//
// view path
//
// Neil Gershenfeld 
// (c) Massachusetts Institute of Technology 2019
// 
// This work may be reproduced, modified, distributed, performed, and 
// displayed for any purpose, but must acknowledge the mods
// project. Copyright is retained and must be preserved. The work is 
// provided as is; no warranty is provided, and users accept all 
// liability.
//
// todo:
//    erase and update new path
//    show depth info
//    show size
//    calculate camera far
//
// closure
//
(function(){
//
// module globals
//
var mod = {}
//
// name
//
var name = 'view path'
//
// initialization
//
var init = function() {
   }
//
// inputs
//
var inputs = {
   path:{type:'',
      event:function(evt){
         mod.path = evt.detail.path
         mod.name = evt.detail.name
         mod.dpi = evt.detail.dpi
         mod.width = evt.detail.width
         mod.height = evt.detail.height
         mod.depth = evt.detail.depth
         show_path_info()
         show_path()
         mods.fit(mod.div)
         outputs.path.event()
         }}}
//
// outputs
//
var outputs = {
   path:{type:'',
      event:function(){
         cmd = {}
         cmd.path = mod.path
         cmd.name = mod.name
         cmd.dpi = mod.dpi
         cmd.width = mod.width
         cmd.height = mod.height
         mods.output(mod,'path',cmd)
         }}}
//
// interface
//
var interface = function(div){
   mod.div = div
   //
   // info
   //
   var text = document.createTextNode('name: ')
      div.appendChild(text)
      mod.nametext = text
   div.appendChild(document.createElement('br'))
   var text = document.createTextNode('(mm)')
      div.appendChild(text)
      mod.mmtext = text
   div.appendChild(document.createElement('br'))
   var text = document.createTextNode('(in)')
      div.appendChild(text)
      mod.intext = text
   //
   // view
   //   
   div.appendChild(document.createElement('br'))   
   var btn = document.createElement('button')
      btn.style.padding = mods.ui.padding
      btn.style.margin = 1
      var span = document.createElement('span')
         var text = document.createTextNode('view')
            span.appendChild(text)
         btn.appendChild(span)
      btn.addEventListener('click',function(){
         open_view_window()
         })
      div.appendChild(btn)
   }
//
// local functions
//
// show_path_info
//
function show_path_info() {
   mod.nametext.nodeValue = 'name: '+mod.name
   var width = (25.4*mod.width/mod.dpi).toFixed(3)
   var height = (25.4*mod.height/mod.dpi).toFixed(3)
   var depth = (25.4*mod.depth/mod.dpi).toFixed(3)
   if (mod.depth == undefined)
      mod.mmtext.nodeValue = width+' x '+height+' (mm)'
   else
      mod.mmtext.nodeValue = width+' x '+height+' x '+depth+' (mm)'
   var width = (mod.width/mod.dpi).toFixed(3)
   var height = (mod.height/mod.dpi).toFixed(3)
   var depth = (mod.depth/mod.dpi).toFixed(3)
   if (mod.depth == undefined)
      mod.intext.nodeValue = width+' x '+height+' (in)'
   else
      mod.intext.nodeValue = width+' x '+height+' x '+depth+' (in)'
   mods.fit(mod.div)
   }
//
// show_path
//
function show_path() {
   var scene = mod.scene
   var camera = mod.camera
   var renderer = mod.renderer
   //
   // check if view window open
   //
   if (mod.win == undefined) {
      open_view_window()
      return
      }
   //
   // check for path
   //
   if (mod.path == undefined)
      return
   //
   // clear scene, leave camera
   //
   var length = scene.children.length
   for (var c = (length-1); c > 1; --c) {
      scene.remove(scene.children[c])
      }
   //
   // fit camera
   //
   mod.thetaxy = 0
   mod.thetaz = 0
   mod.r = mod.height/2
   mod.x0 = mod.width/2
   mod.y0 = mod.height/2
   camera.position.set(mod.x0,mod.y0,mod.r)
   camera.up = new THREE.Vector3(0,1,0)
   camera.lookAt(new THREE.Vector3(mod.x0,mod.y0,0))
   camera.updateProjectionMatrix()
   //
   // draw segments
   //
   var arrow_size = 1+mod.width/200
   var path = mod.path
   for (var segment = 0; segment < path.length; ++segment) {
      if (segment > 0)
         add_arrow(path[segment-1][path[segment-1].length-1],path[segment][0],0xff0000,arrow_size)         
      for (var point = 1; point < path[segment].length; ++point) {
         add_arrow(path[segment][point-1],path[segment][point],0x0000ff,arrow_size)
         }
      }
   //
   // add axes
   //
   var length = mod.height/10
   add_arrow([0,0,0],[length,0,0],0xff0000,arrow_size)
   add_arrow([0,0,0],[0,length,0],0x00ff00,arrow_size)
   add_arrow([0,0,0],[0,0,length],0x0000ff,arrow_size)
   //
   // render
   //
   update()
   //
   // add_arrow
   //
   function add_arrow(start,stop,color,size) {
      var origin = new THREE.Vector3().fromArray(start)
      if (mod.depth == undefined)
         origin.z = 0
      var end  = new THREE.Vector3().fromArray(stop)
      if (mod.depth == undefined)
         end.z = 0
      var length = new THREE.Vector3().subVectors(end,origin).length()
      if (length <= size) {
         add_line(origin,end,color)
         //length = 1.1*size
         return
         }
      var direction = new THREE.Vector3().subVectors(end,origin).normalize()
      var arrow = new THREE.ArrowHelper(direction,origin,length,color,size,size)
      scene.add(arrow)
      }
   //
   // add_line
   //
   function add_line(start,stop,colorhex) {
      var geometry = new THREE.Geometry()
      geometry.vertices.push(start,stop)
      var material = new THREE.LineBasicMaterial({color:colorhex})
      var line = new THREE.Line(geometry,material)
      scene.add(line)
      }
   //
   // update
   //
   function update() {
      renderer.render(scene,camera)
      }
   }
//
// open_view_window
//
function open_view_window() {
   //
   // open window
   //
   win = window.open('')
   mod.win = win
   //
   // load three.js
   //
   var script = document.createElement('script')
   script.type = 'text/javascript'
   script.onload = init_window
   script.src = 'js/three.js/three.min.js'
   mod.div.appendChild(script)
   }
//
// init_window
//
function init_window() {
   //document.write('<script type="text/javascript">'+arg+'</script>')
   //document.close()
   //
   // close button
   //
   var btn = document.createElement('button')
      btn.appendChild(document.createTextNode('close'))
      btn.style.padding = mods.ui.padding
      btn.style.margin = 1
      btn.addEventListener('click',function(){
         mod.win.close()
         mod.win = undefined
         })
      mod.win.document.body.appendChild(btn)
   //
   // label text
   //
   var text = win.document.createTextNode(' left: pan, right: rotate, scroll: zoom')
      mod.win.document.body.appendChild(text)
   //
   // GL container
   //
   mod.win.document.body.appendChild(document.createElement('br'))   
   container = mod.win.document.createElement('div')
   container.style.overflow = 'hidden'
   mod.win.document.body.appendChild(container)
   //
   // event handlers
   //
   container.addEventListener('contextmenu',context_menu)
   container.addEventListener('mousedown',mouse_down)
   container.addEventListener('mouseup',mouse_up)
   container.addEventListener('mousemove',mouse_move)
   container.addEventListener('wheel',mouse_wheel)
   //
   // add scene
   //
   scene = new THREE.Scene()
   mod.scene = scene
   var width = mod.win.innerWidth
   var height = mod.win.innerHeight
   var aspect = width/height
   var near = 0.1
   var far = 1000000
   camera = new THREE.PerspectiveCamera(90,aspect,near,far)
   mod.camera = camera
   scene.add(camera)
   //
   // add renderer
   //
   renderer = new THREE.WebGLRenderer({antialias:true})
   mod.renderer = renderer
   renderer.setClearColor(0xffffff)
   renderer.setSize(width,height)
   container.appendChild(renderer.domElement)
   //
   // show the path if available
   //
   show_path()
   //
   // context_menu
   //
   function context_menu(evt) {
      evt.preventDefault()
      evt.stopPropagation()
      return (false)
      }
   //
   // mouse_down
   //
   function mouse_down(evt) {
      evt.preventDefault()
      evt.stopPropagation()
      mod.button = evt.button
      mod.x = evt.clientX
      mod.y = evt.clientY
      }
   //
   // mouse_up
   //
   function mouse_up(evt) {
      mod.button = undefined
      mod.x = evt.clientX
      mod.y = evt.clientY
      }
   //
   // mouse_move
   //
   function mouse_move(evt) {
      evt.preventDefault()
      evt.stopPropagation()
      var dx = evt.clientX-mod.x
      var dy = evt.clientY-mod.y
      mod.x = evt.clientX
      mod.y = evt.clientY
      if (mod.button == 0) {
         mod.x0 += 
            Math.sin(mod.thetaz)*mod.height*dy/mod.win.innerHeight
            -Math.cos(mod.thetaz)*mod.width*dx/mod.win.innerWidth
         mod.y0 += 
            Math.cos(mod.thetaz)*mod.height*dy/mod.win.innerHeight
            +Math.sin(mod.thetaz)*mod.width*dx/mod.win.innerWidth
         camera.position.x = mod.x0+Math.sin(mod.thetaz)*mod.r*Math.sin(mod.thetaxy)
         camera.position.y = mod.y0+Math.cos(mod.thetaz)*mod.r*Math.sin(mod.thetaxy)
         camera.position.z = mod.r*Math.cos(mod.thetaxy)
         camera.position.z = mod.r*Math.cos(mod.thetaxy)
         camera.up = new THREE.Vector3(Math.sin(mod.thetaz),Math.cos(mod.thetaz),0)
         camera.lookAt(new THREE.Vector3(mod.x0,mod.y0,0))
         camera.updateProjectionMatrix()
         renderer.render(scene,camera)
         }
      else if (mod.button == 2) {
         mod.thetaxy += dy/mod.win.innerHeight
         mod.thetaz += dx/mod.win.innerWidth
         camera.position.x = mod.x0+Math.sin(mod.thetaz)*mod.r*Math.sin(mod.thetaxy)
         camera.position.y = mod.y0+Math.cos(mod.thetaz)*mod.r*Math.sin(mod.thetaxy)
         camera.position.z = mod.r*Math.cos(mod.thetaxy)
         if (Math.cos(mod.thetaxy) > 0)
            camera.up = new THREE.Vector3(Math.sin(mod.thetaz),Math.cos(mod.thetaz),0)
         else
            camera.up = new THREE.Vector3(-Math.sin(mod.thetaz),-Math.cos(mod.thetaz),0)
         camera.lookAt(new THREE.Vector3(mod.x0,mod.y0,0))
         camera.updateProjectionMatrix()
         renderer.render(scene,camera)
         }
      }
   //
   // mouse_wheel
   //
   function mouse_wheel(evt) {
      evt.preventDefault()
      evt.stopPropagation()
      var dy = evt.deltaY/mod.win.innerHeight
      mod.r += mod.height*dy
      camera.position.x = mod.x0+Math.sin(mod.thetaz)*mod.r*Math.sin(mod.thetaxy)
      camera.position.y = mod.y0+Math.cos(mod.thetaz)*mod.r*Math.sin(mod.thetaxy)
      camera.position.z = mod.r*Math.cos(mod.thetaxy)
      camera.lookAt(new THREE.Vector3(mod.x0,mod.y0,0))
      camera.updateProjectionMatrix()
      renderer.render(scene,camera)
      }
   }
//
// return values
//
return ({
   mod:mod,
   name:name,
   init:init,
   inputs:inputs,
   outputs:outputs,
   interface:interface
   })
}())