export default Ember.Component.extend({
  fileInput: null,
  loading: false,
  expectedRootObjectName: null,
  hover: 0,

  classNames: ["json-uploader"],

  _initialize: function() {
    const $this = this.$();
    const self = this;

    const $fileInput = $this.find("#js-file-input");
    this.set("fileInput", $fileInput[0]);

    $fileInput.on("change", function() {
      self.fileSelected(this.files);
    });

    $this.on("dragover", function(e) {
      if (e.preventDefault) e.preventDefault();
      return false;
    });
    $this.on("dragenter", function(e) {
      if (e.preventDefault) e.preventDefault();
      self.set("hover", self.get("hover") + 1);
      return false;
    });
    $this.on("dragleave", function(e) {
      if (e.preventDefault) e.preventDefault();
      self.set("hover", self.get("hover") - 1);
      return false;
    });
    $this.on("drop", function(e) {
      if (e.preventDefault) e.preventDefault();

      self.set("hover", 0);
      self.fileSelected(e.dataTransfer.files);
      return false;
    });
  }.on("didInsertElement"),

  accept: function() {
    return (
      ".json,application/json,application/x-javascript,text/json" +
      (this.get("extension") ? "," + this.get("extension") : "")
    );
  }.property("extension"),

  setReady: function() {
    let parsed;
    try {
      parsed = JSON.parse(this.get("value"));
    } catch (e) {
      this.set("ready", false);
      return;
    }

    const rootObject = parsed[this.get("expectedRootObjectName")];

    if (rootObject !== null && rootObject !== undefined) {
      this.set("ready", true);
    } else {
      this.set("ready", false);
    }
  }.observes("destination", "expectedRootObjectName"),

  actions: {
    selectFile: function() {
      const $fileInput = $(this.get("fileInput"));
      $fileInput.click();
    }
  },

  fileSelected(fileList) {
    const self = this;
    let files = [];
    for (let i = 0; i < fileList.length; i++) {
      files[i] = fileList[i];
    }
    const fileNameRegex = /\.(json|txt)$/;
    files = files.filter(function(file) {
      if (fileNameRegex.test(file.name)) {
        return true;
      }
      if (file.type === "text/plain") {
        return true;
      }
      return false;
    });
    const firstFile = fileList[0];

    this.set("loading", true);

    let reader = new FileReader();
    reader.onload = function(evt) {
      self.set("value", evt.target.result);
      self.set("loading", false);
    };

    reader.readAsText(firstFile);
  }
});