import { HTTPClient } from "../http/HTTPClient";
import { ProviderError } from "../models/errors";
import { SearchOptions } from "../types/search";
import { KeyManager } from "../utils/KeyManager";
import { BaseProvider } from "./BaseProvider";
import { InternalProviderResult } from "./types/InternalProviderResult";

export const DDG_WEB_SEARCH_URL = "https://html.duckduckgo.com/html/";

export interface DuckDuckGoProviderOptions {
  keys?: string[];
  keyManager?: KeyManager;
  httpClient?: HTTPClient;
  cooldownHours?: number;
}

/**
 * DuckDuckGo Web Search provider implementation.
 * Queries DuckDuckGo HTML web search endpoint and extracts candidate result items.
 * Requires no API keys.
 * Mapped from Python `providers/duckduckgo.py` DuckDuckGoProvider.
 */
export class DuckDuckGoProvider extends BaseProvider {
  public static readonly PROVIDER_NAME = "duckduckgo";
  public static readonly DISPLAY_NAME = "DuckDuckGo";

  private httpClient: HTTPClient;

  constructor(options: DuckDuckGoProviderOptions = {}) {
    super({
      providerName: DuckDuckGoProvider.PROVIDER_NAME,
      displayName: DuckDuckGoProvider.DISPLAY_NAME,
      capabilities: ["web"],
      keys: options.keys,
      keyManager: options.keyManager,
      cooldownHours: options.cooldownHours,
    });
    this.httpClient = options.httpClient ?? new HTTPClient();
  }

  /**
   * Execute web search using DuckDuckGo HTML search endpoint.
   */
  public async search(query: string, options: SearchOptions = {}): Promise<InternalProviderResult[]> {
    if (!query || !query.trim()) {
      return [];
    }

    const cleanQuery = query.trim();
    const numResults = options.numResults ?? 10;

    let response;
    try {
      response = await this.httpClient.post(DDG_WEB_SEARCH_URL, {
        body: `q=${encodeURIComponent(cleanQuery)}`,
        headers: {
          "Content-Type": "application/x-www-form-urlencoded",
          "User-Agent":
            "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36",
        },
      });
    } catch (exc: unknown) {
      const err = exc instanceof Error ? exc : new Error(String(exc));
      throw new ProviderError(`DuckDuckGo web search HTTP request failed: ${err.message}`);
    }

    this._lastHttpResponseBytes = response.buffer?.length ?? Buffer.byteLength(response.text ?? "", "utf-8");

    if (response.statusCode !== 200 || !response.text) {
      throw new ProviderError(
        `DuckDuckGo web search failed with status code ${response.statusCode}`
      );
    }

    const results = this.parseHtmlResults(response.text);
    this._lastRawResultsCount = results.length;
    return this.enforceResultLimit(results, numResults);
  }

  private parseHtmlResults(html: string): InternalProviderResult[] {
    const results: InternalProviderResult[] = [];
    const resultRegex =
      /<a[^>]*class="result__a"[^>]*href="([^"]+)"[^>]*>([\s\S]*?)<\/a>[\s\S]*?(?:<a[^>]*class="result__snippet"[^>]*>([\s\S]*?)<\/a>|<div[^>]*class="result__snippet"[^>]*>([\s\S]*?)<\/div>)/gi;

    let match: RegExpExecArray | null;
    while ((match = resultRegex.exec(html)) !== null) {
      let rawUrl = match[1] || "";
      const rawTitle = match[2] || "";
      const rawSnippet = match[3] || match[4] || "";

      if (rawUrl.includes("uddg=")) {
        try {
          const u = new URL("https://duckduckgo.com" + rawUrl);
          const uddg = u.searchParams.get("uddg");
          if (uddg) rawUrl = uddg;
        } catch {
          // Keep rawUrl
        }
      }

      results.push({
        title: rawTitle,
        url: rawUrl.trim(),
        snippetCandidate: rawSnippet,
        source: this.providerName,
        debug: { snippetSource: "native_snippet" },
      });
    }

    return results;
  }
}

import { HTTPClient } from "../http/HTTPClient";
import { ProviderError } from "../models/errors";
import { SearchOptions } from "../types/search";
import { KeyManager } from "../utils/KeyManager";
import { BaseProvider } from "./BaseProvider";
import { InternalProviderResult } from "./types/InternalProviderResult";

export const DDG_WEB_SEARCH_URL = "https://html.duckduckgo.com/html/";

export interface DuckDuckGoProviderOptions {
  keys?: string[];
  keyManager?: KeyManager;
  httpClient?: HTTPClient;
  cooldownHours?: number;
}

/**
 * DuckDuckGo Web Search provider implementation.
 * Queries DuckDuckGo HTML web search endpoint and extracts candidate result items.
 * Requires no API keys.
 * Mapped from Python `providers/duckduckgo.py` DuckDuckGoProvider.
 */
export class DuckDuckGoProvider extends BaseProvider {
  public static readonly PROVIDER_NAME = "duckduckgo";
  public static readonly DISPLAY_NAME = "DuckDuckGo";

  private httpClient: HTTPClient;

  constructor(options: DuckDuckGoProviderOptions = {}) {
    super({
      providerName: DuckDuckGoProvider.PROVIDER_NAME,
      displayName: DuckDuckGoProvider.DISPLAY_NAME,
      capabilities: ["web"],
      keys: options.keys,
      keyManager: options.keyManager,
      cooldownHours: options.cooldownHours,
    });
    this.httpClient = options.httpClient ?? new HTTPClient();
  }

  /**
   * Execute web search using DuckDuckGo HTML search endpoint.
   */
  public async search(query: string, options: SearchOptions = {}): Promise<InternalProviderResult[]> {
    if (!query || !query.trim()) {
      return [];
    }

    const cleanQuery = query.trim();
    const numResults = options.numResults ?? 10;

    let response;
    try {
      response = await this.httpClient.post(DDG_WEB_SEARCH_URL, {
        body: `q=${encodeURIComponent(cleanQuery)}`,
        headers: {
          "Content-Type": "application/x-www-form-urlencoded",
          "User-Agent":
            "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36",
        },
      });
    } catch (exc: unknown) {
      const err = exc instanceof Error ? exc : new Error(String(exc));
      throw new ProviderError(`DuckDuckGo web search HTTP request failed: ${err.message}`);
    }

    this._lastHttpResponseBytes = response.buffer?.length ?? Buffer.byteLength(response.text ?? "", "utf-8");

    if (response.statusCode !== 200 || !response.text) {
      throw new ProviderError(
        `DuckDuckGo web search failed with status code ${response.statusCode}`
      );
    }

    const results = this.parseHtmlResults(response.text);
    this._lastRawResultsCount = results.length;
    return this.enforceResultLimit(results, numResults);
  }

  private parseHtmlResults(html: string): InternalProviderResult[] {
    const results: InternalProviderResult[] = [];
    const resultRegex =
      /<a[^>]*class="result__a"[^>]*href="([^"]+)"[^>]*>([\s\S]*?)<\/a>[\s\S]*?(?:<a[^>]*class="result__snippet"[^>]*>([\s\S]*?)<\/a>|<div[^>]*class="result__snippet"[^>]*>([\s\S]*?)<\/div>)/gi;

    let match: RegExpExecArray | null;
    while ((match = resultRegex.exec(html)) !== null) {
      let rawUrl = match[1] || "";
      const rawTitle = match[2] || "";
      const rawSnippet = match[3] || match[4] || "";

      if (rawUrl.includes("uddg=")) {
        try {
          const u = new URL("https://duckduckgo.com" + rawUrl);
          const uddg = u.searchParams.get("uddg");
          if (uddg) rawUrl = uddg;
        } catch {
          // Keep rawUrl
        }
      }

      results.push({
        title: rawTitle,
        url: rawUrl.trim(),
        snippetCandidate: rawSnippet,
        source: this.providerName,
        debug: { snippetSource: "native_snippet" },
      });
    }

    return results;
  }
}