import {
  CommonActions,
  type NavigationAction,
  type NavigationState,
  type ParamListBase,
  type Router,
} from '@react-navigation/routers';
import * as React from 'react';

import { NavigationBuilderContext } from './NavigationBuilderContext';
import type { NavigationHelpers, NavigationProp } from './types';
import type { NavigationEventEmitter } from './useEventEmitter';

type Options<
  State extends NavigationState,
  ScreenOptions extends {},
  EventMap extends Record<string, any>,
> = {
  state: State;
  getState: () => State;
  navigation: NavigationHelpers<ParamListBase> &
    Partial<NavigationProp<ParamListBase, string, any, any, any>>;
  setOptions: (
    cb: (
      options: Record<string, ScreenOptions>
    ) => Record<string, ScreenOptions>
  ) => void;
  router: Router<State, NavigationAction>;
  emitter: NavigationEventEmitter<EventMap>;
};

type NavigationItem<
  State extends NavigationState,
  ScreenOptions extends {},
  EventMap extends Record<string, any>,
> = NavigationProp<
  ParamListBase,
  string,
  string | undefined,
  State,
  ScreenOptions,
  EventMap
>;

type NavigationCache<
  State extends NavigationState,
  ScreenOptions extends {},
  EventMap extends Record<string, any>,
> = Record<string, NavigationItem<State, ScreenOptions, EventMap>>;

/**
 * Hook to cache navigation objects for each screen in the navigator.
 * It's important to cache them to make sure navigation objects don't change between renders.
 * This lets us apply optimizations like `React.memo` to minimize re-rendering screens.
 */
export function useNavigationCache<
  State extends NavigationState,
  ScreenOptions extends {},
  EventMap extends Record<string, any>,
  ActionHelpers extends Record<string, () => void>,
>({
  state,
  getState,
  navigation,
  setOptions,
  router,
  emitter,
}: Options<State, ScreenOptions, EventMap>) {
  const { stackRef } = React.useContext(NavigationBuilderContext);

  const base = React.useMemo((): NavigationItem<
    State,
    ScreenOptions,
    EventMap
  > &
    ActionHelpers => {
    // eslint-disable-next-line @typescript-eslint/no-unused-vars
    const { emit, ...rest } = navigation;

    const actions = {
      ...router.actionCreators,
      ...CommonActions,
    };

    const dispatch = () => {
      throw new Error(
        'Actions cannot be dispatched from a placeholder screen.'
      );
    };

    const helpers = Object.keys(actions).reduce<Record<string, () => void>>(
      (acc, name) => {
        acc[name] = dispatch;

        return acc;
      },
      {}
    ) as ActionHelpers;

    return {
      ...rest,
      ...helpers,
      addListener: () => {
        // Event listeners are not supported for placeholder screens

        return () => {
          // Empty function
        };
      },
      removeListener: () => {
        // Event listeners are not supported for placeholder screens
      },
      dispatch,
      getParent: (id?: string) => {
        if (id !== undefined && id === rest.getId()) {
          return base;
        }

        return rest.getParent(id);
      },
      setOptions: () => {
        throw new Error('Options cannot be set from a placeholder screen.');
      },
      isFocused: () => false,
    };
  }, [navigation, router.actionCreators]);

  // Cache object which holds navigation objects for each screen
  // We use `React.useMemo` instead of `React.useRef` coz we want to invalidate it when deps change
  // In reality, these deps will rarely change, if ever
  const cache = React.useMemo(
    () => ({ current: {} as NavigationCache<State, ScreenOptions, EventMap> }),
    // eslint-disable-next-line react-hooks/exhaustive-deps
    [base, getState, navigation, setOptions, emitter]
  );

  cache.current = state.routes.reduce<
    NavigationCache<State, ScreenOptions, EventMap>
  >((acc, route) => {
    const previous = cache.current[route.key];

    type Thunk =
      | NavigationAction
      | ((state: State) => NavigationAction | null | undefined);

    if (previous) {
      // If a cached navigation object already exists, reuse it
      acc[route.key] = previous;
    } else {
      const dispatch = (thunk: Thunk) => {
        const action = typeof thunk === 'function' ? thunk(getState()) : thunk;

        if (action != null) {
          navigation.dispatch({ source: route.key, ...action });
        }
      };

      const withStack = (callback: () => void) => {
        let isStackSet = false;

        try {
          if (
            process.env.NODE_ENV !== 'production' &&
            stackRef &&
            !stackRef.current
          ) {
            // Capture the stack trace for devtools
            stackRef.current = new Error().stack;
            isStackSet = true;
          }

          callback();
        } finally {
          if (isStackSet && stackRef) {
            stackRef.current = undefined;
          }
        }
      };

      const actions = {
        ...router.actionCreators,
        ...CommonActions,
      };

      const helpers = Object.keys(actions).reduce<Record<string, () => void>>(
        (acc, name) => {
          acc[name] = (...args: any) =>
            withStack(() =>
              // @ts-expect-error: name is a valid key, but TypeScript is dumb
              dispatch(actions[name](...args))
            );

          return acc;
        },
        {}
      );

      acc[route.key] = {
        ...base,
        ...helpers,
        // FIXME: too much work to fix the types for now
        ...(emitter.create(route.key) as any),
        dispatch: (thunk: Thunk) => withStack(() => dispatch(thunk)),
        getParent: (id?: string) => {
          if (id !== undefined && id === base.getId()) {
            // If the passed id is the same as the current navigation id,
            // we return the cached navigation object for the relevant route
            return acc[route.key];
          }

          return base.getParent(id);
        },
        setOptions: (options: object) => {
          setOptions((o) => ({
            ...o,
            [route.key]: { ...o[route.key], ...options },
          }));
        },
        isFocused: () => {
          const state = base.getState();

          if (state.routes[state.index].key !== route.key) {
            return false;
          }

          // If the current screen is focused, we also need to check if parent navigator is focused
          // This makes sure that we return the focus state in the whole tree, not just this navigator
          return navigation ? navigation.isFocused() : true;
        },
      };
    }

    return acc;
  }, {});

  return {
    base,
    navigations: cache.current,
  };
}