xntalk / xntalk-rnapp

import invariant from '../utils/invariant';

import getScreenForRouteName from './getScreenForRouteName';
import addNavigationHelpers from '../addNavigationHelpers';
import validateScreenOptions from './validateScreenOptions';

function applyConfig(configurer, navigationOptions, configProps) {
  if (typeof configurer === 'function') {
    return {
      ...navigationOptions,
      ...configurer({
        ...configProps,
        navigationOptions
      })
    };
  }
  if (typeof configurer === 'object') {
    return {
      ...navigationOptions,
      ...configurer
    };
  }
  return navigationOptions;
}

export default ((routeConfigs, navigatorScreenConfig) => (navigation, screenProps) => {
  const { state, dispatch } = navigation;
  const route = state;

  invariant(route.routeName && typeof route.routeName === 'string', 'Cannot get config because the route does not have a routeName.');

  const Component = getScreenForRouteName(routeConfigs, route.routeName);

  let outputConfig = {};

  const router = Component.router;
  if (router) {
    // $FlowFixMe
    const { routes, index } = route;
    if (!route || !routes || index == null) {
      throw new Error(`Expect nav state to have routes and index, ${JSON.stringify(route)}`);
    }
    const childRoute = routes[index];
    const childNavigation = addNavigationHelpers({
      state: childRoute,
      dispatch
    });
    outputConfig = router.getScreenOptions(childNavigation, screenProps);
  }

  const routeConfig = routeConfigs[route.routeName];

  const routeScreenConfig = routeConfig.navigationOptions;
  const componentScreenConfig = Component.navigationOptions;

  const configOptions = { navigation, screenProps: screenProps || {} };

  outputConfig = applyConfig(navigatorScreenConfig, outputConfig, configOptions);
  outputConfig = applyConfig(componentScreenConfig, outputConfig, configOptions);
  outputConfig = applyConfig(routeScreenConfig, outputConfig, configOptions);

  validateScreenOptions(outputConfig, route);

  return outputConfig;
});