// Js_of_ocaml runtime support
// http://www.ocsigen.org/js_of_ocaml/
// Copyright (C) 2014 Hugo Heuzard

// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, with linking exception;
// either version 2.1 of the License, or (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Lesser General Public License for more details.

// You should have received a copy of the GNU Lesser General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

//Provides: caml_gr_state
var caml_gr_state;

//Provides: caml_gr_state_get
//Requires: caml_gr_state
//Requires: caml_named_value, caml_string_of_jsbytes
function caml_gr_state_get() {
  if(caml_gr_state) {
    return caml_gr_state;
  }
  throw [0,caml_named_value("Graphics.Graphic_failure"), caml_string_of_jsbytes("Not initialized")]
}
//Provides: caml_gr_state_set
//Requires: caml_gr_state,caml_gr_state_init
function caml_gr_state_set(ctx) {
  caml_gr_state=ctx;
  caml_gr_state_init()
  return 0;
}

//Provides: caml_gr_open_graph
//Requires: caml_gr_state_create
//Requires: caml_gr_state_set
//Requires: caml_failwith
//Requires: caml_jsstring_of_string
function caml_gr_open_graph(info){
  var g = globalThis;
  var info = caml_jsstring_of_string(info);
  function get(name){
    var res = info.match("(^|,) *"+name+" *= *([a-zA-Z0-9_]+) *(,|$)");
    if(res) return res[2];
  }
  var specs = [];
  if(!(info=="")) specs.push(info);
  var target = get("target");
  if(!target) target="";
  var status = get("status");
  if(!status) specs.push("status=1")

  var w = get("width");
  w = w?parseInt(w):200;
  specs.push("width="+w);

  var h = get("height");
  h = h?parseInt(h):200;
  specs.push("height="+h);

  var win = g.open("about:blank",target,specs.join(","));
  if(!win) {caml_failwith("Graphics.open_graph: cannot open the window")}
  var doc = win.document;
  var canvas = doc.createElement("canvas");
  canvas.width = w;
  canvas.height = h;
  var ctx = caml_gr_state_create(canvas,w,h);
  ctx.set_title = function (title) {
    doc.title = title;
  };
  caml_gr_state_set(ctx);
  var body = doc.body;
  body.style.margin = "0px";
  body.appendChild(canvas);
  return 0;
}

//Provides: caml_gr_state_init
//Requires: caml_gr_state
//Requires: caml_gr_set_color,caml_gr_moveto,caml_gr_resize_window
//Requires: caml_gr_set_line_width,caml_gr_set_text_size,caml_gr_set_font
//Requires: caml_gr_set_window_title
function caml_gr_state_init(){
  caml_gr_moveto(caml_gr_state.x,caml_gr_state.y);
  caml_gr_resize_window(caml_gr_state.width,caml_gr_state.height);
  caml_gr_set_line_width(caml_gr_state.line_width);
  caml_gr_set_text_size(caml_gr_state.text_size);
  caml_gr_set_font(caml_gr_state.font);
  caml_gr_set_color(caml_gr_state.color);
  caml_gr_set_window_title(caml_gr_state.title);
  //caml_gr_resize_window might reset some canvas' properties
  caml_gr_state.context.textBaseline = 'bottom';
}

//Provides: caml_gr_state_create
//Requires: caml_string_of_jsbytes
function caml_gr_state_create(canvas,w,h){
  var context = canvas.getContext("2d");
  return {
    context: context,
    canvas : canvas,
    x : 0,
    y : 0,
    width : w,
    height : h,
    line_width : 1,
    font : caml_string_of_jsbytes("fixed"),
    text_size : 26,
    color : 0x000000,
    title : caml_string_of_jsbytes("")
  };
}

//Provides: caml_gr_doc_of_state
function caml_gr_doc_of_state(state) {
  if(state.canvas.ownerDocument)
    return state.canvas.ownerDocument;
}

//Provides: caml_gr_close_graph
//Requires: caml_gr_state_get
function caml_gr_close_graph(){
  var s = caml_gr_state_get();
  s.canvas.width = 0;
  s.canvas.height = 0;
  return 0;
}

//Provides: caml_gr_set_window_title
//Requires: caml_gr_state_get
//Requires: caml_jsstring_of_string
function caml_gr_set_window_title(name){
  var s = caml_gr_state_get();
  s.title = name;
  var jsname = caml_jsstring_of_string(name);
  if(s.set_title) s.set_title(jsname);
  return 0;
}

//Provides: caml_gr_resize_window
//Requires: caml_gr_state_get
function caml_gr_resize_window(w,h){
  var s = caml_gr_state_get()
  s.width = w;
  s.height = h;
  s.canvas.width = w;
  s.canvas.height = h;
  return 0;
}

//Provides: caml_gr_clear_graph
//Requires: caml_gr_state_get
function caml_gr_clear_graph(){
  var s = caml_gr_state_get();
  s.canvas.width = s.width;
  s.canvas.height = s.height;
  //  s.context.strokeRect (0., 0., s.width, s.height);
  return 0;
}

//Provides: caml_gr_size_x
//Requires: caml_gr_state_get
function caml_gr_size_x(){
  var s = caml_gr_state_get();
  return s.width;
}
//Provides: caml_gr_size_y
//Requires: caml_gr_state_get
function caml_gr_size_y(){
  var s = caml_gr_state_get();
  return s.height;
}


//Provides: caml_gr_set_color
//Requires: caml_gr_state_get
function caml_gr_set_color(color){
  var s = caml_gr_state_get();
  function convert(number) {
    var str = '' + number.toString(16);
    while (str.length < 2) str = '0' + str;
    return str;
  }
  var
  r = (color >> 16) & 0xff,
  g = (color >> 8)  & 0xff,
  b = (color >> 0)  & 0xff;
  s.color=color;
  var c_str = '#' + convert(r) + convert(g) + convert(b);
  s.context.fillStyle =   c_str;
  s.context.strokeStyle = c_str;
  return 0;
}
//Provides: caml_gr_plot
//Requires: caml_gr_state_get
function caml_gr_plot(x,y){
  var s = caml_gr_state_get();
  var im=s.context.createImageData(1,1);
  var d = im.data;
  var color = s.color;
  d[0] = (color >> 16) & 0xff; //r
  d[1] = (color >> 8)  & 0xff, //g
  d[2] = (color >> 0)  & 0xff; //b
  d[3] = 0xFF; //a
  s.x=x;
  s.y=y;
  s.context.putImageData(im,x,s.height - y);
  return 0;
}

//Provides: caml_gr_point_color
//Requires: caml_gr_state_get
function caml_gr_point_color(x,y){
  var s = caml_gr_state_get();
  var im=s.context.getImageData(x,s.height - y,1,1);
  var d = im.data;
  return (d[0] << 16) + (d[1] << 8) + d[2];
}
//Provides: caml_gr_moveto
//Requires: caml_gr_state_get
function caml_gr_moveto(x,y){
  var s = caml_gr_state_get();
  s.x=x;
  s.y=y;
  return 0;
}

//Provides: caml_gr_current_x
//Requires: caml_gr_state_get
function caml_gr_current_x(){
  var s = caml_gr_state_get();
  return s.x
}
//Provides: caml_gr_current_y
//Requires: caml_gr_state_get
function caml_gr_current_y(){
  var s = caml_gr_state_get();
  return s.y
}
//Provides: caml_gr_lineto
//Requires: caml_gr_state_get
function caml_gr_lineto(x,y){
  var s = caml_gr_state_get();
  s.context.beginPath();
  s.context.moveTo(s.x,s.height - s.y);
  s.context.lineTo(x,s.height - y);
  s.context.stroke();
  s.x=x;
  s.y=y;
  return 0;
}
//Provides: caml_gr_draw_rect
//Requires: caml_gr_state_get
function caml_gr_draw_rect(x,y,w,h){
  var s = caml_gr_state_get();
  s.context.strokeRect(x,s.height - y,w,-h);
  return 0;
}

//Provides: caml_gr_arc_aux
function caml_gr_arc_aux(ctx,cx,cy,ry,rx,a1,a2){
  while(a1>a2) a2+=360;
  a1 /= 180;
  a2 /= 180;
  var rot = 0,xPos,yPos,xPos_prev,yPos_prev;
  var space = 2;
  var num = (((a2 - a1) * Math.PI * ((rx+ry)/2)) / space) | 0;
  var delta = (a2 - a1) * Math.PI / num;
  var i = a1 * Math.PI;
  for (var j=0;j<=num;j++){
    xPos = cx - (rx * Math.sin(i)) * Math.sin(rot * Math.PI) + (ry * Math.cos(i)) * Math.cos(rot * Math.PI);
    xPos = xPos.toFixed(2);
    yPos = cy + (ry * Math.cos(i)) * Math.sin(rot * Math.PI) + (rx * Math.sin(i)) * Math.cos(rot * Math.PI);
    yPos = yPos.toFixed(2);
    if (j==0) {
      ctx.moveTo(xPos, yPos);
    } else if (xPos_prev!=xPos || yPos_prev!=yPos){
      ctx.lineTo(xPos, yPos);
    }
    xPos_prev=xPos;
    yPos_prev=yPos;
    i-= delta;//ccw
  }
  return 0;
}


//Provides: caml_gr_draw_arc
//Requires: caml_gr_state_get, caml_gr_arc_aux
function caml_gr_draw_arc(x,y,rx,ry,a1,a2){
  var s = caml_gr_state_get();
  s.context.beginPath();
  caml_gr_arc_aux(s.context,x,s.height - y,rx,ry,a1,a2);
  s.context.stroke();
  return 0;
}

//Provides: caml_gr_set_line_width
//Requires: caml_gr_state_get
function caml_gr_set_line_width(w){
  var s = caml_gr_state_get();
  s.line_width = w;
  s.context.lineWidth = w
  return 0;
}

//Provides: caml_gr_fill_rect
//Requires: caml_gr_state_get
function caml_gr_fill_rect(x,y,w,h){
  var s = caml_gr_state_get();
  s.context.fillRect(x,s.height - y,w,-h);
  return 0;
}
//Provides: caml_gr_fill_poly
//Requires: caml_gr_state_get
function caml_gr_fill_poly(ar){
  var s = caml_gr_state_get();
  s.context.beginPath();
  s.context.moveTo(ar[1][1],s.height - ar[1][2]);
  for(var i = 2; i < ar.length; i++)
    s.context.lineTo(ar[i][1],s.height - ar[i][2]);
  s.context.lineTo(ar[1][1],s.height - ar[1][2]);
  s.context.fill();
  return 0;
}

//Provides: caml_gr_fill_arc
//Requires: caml_gr_state_get, caml_gr_arc_aux
function caml_gr_fill_arc(x,y,rx,ry,a1,a2){
  var s = caml_gr_state_get();
  s.context.beginPath();
  caml_gr_arc_aux(s.context,x,s.height - y,rx,ry,a1,a2);
  s.context.fill();
  return 0;
}

//Provides: caml_gr_draw_str
//Requires: caml_gr_state_get
function caml_gr_draw_str(str){
  var s = caml_gr_state_get();
  var m = s.context.measureText(str);
  var dx = m.width;
  s.context.fillText(str,s.x,s.height - s.y);
  s.x += dx | 0;
  return 0;
}

//Provides: caml_gr_draw_char
//Requires: caml_gr_draw_str
function caml_gr_draw_char(c){
  caml_gr_draw_str(String.fromCharCode(c));
  return 0;
}

//Provides: caml_gr_draw_string
//Requires: caml_gr_draw_str
//Requires: caml_jsstring_of_string
function caml_gr_draw_string(str){
  caml_gr_draw_str(caml_jsstring_of_string(str));
  return 0;
}

//Provides: caml_gr_set_font
//Requires: caml_gr_state_get
//Requires: caml_jsstring_of_string
function caml_gr_set_font(f){
  var s = caml_gr_state_get();
  s.font = f;
  s.context.font = s.text_size + "px " + caml_jsstring_of_string(s.font);
  return 0;
}

//Provides: caml_gr_set_text_size
//Requires: caml_gr_state_get
//Requires: caml_jsstring_of_string
function caml_gr_set_text_size(size){
  var s = caml_gr_state_get();
  s.text_size = size;
  s.context.font = s.text_size + "px " + caml_jsstring_of_string(s.font);
  return 0;
}

//Provides: caml_gr_text_size
//Requires: caml_gr_state_get
//Requires: caml_jsstring_of_string
function caml_gr_text_size(txt){
  var s = caml_gr_state_get();
  var w = s.context.measureText(caml_jsstring_of_string(txt)).width;
  return [0,w,s.text_size];
}


//Provides: caml_gr_make_image
//Requires: caml_gr_state_get
function caml_gr_make_image(arr){
  var s = caml_gr_state_get();
  var h = arr.length - 1 ;
  var w = arr[1].length - 1;
  var im = s.context.createImageData(w,h);
  for(var i=0;i<h;i++){
    for(var j=0;j<w;j++){
      var c = arr[i+1][j+1];
      var o = i*(w*4) + (j * 4);
      if(c == -1) {
        im.data[o + 0] = 0;
        im.data[o + 1] = 0;
        im.data[o + 2] = 0;
        im.data[o + 3] = 0;
      } else {
        im.data[o + 0] = c >> 16 & 0xff;
        im.data[o + 1] = c >>  8 & 0xff;
        im.data[o + 2] = c >>  0 & 0Xff;
        im.data[o + 3] = 0xff;
      }
    }
  }
  return im
}
//Provides: caml_gr_dump_image
//Requires: caml_gr_state_get
function caml_gr_dump_image(im){
  var data = [0]
  for(var i=0; i<im.height;i++){
    data[i+1] = [0]
    for(var j=0; j<im.width;j++){
      var o = i*(im.width*4) + (j * 4),
          r = im.data[o+0],
          g = im.data[o+1],
          b = im.data[o+2];
      data[i+1][j+1] = (r << 16) + (g << 8) + b
    }
  }
  return data
}
//Provides: caml_gr_draw_image
//Requires: caml_gr_state_get
function caml_gr_draw_image(im,x,y){
  var s = caml_gr_state_get();
  if(!im.image) {
    var canvas = document.createElement("canvas");
    canvas.width = s.width;
    canvas.height = s.height;
    canvas.getContext("2d").putImageData(im,0,0);
    var image = new globalThis.Image();
    image.onload = function () {
      s.context.drawImage(image,x,s.height - im.height - y);
      im.image = image;
    }
    image.src = canvas.toDataURL("image/png");
  } else {
    s.context.drawImage(im.image,x,s.height - im.height - y);
  }
  return 0;
}
//Provides: caml_gr_create_image
//Requires: caml_gr_state_get
function caml_gr_create_image(x,y){
  var s = caml_gr_state_get();
  return s.context.createImageData(x,y);
}
//Provides: caml_gr_blit_image
//Requires: caml_gr_state_get
function caml_gr_blit_image(im,x,y){
  var s = caml_gr_state_get();
  var im2 = s.context.getImageData(x,s.height - im.height - y,im.width,im.height);
  for (var i = 0; i < im2.data.length; i+=4){
    im.data[i] = im2.data[i];
    im.data[i+1] = im2.data[i+1];
    im.data[i+2] = im2.data[i+2];
    im.data[i+3] = im2.data[i+3];
  }
  return 0;
}
//Provides: caml_gr_sigio_handler
function caml_gr_sigio_handler(){return 0}
//Provides: caml_gr_sigio_signal
function caml_gr_sigio_signal(){return 0}
//Provides: caml_gr_wait_event
//Requires: caml_failwith
function caml_gr_wait_event(_evl){
  caml_failwith("caml_gr_wait_event not Implemented: use Graphics_js instead");
}

//Provides: caml_gr_synchronize
//Requires: caml_failwith
function caml_gr_synchronize () {
  caml_failwith("caml_gr_synchronize not Implemented");
}
//Provides: caml_gr_remember_mode
//Requires: caml_failwith
function caml_gr_remember_mode () {
  caml_failwith("caml_gr_remember_mode not Implemented");
}
//Provides: caml_gr_display_mode
//Requires: caml_failwith
function caml_gr_display_mode() {
  caml_failwith("caml_gr_display_mode not Implemented");
}

//Provides: caml_gr_window_id
//Requires: caml_failwith
function caml_gr_window_id(a) {
  caml_failwith("caml_gr_window_id not Implemented");
}

//Provides: caml_gr_open_subwindow
//Requires: caml_failwith
function caml_gr_open_subwindow(a,b,c,d) {
  caml_failwith("caml_gr_open_subwindow not Implemented");
}

//Provides: caml_gr_close_subwindow
//Requires: caml_failwith
function caml_gr_close_subwindow(a) {
  caml_failwith("caml_gr_close_subwindow not Implemented");
}