import hyphenateStyleName from "hyphenate-style-name";
import createReactDOMStyle from "react-native-web/dist/exports/StyleSheet/createReactDOMStyle";
import prefixStyles from "react-native-web/dist/modules/prefixStyles";

export function createWebCssRule(selector: string, cssRules: {}) {
  const css = createDeclarationBlock(cssRules);
  const identifier = murmurHash(`${selector}${css}`);

  if (selector.substr(0, 1) === "@") {
    // selector is a media query
    return {
      identifier,
      rule: `/*${identifier}*/${selector}{[data-testid~="${identifier}"][data-testid~="${identifier}"]${css}}`,
    };
  }

  // selector is something else such as ":hover"
  return {
    identifier,
    rule: `[data-testid~="${identifier}"][data-testid~="${identifier}"]${selector}${css}`,
  };
}

function createDeclarationBlock(style: any) {
  const domStyle = prefixStyles(createReactDOMStyle(style));
  const declarationsString = Object.keys(domStyle)
    .map((property) => {
      const value = domStyle[property];
      const prop = hyphenateStyleName(property);
      if (Array.isArray(value)) {
        return value.map((v) => `${prop}:${v}`).join(";");
      } else {
        return `${prop}:${value}`;
      }
    })
    .sort()
    .join(";");

  return `{${declarationsString};}`;
}

export function murmurHash(str: string) {
  /* tslint:disable:no-bitwise */
  let l = str.length;
  let h = l ^ l;
  let i = 0;
  let k;

  while (l >= 4) {
    k =
      (str.charCodeAt(i) & 0xff) |
      ((str.charCodeAt(++i) & 0xff) << 8) |
      ((str.charCodeAt(++i) & 0xff) << 16) |
      ((str.charCodeAt(++i) & 0xff) << 24);

    k =
      (k & 0xffff) * 0x5bd1e995 + ((((k >>> 16) * 0x5bd1e995) & 0xffff) << 16);
    k ^= k >>> 24;
    k =
      (k & 0xffff) * 0x5bd1e995 + ((((k >>> 16) * 0x5bd1e995) & 0xffff) << 16);

    h =
      ((h & 0xffff) * 0x5bd1e995 +
        ((((h >>> 16) * 0x5bd1e995) & 0xffff) << 16)) ^
      k;

    l -= 4;
    ++i;
  }

  switch (l) {
    case 3:
      h ^= (str.charCodeAt(i + 2) & 0xff) << 16;
    case 2:
      h ^= (str.charCodeAt(i + 1) & 0xff) << 8;
    case 1:
      h ^= str.charCodeAt(i) & 0xff;
      h =
        (h & 0xffff) * 0x5bd1e995 +
        ((((h >>> 16) * 0x5bd1e995) & 0xffff) << 16);
  }

  h ^= h >>> 13;
  h = (h & 0xffff) * 0x5bd1e995 + ((((h >>> 16) * 0x5bd1e995) & 0xffff) << 16);
  h ^= h >>> 15;

  return (h >>> 0).toString(36);
  /* tslint:enable */
}