// ==UserScript==
// @name     Breizh autoplay
// @version  1
// @grant    none
// @include  https://fichiers.breizh.pm/*
// ==/UserScript==

function ap_next(event) {
  let item = event.target;
  let autoplay = document.getElementById("ap-autoplay").checked;
  let random = document.getElementById("ap-random").checked;
  let loop = document.getElementById("ap-loop").checked;
  let currentId = medias.indexOf(item);
  let nextId = -1;
  
  // If no autoplay, exit
  if(!autoplay) return;
  
  // If function applied to something that is not an audio song, exit
  // Note that this should not happen in a regular use
  if(currentId == -1) return;
  
  // If random, pick a random song in the list
  // Else pick the next one
  if(random) {
    nextId = Math.floor(Math.random() * medias.length);
  } else {
    nextId = currentId + 1;
  }
  
  // If looping, stay in the range
  if(loop) {
    nextId %= medias.length;
  }
  
  // If the next song is out, exit
  if(nextId == medias.length) return;
  
  // Finally, set the volume back and jump to the selected song
  medias[nextId].volume = item.volume;
  medias[nextId].play();
}

// Get all audio medias on the page
let medias = Array.from(document.querySelectorAll("audio"));

// If there is at least one media
if(medias.length > 0) {
  // Create the menu
  var ap_menu = document.createElement("div");
  ap_menu.id = "ap-menu";
  ap_menu.innerHTML = `<label for="ap-autoplay">Autoplay</label><input type="checkbox" id="ap-autoplay" />
  <label for="ap-random">Aléatoire</label><input type="checkbox" id="ap-random" />
  <label for="ap-loop">Boucle</label><input type="checkbox" id="ap-loop" />`;
  document.querySelector("body").insertBefore(ap_menu, document.getElementById("maintable"));

  // Apply the event listener to all medias
  medias.map(function(e) {
    e.addEventListener("ended", ap_next);
  });
}