import { useQuery, useMutation, useQueryClient, keepPreviousData } from "@tanstack/react-query";
import * as React from "react";
import { api } from "../api/client";
import { ResourceConfig } from "../types/config";
import { ConfigContext } from "../providers/ConfigContext";
import { FieldComponents, FieldComponentProps } from "../types/overrides";
import { defaultFieldComponents } from "../components/fields/DefaultFieldComponents";
import FormField from "../components/fields/FormField";
import GenericForm from "../components/GenericForm";

function wrapFormField(merged: FieldComponents) {
  return (props: Omit<React.ComponentProps<typeof FormField>, 'components'>) =>
    React.createElement(FormField, { ...props, components: merged });
}

function wrapGenericForm(merged: FieldComponents) {
  return (props: Omit<React.ComponentProps<typeof GenericForm>, 'fieldComponents'>) =>
    React.createElement(GenericForm, { ...props, fieldComponents: merged });
}

export function useResource<T = any>(config: ResourceConfig | undefined, options?: { fieldComponents: FieldComponents }) {
  const queryClient = useQueryClient();

  const { name = '', endpoint = '', primaryKey = 'id' } = config || {};

  const mergedComponents = React.useMemo(
    () => options?.fieldComponents ? ({ ...defaultFieldComponents, ...options.fieldComponents }) : undefined,
    [options?.fieldComponents],
  );

  // --- READ ALL ---
  const useList = (params?: any) =>
    useQuery({
      queryKey: [name, "list", params],
      queryFn: async () => {
        if (!endpoint) return { data: [], total: 0 };
        const res = await api.get<T[]>(endpoint, { params });
        const total = res.headers ? parseInt(res.headers['x-total-count'] || res.headers['X-Total-Count']) : undefined;
        return {
            data: res.data,
            total: isNaN(total as any) ? undefined : total
        };
      },
      enabled: !!endpoint,
      placeholderData: keepPreviousData,
    });

  // --- READ ONE ---
  const useRead = (id: string, params?: any | null) =>
    useQuery({
      queryKey: [name, "detail", id, params],
      queryFn: async () => {
        if (!id || !endpoint) return null;
        const res = await api.get<T>(`${endpoint}/${id}`, params ? { params } : undefined);
        return res.data;
      },
      enabled: !!id && !!endpoint,
    });

  // --- CREATE ---
  const useCreate = () =>
    useMutation({
      mutationFn: async (data: Partial<T>) => {
        if (!endpoint) throw new Error("Endpoint not defined");
        const res = await api.post<T>(endpoint, data);
        return res.data;
      },
      onSuccess: () => {
        queryClient.invalidateQueries({ queryKey: [name, "list"] });
      },
    });

  // --- UPDATE ---
  const useUpdate = () =>
    useMutation({
      mutationFn: async ({ id, data }: { id: string; data: Partial<T> }) => {
        if (!endpoint) throw new Error("Endpoint not defined");
        const res = await api.put<T>(`${endpoint}/${id}`, data);
        return res.data;
      },
      onSuccess: (updatedItem: any) => {
        const id = updatedItem[primaryKey];
        queryClient.invalidateQueries({ queryKey: [name, "list"] });
        queryClient.invalidateQueries({ queryKey: [name, "detail", id] });
      },
    });

  // --- PATCH ---
  const usePatch = () =>
    useMutation({
      mutationFn: async ({ id, data }: { id: string; data: Partial<T> }) => {
        if (!endpoint) throw new Error("Endpoint not defined");
        const res = await api.patch<T>(`${endpoint}/${id}`, data);
        return res.data;
      },
      onSuccess: (updatedItem: any) => {
        const listId = updatedItem[primaryKey];
        queryClient.invalidateQueries({ queryKey: [name, "list"] });
        queryClient.invalidateQueries({ queryKey: [name, "detail", listId] });
      },
    });

  // --- DELETE ---
  const useDelete = () =>
    useMutation({
      mutationFn: async (id: string) => {
        if (!endpoint) throw new Error("Endpoint not defined");
        await api.delete(`${endpoint}/${id}`);
        return id;
      },
      onSuccess: () => {
        queryClient.invalidateQueries({ queryKey: [name, "list"] });
      },
    });

  // --- HELPERS FOR useQueries ---
  const getListQueryOptions = (params?: any) => ({
    queryKey: [name, "list", params],
    queryFn: async () => {
      if (!endpoint) return { data: [], total: 0 };
      const res = await api.get<T[]>(endpoint, { params });
      const total = res.headers ? parseInt(res.headers['x-total-count'] || res.headers['X-Total-Count']) : undefined;
      return {
          data: res.data,
          total: isNaN(total as any) ? undefined : total
      };
    },
    enabled: !!endpoint,
  });

  // --- READ ME ---
  const useMe = () =>
    useQuery({
      queryKey: [name, "me"],
      queryFn: async () => {
        if (!endpoint) return null;
        const res = await api.get<T>(`${endpoint}/me`);
        return res.data;
      },
      enabled: !!endpoint,
    });

  // --- UPDATE ME ---
  const useUpdateMe = () =>
    useMutation({
      mutationFn: async (data: Partial<T>) => {
        if (!endpoint) throw new Error("Endpoint not defined");
        const res = await api.put<T>(`${endpoint}/me`, data);
        return res.data;
      },
      onSuccess: () => {
        queryClient.invalidateQueries({ queryKey: [name, "me"] });
        queryClient.invalidateQueries({ queryKey: [name, "list"] });
      },
    });

  const components = React.useMemo(() => {
    if (!mergedComponents) return undefined;
    return {
      ...mergedComponents,
      FormField: wrapFormField(mergedComponents),
      GenericForm: wrapGenericForm(mergedComponents),
    };
  }, [mergedComponents]);

  return {
    useList,
    useRead,
    useMe,
    useCreate,
    useUpdate,
    usePatch,
    useUpdateMe,
    useDelete,
    getListQueryOptions,
    components,
  };
}

export function useResourceByName<T = any>(name: string, options?: { fieldComponents: FieldComponents }) {
  const config = React.useContext(ConfigContext);
  const resourceConfig = config?.resources.find((r) => r.name === name);
  return useResource<T>(resourceConfig, options);
}