import memoize from 'lodash.memoize';
import {invokeHookFlat, registerHooks} from 'scwp';

export const compilers = memoize(() => (
  invokeHookFlat('behaviorCompilers')
    .reduce((r, results) => ({
      ...r,
      ...results,
    }), {})
));

export default function compile(variant) {
  const {[variant.type]: compiler} = compilers();
  if (!compiler) {
    return () => Promise.reject(new Error(`No compiler for '${variant.type}'`));
  }
  return compiler(variant);
}

export function isCompilable(variant) {
  if ('object' !== typeof variant || null === variant) {
    return false;
  }
  if (!variant.type) {
    return false;
  }
  return !!compilers()[variant.type];
}

export function makeCompilable(variant) {
  return isCompilable(variant) ? variant : {type: 'literal', value: variant};
}

registerHooks({
  autoreg$accept: (type, M) => {
    if ('hooks' === type && 'behaviorCompilers' in M) {
      compilers.cache.clear();
    }
  },
}, module.id);