import { tryParseJson } from "@oh-my-pi/pi-utils";
import { buildResult, formatIsoDate, loadPage, type RenderResult, type SpecialHandler } from "./types";

interface RedditPost {
	title: string;
	selftext: string;
	author: string;
	score: number;
	num_comments: number;
	created_utc: number;
	subreddit: string;
	url: string;
	is_self: boolean;
}

interface RedditComment {
	body: string;
	author: string;
	score: number;
	created_utc: number;
	replies?: { data: { children: Array<{ data: RedditComment }> } };
}

/**
 * Handle Reddit URLs via JSON API
 */
export const handleReddit: SpecialHandler = async (
	url: string,
	timeout: number,
	signal?: AbortSignal,
): Promise<RenderResult | null> => {
	try {
		const parsed = new URL(url);
		if (!parsed.hostname.includes("reddit.com")) return null;

		const fetchedAt = new Date().toISOString();

		// Append .json to get JSON response
		let jsonUrl = `${url.replace(/\/$/, "")}.json`;
		if (parsed.search) {
			jsonUrl = `${url.replace(/\/$/, "").replace(parsed.search, "")}.json${parsed.search}`;
		}

		const result = await loadPage(jsonUrl, { timeout, signal });
		if (!result.ok) return null;

		const data = tryParseJson<any>(result.content);
		if (!data) return null;
		let md = "";

		// Handle different Reddit URL types
		if (Array.isArray(data) && data.length >= 1) {
			// Post page (with comments)
			const postData = data[0]?.data?.children?.[0]?.data as RedditPost | undefined;
			if (postData) {
				md = `# ${postData.title}\n\n`;
				md += `**r/${postData.subreddit}** · u/${postData.author} · ${postData.score} points · ${postData.num_comments} comments\n`;
				md += `*${formatIsoDate(postData.created_utc * 1000)}*\n\n`;

				if (postData.is_self && postData.selftext) {
					md += `---\n\n${postData.selftext}\n\n`;
				} else if (!postData.is_self) {
					md += `**Link:** ${postData.url}\n\n`;
				}

				// Add comments if available
				if (data.length >= 2 && data[1]?.data?.children) {
					md += `---\n\n## Top Comments\n\n`;
					const comments = data[1].data.children.filter((c: { kind: string }) => c.kind === "t1").slice(0, 10);

					for (const { data: comment } of comments as Array<{ data: RedditComment }>) {
						md += `### u/${comment.author} · ${comment.score} points\n\n`;
						md += `${comment.body}\n\n---\n\n`;
					}
				}
			}
		} else if (data?.data?.children) {
			// Subreddit or listing page
			const posts = data.data.children.slice(0, 20) as Array<{ data: RedditPost }>;
			const subreddit = posts[0]?.data?.subreddit;

			md = `# r/${subreddit || "Reddit"}\n\n`;
			for (const { data: post } of posts) {
				md += `- **${post.title}** (${post.score} pts, ${post.num_comments} comments)\n`;
				md += `  by u/${post.author}\n\n`;
			}
		}

		if (!md) return null;

		return buildResult(md, { url, method: "reddit", fetchedAt, notes: ["Fetched via Reddit JSON API"] });
	} catch {}

	return null;
};