/*
 * Copyright 2017 WebAssembly Community Group participants
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

var editorEl = document.querySelector('.editor');
var uploadEl = document.getElementById('upload');
var selectEl = document.getElementById('select');
var uploadInputEl = document.getElementById('uploadInput');
var generateNamesEl = document.getElementById('generateNames');
var foldExprsEl = document.getElementById('foldExprs');
var inlineExportEl = document.getElementById('inlineExport');
var readDebugNamesEl = document.getElementById('readDebugNames');

var options = {mode: 'wast', lineNumbers: true};
var editor = CodeMirror.fromTextArea(editorEl, options);

var fileBuffer = null;

function compile(contents) {
  if (!contents) {
    return;
  }

  var readDebugNames = readDebugNamesEl.checked;
  var generateNames = generateNamesEl.checked;
  var foldExprs = foldExprsEl.checked;
  var inlineExport = inlineExportEl.checked;

  WabtModule().then(function(wabt) {
    try {
      var module = wabt.readWasm(contents, {readDebugNames: readDebugNames});
      if (generateNames) {
        module.generateNames();
        module.applyNames();
      }
      var result =
          module.toText({foldExprs: foldExprs, inlineExport: inlineExport});
      editor.setValue(result);
    } catch (e) {
      editor.setValue(e.toString());
    } finally {
      if (module) module.destroy();
    }
  });
}

function onUploadClicked(e) {
  uploadInput.value = '';
  // See https://developer.mozilla.com/en-US/docs/Web/API/MouseEvent
  var event = new MouseEvent('click', {
    view: window,
    bubbles: true,
    cancelable: true,
  });
  uploadInput.dispatchEvent(event);
}

function onUploadedFile(e) {
  var file = e.target.files[0];
  var reader = new FileReader();
  reader.onload = function(e) {
    fileBuffer = new Uint8Array(e.target.result);
    compile(fileBuffer);
  };
  reader.readAsArrayBuffer(file);
}

function recompileIfChanged(el) {
  el.addEventListener('change', function() { compile(fileBuffer); });
}

function setExample(index) {
  var contents = examples[index].contents;
  fileBuffer = contents;
  compile(contents);
}

function onSelectChanged(e) {
  setExample(this.selectedIndex);
}

uploadEl.addEventListener('click', onUploadClicked);
uploadInputEl.addEventListener('change', onUploadedFile);
recompileIfChanged(generateNamesEl);
recompileIfChanged(foldExprsEl);
recompileIfChanged(inlineExportEl);
recompileIfChanged(readDebugNamesEl);
selectEl.addEventListener('change', onSelectChanged);

for (var i = 0; i < examples.length; ++i) {
  var example = examples[i];
  var option = document.createElement('option');
  option.textContent = example.name;
  selectEl.appendChild(option);
}
selectEl.selectedIndex = 0;
setExample(selectEl.selectedIndex);