import { StyleProp, StyleSheet, ViewStyle } from 'react-native';

// @see https://facebook.github.io/react-native/docs/layout-props.html
// @see https://facebook.github.io/react-native/docs/view-style-props.html
// @todo According to the source code of ScrollView, ['alignItems','justifyContent'] should be set to contentContainerStyle

const WRAPPER_TYPE_STYLE_REGEX =
  /alignSelf|aspectRatio|border.*|bottom|direction|display|end|left|margin.*|position|right|start|top|zIndex|opacity|elevation/;
// const INNER_TYPE_STYLE_REGEX: RegExp = /alignContent|alignItems|flexDirection|flexWrap|height|justifyContent|.*[wW]idth|.*[hH]eight|overflow|padding.*/
const SYNC_TYPE_STYLE_REGEX = /flex|flexBasis|flexGrow|flexShrink/;

export const omit = (obj: any = {}, fields: string[] = []): { [key: string]: any } => {
  const shallowCopy = { ...obj };
  fields.forEach((key) => {
    delete shallowCopy[key];
  });
  return shallowCopy;
};

export const dismemberStyle = (
  style?: StyleProp<ViewStyle>,
): { wrapperStyle: ViewStyle; innerStyle: ViewStyle } => {
  const flattenStyle: ViewStyle & { [key: string]: any } = StyleSheet.flatten(style);
  const wrapperStyle: ViewStyle & { [key: string]: any } = {};
  const innerStyle: ViewStyle & { [key: string]: any } = {};
  if (flattenStyle) {
    Object.keys(flattenStyle).forEach((key: string) => {
      if (SYNC_TYPE_STYLE_REGEX.test(key)) {
        wrapperStyle[key] = flattenStyle[key];
        innerStyle[key] = flattenStyle[key];
      } else if (WRAPPER_TYPE_STYLE_REGEX.test(key)) {
        wrapperStyle[key] = flattenStyle[key];
      } else {
        innerStyle[key] = flattenStyle[key];
      }
    });
  }
  return {
    wrapperStyle,
    innerStyle,
  };
};

/**
 * Parses a string of inline styles into a javascript object with casing for react
 *
 * @param {string} styles
 * @returns {Object}
 */
export const parseStyles = (styles = ''): { [key: string]: string } => {
  return styles
    .split(';')
    .filter((style) => style.split(':').length === 2)
    .map((style) => [
      style
        .split(':')[0]
        .trim()
        .replace(/-./g, (c) => c.substr(1).toUpperCase()),
      style.split(':')[1].trim(),
    ])
    .reduce(
      (styleObj, style) => ({
        ...styleObj,
        [style[0]]: style[1],
      }),
      {},
    );
};

// eslint-disable-next-line
export const noop = (...args: any[]): void => {};

export default {
  omit,
  dismemberStyle,
  parseStyles,
  noop,
};