import hash from '@emotion/hash';
import canUseDom from '../../canUseDom';
import { removeCSS, updateCSS } from '../../../vc-util/Dom/dynamicCSS';
import { ATTR_MARK, ATTR_TOKEN } from '../StyleContext';
import { Theme } from '../theme';

// Create a cache for memo concat
type NestWeakMap<T> = WeakMap<object, NestWeakMap<T> | T>;
const resultCache: NestWeakMap<object> = new WeakMap();
const RESULT_VALUE = {};

export function memoResult<T extends object, R>(callback: () => R, deps: T[]): R {
  let current: WeakMap<any, any> = resultCache;
  for (let i = 0; i < deps.length; i += 1) {
    const dep = deps[i];
    if (!current.has(dep)) {
      current.set(dep, new WeakMap());
    }
    current = current.get(dep)!;
  }

  if (!current.has(RESULT_VALUE)) {
    current.set(RESULT_VALUE, callback());
  }

  return current.get(RESULT_VALUE);
}

// Create a cache here to avoid always loop generate
const flattenTokenCache = new WeakMap<any, string>();

/**
 * Flatten token to string, this will auto cache the result when token not change
 */
export function flattenToken(token: any) {
  let str = flattenTokenCache.get(token) || '';

  if (!str) {
    Object.keys(token).forEach(key => {
      const value = token[key];
      str += key;
      if (value instanceof Theme) {
        str += value.id;
      } else if (value && typeof value === 'object') {
        str += flattenToken(value);
      } else {
        str += value;
      }
    });

    // Put in cache
    flattenTokenCache.set(token, str);
  }
  return str;
}

/**
 * Convert derivative token to key string
 */
export function token2key(token: any, salt: string): string {
  return hash(`${salt}_${flattenToken(token)}`);
}

const randomSelectorKey = `random-${Date.now()}-${Math.random()}`.replace(/\./g, '');

// Magic `content` for detect selector support
const checkContent = '_bAmBoO_';

function supportSelector(
  styleStr: string,
  handleElement: (ele: HTMLElement) => void,
  supportCheck?: (ele: HTMLElement) => boolean,
): boolean {
  if (canUseDom()) {
    updateCSS(styleStr, randomSelectorKey);

    const ele = document.createElement('div');
    ele.style.position = 'fixed';
    ele.style.left = '0';
    ele.style.top = '0';
    handleElement?.(ele);
    document.body.appendChild(ele);

    if (process.env.NODE_ENV !== 'production') {
      ele.innerHTML = 'Test';
      ele.style.zIndex = '9999999';
    }

    const support = supportCheck
      ? supportCheck(ele)
      : getComputedStyle(ele).content?.includes(checkContent);

    ele.parentNode?.removeChild(ele);
    removeCSS(randomSelectorKey);

    return support;
  }

  return false;
}

let canLayer: boolean | undefined = undefined;
export function supportLayer(): boolean {
  if (canLayer === undefined) {
    canLayer = supportSelector(
      `@layer ${randomSelectorKey} { .${randomSelectorKey} { content: "${checkContent}"!important; } }`,
      ele => {
        ele.className = randomSelectorKey;
      },
    );
  }

  return canLayer!;
}

let canWhere: boolean | undefined = undefined;
export function supportWhere(): boolean {
  if (canWhere === undefined) {
    canWhere = supportSelector(
      `:where(.${randomSelectorKey}) { content: "${checkContent}"!important; }`,
      ele => {
        ele.className = randomSelectorKey;
      },
    );
  }

  return canWhere!;
}

let canLogic: boolean | undefined = undefined;
export function supportLogicProps(): boolean {
  if (canLogic === undefined) {
    canLogic = supportSelector(
      `.${randomSelectorKey} { inset-block: 93px !important; }`,
      ele => {
        ele.className = randomSelectorKey;
      },
      ele => getComputedStyle(ele).bottom === '93px',
    );
  }

  return canLogic!;
}

export const isClientSide = canUseDom();

export function unit(num: string | number) {
  if (typeof num === 'number') {
    return `${num}px`;
  }
  return num;
}

export function toStyleStr(
  style: string,
  tokenKey?: string,
  styleId?: string,
  customizeAttrs: Record<string, string> = {},
  plain = false,
) {
  if (plain) {
    return style;
  }
  const attrs: Record<string, string | undefined> = {
    ...customizeAttrs,
    [ATTR_TOKEN]: tokenKey,
    [ATTR_MARK]: styleId,
  };

  const attrStr = Object.keys(attrs)
    .map(attr => {
      const val = attrs[attr];
      return val ? `${attr}="${val}"` : null;
    })
    .filter(v => v)
    .join(' ');

  return `<style ${attrStr}>${style}</style>`;
}