class AnimSys {
   
    constructor(fps, frame_limit, onions_tint, initial_frame_nb){
      this.fps = fps;
      this.frame_limit = frame_limit;
      this.onions_tint = onions_tint;
      this.initial_frame_nb = initial_frame_nb; 
      this.framesList = [];
      
      this.frameGraphics = createGraphics(width, height);
      this.onionGraphics = createGraphics(width, height);
      
      this.UI = createDiv('');
      this.UI.id('ui-container');
      
      this.createFrame_btn = createButton('<i class="fa-solid fa-circle-plus"></i>');
      this.createFrame_btn.mousePressed(this.create_new_frame.bind(this))
        .attribute('title', 'Create new virgin frame');
      //this.createFrame_btn.parent(this.UI);
      this.createFrame_btn.parent('right-panel');
      
      this.show_onion_btn = createButton('<span class="spec-onions"><i class="fa-regular fa-circle"></i><i class="fa-solid fa-circle"></i><span>');
      this.show_onion_btn.mousePressed(this.switch_onions.bind(this))
        .attribute('title', 'Show onions');
      //this.show_onion_btn.parent(this.UI);
      this.show_onion_btn.parent('right-panel');
      
      this.hide_onion_btn = createButton('<span class="spec-onions"><i class="fa-regular fa-circle"></i><i class="fa-solid fa-circle"></i><span>').hide();
      this.hide_onion_btn.id('hide-onion-btn');
      this.hide_onion_btn.mousePressed(this.switch_onions.bind(this))
        .attribute('title', 'Hide onions');
      //this.hide_onion_btn.parent(this.UI);
      this.hide_onion_btn.parent('right-panel');
      
      this.clear_frame_btn = createButton('<i class="fa-solid fa-hand-sparkles"></i>');
      this.clear_frame_btn.mousePressed(this.clear_frame.bind(this))
        .attribute('title', 'Clear the canvas');
      //this.clear_frame_btn.parent(this.UI);
      this.clear_frame_btn.parent('left-panel');   
      
      this.play_btn = createButton('<i class="fa-solid fa-play"></i>');
      this.play_btn.id('play-btn');
      this.play_btn.mousePressed(this.play_anim.bind(this))
        .attribute('title', 'Play animation');
      //this.play_btn.parent(this.UI);
      this.play_btn.parent('right-panel');
      
      this.stop_btn = createButton('<i class="fa-solid fa-pause"></i>').hide();
      this.stop_btn.id('stop-btn');
      this.stop_btn.mousePressed(this.play_anim.bind(this))
        .attribute('title', 'Pause animation');
      //this.stop_btn.parent(this.UI);
      this.stop_btn.parent('right-panel');
      
      this.timeline = createDiv('timeline');
      this.timeline.id('timeline');
      this.timeline.parent('timeline-ctn');
      
      this.frame_displayed = 0;
      
      this.isPlaying = false;
      this.play_interval = null;
      
      this.showOnions = false;
      
    }
    
    // -----------------------------------------
    // -----------------------------------------
    
    
    update_frame_list(){
      //flush timeline elements
      this.timeline.html('');
      //insert frames + new one in timeline
      for (let [i,frame] of this.framesList.entries()){
        let frameDiv = createDiv(i+1);
        frameDiv.id('frame-number-' + i);
        frameDiv.class('aframe');
        frameDiv.parent(this.timeline);
        frameDiv.mousePressed( () =>{    
          this.display_frame(i);
        })
        redraw();
      } 
    }
    
    // -----------------------------------------
    // -----------------------------------------
    
    
    create_new_frame(data){
      
      if(this.framesList.length == this.frame_limit){
        console.warn('you cannot create more than ' + this.frame_limit + ' frames for this project')
      } else {
          let image64;
          let diff64;  
          if(data){
            image64 = data.image64;
          } else {
            this.frameGraphics.clear();
            this.frameGraphics.loadPixels(); 
            image64 = this.frameGraphics.canvas.toDataURL('image/png');
          }
  
          let new_frame = {
            "img_data": image64,
            "diffused_data": diff64
          };
          this.framesList.push(new_frame);
  
          this.update_frame_list();
  
          if(this.framesList.length > 0){
            this.frame_displayed = this.framesList.length -1;
          }
  
          this.display_frame(this.frame_displayed);
      }    
        
    }
    
    // -----------------------------------------
    // -----------------------------------------
    
    
    display_frame(frame_index){
      
      if(this.isPlaying == true){
        
        if(frame_index == this.framesList.length - 1){
          frame_index = 0;
        } else {       
          frame_index++;
        }
        
      }
      
      this.frame_displayed = frame_index;
      
      let getAllDiv = document.querySelectorAll('.aframe');
      getAllDiv.forEach(aframe => {  
        aframe.classList.remove('current-frame');
      });
      
      let getDiv = select('#frame-number-' + this.frame_displayed);
      getDiv.addClass('current-frame');
  
      if(this.framesList[frame_index].img_data !== undefined){
        
        let display = loadImage(this.framesList[frame_index].img_data, function(){
        
          this.frameGraphics.clear();
          this.frameGraphics.image(display, 0, 0);
  
        }.bind(this));
      
      }
      
      
      if(grAPI !== undefined && grAPI.show_diffused == true){
        
        grAPI.diffusedGraphics.clear();
        
        if(this.framesList[frame_index].diffused_data !== undefined ){
          
          let diff_data = this.framesList[this.frame_displayed].diffused_data;
          
          grAPI.diffusedGraphics.image(diff_data, 0, 0);
          
        }   
      
      }
      
      
      //redraw();
      // ONIONS À TRAITER DANS UNE FUNCTION À PART POUR + D'EFFICACITÉ
          
      
  
      if( (this.isPlaying == false && this.showOnions == true) || (this.isPlaying == true && this.showOnions == true) ){
        
        let onion_index;
      
        if (frame_index == 0){
  
          onion_index = this.framesList.length - 1;
  
        } else {
  
          onion_index = frame_index - 1;
  
        }
        
        let displayOnions = loadImage(this.framesList[onion_index].img_data, function(){
  
          this.onionGraphics.clear();
          this.onionGraphics.tint(255, this.onions_tint);
          this.onionGraphics.image(displayOnions, 0, 0);
          
        }.bind(this));
      }
  
      
      
      
      setTimeout(redraw, 10)
          
    }
    
    // -----------------------------------------
    // -----------------------------------------
    
    update_frame(){
        
      this.frameGraphics.loadPixels();   
      let image64 = this.frameGraphics.canvas.toDataURL('image/png');
      
      let data = {"image64": image64}
      
      if(this.framesList.length == 0){
        
        this.create_new_frame(data);
        
      } else {
        
        this.framesList[this.frame_displayed].img_data = image64;
        
        
      }
      
      setTimeout(redraw, 10)
    }
    
    // -----------------------------------------
    // -----------------------------------------
    
    clear_frame(){ 
      // add here all the graphics layer you need to clear
      grAPI.diffusedGraphics.clear();
      this.framesList[this.frame_displayed].diffused_data = undefined;
      this.frameGraphics.clear();
      this.update_frame();
      //redraw();
    }
    
    // -----------------------------------------
    // -----------------------------------------
    
    switch_onions(){
      if(this.showOnions == false){
        
        this.showOnions = true;
        this.show_onion_btn.hide();
        this.hide_onion_btn.show();
        
      } else {
        
        this.showOnions = false;
        this.hide_onion_btn.hide();
        this.show_onion_btn.show();
      
      }
      if(this.framesList.length != 0){
        setTimeout(function(){
          this.display_frame(this.frame_displayed)
        }.bind(this), 10);
      }
      
      
    }
    
    // -----------------------------------------
    // -----------------------------------------
  
    play_anim(){
      if(this.framesList.length > 0){
        if (this.isPlaying == false){
          if(this.showOnions == true){
            this.switch_onions();
          }
          this.isPlaying = true;
          this.play_interval = setInterval(function(){
              this.display_frame(this.frame_displayed)
            }.bind(this), 1000/this.fps);
          this.play_btn.hide();
          this.stop_btn.show();
        } else {
          clearInterval(this.play_interval);
          this.isPlaying = false;
          this.stop_btn.hide();
          this.play_btn.show();
          
        }
      } else {
        console.log("Create a first capture before playing")
      }
    }
    
  }