import React from 'react';
import ReactDOM from 'react-dom';
import ClassNames from 'classnames';
import Input from '../input';
import events from '../utils/events';
import style from './style';

class Dropdown extends React.Component {
  static propTypes = {
    allowBlank: React.PropTypes.bool,
    auto: React.PropTypes.bool,
    className: React.PropTypes.string,
    disabled: React.PropTypes.bool,
    error: React.PropTypes.string,
    label: React.PropTypes.string,
    onBlur: React.PropTypes.func,
    onChange: React.PropTypes.func,
    onFocus: React.PropTypes.func,
    source: React.PropTypes.array.isRequired,
    template: React.PropTypes.func,
    value: React.PropTypes.oneOfType([
      React.PropTypes.string,
      React.PropTypes.number
    ])
  };

  static defaultProps = {
    auto: true,
    className: '',
    allowBlank: true,
    disabled: false
  };

  state = {
    active: false,
    up: false
  };

  componentWillUpdate (nextProps, nextState) {
    if (!this.state.active && nextState.active) {
      events.addEventsToDocument({click: this.handleDocumentClick});
    }
  }

  componentDidUpdate (prevProps, prevState) {
    if (prevState.active && !this.state.active) {
      events.removeEventsFromDocument({click: this.handleDocumentClick});
    }
  }

  componentWillUnmount () {
    if (this.state.active) {
      events.removeEventsFromDocument({click: this.handleDocumentClick});
    }
  }

  close = () => {
    if (this.state.active) {
      this.setState({active: false});
    }
  }

  handleDocumentClick = (event) => {
    if (this.state.active && !events.targetIsDescendant(event, ReactDOM.findDOMNode(this))) {
      this.setState({active: false});
    }
  };

  handleMouseDown = (event) => {
    events.pauseEvent(event);
    const client = event.target.getBoundingClientRect();
    const screen_height = window.innerHeight || document.documentElement.offsetHeight;
    const up = this.props.auto ? client.top > ((screen_height / 2) + client.height) : false;
    if (this.props.onFocus) this.props.onFocus(event);
    this.setState({active: true, up});
  };

  handleSelect = (item, event) => {
    if (this.props.onBlur) this.props.onBlur(event);
    if (!this.props.disabled && this.props.onChange) {
      this.props.onChange(item, event);
      this.setState({active: false});
    }
  };

  getSelectedItem = () => {
    for (const item of this.props.source) {
      if (item.value === this.props.value) return item;
    }
    if (!this.props.allowBlank) {
      return this.props.source[0];
    }
  };

  renderTemplateValue (selected) {
    const className = ClassNames(style.field, {
      [style.errored]: this.props.error,
      [style.disabled]: this.props.disabled
    });

    return (
      <div className={className} onMouseDown={this.handleMouseDown}>
        <div className={`${style.templateValue} ${style.value}`}>
          {this.props.template(selected)}
        </div>
        {this.props.label ? <label className={style.label}>{this.props.label}</label> : null}
        {this.props.error ? <span className={style.error}>{this.props.error}</span> : null}
      </div>
    );
  }

  renderValue (item, idx) {
    const className = item.value === this.props.value ? style.selected : null;
    return (
      <li key={idx} className={className} onMouseDown={this.handleSelect.bind(this, item.value)}>
        {this.props.template ? this.props.template(item) : item.label}
      </li>
    );
  }

  render () {
    const {template, source, ...others} = this.props;
    const selected = this.getSelectedItem();
    const className = ClassNames(style.root, {
      [style.up]: this.state.up,
      [style.active]: this.state.active,
      [style.disabled]: this.props.disabled
    }, this.props.className);

    return (
      <div data-react-toolbox='dropdown' className={className}>
        <Input
          {...others}
          className={style.value}
          onMouseDown={this.handleMouseDown}
          readOnly
          type={template && selected ? 'hidden' : null}
          value={selected && selected.label}
        />
      {template && selected ? this.renderTemplateValue(selected) : null}
        <ul className={style.values} ref='values'>
          {source.map(this.renderValue.bind(this))}
        </ul>
      </div>
    );
  }
}

export default Dropdown;