/* Get correct download button by OS */
let ready = ( callback ) => {
  if ( document.readyState != "loading" ) callback();
  else document.addEventListener( "DOMContentLoaded", callback );
}

ready( () => {
  let downloader = document.getElementsByClassName( 'downloader' );

  for ( let element of downloader ) {
    let version = element.dataset.version;

    if ( version == '0.49.19.1' ) {
      let url = "https://github.com/MegaMek/mekhq/releases/download/v" + version + "/MekHQ-" + version + ".tar.gz";
      let platform = "<i class='fab fa-linux'></i> Linux/Unix";

      if ( navigator.userAgent.indexOf( "Win" ) != -1 ) {
        url = "https://github.com/MegaMek/mekhq/releases/download/v" + version + "/mekhq-windows-" + version + ".zip";
        platform = "<i class='fab fa-windows'></i> Windows";
      } else if ( navigator.userAgent.indexOf( "Mac OS X" ) != -1 ) {
        platform = "<i class='fab fa-apple'></i> Mac OSX";
      }

      updateDownloadLinks( element, version, url, platform );
    } else {
      let url = "https://github.com/MegaMek/mekhq/releases/download/v" + version + "/MekHQ-" + version + ".tar.gz";
      updateDownloadLinks( element, version, url, null );
    }

  }

  loadDownloadStats( "megamek-download-stats", "megamek" );
  loadDownloadStats( "megameklab-download-stats", "megameklab" );
  loadDownloadStats( "mekhq-download-stats", "mekhq" );

  setInterval( function () { loadXMLDoc(); }, 1000 );
} );

function updateDownloadLinks( element, version, url, platform ) {
  let downloadLink = element.getElementsByClassName( 'download_link' )[ 0 ];
  let versionText = element.getElementsByClassName( 'version_display' )[ 0 ];
  let platformText = element.getElementsByClassName( 'version_platform' )[ 0 ];

  downloadLink.href = url;
  versionText.innerHTML = version;

  if ( platformText ) {
    platformText.innerHTML = platform;
  }
}

function isDarkModeEnabled() {
  return window.matchMedia && window.matchMedia( '(prefers-color-scheme: dark)' ).matches
}

const toggleSwitch = document.querySelector( '.theme-switch input[type="checkbox"]' );
toggleSwitch.addEventListener( 'change', switchTheme, false );

function switchTheme( e ) {
  if ( e.target.checked ) {
    document.documentElement.setAttribute( 'data-theme', 'dark' );
    localStorage.setItem( 'theme', 'dark' ); //add this
  }
  else {
    document.documentElement.setAttribute( 'data-theme', 'light' );
    localStorage.setItem( 'theme', 'light' ); //add this
  }
}

const currentTheme = localStorage.getItem( 'theme' ) ? localStorage.getItem( 'theme' ) : null;

if ( currentTheme ) {
  document.documentElement.setAttribute( 'data-theme', currentTheme );

  if ( currentTheme === 'dark' ) {
    toggleSwitch.checked = true;
  }
} else if ( isDarkModeEnabled() ) {
  toggleSwitch.checked = true
  document.documentElement.setAttribute( 'data-theme', 'dark' );
}

function loadDownloadStats( elementId, repoName ) {
  let element = document.getElementById( elementId );

  if ( element ) {
    fetch( "https://api.github.com/repos/megamek/" + repoName + "/releases" )
      .then( ( response ) => response.json() )
      .then( ( response ) => addStatsToElement( element, response ) )
      .catch( ( error ) => console.log( error ) );
  }
}

function addStatsToElement( element, releases ) {
  while ( element.lastChild ) { element.removeChild( element.lastChild ) };

  releases.forEach( ( release ) => {
    let child = document.createElement( "li" );
    let text = "<strong>" + release.tag_name + "</strong>";
    let totalDownloads = 0;

    release.assets.forEach( ( asset ) => {
      totalDownloads += asset.download_count;
    } )

    text += ": <span class='float-right'>" + totalDownloads + "</span>";

    child.className = "list-group-item";
    child.innerHTML = text;
    element.appendChild( child );
  } );
}

function loadXMLDoc() {
  let servers = document.getElementById( "servers" )

  if ( servers ) {
    fetch( 'https://api.megamek.org/servers.js' )
      .then( ( response ) => response.text() )
      .then( ( response ) => {
        servers.innerHTML = response;
      } )
  }
}