// @flow strict
import * as React from 'react';

import {classify} from '../../utils/classify';

import css from './Grid.module.css';


export type RowProps = {
  className?: string,
  children?: React.Node,
  span?: number,
  offset?: number,
  gridType?: 'small' | 'medium' | 'large' | 'autoFill' | 'autoFit',
  repeatTracks?: string,
};

const GRID_SYSTEM_MAP = {
  small: 24,
  medium: 12,
  large: 6,
  autoFill: 'auto-fill',
  autoFit: 'auto-fit',
};

export const Row = ({
  className,
  children,
  span = 1,
  gridType = 'medium',
  repeatTracks = '1fr',
}: RowProps): React.Node => {
  const gridRepeatCount = GRID_SYSTEM_MAP[gridType];
  let columnSpanCount = 0;
  let lastChildColCount = 0;
  const childrenWithProps = React.Children.map(children, (child) => {
    if (React.isValidElement(child)) {
      const {span = 1, offset = 0} = child.props;
      if (span < 1) {
        console.error(`span can not be less than one`);
        return;
      }
      if (offset < 0) {
        console.error(`offset can not be negative`);
        return;
      }
      lastChildColCount = columnSpanCount;
      columnSpanCount = lastChildColCount + offset + span;
      let gridColumnStart = 0,
        gridColumnEnd = 0;
      if (gridType === 'autoFill' || gridType === 'autoFit') {
        gridColumnStart = 'auto';
        return React.cloneElement(child, {
          gridColumnStart,
          gridColumnEnd: `span ${span}`,
        });
      } else if (
        typeof gridRepeatCount === 'number' &&
        columnSpanCount <= gridRepeatCount
      ) {
        gridColumnStart = lastChildColCount + offset + 1;
        return React.cloneElement(child, {
          gridColumnStart,
          gridColumnEnd: `span ${span}`,
        });
      } else {
        console.error(`number of column exceed ${gridRepeatCount}`);
      }
    }
  });

  return (
    <div
      data-testid="Grid"
      className={classify(css.gridRow, className)}
      style={{
        '--grid-repeat-count': gridRepeatCount,
        '--repeat-tracks': repeatTracks,
      }}
    >
      {childrenWithProps}
    </div>
  );
};

export type ColProps = {
  className?: string,
  children?: React.Node,
  span?: number,
  offset?: number,
  gridColumnStart?: number,
  gridColumnEnd?: number,
};

export const Col = ({
  className,
  children,
  gridColumnStart,
  gridColumnEnd,
}: ColProps): React.Node => (
  <div
    className={classify(css.gridColumn, className)}
    style={{
      '--grid-column-start': gridColumnStart,
      '--grid-column-end': gridColumnEnd,
    }}
  >
    {children}
  </div>
);