import { useState, useEffect, useCallback, useMemo } from "react";
import { useDebounce } from "../useDebounce";
import useProjectService from "./useProjectService";
import {
  type Project,
  type ProjectFilters,
  type CreateProjectData,
  type UpdateProjectData,
} from "../../services/projectService";
import { useSearchParams } from "next/navigation";

interface UseProjectState {
  projects: Project[];
  total: number;
  currentPage: number;
  totalPages: number;
  itemsPerPage: number;
  searchTerm: string;
  statusFilters: string[];
  projectManagerFilter: string;
  order: string;
  columnName: string | null;
  loading: boolean;
  error: string | null;
}

interface UseProjectActions {
  setSearchTerm: (term: string) => void;
  setStatusFilter: (filters: string[]) => void;
  setProjectManagerFilter: (managerId: string) => void;
  setOrder: (order: string) => void;
  setColumnName: (columnName: string | null) => void;
  setCurrentPage: (page: number) => void;
  setItemsPerPage: (items: number) => void;
  clearFilters: () => void;
  refreshData: () => Promise<void>;
  createProject: (data: CreateProjectData) => Promise<boolean>;
  updateProject: (data: UpdateProjectData) => Promise<boolean>;
  deleteProject: (id: string) => Promise<boolean>;
  getProjectById: (id: string) => Promise<Project | null>;
}

const INITIAL_STATE: UseProjectState = {
  projects: [],
  total: 0,
  currentPage: 1,
  totalPages: 0,
  itemsPerPage: 100,
  searchTerm: "",
  statusFilters: [],
  projectManagerFilter: "All",
  order: "",
  columnName: null,
  loading: false,
  error: null,
};

function useProject() {
  const searchParams = useSearchParams();
  const filter = searchParams.get("filter");
  const statusesParam = searchParams.get("statuses");
  const statusParam = searchParams.get("status");
  const [state, setState] = useState<UseProjectState>(() => {
    const initialStatuses = (statusesParam || statusParam || "")
      .split(",")
      .map((item) => item.trim())
      .filter(Boolean);

    return {
      ...INITIAL_STATE,
      statusFilters: initialStatuses,
    };
  });
  const service = useProjectService();
  // Debounce search term with 500ms delay
  const debouncedSearchTerm = useDebounce(state.searchTerm, 500);

  // Memoize filters to prevent unnecessary API calls
  const filters = useMemo<ProjectFilters>(() => {
    const result: ProjectFilters = {
      search: debouncedSearchTerm,
      page: state.currentPage,
      limit: state.itemsPerPage,
    };

    if (state.statusFilters.length === 1) {
      result.status = state.statusFilters[0];
    } else if (state.statusFilters.length > 1) {
      result.statuses = state.statusFilters.join(",");
    }

    if (state.order && state.columnName) {
      result.order = state.order.toLowerCase() as 'ASC' | 'DESC';
      result.column_name = state.columnName;
    }

    if (filter) {
      result.filter_by = filter;
    }

    if (state.projectManagerFilter && state.projectManagerFilter !== "All") {
      result.managed_by = state.projectManagerFilter;
    }

    return result;
  }, [
    debouncedSearchTerm,
    state.statusFilters,
    state.projectManagerFilter,
    state.currentPage,
    state.itemsPerPage,
    state.order,
    state.columnName,
  ]);

  // Auto-fetch when filters change
  useEffect(() => {
    const parsedStatuses = (statusesParam || statusParam || "")
      .split(",")
      .map((item) => item.trim())
      .filter(Boolean);

    setState((prev) => ({
      ...prev,
      statusFilters: parsedStatuses,
      currentPage: 1,
    }));
  }, [statusesParam, statusParam]);

  useEffect(() => {
    const fetchProjects = async () => {
      setState((prev) => ({ ...prev, loading: true, error: null }));

      const result = await service.getProjects(filters);

      if (result.success && result.data) {
        const total = result.data.data?.count ?? 0;
        const limit = filters.limit ?? 10;

        setState((prev) => ({
          ...prev,
          projects: result.data!.data?.data ?? [],
          total,
          totalPages: Math.ceil(total / limit),
          loading: false,
          error: null,
        }));
      } else {
        setState((prev) => ({
          ...prev,
          projects: [],
          total: 0,
          totalPages: 0,
          loading: false,
          error: result.message,
        }));
      }
    };

    fetchProjects();
  }, [filters]);

  // Action handlers
  const setSearchTerm = useCallback((term: string) => {
    setState((prev) => ({ ...prev, searchTerm: term, currentPage: 1 }));
  }, []);

  const setStatusFilter = useCallback((filters: string[]) => {
    setState((prev) => ({
      ...prev,
      statusFilters: filters,
      currentPage: 1,
    }));
  }, []);

  const setProjectManagerFilter = useCallback((managerId: string) => {
    setState((prev) => ({ ...prev, projectManagerFilter: managerId, currentPage: 1 }));
  }, []);

  const setOrder = useCallback((order: string) => {
    setState((prev) => ({ ...prev, order }));
  }, []);

  const setColumnName = useCallback((columnName: string | null) => {
    setState((prev) => ({ ...prev, columnName }));
  }, []);

  const setCurrentPage = useCallback((page: number) => {
    setState((prev) => ({ ...prev, currentPage: page }));
  }, []);

  const setItemsPerPage = useCallback((items: number) => {
    setState((prev) => ({ ...prev, itemsPerPage: items, currentPage: 1 }));
  }, []);

  // Clear only filter dropdowns (Status, Project Manager); do not clear search
  const clearFilters = useCallback(() => {
    setState((prev) => ({
      ...prev,
      statusFilters: [],
      projectManagerFilter: "All",
      order: "",
      columnName: null,
      currentPage: 1,
    }));
  }, []);

  const refreshData = useCallback(async () => {
    setState((prev) => ({ ...prev, loading: true, error: null }));

    const result = await service.getProjects(filters);

    if (result.success && result.data) {
      const total = result.data.data?.count ?? 0;
      const limit = filters.limit ?? 10;

      setState((prev) => ({
        ...prev,
        projects: result.data!.data?.data ?? [],
        total,
        totalPages: Math.ceil(total / limit),
        loading: false,
        error: null,
      }));
    } else {
      setState((prev) => ({
        ...prev,
        projects: [],
        total: 0,
        totalPages: 0,
        loading: false,
        error: result.message,
      }));
    }
  }, [service, filters]);

  // CRUD operations
  const createProject = useCallback(
    async (data: CreateProjectData): Promise<boolean> => {
      const result = await service.createProject(data);
      if (result.success) {
        await refreshData();
      }
      return result.success;
    },
    [service, refreshData]
  );

  const updateProject = useCallback(
    async (data: UpdateProjectData): Promise<boolean> => {
      const result = await service.updateProject(data);
      if (result.success) {
        await refreshData();
      }
      return result.success;
    },
    [service, refreshData]
  );

  const deleteProject = useCallback(
    async (id: string): Promise<boolean> => {
      const result = await service.deleteProject(id);
      if (result.success) {
        await refreshData();
      }
      return result.success;
    },
    [service, refreshData]
  );

  const getProjectById = useCallback(
    async (id: string): Promise<Project | null> => {
      const result = await service.getProjectById(id);
      return result.success && result.data ? result.data.data : null;
    },
    []
  );

  const actions: UseProjectActions = {
    setSearchTerm,
    setStatusFilter,
    setProjectManagerFilter,
    setOrder,
    setColumnName,
    setCurrentPage,
    setItemsPerPage,
    clearFilters,
    refreshData,
    createProject,
    updateProject,
    deleteProject,
    getProjectById,
  };

  return {
    ...state,
    loading: state.loading || service.loading,
    ...actions,
  };
}

export default useProject;