var _extends = Object.assign || function (target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i]; for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; } } } return target; };

import warning from './routerWarning';
import computeChangedRoutes from './computeChangedRoutes';
import { runEnterHooks, runChangeHooks, runLeaveHooks } from './TransitionUtils';
import _isActive from './isActive';
import getComponents from './getComponents';
import matchRoutes from './matchRoutes';

function hasAnyProperties(object) {
  for (var p in object) {
    if (Object.prototype.hasOwnProperty.call(object, p)) return true;
  }return false;
}

export default function createTransitionManager(history, routes) {
  var state = {};

  // Signature should be (location, indexOnly), but needs to support (path,
  // query, indexOnly)
  function isActive(location) {
    var indexOnlyOrDeprecatedQuery = arguments.length <= 1 || arguments[1] === undefined ? false : arguments[1];
    var deprecatedIndexOnly = arguments.length <= 2 || arguments[2] === undefined ? null : arguments[2];

    var indexOnly = void 0;
    if (indexOnlyOrDeprecatedQuery && indexOnlyOrDeprecatedQuery !== true || deprecatedIndexOnly !== null) {
      process.env.NODE_ENV !== 'production' ? warning(false, '`isActive(pathname, query, indexOnly) is deprecated; use `isActive(location, indexOnly)` with a location descriptor instead. http://tiny.cc/router-isActivedeprecated') : void 0;
      location = { pathname: location, query: indexOnlyOrDeprecatedQuery };
      indexOnly = deprecatedIndexOnly || false;
    } else {
      location = history.createLocation(location);
      indexOnly = indexOnlyOrDeprecatedQuery;
    }

    return _isActive(location, indexOnly, state.location, state.routes, state.params);
  }

  var partialNextState = void 0;

  function match(location, callback) {
    if (partialNextState && partialNextState.location === location) {
      // Continue from where we left off.
      finishMatch(partialNextState, callback);
    } else {
      matchRoutes(routes, location, function (error, nextState) {
        if (error) {
          callback(error);
        } else if (nextState) {
          finishMatch(_extends({}, nextState, { location: location }), callback);
        } else {
          callback();
        }
      });
    }
  }

  function finishMatch(nextState, callback) {
    var _computeChangedRoutes = computeChangedRoutes(state, nextState);

    var leaveRoutes = _computeChangedRoutes.leaveRoutes;
    var changeRoutes = _computeChangedRoutes.changeRoutes;
    var enterRoutes = _computeChangedRoutes.enterRoutes;


    runLeaveHooks(leaveRoutes, state);

    // Tear down confirmation hooks for left routes
    leaveRoutes.filter(function (route) {
      return enterRoutes.indexOf(route) === -1;
    }).forEach(removeListenBeforeHooksForRoute);

    // change and enter hooks are run in series
    runChangeHooks(changeRoutes, state, nextState, function (error, redirectInfo) {
      if (error || redirectInfo) return handleErrorOrRedirect(error, redirectInfo);

      runEnterHooks(enterRoutes, nextState, finishEnterHooks);
    });

    function finishEnterHooks(error, redirectInfo) {
      if (error || redirectInfo) return handleErrorOrRedirect(error, redirectInfo);

      // TODO: Fetch components after state is updated.
      getComponents(nextState, function (error, components) {
        if (error) {
          callback(error);
        } else {
          // TODO: Make match a pure function and have some other API
          // for "match and update state".
          callback(null, null, state = _extends({}, nextState, { components: components }));
        }
      });
    }

    function handleErrorOrRedirect(error, redirectInfo) {
      if (error) callback(error);else callback(null, redirectInfo);
    }
  }

  var RouteGuid = 1;

  function getRouteID(route) {
    var create = arguments.length <= 1 || arguments[1] === undefined ? true : arguments[1];

    return route.__id__ || create && (route.__id__ = RouteGuid++);
  }

  var RouteHooks = Object.create(null);

  function getRouteHooksForRoutes(routes) {
    return routes.reduce(function (hooks, route) {
      hooks.push.apply(hooks, RouteHooks[getRouteID(route)]);
      return hooks;
    }, []);
  }

  function transitionHook(location, callback) {
    matchRoutes(routes, location, function (error, nextState) {
      if (nextState == null) {
        // TODO: We didn't actually match anything, but hang
        // onto error/nextState so we don't have to matchRoutes
        // again in the listen callback.
        callback();
        return;
      }

      // Cache some state here so we don't have to
      // matchRoutes() again in the listen callback.
      partialNextState = _extends({}, nextState, { location: location });

      var hooks = getRouteHooksForRoutes(computeChangedRoutes(state, partialNextState).leaveRoutes);

      var result = void 0;
      for (var i = 0, len = hooks.length; result == null && i < len; ++i) {
        // Passing the location arg here indicates to
        // the user that this is a transition hook.
        result = hooks[i](location);
      }

      callback(result);
    });
  }

  /* istanbul ignore next: untestable with Karma */
  function beforeUnloadHook() {
    // Synchronously check to see if any route hooks want
    // to prevent the current window/tab from closing.
    if (state.routes) {
      var hooks = getRouteHooksForRoutes(state.routes);

      var message = void 0;
      for (var i = 0, len = hooks.length; typeof message !== 'string' && i < len; ++i) {
        // Passing no args indicates to the user that this is a
        // beforeunload hook. We don't know the next location.
        message = hooks[i]();
      }

      return message;
    }
  }

  var unlistenBefore = void 0,
      unlistenBeforeUnload = void 0;

  function removeListenBeforeHooksForRoute(route) {
    var routeID = getRouteID(route, false);
    if (!routeID) {
      return;
    }

    delete RouteHooks[routeID];

    if (!hasAnyProperties(RouteHooks)) {
      // teardown transition & beforeunload hooks
      if (unlistenBefore) {
        unlistenBefore();
        unlistenBefore = null;
      }

      if (unlistenBeforeUnload) {
        unlistenBeforeUnload();
        unlistenBeforeUnload = null;
      }
    }
  }

  /**
   * Registers the given hook function to run before leaving the given route.
   *
   * During a normal transition, the hook function receives the next location
   * as its only argument and can return either a prompt message (string) to show the user,
   * to make sure they want to leave the page; or `false`, to prevent the transition.
   * Any other return value will have no effect.
   *
   * During the beforeunload event (in browsers) the hook receives no arguments.
   * In this case it must return a prompt message to prevent the transition.
   *
   * Returns a function that may be used to unbind the listener.
   */
  function listenBeforeLeavingRoute(route, hook) {
    // TODO: Warn if they register for a route that isn't currently
    // active. They're probably doing something wrong, like re-creating
    // route objects on every location change.
    var routeID = getRouteID(route);
    var hooks = RouteHooks[routeID];

    if (!hooks) {
      var thereWereNoRouteHooks = !hasAnyProperties(RouteHooks);

      RouteHooks[routeID] = [hook];

      if (thereWereNoRouteHooks) {
        // setup transition & beforeunload hooks
        unlistenBefore = history.listenBefore(transitionHook);

        if (history.listenBeforeUnload) unlistenBeforeUnload = history.listenBeforeUnload(beforeUnloadHook);
      }
    } else {
      if (hooks.indexOf(hook) === -1) {
        process.env.NODE_ENV !== 'production' ? warning(false, 'adding multiple leave hooks for the same route is deprecated; manage multiple confirmations in your own code instead') : void 0;

        hooks.push(hook);
      }
    }

    return function () {
      var hooks = RouteHooks[routeID];

      if (hooks) {
        var newHooks = hooks.filter(function (item) {
          return item !== hook;
        });

        if (newHooks.length === 0) {
          removeListenBeforeHooksForRoute(route);
        } else {
          RouteHooks[routeID] = newHooks;
        }
      }
    };
  }

  /**
   * This is the API for stateful environments. As the location
   * changes, we update state and call the listener. We can also
   * gracefully handle errors and redirects.
   */
  function listen(listener) {
    // TODO: Only use a single history listener. Otherwise we'll
    // end up with multiple concurrent calls to match.
    return history.listen(function (location) {
      if (state.location === location) {
        listener(null, state);
      } else {
        match(location, function (error, redirectLocation, nextState) {
          if (error) {
            listener(error);
          } else if (redirectLocation) {
            history.replace(redirectLocation);
          } else if (nextState) {
            listener(null, nextState);
          } else {
            process.env.NODE_ENV !== 'production' ? warning(false, 'Location "%s" did not match any routes', location.pathname + location.search + location.hash) : void 0;
          }
        });
      }
    });
  }

  return {
    isActive: isActive,
    match: match,
    listenBeforeLeavingRoute: listenBeforeLeavingRoute,
    listen: listen
  };
}

//export default useRoutes