import React, { PropTypes } from 'react';
import GregorianCalendar from 'gregorian-calendar';
import defaultLocale from './locale/zh_CN';
import FullCalendar from 'rc-calendar/lib/FullCalendar';
import { PREFIX_CLS } from './Constants';
import Header from './Header';

function noop() { return null; }

function zerofixed(v) {
  if (v < 10) return `0${v}`;
  return `${v}`;
}

export default class Calendar extends React.Component {
  static defaultProps = {
    monthCellRender: noop,
    dateCellRender: noop,
    locale: {},
    fullscreen: true,
    prefixCls: PREFIX_CLS,
    onPanelChange: noop,
    mode: 'month',
  }

  static propTypes = {
    monthCellRender: PropTypes.func,
    dateCellRender: PropTypes.func,
    fullscreen: PropTypes.bool,
    locale: PropTypes.object,
    prefixCls: PropTypes.string,
    className: PropTypes.string,
    style: PropTypes.object,
    onPanelChange: PropTypes.func,
    value: PropTypes.instanceOf(Date),
  }

  static contextTypes = {
    antLocale: PropTypes.object,
  }

  constructor(props) {
    super(props);
    this.state = {
      value: this.parseDateFromValue(props.value || new Date()),
      mode: props.mode,
    };
  }

  parseDateFromValue(value) {
    const date = new GregorianCalendar(this.getLocale());
    date.setTime(+value);
    return date;
  }

  componentWillReceiveProps(nextProps) {
    if ('value' in nextProps) {
      this.setState({
        value: this.parseDateFromValue(nextProps.value),
      });
    }
  }

  getLocale = () => {
    const props = this.props;
    let locale = defaultLocale;
    const context = this.context;
    if (context && context.antLocale && context.antLocale.Calendar) {
      locale = context.antLocale.Calendar;
    }
    // 统一合并为完整的 Locale
    const result = { ...locale, ...props.locale };
    result.lang = { ...locale.lang, ...props.locale.lang };
    return result;
  }

  monthCellRender = (value, locale) => {
    const prefixCls = this.props.prefixCls;
    const month = value.getMonth();
    return (
      <div className={`${prefixCls}-month`}>
        <div className={`${prefixCls}-value`}>
          {locale.format.shortMonths[month]}
        </div>
        <div className={`${prefixCls}-content`}>
          {this.props.monthCellRender(value)}
        </div>
      </div>
    );
  }

  dateCellRender = (value) => {
    const prefixCls = this.props.prefixCls;
    return (
      <div className={`${prefixCls}-date`}>
        <div className={`${prefixCls}-value`}>
          {zerofixed(value.getDayOfMonth())}
        </div>
        <div className={`${prefixCls}-content`}>
          {this.props.dateCellRender(value)}
        </div>
      </div>
    );
  }

  setValue = (value) => {
    if (!('value' in this.props) && this.state.value !== value) {
      this.setState({ value });
    }
    this.props.onPanelChange(value, this.state.mode);
  }

  setType = (type) => {
    const mode = (type === 'date') ? 'month' : 'year';
    if (this.state.mode !== mode) {
      this.setState({ mode });
      this.props.onPanelChange(this.state.value, mode);
    }
  }

  render() {
    const props = this.props;
    const { value, mode } = this.state;
    const { prefixCls, style, className, fullscreen } = props;
    const type = (mode === 'year') ? 'month' : 'date';
    const locale = this.getLocale();

    let cls = className || '';
    if (fullscreen) {
      cls += (` ${prefixCls}-fullscreen`);
    }

    return (
      <div className={cls} style={style}>
        <Header
          fullscreen={fullscreen}
          type={type}
          value={value}
          locale={locale.lang}
          prefixCls={prefixCls}
          onTypeChange={this.setType}
          onValueChange={this.setValue}
        />
        <FullCalendar
          {...props}
          Select={noop}
          locale={locale.lang}
          type={type}
          prefixCls={prefixCls}
          showHeader={false}
          value={value}
          monthCellRender={this.monthCellRender}
          dateCellRender={this.dateCellRender}
        />
      </div>
    );
  }
}