import { ExtractedWebpage } from "../../cache/WebpageCache";
import { HTTPClientError } from "../../models/errors";
import { Logger } from "../../utils/Logger";
import { AdapterContext, AdapterResult, SiteAdapter } from "../SiteAdapter";
import { extractRedditContent } from "./redditExtractor";

export class RedditAdapter implements SiteAdapter {
  public readonly name = "RedditAdapter";

  /**
   * Synchronously evaluates if the target URL belongs to Reddit.
   * Matches reddit.com, *.reddit.com, and redd.it (excluding media domains like i.redd.it, v.redd.it).
   */
  public matches(parsedUrl: URL): boolean {
    const host = parsedUrl.hostname.toLowerCase();
    if (host === "i.redd.it" || host === "v.redd.it" || host === "preview.redd.it") {
      return false;
    }
    return host === "reddit.com" || host.endsWith(".reddit.com") || host === "redd.it";
  }

  /**
   * Rewrites Reddit URLs to old.reddit.com server-rendered variants and extracts content.
   */
  public async extract(context: AdapterContext): Promise<AdapterResult> {
    const transformedUrl = this.transformUrl(context.parsedUrl);

    Logger.debug(
      "[RedditAdapter]",
      `Rewriting Reddit URL '${context.originalUrl}' -> '${transformedUrl}'`
    );

    const res = await context.httpClient.get<string>(transformedUrl, {
      headers: {
        Accept: "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
        "Accept-Language": "en-US,en;q=0.9",
      },
    });

    if (res.statusCode >= 400) {
      throw new HTTPClientError(
        `Reddit server responded with status code ${res.statusCode} for ${transformedUrl}`
      );
    }

    const pageHtml = res.text || "";
    if (!pageHtml.trim()) {
      throw new Error(`Reddit returned an empty HTML payload for ${transformedUrl}`);
    }

    // Use Reddit-specific content extractor preserving post body, comments, hierarchy, links, and images
    const extracted = extractRedditContent(pageHtml, context.originalUrl);

    return {
      extracted,
      actualFetchUrl: transformedUrl,
      adapterName: this.name,
    };
  }

  /**
   * Transforms any Reddit URL to an old.reddit.com server-rendered equivalent.
   */
  public transformUrl(parsedUrl: URL): string {
    const targetUrl = new URL(parsedUrl.toString());
    targetUrl.protocol = "https:";
    targetUrl.hostname = "old.reddit.com";

    // Handle redd.it shortlinks (e.g. redd.it/18x9999 -> old.reddit.com/comments/18x9999)
    if (parsedUrl.hostname.toLowerCase() === "redd.it") {
      const cleanPath = parsedUrl.pathname.replace(/^\/+/, "");
      if (cleanPath && !cleanPath.startsWith("r/") && !cleanPath.startsWith("comments/")) {
        targetUrl.pathname = `/comments/${cleanPath}`;
      }
    }

    return targetUrl.toString();
  }
}

export const redditAdapter = new RedditAdapter();

import { ExtractedWebpage } from "../../cache/WebpageCache";
import { HTTPClientError } from "../../models/errors";
import { Logger } from "../../utils/Logger";
import { AdapterContext, AdapterResult, SiteAdapter } from "../SiteAdapter";
import { extractRedditContent } from "./redditExtractor";

export class RedditAdapter implements SiteAdapter {
  public readonly name = "RedditAdapter";

  /**
   * Synchronously evaluates if the target URL belongs to Reddit.
   * Matches reddit.com, *.reddit.com, and redd.it (excluding media domains like i.redd.it, v.redd.it).
   */
  public matches(parsedUrl: URL): boolean {
    const host = parsedUrl.hostname.toLowerCase();
    if (host === "i.redd.it" || host === "v.redd.it" || host === "preview.redd.it") {
      return false;
    }
    return host === "reddit.com" || host.endsWith(".reddit.com") || host === "redd.it";
  }

  /**
   * Rewrites Reddit URLs to old.reddit.com server-rendered variants and extracts content.
   */
  public async extract(context: AdapterContext): Promise<AdapterResult> {
    const transformedUrl = this.transformUrl(context.parsedUrl);

    Logger.debug(
      "[RedditAdapter]",
      `Rewriting Reddit URL '${context.originalUrl}' -> '${transformedUrl}'`
    );

    const res = await context.httpClient.get<string>(transformedUrl, {
      headers: {
        Accept: "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
        "Accept-Language": "en-US,en;q=0.9",
      },
    });

    if (res.statusCode >= 400) {
      throw new HTTPClientError(
        `Reddit server responded with status code ${res.statusCode} for ${transformedUrl}`
      );
    }

    const pageHtml = res.text || "";
    if (!pageHtml.trim()) {
      throw new Error(`Reddit returned an empty HTML payload for ${transformedUrl}`);
    }

    // Use Reddit-specific content extractor preserving post body, comments, hierarchy, links, and images
    const extracted = extractRedditContent(pageHtml, context.originalUrl);

    return {
      extracted,
      actualFetchUrl: transformedUrl,
      adapterName: this.name,
    };
  }

  /**
   * Transforms any Reddit URL to an old.reddit.com server-rendered equivalent.
   */
  public transformUrl(parsedUrl: URL): string {
    const targetUrl = new URL(parsedUrl.toString());
    targetUrl.protocol = "https:";
    targetUrl.hostname = "old.reddit.com";

    // Handle redd.it shortlinks (e.g. redd.it/18x9999 -> old.reddit.com/comments/18x9999)
    if (parsedUrl.hostname.toLowerCase() === "redd.it") {
      const cleanPath = parsedUrl.pathname.replace(/^\/+/, "");
      if (cleanPath && !cleanPath.startsWith("r/") && !cleanPath.startsWith("comments/")) {
        targetUrl.pathname = `/comments/${cleanPath}`;
      }
    }

    return targetUrl.toString();
  }
}

export const redditAdapter = new RedditAdapter();