/*
 * InvidiousAPI.ts
 * Copyleft 2025 James Magahern <buzzert@buzzert.net>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation, either version 3 of the License,
 * or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <https://www.gnu.org/licenses/>.
*/

import fetch from 'node-fetch';

interface InvidiousVideoThumbnail {
  quality: string;
  url: string;
  width: number;
  height: number;
}

interface InvidiousResult {
  type: string;
  title: string;
  videoId: string;
  playlistId: string;
  author: string;
  videoThumbnails?: InvidiousVideoThumbnail[];
}

export interface SearchResult {
  type: string;
  title: string;
  author: string;
  mediaUrl: string;
  thumbnailUrl: string;
}

export interface ThumbnailResponse {
  data: NodeJS.ReadableStream;
  contentType: string;
}

const USE_INVIDIOUS = process.env.USE_INVIDIOUS || true;
const INVIDIOUS_BASE_URL = process.env.INVIDIOUS_BASE_URL || process.env.INVIDIOUS_URL || 'http://invidious.nor';
const INVIDIOUS_API_ENDPOINT = `${INVIDIOUS_BASE_URL}/api/v1`;

export const getInvidiousSearchURL = (query: string): string => 
  `${INVIDIOUS_API_ENDPOINT}/search?q=${encodeURIComponent(query)}`;

export const getInvidiousThumbnailURL = (url: string): string =>
  `${INVIDIOUS_BASE_URL}/${url}`;

const preferredThumbnailAPIURL = (thumbnails: InvidiousVideoThumbnail[] | undefined): string => {
  if (!thumbnails || thumbnails.length === 0) {
    return '/assets/placeholder.jpg';
  }

  const mediumThumbnail = thumbnails.find(t => t.quality === 'medium');
  const thumbnail = mediumThumbnail || thumbnails[0];
  return `/api/thumbnail?url=${encodeURIComponent(thumbnail.url)}`;
};

const getMediaURL = (result: InvidiousResult): string => {
  if (result.type === 'video') {
    return `https://www.youtube.com/watch?v=${result.videoId}`;
  } else if (result.type === 'playlist') {
    return `https://www.youtube.com/playlist?list=${result.playlistId}`;
  }

  throw new Error(`Unknown result type: ${result.type}`);
};

export const searchInvidious = async (query: string): Promise<SearchResult[]> => {
  try {
    const response = await fetch(getInvidiousSearchURL(query));
    if (!response.ok) {
      throw new Error(`Invidious HTTP error: ${response.status}`);
    }

    const data = await response.json() as Array<InvidiousResult>;
    return data.filter(item => {
      return item.type === 'video' || item.type === 'playlist';
    }).map(item => ({
      type: item.type,
      title: item.title,
      author: item.author,
      mediaUrl: getMediaURL(item),
      thumbnailUrl: preferredThumbnailAPIURL(item.videoThumbnails)
    }));
  } catch (error) {
    console.error('Failed to search Invidious:', error);
    throw error;
  }
}

export const fetchThumbnail = async (thumbnailUrl: string): Promise<ThumbnailResponse> => {
  let path = thumbnailUrl;
  if (thumbnailUrl.startsWith('http://') || thumbnailUrl.startsWith('https://')) {
    const url = new URL(thumbnailUrl);
    path = url.pathname + url.search;
  }
  path = path.replace(/^\/+/, ''); // Strip leading slash
  
  const response = await fetch(getInvidiousThumbnailURL(path));
  if (!response.ok) {
    throw new Error(`HTTP error! status: ${response.status}`);
  }

  return {
    data: response.body,
    contentType: response.headers.get('content-type') || 'image/jpeg'
  };
};