import apiFetch from '@wordpress/api-fetch';
import { parse } from '@wordpress/block-serialization-default-parser';

export default async ({ postId, postType }) => {
	const type = postType === 'page' ? 'pages' : 'posts';
	const response = await apiFetch({
		path: `/wp/v2/${type}/${postId}?context=edit`,
	});
	const blocks = parse(response.content.raw);
	const postStrings = [response.title.raw, ...extractTextFromBlocks(blocks)];

	// Get active template part slugs from the DOM
	const slugs = [
		...new Set(
			[...document.querySelectorAll('[data-extendify-part-slug]')].map(
				(el) => el.dataset.extendifyPartSlug,
			),
		),
	];

	if (!slugs.length) {
		return { post_strings: dedupeStrings(postStrings), parts_used: [] };
	}

	let allParts = [];
	try {
		allParts = await apiFetch({
			path: '/wp/v2/template-parts?per_page=100&context=edit',
		});
	} catch {
		try {
			await new Promise((resolve) => setTimeout(resolve, 1000));
			allParts = await apiFetch({
				path: '/wp/v2/template-parts?per_page=100&context=edit',
			});
		} catch {
			// Maybe error to the user, but we retried twice
		}
	}
	const activeParts = allParts.filter((p) => slugs.includes(p.slug));
	const partsUsed = activeParts.map((part) => {
		const partBlocks = parse(part.content.raw);
		postStrings.push(...extractTextFromBlocks(partBlocks));
		return { id: part.id, area: part.area };
	});

	return {
		post_strings: dedupeStrings(postStrings),
		parts_used: partsUsed,
	};
};

const newSet = (arr) => new Set(arr.filter(Boolean));
const dedupeStrings = (arr) => [...newSet(arr)];

const stripHtml = (html) =>
	html
		.replace(/<[^>]+>/g, '')
		.replace(/\s+/g, ' ')
		.trim();

// Handles image stuff
const extractAltAndTitleFromHtml = (html) => {
	const matches = [];
	const altMatch = html.match(/alt="([^"]*)"/);
	if (altMatch?.[1]) matches.push(altMatch[1].trim());
	const titleMatch = html.match(/title="([^"]*)"/);
	if (titleMatch?.[1]) matches.push(titleMatch[1].trim());
	return matches;
};

const extractTextFromBlocks = (blocks) => {
	if (!blocks || blocks.length === 0) return [];
	return blocks.flatMap((block) => [
		// Extract from innerContent (rendered HTML)
		...(block.innerContent
			? block.innerContent
					.filter(Boolean)
					.flatMap((html) => [
						stripHtml(html),
						...extractAltAndTitleFromHtml(html),
					])
					.filter(Boolean)
			: []),
		// Extract from relevant string attributes
		...['content', 'caption', 'alt', 'title', 'value']
			.map((key) =>
				typeof block.attrs?.[key] === 'string' ? block.attrs[key].trim() : null,
			)
			.filter(Boolean),
		// Recurse into innerBlocks
		...extractTextFromBlocks(block.innerBlocks || []),
	]);
};