import * as React from 'react';
import {graphql} from 'react-apollo';
import {getQueryOptions, resolveFragments} from 'coral-framework/services/graphqlRegistry';
import {getDefinitionName, separateDataAndRoot, getResponseErrors} from '../utils';

const withSkipOnErrors = (reducer) => (prev, action, ...rest) => {
  if (action.type === 'APOLLO_MUTATION_RESULT' && getResponseErrors(action.result)) {
    return prev;
  }
  return reducer(prev, action, ...rest);
};

/**
 * Exports a HOC with the same signature as `graphql`, that will
 * apply query options registered in the graphRegistry.
 */
export default (document, config = {}) => (WrappedComponent) => {
  config = {
    ...config,
    options: config.options || {},
    props: config.props || (({data}) => separateDataAndRoot(data)),
  };

  const wrappedOptions = (data) => {
    const base = (typeof config.options === 'function') ? config.options(data) : config.options;
    const name = getDefinitionName(document);
    const configs = getQueryOptions(name);
    const reducerCallbacks =
      [base.reducer || ((i) => i)]
      .concat(...configs.map((cfg) => cfg.reducer))
      .filter((i) => i);

    const reducer = withSkipOnErrors(
      reducerCallbacks.reduce(
        (a, b) => (prev, ...rest) =>
          b(a(prev, ...rest), ...rest),
      ));

    return {
      ...base,
      reducer,
    };
  };

  let memoized = null;
  const getWrapped = () => {
    if (!memoized) {
      memoized = graphql(resolveFragments(document), {...config, options: wrappedOptions})(WrappedComponent);
    }
    return memoized;
  };

  return (props) => {
    const Wrapped = getWrapped();
    return <Wrapped {...props} />;
  };
};