// 第一方广告渲染器：API 仅返回结构化字段，后台内容不会作为 HTML/JavaScript 执行。
(function () {
	const slots = document.querySelectorAll("[data-ad-slot]");
	const device = window.matchMedia("(max-width: 640px)").matches ? "mobile" : "desktop";
	let googleLoader;

	const loadGoogle = (publisherId) => {
		if (googleLoader) return googleLoader;
		googleLoader = new Promise((resolve, reject) => {
			const script = document.createElement("script");
			script.async = true;
			script.crossOrigin = "anonymous";
			script.src = `https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=${encodeURIComponent(publisherId)}`;
			script.onload = resolve;
			script.onerror = reject;
			document.head.append(script);
		});
		return googleLoader;
	};

	const clear = (slot) => slot.querySelectorAll("[data-ad-placeholder]").forEach((item) => item.remove());
	const eventUrl = (slot, ad, eventType) =>
		`/api/ads/${encodeURIComponent(ad.campaignId)}/events/${eventType}?placementKey=${encodeURIComponent(slot.dataset.adSlot)}&device=${device}`;
	const recordEvent = (slot, ad, eventType) => {
		if (!ad.campaignId || (ad.providerKind !== "direct" && ad.providerKind !== "house")) return;
		fetch(eventUrl(slot, ad, eventType), { method: "POST", credentials: "same-origin", keepalive: true })
			.catch(() => { /* 统计失败不影响广告跳转或页面体验。 */ });
	};
	const enableClickTracking = (link, slot, ad) => {
		link.addEventListener("click", () => recordEvent(slot, ad, "click"), { once: true });
	};
	const renderImage = (slot, ad) => {
		clear(slot);
		const link = document.createElement("a");
		link.href = ad.targetUrl;
		link.target = "_blank";
		link.rel = "sponsored noopener noreferrer";
		enableClickTracking(link, slot, ad);
		const image = document.createElement("img");
		image.src = ad.imageUrl;
		image.alt = "广告";
		image.loading = "lazy";
		link.append(image);
		slot.append(link);
		slot.classList.add("is-filled", "is-image-ad");
		recordEvent(slot, ad, "impression");
	};
	const renderText = (slot, ad) => {
		clear(slot);
		const link = document.createElement("a");
		link.href = ad.targetUrl;
		link.target = "_blank";
		link.rel = "sponsored noopener noreferrer";
		link.className = "ad-text-creative";
		enableClickTracking(link, slot, ad);
		const headline = document.createElement("strong");
		headline.textContent = ad.headline;
		const body = document.createElement("small");
		body.textContent = ad.bodyText;
		link.append(headline, body);
		if (ad.callToAction) {
			const action = document.createElement("b");
			action.textContent = ad.callToAction;
			link.append(action);
		}
		slot.append(link);
		slot.classList.add("is-filled", "is-text-ad");
		recordEvent(slot, ad, "impression");
	};
	const renderGoogle = async (slot, ad) => {
		clear(slot);
		const unit = document.createElement("ins");
		unit.className = "adsbygoogle";
		unit.style.display = "block";
		unit.dataset.adClient = ad.publisherId;
		unit.dataset.adSlot = ad.slotId;
		unit.dataset.adFormat = "auto";
		unit.dataset.fullWidthResponsive = "true";
		slot.append(unit);
		try {
			await loadGoogle(ad.publisherId);
			(window.adsbygoogle = window.adsbygoogle || []).push({});
			slot.classList.add("is-filled");
		} catch (error) { console.error("Google 广告加载失败", error); }
	};

	const loadAutoAds = async () => {
		try {
			const response = await fetch("/api/ads-config", { headers: { Accept: "application/json" } });
			if (response.status === 204 || !response.ok) return;
			const config = await response.json();
			if (config.autoAdsEnabled && config.publisherId) await loadGoogle(config.publisherId);
		} catch (error) { console.error("自动广告配置请求失败", error); }
	};

	loadAutoAds();
	slots.forEach(async (slot) => {
		try {
			const query = new URLSearchParams({ device });
			if (slot.dataset.adCategoryId) query.set("categoryId", slot.dataset.adCategoryId);
			const response = await fetch(`/api/ads/${encodeURIComponent(slot.dataset.adSlot)}?${query}`, { headers: { Accept: "application/json" } });
			if (response.status === 204 || !response.ok) return;
			const ad = await response.json();
			if ((ad.kind === "direct" || ad.kind === "house") && ad.imageUrl && ad.targetUrl) renderImage(slot, ad);
			else if (ad.kind === "text" && ad.headline && ad.bodyText && ad.targetUrl) renderText(slot, ad);
			else if (ad.kind === "google" && ad.publisherId && ad.slotId) await renderGoogle(slot, ad);
		} catch (error) { console.error("广告请求失败", error); }
	});
})();