var Item = require('./Item');

/**
 * @constructor PointItem
 * @extends Item
 * @param {Object} data             Object containing parameters start
 *                                  content, className.
 * @param {{toScreen: function, toTime: function}} conversion
 *                                  Conversion functions from time to screen and vice versa
 * @param {Object} [options]        Configuration options
 *                                  // TODO: describe available options
 */
function PointItem (data, conversion, options) {
  this.props = {
    dot: {
      top: 0,
      width: 0,
      height: 0
    },
    content: {
      height: 0,
      marginLeft: 0,
      marginRight: 0
    }
  };
  this.options = options;
  // validate data
  if (data) {
    if (data.start == undefined) {
      throw new Error('Property "start" missing in item ' + data);
    }
  }

  Item.call(this, data, conversion, options);
}

PointItem.prototype = new Item (null, null, null);

/**
 * Check whether this item is visible inside given range
 * @param {{start: number, end: number}} range with a timestamp for start and end
 * @returns {boolean} True if visible
 */
PointItem.prototype.isVisible = function(range) {
  // determine visibility
  var widthInMs = this.width * range.getMillisecondsPerPixel();
  
  return (this.data.start.getTime() + widthInMs > range.start ) && (this.data.start < range.end);
};


PointItem.prototype._createDomElement = function() {
  if (!this.dom) {
    // create DOM
    this.dom = {};

    // background box
    this.dom.point = document.createElement('div');
    // className is updated in redraw()

    // contents box, right from the dot
    this.dom.content = document.createElement('div');
    this.dom.content.className = 'vis-item-content';
    this.dom.point.appendChild(this.dom.content);

    // dot at start
    this.dom.dot = document.createElement('div');
    this.dom.point.appendChild(this.dom.dot);

    // attach this item as attribute
    this.dom.point['timeline-item'] = this;

    this.dirty = true;
  }
}

PointItem.prototype._appendDomElement = function() {
  if (!this.parent) {
    throw new Error('Cannot redraw item: no parent attached');
  }
  if (!this.dom.point.parentNode) {
    var foreground = this.parent.dom.foreground;
    if (!foreground) {
      throw new Error('Cannot redraw item: parent has no foreground container element');
    }
    foreground.appendChild(this.dom.point);
  }
  this.displayed = true;
}

PointItem.prototype._updateDirtyDomComponents = function() {
  // An item is marked dirty when:
  // - the item is not yet rendered
  // - the item's data is changed
  // - the item is selected/deselected
  if (this.dirty) {
    this._updateContents(this.dom.content);
    this._updateDataAttributes(this.dom.point);
    this._updateStyle(this.dom.point);

    var editable = (this.editable.updateTime || this.editable.updateGroup);
    // update class
    var className = (this.data.className ? ' ' + this.data.className : '') +
        (this.selected ? ' vis-selected' : '') +
        (editable ? ' vis-editable' : ' vis-readonly');
    this.dom.point.className  = 'vis-item vis-point' + className;
    this.dom.dot.className  = 'vis-item vis-dot' + className;
  }
}

PointItem.prototype._getDomComponentsSizes = function() {
  return {
    dot:  {
      width: this.dom.dot.offsetWidth,
      height: this.dom.dot.offsetHeight
    },
    content: {
      width: this.dom.content.offsetWidth,
      height: this.dom.content.offsetHeight
    },
    point: {
      width: this.dom.point.offsetWidth,
      height: this.dom.point.offsetHeight
    }
  }
}

PointItem.prototype._updateDomComponentsSizes = function(sizes) {
  // recalculate size of dot and contents
  this.props.dot.width = sizes.dot.width;
  this.props.dot.height = sizes.dot.height;
  this.props.content.height = sizes.content.height;

  // resize contents
  if (this.options.rtl) {
    this.dom.content.style.marginRight = 2 * this.props.dot.width + 'px';
  } else {
    this.dom.content.style.marginLeft = 2 * this.props.dot.width + 'px';
  }
  //this.dom.content.style.marginRight = ... + 'px'; // TODO: margin right

  // recalculate size
  this.width = sizes.point.width;
  this.height = sizes.point.height;

  // reposition the dot
  this.dom.dot.style.top = ((this.height - this.props.dot.height) / 2) + 'px';
  if (this.options.rtl) {
    this.dom.dot.style.right = (this.props.dot.width / 2) + 'px';
  } else {
    this.dom.dot.style.left = (this.props.dot.width / 2) + 'px';
  }

  this.dirty = false;
}

PointItem.prototype._repaintDomAdditionals = function() {
  this._repaintOnItemUpdateTimeTooltip(this.dom.point);
  this._repaintDragCenter();
  this._repaintDeleteButton(this.dom.point);
}

/**
 * Repaint the item
 * @param {boolean} [returnQueue=false]  return the queue
 * @return {boolean} the redraw queue if returnQueue=true
 */
PointItem.prototype.redraw = function(returnQueue) {
  var sizes
  var queue = [
    // create item DOM
    this._createDomElement.bind(this),

    // append DOM to parent DOM
    this._appendDomElement.bind(this),

    // update dirty DOM
    this._updateDirtyDomComponents.bind(this),

    (function() {
      if (this.dirty) {
        sizes = this._getDomComponentsSizes();
      }
    }).bind(this),

    (function() {
      if (this.dirty) {
        this._updateDomComponentsSizes.bind(this)(sizes);
      }
    }).bind(this),

    // repaint DOM additionals
    this._repaintDomAdditionals.bind(this)
  ];

  if (returnQueue) {
    return queue;
  } else {
    var result;
    queue.forEach(function (fn) {
      result = fn();
    });
    return result;
  }
};

/**
 * Show the item in the DOM (when not already visible). The items DOM will
 * be created when needed.
 * @param {boolean} [returnQueue=false]  whether to return a queue of functions to execute instead of just executing them
 * @return {boolean} the redraw queue if returnQueue=true
 */
PointItem.prototype.show = function(returnQueue) {
  if (!this.displayed) {
    return this.redraw(returnQueue);
  }
};

/**
 * Hide the item from the DOM (when visible)
 */
PointItem.prototype.hide = function() {
  if (this.displayed) {
    if (this.dom.point.parentNode) {
      this.dom.point.parentNode.removeChild(this.dom.point);
    }

    this.displayed = false;
  }
};

/**
 * Reposition the item horizontally
 * @Override
 */
PointItem.prototype.repositionX = function() {
  var start = this.conversion.toScreen(this.data.start);

  if (this.options.rtl) {
    this.right = start - this.props.dot.width;

    // reposition point
    this.dom.point.style.right = this.right + 'px';
  } else {
    this.left = start - this.props.dot.width;

    // reposition point
    this.dom.point.style.left = this.left + 'px';
  }
};

/**
 * Reposition the item vertically
 * @Override
 */
PointItem.prototype.repositionY = function() {
  var orientation = this.options.orientation.item;
  var point = this.dom.point;
  if (orientation == 'top') {
    point.style.top = this.top + 'px';
  }
  else {
    point.style.top = (this.parent.height - this.top - this.height) + 'px';
  }
};

/**
 * Return the width of the item left from its start date
 * @return {number}
 */
PointItem.prototype.getWidthLeft = function () {
  return this.props.dot.width;
};

/**
 * Return the width of the item right from  its start date
 * @return {number}
 */
PointItem.prototype.getWidthRight = function () {
  return this.props.dot.width;
};

module.exports = PointItem;