 product link on the page gets the same token
 *   appended, for as long as that token stays valid. This is deliberate:
 *   the token is single-use, and IS60 already redeems and invalidates it on
 *   the very first request that carries it (Phase 6K, live and unmodified),
 *   so only the first product link a visitor actually clicks ever redeems
 *   anything -- a later click on a different link that same session simply
 *   carries an already-used token, which IS60's existing redemption logic
 *   already fails open on (no error, no attribution, page loads normally).
 *   This file does not choose a single "primary" link to favor; doing so
 *   would be new steering logic this phase does not add.
 *
 * WHAT THIS FILE DELIBERATELY DOES NOT DO:
 *   - It never puts consultation_ref or customer_ref in a URL, a query
 *     string, or anywhere else -- the only new value it ever writes into a
 *     URL is the single, opaque, already-issued handoff token itself.
 *   - It never creates a handoff token, never asks IS60 for one, and never
 *     extends or refreshes one -- it only reads whatever Phase 6L already
 *     stored, exactly as-is.
 *   - It never accepts a token from anywhere other than that one reserved
 *     localStorage slot -- never a URL parameter, a global variable, a
 *     postMessage, or any other page input, so nothing on the page can hand
 *     this file a token to relay on its behalf.
 *   - It never attempts to reuse a token after this browser believes it
 *     has been redeemed -- it has no way to know that (redemption happens
 *     server-side, on IS60, outside this file's visibility) and does not
 *     try to guess; it simply keeps offering the same still-unexpired token
 *     until Phase 6L's own localStorage slot changes or the token expires,
 *     matching the "every eligible link may carry the current token"
 *     product behavior above.
 *   - It never touches is60-bridge.js -- it wraps getProductUrl() a second
 *     time, independently, the same non-destructive way is60-bridge.js
 *     itself wrapped it a first time. is60-bridge.js's own source is not
 *     read, opened, or modified by this file's installation.
 *   - It does not touch product matching, assessment, results rendering,
 *     NuvaCart, NuvaCheckout, pricing, entitlements, or attribution logic.
 *     Attribution is IS60's own, already-live, already-tested concern
 *     (Phase 6I/6J/6K) that this file's only job is to make reachable.
 *   - It never logs the token. No console output, no analytics event, no
 *     network call of any kind -- this file only edits a URL string that
 *     was already about to be rendered as a link.
 *   - If no valid token exists for the current consultation type, or if
 *     anything about reading/parsing it fails, every product URL is
 *     returned completely unchanged -- fail open, exactly like every other
 *     new capability added since Phase 6D.
 *
 * INTEGRATION POINT: window.NuvaProductCatalogAdmin.getProductUrl(product)
 * -- the same function is60-bridge.js wraps. (Not a separate "matching
 * engine" object; NuvaProductRecommendationUI's card-building code already
 * calls this one function for every rendered link, which is what makes
 * wrapping it here sufficient for "every View Product link" without
 * touching the recommendation UI itself.)
 *
 * Runs on the Quick Skin Match (free) and Advanced Skin Scan (advanced)
 * pages, same as Phase 6D and Phase 6L.
 */
(function () {
	'use strict';

	var TOKEN_KEY_BY_SLUG = {
		'quick-skin-match': 'nuva_quick_skin_match_handoff_token',
		'ai-skin-scan': 'nuva_advanced_skin_scan_handoff_token'
	};

	// Same slug-detection approach is60-bridge.js already uses for its own
	// ref tag -- not a new pattern, just applied to a different lookup table.
	function currentTokenKey() {
		var slug = (window.location.pathname || '').replace(/\/+$/, '').split('/').pop();
		return TOKEN_KEY_BY_SLUG[slug] || null;
	}

	// Reads the current, still-valid handoff token for this page's
	// consultation type, or null for any reason at all -- wrong page,
	// nothing stored yet, malformed JSON, missing fields, or expired.
	// Never throws; every branch below returns rather than raising.
	function getValidToken() {
		try {
			var key = currentTokenKey();
			if (!key) {
				return null;
			}
			var raw = window.localStorage.getItem(key);
			if (!raw) {
				return null;
			}
			var parsed = JSON.parse(raw);
			if (!parsed || typeof parsed.token !== 'string' || !parsed.token) {
				return null;
			}
			if (typeof parsed.expiresAt !== 'number' || Date.now() >= parsed.expiresAt) {
				return null; // expired, or malformed expiry -- treat as absent either way
			}
			return parsed.token;
		} catch (e) {
			return null; // fail open -- never let a storage/parse error propagate
		}
	}

	// Eligibility check: only ever append the token to a URL that is
	// actually an IS60 product link -- never to any other host.
	function isIS60Url(url) {
		return typeof url === 'string' && /^https?:\/\/is60\.store(\/|\?|$)/i.test(url);
	}

	// Appends exactly one query parameter, `is60_ho`, using the same
	// separator convention is60-bridge.js's own withRefTag() already uses --
	// '?' when the URL has no query string yet, '&' otherwise -- so every
	// existing query parameter (including is60-bridge.js's own utm_source/
	// utm_medium/nuva_ref tag) is preserved untouched, in place, in order.
	function appendHandoffToken(url, token) {
		var sep = url.indexOf('?') === -1 ? '?' : '&';
		return url + sep + 'is60_ho=' + encodeURIComponent(token);
	}

	function patchCatalogAdminForHandoffDelivery(admin) {
		if (!admin || admin.__is60HandoffDeliveryApplied) {
			return;
		}
		admin.__is60HandoffDeliveryApplied = true;

		var previousGetProductUrl = admin.getProductUrl.bind(admin);

		admin.getProductUrl = function (product) {
			// The existing link-resolution logic runs first, completely
			// unmodified -- its own behavior and any of its own errors are
			// not this file's concern and are never caught here.
			var url = previousGetProductUrl(product);

			try {
				if (!isIS60Url(url)) {
					return url; // not an IS60 link -- nothing to add
				}
				var token = getValidToken();
				if (!token) {
					return url; // no valid token -- normal link, unchanged
				}
				return appendHandoffToken(url, token);
			} catch (e) {
				// Fail open -- a bug in this file's own token handling must
				// never break or alter the underlying product link.
				return url;
			}
		};
	}

	function init() {
		var admin = window.NuvaProductCatalogAdmin;
		if (!admin || typeof admin.getProductUrl !== 'function') {
			return; // this page doesn't load the shared catalog module
		}
		patchCatalogAdminForHandoffDelivery(admin);
	}

	init();
	if (document.readyState !== 'complete') {
		window.addEventListener('load', init); // retry once, same as is60-bridge.js
	}
})();