import React from 'react';
import ReactDOM from 'react-dom';
import WindowListenable from '../mixins/window-listenable';
import RenderToLayer from '../render-to-layer';
import StylePropable from '../mixins/style-propable';
import PropTypes from '../utils/prop-types';
import Paper from '../paper';
import throttle from 'lodash.throttle';
import getMuiTheme from '../styles/getMuiTheme';
import PopoverDefaultAnimation from './popover-default-animation';

const Popover = React.createClass({

  propTypes: {
    /**
     * This is the DOM element that will be used to set the position of the
     * component.
     */
    anchorEl: React.PropTypes.object,

    /**
     * This is the point on the anchor where the popover
     * targetOrigin will stick to.
     * Options:
     * vertical: [top, middle, bottom]
     * horizontal: [left, center, right]
     */
    anchorOrigin: PropTypes.origin,

    /**
     * If true, the popover will apply transitions when
     * added it gets added to the DOM.
     */
    animated: React.PropTypes.bool,

    /**
     * Override the default animation component used.
     */
    animation: React.PropTypes.func,

    /**
     * If true, the popover will hide when the anchor scrolls off the screen
     */
    autoCloseWhenOffScreen: React.PropTypes.bool,

    /**
     * If true, the popover (potentially) ignores targetOrigin
     * and anchorOrigin to make itself fit on screen,
     * which is useful for mobile devices.
     */
    canAutoPosition: React.PropTypes.bool,

    /**
     * Use this property to render your component inside the `Popover`.
     */
    children: React.PropTypes.node,

    /**
     * The css class name of the root element.
     */
    className: React.PropTypes.string,

    /**
     * This is a callback that fires when the popover
     * thinks it should close. (e.g. clickAway or offScreen)
     *
     * @param {string} reason Determines what triggered this request.
     */
    onRequestClose: React.PropTypes.func,

    /**
     * Controls the visibility of the popover.
     */
    open: React.PropTypes.bool,

    /**
     * Override the inline-styles of the root element.
     */
    style: React.PropTypes.object,

    /**
     * This is the point on the popover which will stick to
     * the anchors origin.
     * Options:
     * vertical: [top, middle, bottom]
     * horizontal: [left, center, right]
     */
    targetOrigin: PropTypes.origin,

    /**
     * If true, the popover will render on top of an invisible
     * layer, which will prevent clicks to the underlying
     * elements, and trigger an onRequestClose(clickAway) event.
     */
    useLayerForClickAway: React.PropTypes.bool,

    /**
     * This number represents the zDepth of the paper shadow.
     */
    zDepth: PropTypes.zDepth,
  },

  contextTypes: {
    muiTheme: React.PropTypes.object,
  },

  //for passing default theme context to children
  childContextTypes: {
    muiTheme: React.PropTypes.object,
  },

  mixins: [
    StylePropable,
    WindowListenable,
  ],

  getDefaultProps() {
    return {
      anchorOrigin: {
        vertical: 'bottom',
        horizontal: 'left',
      },
      animated: true,
      autoCloseWhenOffScreen: true,
      canAutoPosition: true,
      onRequestClose: () => {},
      open: false,
      style: {
        overflowY: 'auto',
      },
      targetOrigin: {
        vertical: 'top',
        horizontal: 'left',
      },
      useLayerForClickAway: true,
      zDepth: 1,
    };
  },

  getInitialState() {
    this.setPlacementThrottled = throttle(this.setPlacement, 100);
    this.setPlacementThrottledScrolled = throttle(this.setPlacement.bind(this, true), 100);

    return {
      open: this.props.open,
      closing: false,
      muiTheme: this.context.muiTheme || getMuiTheme(),
    };
  },

  getChildContext() {
    return {
      muiTheme: this.state.muiTheme,
    };
  },

  componentWillReceiveProps(nextProps, nextContext) {
    let newMuiTheme = nextContext.muiTheme ? nextContext.muiTheme : this.state.muiTheme;

    if (nextProps.open !== this.state.open) {
      if (nextProps.open) {
        this.anchorEl = nextProps.anchorEl || this.props.anchorEl;
        this.setState({
          open: true,
          closing: false,
          muiTheme: newMuiTheme,
        });
      } else {
        if (nextProps.animated) {
          this.setState({closing: true});
          this._timeout = setTimeout(() => {
            if (this.isMounted()) {
              this.setState({
                open: false,
                muiTheme: newMuiTheme,
              });
            }
          }, 500);
        } else {
          this.setState({
            open: false,
            muiTheme: newMuiTheme,
          });
        }
      }
    }
  },

  componentDidUpdate() {
    this.setPlacement();
  },

  windowListeners: {
    resize: 'setPlacementThrottled',
    scroll: 'setPlacementThrottledScrolled',
  },

  renderLayer() {
    let {
      animated,
      animation,
      children,
      style,
      ...other,
    } = this.props;

    let Animation = animation || PopoverDefaultAnimation;

    if (!Animation) {
      Animation = Paper;
      style = {
        position: 'fixed',
      };
      if (!this.state.open) {
        return null;
      }
    }

    return (
      <Animation {...other} style={style} open={this.state.open && !this.state.closing}>
        {children}
      </Animation>
    );
  },

  requestClose(reason) {
    if (this.props.onRequestClose) {
      this.props.onRequestClose(reason);
    }
  },

  componentClickAway() {
    this.requestClose('clickAway');
  },

  _resizeAutoPosition() {
    this.setPlacement();
  },

  getAnchorPosition(el) {
    if (!el) {
      el = ReactDOM.findDOMNode(this);
    }

    const rect = el.getBoundingClientRect();
    const a = {
      top: rect.top,
      left: rect.left,
      width: el.offsetWidth,
      height: el.offsetHeight,
    };

    a.right = rect.right || a.left + a.width;
    a.bottom = rect.bottom || a.top + a.height;
    a.middle = a.left + ((a.right - a.left) / 2);
    a.center = a.top + ((a.bottom - a.top) / 2);

    return a;
  },

  getTargetPosition(targetEl) {
    return {
      top: 0,
      center: targetEl.offsetHeight / 2,
      bottom: targetEl.offsetHeight,
      left: 0,
      middle: targetEl.offsetWidth / 2,
      right: targetEl.offsetWidth,
    };
  },

  setPlacement(scrolling) {
    if (!this.state.open) {
      return;
    }

    const anchorEl = this.props.anchorEl || this.anchorEl;

    if (!this.refs.layer.getLayer()) {
      return;
    }

    const targetEl = this.refs.layer.getLayer().children[0];
    if (!targetEl) {
      return;
    }

    let {targetOrigin, anchorOrigin} = this.props;

    let anchor = this.getAnchorPosition(anchorEl);
    let target = this.getTargetPosition(targetEl);

    let targetPosition = {
      top: anchor[anchorOrigin.vertical] - target[targetOrigin.vertical],
      left: anchor[anchorOrigin.horizontal] - target[targetOrigin.horizontal],
    };

    if (scrolling && this.props.autoCloseWhenOffScreen) {
      this.autoCloseWhenOffScreen(anchor);
    }

    if (this.props.canAutoPosition) {
      target = this.getTargetPosition(targetEl); // update as height may have changed
      targetPosition = this.applyAutoPositionIfNeeded(anchor, target, targetOrigin, anchorOrigin, targetPosition);
    }


    targetEl.style.top = Math.max(0, targetPosition.top) + 'px';
    targetEl.style.left = Math.max(0, targetPosition.left) + 'px';
    targetEl.style.maxHeight = window.innerHeight + 'px';
  },

  autoCloseWhenOffScreen(anchorPosition) {
    if (anchorPosition.top < 0
        || anchorPosition.top > window.innerHeight
        || anchorPosition.left < 0
        || anchorPosition.left > window.innerWith
        ) {
      this.requestClose('offScreen');
    }
  },

  getOverlapMode(anchor, target, median) {
    if ([anchor, target].indexOf(median) >= 0) return 'auto';
    if (anchor === target) return 'inclusive';
    return 'exclusive';
  },

  getPositions(anchor, target) {
    let a = {...anchor};
    let t = {...target};

    let positions = {
      x: ['left', 'right'].filter((p) => p !== t.horizontal),
      y: ['top', 'bottom'].filter((p) => p !== t.vertical),
    };

    let overlap = {
      x: this.getOverlapMode(a.horizontal, t.horizontal, 'middle'),
      y: this.getOverlapMode(a.vertical, t.vertical, 'center'),
    };

    positions.x.splice(overlap.x === 'auto' ? 0 : 1, 0, 'middle');
    positions.y.splice(overlap.y === 'auto' ? 0 : 1, 0, 'center');

    if (overlap.y !== 'auto') {
      a.vertical = a.vertical === 'top' ? 'bottom' : 'top';
      if (overlap.y === 'inclusive') {
        t.vertical = t.vertical;
      }
    }

    if (overlap.x !== 'auto') {
      a.horizontal = a.horizontal === 'left' ? 'right' : 'left';
      if (overlap.y === 'inclusive') {
        t.horizontal = t.horizontal;
      }
    }

    return {
      positions: positions,
      anchorPos: a,
    };
  },

  applyAutoPositionIfNeeded(anchor, target, targetOrigin, anchorOrigin, targetPosition) {
    let {positions, anchorPos} = this.getPositions(anchorOrigin, targetOrigin);

    if (targetPosition.top < 0 || targetPosition.top + target.bottom > window.innerHeight) {
      let newTop = anchor[anchorPos.vertical] - target[positions.y[0]];
      if (newTop + target.bottom <= window.innerHeight)
        targetPosition.top = Math.max(0, newTop);
      else {
        newTop = anchor[anchorPos.vertical] - target[positions.y[1]];
        if (newTop + target.bottom <= window.innerHeight)
          targetPosition.top = Math.max(0, newTop);
      }
    }
    if (targetPosition.left < 0 || targetPosition.left + target.right > window.innerWidth) {
      let newLeft = anchor[anchorPos.horizontal] - target[positions.x[0]];
      if (newLeft + target.right <= window.innerWidth)
        targetPosition.left = Math.max(0, newLeft);
      else {
        newLeft = anchor[anchorPos.horizontal] - target[positions.x[1]];
        if (newLeft + target.right <= window.innerWidth)
          targetPosition.left = Math.max(0, newLeft);
      }
    }
    return targetPosition;
  },

  render() {
    return (
      <RenderToLayer
        ref="layer"
        open={this.state.open}
        componentClickAway={this.componentClickAway}
        useLayerForClickAway={this.props.useLayerForClickAway}
        render={this.renderLayer}
      />
    );
  },

});

export default Popover;