globalThis.mum = {};

var panel;

var selected = undefined;

mum.inputs = {};
mum.inputs.lm = function()
{
  if (!selected) return;
  if (!selected.action) return;
  selected.action();
}

mum.base = {
  pos: null, // If set, puts the cursor to this position before drawing the element
  offset:[0,0], // Move x,y to the right and down before drawing
  padding:[0,0], // Pad inwards after drawing, to prepare for the next element  
  font: "fonts/c64.ttf",
  selectable: false,
  selected: false,
  font_size: 16,
  scale: 1,
  angle: 0,
  inset: null,
  anchor: [0,1], // where to draw the item from, relative to the cursor. [0,1] is from the top left corner. [1,0] is from the bottom right
  background_image: null,
  slice: null,
  hover: {
    color: Color.red,
  },
  text_shadow: {
    pos: [0,0],
    color: Color.white,
  },
  border: 0, // Draw a border around the element. For text, an outline.
  overflow: "wrap", // how to deal with overflow from parent element
  wrap: -1,
  text_align: "left", /* left, center, right */
  shader: null, // Use this shader, instead of the engine provided one
  color: Color.white,
  opacity:1,
  width:0,
  height:0,
  max_width: Infinity,
  max_height: Infinity,
  image_repeat: false,
  image_repeat_offset: [0,0],
  debug: false, /* set to true to draw debug boxes */
  hide: false,
  tooltip: null,
}

// data is passed into each function, and various stats are generated
// drawpos: the point to start the drawing from
// wh: an array of [width,height]
// bound: a boundingbox around the drawn UI element
// extent: a boundingbox around the total extents of the element (ie before padding)

function show_debug() { return prosperon.debug && mum.debug; }

mum.debug = false;

var post = function() {};
var posts = [];

mum.style = mum.base;

var cursor = [0,0];

var pre = function(data)
{
  if (data.hide) return true;
  data.__proto__ = mum.style;
  
  if (data.pos) cursor = data.pos.slice();
  data.drawpos = cursor.slice().add(data.offset);

  if (data.opacity !== 1) {
    data.color = data.color.slice();
    data.color[3] = data.opacity;
  }

  data.wh = [data.width,data.height];
}

var anchor_calc = function(data)
{
  var aa = [0,1].sub(data.anchor);
  data.drawpos = data.drawpos.add([data.width,data.height]).scale(aa);
}

var end = function(data)
{
  cursor = cursor.add(data.padding);
  post(data);
}

mum.list = function(fn, data = {})
{
  if (pre(data)) return;
  var aa = [0,1].sub(data.anchor);
  cursor = cursor.add([data.width,data.height].scale(aa)).add(data.offset).add(data.padding);

  posts.push(post);
  post = mum.list.post.bind(data);
  
  if (show_debug())
    render.boundingbox({
      t:cursor.y,
      b:cursor.y-data.height,
      l:cursor.x,
      r:cursor.x+data.width
    });
    
  //if (data.background_image) mum.image(null, Object.create(data)) 
  if (data.background_image) {
    var imgpos = data.pos.slice();
    imgpos.y -= data.height/2;
    imgpos.x -= data.width/2;
    var imgscale = [data.width,data.height];
    if (data.slice)
      render.slice9(game.texture(data.background_image), imgpos, data.slice, imgscale);
    else
      render.image(game.texture(data.background_image), imgpos, [data.width,data.height]);
  }
    
  fn();
  
  data.bb.l -= data.padding.x;
  data.bb.r += data.padding.x;
  data.bb.t += data.padding.y;
  data.bb.b -= data.padding.y;

  if (show_debug())
    render.boundingbox(data.bb);

  post = posts.pop();
  end(data);
}

mum.list.post = function(e)
{
  cursor.y -= (e.bb.t - e.bb.b);
  cursor.y -= e.padding.y;
  
  if (this.bb)
    this.bb = bbox.expand(this.bb,e.bb)
  else
    this.bb = e.bb;
}

mum.label = function(str, data = {})
{
  if (pre(data)) return;

  render.set_font(data.font, data.font_size);
 
  data.bb = render.text_bb(str, data.scale, -1, cursor);
  data.wh = bbox.towh(data.bb);
  
  var aa = [0,1].sub(data.anchor);  
  
  data.drawpos.y -= (data.bb.t-cursor.y);
  data.drawpos = data.drawpos.add(data.wh.scale(aa)).add(data.offset);

  data.bb = render.text_bb(str, data.scale, data.wrap, data.drawpos);

  if (data.action && bbox.pointin(data.bb, input.mouse.screenpos())) {
    if (data.hover) {
      data.hover.__proto__ = data;
      data = data.hover;
      selected = data;
    }
  }

  data.bb = render.text(str, data.drawpos, data.scale, data.color, data.wrap);
    
  if (show_debug())
    render.boundingbox(data.bb);
  
  end(data);
}

mum.image = function(path, data = {})
{
  if (pre(data)) return;
  path ??= data.background_image;
  var tex = path;
  if (typeof path === 'string')
    tex = game.texture(path);

  if (!data.height)
    if (data.width)
      data.height = tex.height * (data.width/tex.width);
    else
      data.height = tex.height;

  if (!data.width)
    if (data.height)
      data.width = tex.width * (data.height/tex.height);
    else
      data.height = tex.height;


    
  if (!data.width) data.width = tex.width;
  if (!data.height) data.height = tex.height;

  var aa = [0,1].sub(data.anchor);
  data.drawpos = data.drawpos.add(aa.scale([data.width,data.height]));
  
  if (data.slice)
    render.slice9(tex, data.drawpos, data.slice, [data.width,data.height]);
  else
    data.bb = render.image(tex, data.drawpos, [data.width, data.height]);
  
  end(data);
}

mum.rectangle = function(data = {})
{
  if (pre(data)) return;
  var aa = [0,0].sub(data.anchor);
  data.drawpos = data.drawpos.add(aa.scale([data.width,data.height]));
 
  render.rectangle(data.drawpos, data.drawpos.add([data.width,data.height]), data.color);

  end(data);
}

var btnbb;
var btnpost = function()
{
  btnbb = data.bb;
}

mum.button = function(str, data = {padding:[4,4], color:Color.black})
{
  if (pre(data)) return;
  posts.push(post);
  post = btnpost;
  if (typeof str === 'string')
    render.text(str, cursor.add(data.padding), data.scale, data.color);
  else
    str();

  if (data.action && data.hover && bbox.pointin(btnbb, input.mouse.screenpos())) {
    data.hover.__proto__ = data;
    data = data.hover;
  }
  render.rectangle([btnbb.l-data.padding.x, btnbb.b-data.padding.y], [btnbb.r+data.padding.y, btnbb.t+data.padding.y], data.color);
  data.bb = btnbb;

  post = posts.pop();
  end(data);
}

mum.window = function(fn, data = {})
{
  if (pre(data)) return;

  render.rectangle(cursor, cursor.add(data.size), data.color);
  cursor.y += data.height;
  cursor = cursor.add(data.padding);
  fn();
  end(data);
}

mum.ex_hud = function()
{
  mum.label("TOP LEFT", {pos:[0,game.size.y], anchor:[0,1]});
  mum.label("BOTTOM LEFT", {pos:[0,0], anchor:[0,0]});
  mum.label("TOP RIGHT", {pos:game.size, anchor:[1,1]});
  mum.label("BOTTOM RIGHT", {pos:[game.size.x, 0], anchor:[1,0]});
}