//
// read text
//
// Neil Gershenfeld 
// (c) Massachusetts Institute of Technology 2017
// 
// 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.
//
// closure
//
(function(){
//
// module globals
//
var mod = {}
//
// name
//
var name = 'read text'
//
// initialization
//
var init = function() {
   mod.text.value = "hello world"
   }
//
// inputs
//
var inputs = {
   text:{type:'',
      event:function(evt) {
         mod.text.value = evt.detail
         }}}
//
// outputs
//
var outputs = {
   text:{type:'',
      event:function(){
         mods.output(mod,'text',mod.text.value)}}}
//
// interface
//
var interface = function(div){
   mod.div = div
   //
   // file input control
   //
   var file = document.createElement('input')
      file.setAttribute('type','file')
      file.setAttribute('id',div.id+'file_input')
      file.style.position = 'absolute'
      file.style.left = 0
      file.style.top = 0
      file.style.width = 0
      file.style.height = 0
      file.style.opacity = 0
      file.addEventListener('change',function() {
         text_read_handler()
         })
      div.appendChild(file)
      mod.file = file
   //
   // text
   //
   var text = document.createElement('textarea')
      text.setAttribute('rows',mods.ui.rows)
      text.setAttribute('cols',mods.ui.cols)
      text.addEventListener('input',function() {
         outputs.text.event()
         })
      div.appendChild(text)
      mod.text = text
   div.appendChild(document.createElement('br'))
   //
   // file select button
   //
   var btn = document.createElement('button')
      btn.style.padding = mods.ui.padding
      btn.style.margin = 1
      btn.appendChild(document.createTextNode('select text file'))
      btn.addEventListener('click',function(){
         var file = document.getElementById(div.id+'file_input')
         file.value = null
         file.click()
         })
      div.appendChild(btn)
   div.appendChild(document.createElement('br'))
   }
//
// local functions
//
// read handler
//
function text_read_handler(event) {
   //
   // read as text
   //
   var file_reader = new FileReader()
   file_reader.onload = text_load_handler
   var input_file = mod.file.files[0]
   file_reader.readAsText(input_file)
   }
//
// load handler
//
function text_load_handler(event) {
   mod.text.value = event.target.result
   outputs.text.event()
   }
//
// return values
//
return ({
   mod:mod,
   name:name,
   init:init,
   inputs:inputs,
   outputs:outputs,
   interface:interface
   })
}())