text: import _without from "lodash/without";
  import _isFunction from "lodash/isFunction";
  import _isEmpty from "lodash/isEmpty";
  import _partial from "lodash/partial";
  import _merge from "lodash/merge";
  import _extend from "lodash/extend";
  import _assign from "lodash/assign";
  
  function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
  
  function _toConsumableArray(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) { arr2[i] = arr[i]; } return arr2; } else { return Array.from(arr); } }
  
  export default {
    /* Returns all own and shared events that should be attached to a single target element,
     * i.e. an individual bar specified by target: "data", eventKey: [index].
     * Returned events are scoped to the appropriate state. Either that of the component itself
     * (i.e. VictoryBar) in the case of own events, or that of the parent component
     * (i.e. VictoryChart) in the case of shared events
     */
    getEvents: function (props, target, eventKey, getScopedEvents) {
      var _this = this;
  
      // Returns all events that apply to a particular target element
      var getEventsByTarget = function (events) {
        var getSelectedEvents = function () {
          var targetEvents = events.reduce(function (memo, event) {
            if (event.target !== undefined) {
              return "" + event.target === "" + target ? memo.concat(event) : memo;
            }
            return memo.concat(event);
          }, []);
  
          if (eventKey !== undefined && target !== "parent") {
            return targetEvents.filter(function (obj) {
              var targetKeys = obj.eventKey;
              var useKey = function (key) {
                return key ? "" + key === "" + eventKey : true;
              };
              return Array.isArray(targetKeys) ? targetKeys.some(function (k) {
                return useKey(k);
              }) : useKey(targetKeys);
            });
          }
          return targetEvents;
        };
  
        var selectedEvents = getSelectedEvents();
        return Array.isArray(selectedEvents) && selectedEvents.reduce(function (memo, event) {
          return event ? _assign(memo, event.eventHandlers) : memo;
        }, {});
      };
  
      /* Returns all events from props and defaultEvents from components. Events handlers
       * specified in props will override handlers for the same event if they are also
       * specified in defaultEvents of a sub-component
       */
      var getAllEvents = function () {
        if (Array.isArray(_this.componentEvents)) {
          var _componentEvents;
  
          return Array.isArray(props.events) ? (_componentEvents = _this.componentEvents).concat.apply(_componentEvents, _toConsumableArray(props.events)) : _this.componentEvents;
        }
        return props.events;
      };
  
      var allEvents = getAllEvents();
      var ownEvents = allEvents && _isFunction(getScopedEvents) ? getScopedEvents(getEventsByTarget(allEvents), target) : undefined;
      if (!props.sharedEvents) {
        return ownEvents;
      }
      var getSharedEvents = props.sharedEvents.getEvents;
      var sharedEvents = props.sharedEvents.events && getSharedEvents(getEventsByTarget(props.sharedEvents.events), target);
      return _assign({}, sharedEvents, ownEvents);
    },
  
  
    /* Returns a modified events object where each event handler is replaced by a new
     * function that calls the original handler and then calls setState with the return
     * of the original event handler assigned to state property that maps to the target
     * element.
     */
    getScopedEvents: function (events, namespace, childType, baseProps) {
      var _this2 = this;
  
      if (_isEmpty(events)) {
        return {};
      }
  
      baseProps = baseProps || this.baseProps;
      // returns the original base props or base state of a given target element
      var getTargetProps = function (identifier, type) {
        var childName = identifier.childName,
            target = identifier.target,
            key = identifier.key;
  
        var baseType = type === "props" ? baseProps : _this2.state || {};
        var base = childName === undefined || childName === null || !baseType[childName] ? baseType : baseType[childName];
        return key === "parent" ? base.parent : base[key] && base[key][target];
      };
  
      // Returns the state object with the mutation caused by a given eventReturn
      // applied to the appropriate property on the state object
      var parseEvent = function (eventReturn, eventKey) {
        var childNames = namespace === "parent" ? eventReturn.childName : eventReturn.childName || childType;
        var target = eventReturn.target || namespace;
  
        // returns all eventKeys to modify for a targeted childName
        var getKeys = function (childName) {
          if (eventReturn.eventKey === "all") {
            return baseProps[childName] ? _without(Object.keys(baseProps[childName]), "parent") : _without(Object.keys(baseProps), "parent");
          } else if (eventReturn.eventKey === undefined && eventKey === "parent") {
            return baseProps[childName] ? Object.keys(baseProps[childName]) : Object.keys(baseProps);
          }
          return eventReturn.eventKey !== undefined ? eventReturn.eventKey : eventKey;
        };
  
        // returns the state object with mutated props applied for a single key
        var getMutationObject = function (key, childName) {
          var nullFunction = function () {
            return null;
          };
          var mutationTargetProps = getTargetProps({ childName: childName, key: key, target: target }, "props");
          var mutationTargetState = getTargetProps({ childName: childName, key: key, target: target }, "state");
          var mutation = eventReturn.mutation || nullFunction;
          var mutatedProps = mutation(_assign({}, mutationTargetProps, mutationTargetState), baseProps);
          var baseState = _this2.state || {};
          var childState = baseState[childName] || {};
          var extendState = function (state) {
            return target === "parent" ? _extend(state[key], mutatedProps) : _extend(state[key], _defineProperty({}, target, mutatedProps));
          };
          return childName !== undefined && childName !== null ? _extend(baseState, _defineProperty({}, childName, _extend(childState, _defineProperty({}, key, extendState(childState))))) : _extend(baseState, _defineProperty({}, key, extendState(baseState)));
        };
  
        // returns entire mutated state for a given childName
        var getReturnByChild = function (childName) {
          var mutationKeys = getKeys(childName);
          return Array.isArray(mutationKeys) ? mutationKeys.reduce(function (memo, key) {
            return _assign(memo, getMutationObject(key, childName));
          }, {}) : getMutationObject(mutationKeys, childName);
        };
  
        // returns an entire mutated state for all children
        var allChildNames = childNames === "all" ? _without(Object.keys(baseProps), "parent") : childNames;
        return Array.isArray(allChildNames) ? allChildNames.reduce(function (memo, childName) {
          return _assign(memo, getReturnByChild(childName));
        }, {}) : getReturnByChild(allChildNames);
      };
  
      // Parses an array of event returns into a single state mutation
      var parseEventReturn = function (eventReturn, eventKey) {
        return Array.isArray(eventReturn) ? eventReturn.reduce(function (memo, props) {
          memo = _merge({}, memo, parseEvent(props, eventKey));
          return memo;
        }, {}) : parseEvent(eventReturn, eventKey);
      };
  
      var compileCallbacks = function (eventReturn) {
        var getCallback = function (obj) {
          return _isFunction(obj.callback) && obj.callback;
        };
        var callbacks = Array.isArray(eventReturn) ? eventReturn.map(function (evtObj) {
          return getCallback(evtObj);
        }) : [getCallback(eventReturn)];
        var callbackArray = callbacks.filter(function (callback) {
          return callback !== false;
        });
        return callbackArray.length ? function () {
          return callbackArray.forEach(function (callback) {
            return callback();
          });
        } : undefined;
      };
  
      // A function that calls a particular event handler, parses its return
      // into a state mutation, and calls setState
      var onEvent = function (evt, childProps, eventKey, eventName) {
        var eventReturn = events[eventName](evt, childProps, eventKey, _this2);
        if (eventReturn) {
          var callbacks = compileCallbacks(eventReturn);
          _this2.setState(parseEventReturn(eventReturn, eventKey), callbacks);
        }
      };
  
      // returns a new events object with enhanced event handlers
      return Object.keys(events).reduce(function (memo, event) {
        memo[event] = onEvent;
        return memo;
      }, {});
    },
  
  
    /* Returns a partially applied event handler for a specific target element
     * This allows event handlers to have access to props controlling each element
     */
    getPartialEvents: function (events, eventKey, childProps) {
      return events ? Object.keys(events).reduce(function (memo, eventName) {
        /* eslint max-params: 0 */
        memo[eventName] = _partial(events[eventName], _partial.placeholder, // evt will still be the first argument for event handlers
        childProps, // event handlers will have access to data component props, including data
        eventKey, // used in setting a unique state property
        eventName // used in setting a unique state property
        );
        return memo;
      }, {}) : {};
    },
  
  
    /* Returns the property of the state object corresponding to event changes for
     * a particular element
     */
    getEventState: function (eventKey, namespace, childType) {
      var state = this.state || {};
      if (!childType) {
        return eventKey === "parent" ? state[eventKey] && state[eventKey][namespace] || state[eventKey] : state[eventKey] && state[eventKey][namespace];
      }
      return state[childType] && state[childType][eventKey] && state[childType][eventKey][namespace];
    },
  
  
    /* Returns an array of defaultEvents from sub-components of a given component.
     * i.e. any static `defaultEvents` on `labelComponent` will be returned
    */
    getComponentEvents: function (props, components) {
      var events = Array.isArray(components) && components.reduce(function (memo, componentName) {
        var _memo;
  
        var component = props[componentName];
        var defaultEvents = component && component.type && component.type.defaultEvents;
        var componentEvents = _isFunction(defaultEvents) ? defaultEvents(component.props) : defaultEvents;
        memo = Array.isArray(componentEvents) ? (_memo = memo).concat.apply(_memo, _toConsumableArray(componentEvents)) : memo;
        return memo;
      }, []);
      return events && events.length ? events : undefined;
    }
  };