import { useState, useCallback } from 'react';

interface LoadingState<T> {
  data: T | null;
  isLoading: boolean;
  error: string | null;
  isRefreshing: boolean;
}

interface UseLoadingStateOptions<T> {
  initialData?: T | null;
}

interface UseLoadingStateReturn<T> extends LoadingState<T> {
  setData: (data: T | null) => void;
  setLoading: (loading: boolean) => void;
  setError: (error: string | null) => void;
  setRefreshing: (refreshing: boolean) => void;
  reset: () => void;
  execute: <R = T>(
    asyncFn: () => Promise<R>,
    options?: { refresh?: boolean; transform?: (result: R) => T }
  ) => Promise<R | undefined>;
}

/**
 * Custom hook for managing loading states
 * Provides consistent loading, error, and data state management
 */
export function useLoadingState<T>(
  options: UseLoadingStateOptions<T> = {}
): UseLoadingStateReturn<T> {
  const { initialData = null } = options;

  const [state, setState] = useState<LoadingState<T>>({
    data: initialData,
    isLoading: false,
    error: null,
    isRefreshing: false,
  });

  const setData = useCallback((data: T | null) => {
    setState((prev) => ({ ...prev, data, error: null }));
  }, []);

  const setLoading = useCallback((isLoading: boolean) => {
    setState((prev) => ({ ...prev, isLoading }));
  }, []);

  const setError = useCallback((error: string | null) => {
    setState((prev) => ({ ...prev, error, isLoading: false, isRefreshing: false }));
  }, []);

  const setRefreshing = useCallback((isRefreshing: boolean) => {
    setState((prev) => ({ ...prev, isRefreshing }));
  }, []);

  const reset = useCallback(() => {
    setState({
      data: initialData,
      isLoading: false,
      error: null,
      isRefreshing: false,
    });
  }, [initialData]);

  /**
   * Execute an async function with automatic loading state management
   * @param asyncFn - The async function to execute
   * @param options.refresh - If true, sets isRefreshing instead of isLoading
   * @param options.transform - Optional function to transform the result before setting data
   */
  const execute = useCallback(
    async <R = T>(
      asyncFn: () => Promise<R>,
      execOptions?: { refresh?: boolean; transform?: (result: R) => T }
    ): Promise<R | undefined> => {
      const { refresh = false, transform } = execOptions || {};

      try {
        if (refresh) {
          setState((prev) => ({ ...prev, isRefreshing: true, error: null }));
        } else {
          setState((prev) => ({ ...prev, isLoading: true, error: null }));
        }

        const result = await asyncFn();

        // Transform and set data if transform function provided
        if (transform) {
          const transformedData = transform(result);
          setState((prev) => ({
            ...prev,
            data: transformedData,
            isLoading: false,
            isRefreshing: false,
          }));
        } else {
          // If no transform, try to set result as data (if types match)
          setState((prev) => ({
            ...prev,
            data: result as unknown as T,
            isLoading: false,
            isRefreshing: false,
          }));
        }

        return result;
      } catch (err) {
        const errorMessage =
          err instanceof Error ? err.message : 'An error occurred';
        setState((prev) => ({
          ...prev,
          error: errorMessage,
          isLoading: false,
          isRefreshing: false,
        }));
        return undefined;
      }
    },
    []
  );

  return {
    ...state,
    setData,
    setLoading,
    setError,
    setRefreshing,
    reset,
    execute,
  };
}

/**
 * Simple boolean loading state hook
 * For cases where you just need a loading flag
 */
export function useSimpleLoading(initialState = false) {
  const [isLoading, setIsLoading] = useState(initialState);

  const startLoading = useCallback(() => setIsLoading(true), []);
  const stopLoading = useCallback(() => setIsLoading(false), []);
  const toggleLoading = useCallback(() => setIsLoading((prev) => !prev), []);

  const withLoading = useCallback(
    async <T>(asyncFn: () => Promise<T>): Promise<T> => {
      setIsLoading(true);
      try {
        return await asyncFn();
      } finally {
        setIsLoading(false);
      }
    },
    []
  );

  return {
    isLoading,
    setIsLoading,
    startLoading,
    stopLoading,
    toggleLoading,
    withLoading,
  };
}

/**
 * Hook for managing multiple loading states by key
 * Useful for list items that can have individual loading states
 */
export function useMultipleLoadingStates() {
  const [loadingStates, setLoadingStates] = useState<Record<string, boolean>>({});

  const setLoading = useCallback((key: string, loading: boolean) => {
    setLoadingStates((prev) => ({ ...prev, [key]: loading }));
  }, []);

  const isLoading = useCallback(
    (key: string) => loadingStates[key] || false,
    [loadingStates]
  );

  const anyLoading = Object.values(loadingStates).some(Boolean);

  const clearAll = useCallback(() => {
    setLoadingStates({});
  }, []);

  return {
    loadingStates,
    setLoading,
    isLoading,
    anyLoading,
    clearAll,
  };
}