const searchEngineRegex = /www\.google\.|duckduckgo\.com|www\.bing\.com/;
const fandomRegex = /\.fandom\.com$/;
const breezeWikiRegex = /breezewiki\.pussthecat\.org$|bw\.odyssey346\.dev$|bw\.vern\.cc$|breezewiki\.esmailelbob\.xyz$|bw\.artemislena\.eu$/;
const currentURL = new URL(document.location);

// Create object prototypes for getting and setting attributes:
Object.prototype.get = function (prop) {
  this[prop] = this[prop] || {};
  return this[prop];
};
Object.prototype.set = function (prop, value) {
  this[prop] = value;
}

// Create an observer to watch for mutations
function addLocationObserver(callback) {
  const config = {
    attributes: false,
    childList: true,
    subtree: true
  }
  const observer = new MutationObserver(callback);
  observer.observe(document.body, config);
}

// Load website data
async function getData() {
  const LANGS = ["DE", "EN", "ES", "IT"];
  let sites = [];
  let promises = [];
  for (let i = 0; i < LANGS.length; i++) {
    promises.push(fetch(chrome.runtime.getURL('data/sites' + LANGS[i] + '.json'))
      .then((resp) => resp.json())
      .then(function (jsonData) {
        sites = sites.concat(jsonData);
      }));
  }
  await Promise.all(promises);
  return sites;
}

function displayRedirectBanner(url, destination, storage) {
  // Output banner
  var banner = document.createElement('div');
  banner.id = 'indie-wiki-banner';
  banner.style.fontSize = '1.2em';
  banner.style.fontFamily = 'sans-serif';
  banner.style.width = '100%';
  banner.style.zIndex = '2147483647';
  banner.style.position = 'fixed';
  banner.style.textAlign = 'center';
  banner.style.backgroundColor = '#acdae2';
  banner.style.minHeight = '40px';
  banner.style.lineHeight = '40px';
  var bannerExit = document.createElement('div');
  banner.appendChild(bannerExit);
  bannerExit.style.float = 'right';
  bannerExit.style.paddingRight = '10px';
  bannerExit.style.fontSize = '1.5em';
  bannerExit.style.color = '#333';
  bannerExit.style.cursor = 'pointer';
  bannerExit.innerText = '✕';
  bannerExit.onclick = function () { this.parentElement.remove(); };
  var bannerText = document.createElement('span');
  banner.appendChild(bannerText);
  bannerText.innerHTML = 'There is an independent wiki covering this topic! <br/>'
  var bannerLink = document.createElement('a');
  bannerText.appendChild(bannerLink);
  bannerLink.href = url;
  bannerLink.style.color = 'navy';
  bannerLink.style.fontWeight = '600';
  bannerLink.innerText = 'Visit ' + destination + '→';
  if (document.readyState === 'interactive' || document.readyState === 'complete') {
    document.body.insertAdjacentElement('beforeBegin', banner);
    if (storage.breezewiki === 'on') {
      if (currentURL.hostname.match(breezeWikiRegex)) {
        chrome.storage.sync.set({ 'countAlerts': (storage.countAlerts ?? 0) + 1 });
      }
    } else {
      chrome.storage.sync.set({ 'countAlerts': (storage.countAlerts ?? 0) + 1 });
    }
  } else {
    document.addEventListener('readystatechange', e => {
      if (document.readyState === 'interactive' || document.readyState === 'complete') {
        document.body.insertAdjacentElement('beforeBegin', banner);
        if (storage.breezewiki === 'on') {
          if (currentURL.hostname.match(breezeWikiRegex)) {
            chrome.storage.sync.set({ 'countAlerts': (storage.countAlerts ?? 0) + 1 });
          }
        } else {
          chrome.storage.sync.set({ 'countAlerts': (storage.countAlerts ?? 0) + 1 });
        }
      }
    });
  }
}

function filterSearchResults(fandomSearchResults, searchEngine, storage) {
  getData().then(sites => {
    countFiltered = 0;
    fandomSearchResults.forEach(searchResult => {
      let searchResultLink = '';
      try {
        if (searchEngine === 'bing') {
          searchResultLink = searchResult.innerHTML.replaceAll('<strong>', '').replaceAll('</strong>', '');
        } else {
          searchResultLink = searchResult.closest('[href]').href;
        }
      } catch(e) {
        console.log('Indie Wiki Buddy failed to properly parse search results with error: ' + e);
      }
      // Check if site is in our list of wikis:
      let matchingSites = sites.filter(el => String(searchResultLink).replace(/^https?:\/\//, '').startsWith(el.origin_base_url));
      if (matchingSites.length > 0) {
        // Select match with longest base URL 
        let closestMatch = "";
        matchingSites.forEach(site => {
          if (site.origin_base_url.length > closestMatch.length) {
            closestMatch = site.origin_base_url;
          }
        });
        let site = matchingSites.find(site => site.origin_base_url === closestMatch);
        if (site) {
          // Get user's settings for the wiki
          let settings = storage.siteSettings || {};
          let id = site['id'];
          let searchFilterSetting = 'true';
          if (settings.hasOwnProperty(id) && settings[id].searchFilter) {
            searchFilterSetting = settings[id].searchFilter;
          }
          if (searchFilterSetting === 'true') {
            let cssQuery = '';
            switch (searchEngine) {
              case 'google':
                if (searchResult.closest('div[data-hveid]')) {
                  cssQuery = 'div[data-hveid]';
                }
                break;
              case 'bing':
                if (searchResult.closest('li.b_algo')) {
                  cssQuery = 'li.b_algo';
                }
                break;
              case 'duckduckgo':
                if (searchResult.closest('div.nrn-react-div')) {
                  cssQuery = 'div.nrn-react-div';
                }
                break;
              default:
            }
            if (cssQuery) {
              searchResult.closest(cssQuery).innerHTML = '<i>A Fandom result has been removed by Indie Wiki Buddy. Look for results from <a href="https://' + site.destination_base_url + '">' + site.destination + '</a> instead!</i>';
              countFiltered++;
            }
          }
        }
      }
    });
    chrome.storage.sync.set({ 'countSearchFilters': (storage.countSearchFilters ?? 0) + countFiltered });
  });
}

// Check if search engine results, Fandom, or a BreezeWiki host:
function checkSite() {
  if (currentURL.hostname.match(searchEngineRegex) || currentURL.hostname.match(fandomRegex) || currentURL.hostname.match(breezeWikiRegex)) {
    return true;
  }
}

function main(mutations = null, observer = null) {
  if (observer) {
    observer.disconnect();
  }
  chrome.storage.sync.get(function (storage) {
    // Check if extension is on:
    if ((storage.power ?? 'on') === 'on') {
      // Check if on Fandom or BreezeWiki
      // If on BreezeWiki, check if there is a pathname (which indicates we are looking at a wiki)
      if (currentURL.hostname.match(fandomRegex) || (currentURL.hostname.match(breezeWikiRegex) && currentURL.pathname.length > 1)) {
        // Check if notifications are enabled:
        if ((storage.notifications ?? 'on') === 'on') {
          let origin = currentURL;
          // If on a BreezeWiki site, convert to Fandom link to match with our list of wikis:
          if (currentURL.hostname.match(breezeWikiRegex)) {
            origin = String(currentURL.pathname).split('/')[1] + '.fandom.com/wiki/';
            if (currentURL.search.includes('?q=')) {
              origin = origin + currentURL.search.substring(3).split('&')[0];
            } else {
              origin = origin + currentURL.pathname.split('/')[3];
            }
          }
          getData().then(sites => {
            // Check if site is in our list of wikis:
            let matchingSites = sites.filter(el => String(origin).replace(/^https?:\/\//, '').startsWith(el.origin_base_url));
            if (matchingSites.length > 0) {
              // Select match with longest base URL 
              let closestMatch = "";
              matchingSites.forEach(site => {
                if (site.origin_base_url.length > closestMatch.length) {
                  closestMatch = site.origin_base_url;
                }
              });
              let site = matchingSites.find(site => site.origin_base_url === closestMatch);
              if (site) {
                // Get user's settings for the wiki
                let settings = storage.siteSettings || {};
                let id = site['id'];
                let siteSetting = 'alert';
                if (settings.hasOwnProperty(id) && settings[id].hasOwnProperty('action')) {
                  siteSetting = settings[id].action;
                }
                // Notify if enabled for the wiki:
                if (siteSetting === 'alert') {
                  // Get article name from the end of the URL;
                  // We can't just take the last part of the path due to subpages;
                  // Instead, we take everything after the wiki's base URL + content path:
                  let article = String(origin).split(site['origin_base_url'] + site['origin_content_path'])[1];
                  // Set up URL to redirect user to based on wiki platform:
                  if (article || (!article && !url.href.split(site['origin_base_url'] + '/')[1])) {
                    let newURL = '';
                    if (article) {
                      let searchParams = '';
                      switch (site['destination_platform']) {
                        case 'mediawiki':
                          searchParams = '?title=Special:Search&search=' + article;
                          break;
                        case 'doku':
                          searchParams = 'start?do=search&q=' + article;
                          break;
                      }
                      newURL = 'https://' + site["destination_base_url"] + site["destination_content_path"] + searchParams;
                    } else {
                      newURL = 'https://' + site["destination_base_url"];
                    }
                    // Notify that another wiki is available
                    displayRedirectBanner(newURL, site['destination'], storage);

                    // Unused code to notify user of alternative via browser notification:
                    // let notifID = 'independent-wiki-redirector-notification-' + Math.floor(Math.random() * 1E16);
                    // chrome.notifications.create(notifID, {
                    //   "type": "basic",
                    //   "iconUrl": 'images/logo-48.png',
                    //   "title": "An independent wiki is available!",
                    //   "message": "Check out " + site['destination']
                    // });
                    // chrome.notifications.onClicked.addListener(function () {
                    //   chrome.tabs.update(undefined, { url: newURL });
                    // });
                    // chrome.storage.sync.set({ 'countAlerts': (storage.countAlerts ?? 0) + 1 });
                    // setTimeout(function () { chrome.notifications.clear(notifID); }, 6000);
                  }
                }
              }
            }
          });
        }
      } else if (currentURL.hostname.includes('www.google.')) {
        // Check if doing a Google search:
        function filterGoogle() {
          let fandomSearchResults = document.querySelectorAll("a[href*='fandom.com']>h3, h3>a[href*='fandom.com']");
          filterSearchResults(fandomSearchResults, 'google', storage);
        }
        addLocationObserver(main);
        filterGoogle();
      } else if (currentURL.hostname.includes('duckduckgo.com') && currentURL.search.includes('q=')) {
        // Check if doing a Duck Duck Go search:
        function filterDuckDuckGo() {
          let fandomSearchResults = document.querySelectorAll("h2>a[href*='fandom.com']");
          filterSearchResults(fandomSearchResults, 'duckduckgo', storage);
        }
        // Need to wait for document to be ready
        if (document.readyState === 'complete') {
          addLocationObserver(main);
          filterDuckDuckGo();
        } else {
          document.addEventListener('readystatechange', e => {
            if (document.readyState === 'complete') {
              addLocationObserver(main);
              filterDuckDuckGo();
            }
          });
        }
      } else if (currentURL.hostname.includes('www.bing.com')) {
        // Check if doing a Bing search:
        function filterBing() {
          let fandomSearchResults = Array.from(document.querySelectorAll(".b_attribution>cite")).filter(el => el.innerHTML.includes('fandom.com'));
          filterSearchResults(fandomSearchResults, 'bing', storage);
        }
        // Need to wait for document to be ready
        if (document.readyState === 'complete') {
          addLocationObserver(main);
          filterBing();
        } else {
          document.addEventListener('readystatechange', e => {
            if (document.readyState === 'complete') {
              addLocationObserver(main);
              filterBing();
            }
          });
        }
      }
    }
  });
}

if (checkSite()) {
  main();
}