import React, { useEffect, useRef, useState, useMemo } from "react";
import { useForm } from "react-hook-form";
import { z } from "zod";
import { zodResolver } from "@hookform/resolvers/zod";
import { useDispatch } from "react-redux";

import { useEmployeeRoles, useUpdateEmployeeRoles } from "../../hooks/useEmployees";
import useMaster from "../../hooks/masterHook/useMaster";
import { changeMaster } from "../../slices/localVariablesSlice";
import { RolesRepository } from "../../repositories/MastersRepository";
import showToast from "../../services/toastService";

const formSchema = z.object({
  selectedRole: z.record(z.boolean()),
});

const ManageRole = ( {employeeId, onClosed} ) =>
{
  const dispatch = useDispatch();
  const formStateRef = useRef({});


  useEffect(() => {
    dispatch(changeMaster("Application Role"));
  }, [dispatch]);


  const { employeeRoles = [], loading: empLoading } = useEmployeeRoles(employeeId);
  const { data: roles = [], loading: roleLoading } = useMaster();
  const {
    register,
    handleSubmit,
    formState: { errors },
    reset,
  } = useForm({
    resolver: zodResolver(formSchema),
    defaultValues: { selectedRole: {} },
  });
  const {
    updateRoles,
    isPending : isLoading,
    isError,
    error,
  } = useUpdateEmployeeRoles({
    onClose: onClosed,
    resetForm: reset,
  });
  // Prepare default form values based on roles and current assignments
  const selectedRoleDefaults = useMemo(() => {
    const defaults = {};
    roles.forEach((role) => {
      const enabled = employeeRoles.some(
        (empRole) => empRole.roleId === role.id && empRole.isEnabled
      );
      defaults[role.id] = enabled;
    });
    return defaults;
  }, [roles, employeeRoles]);

  // Avoid infinite loop by comparing previous form values
  useEffect(() => {
    const prev = JSON.stringify(formStateRef.current);
    const next = JSON.stringify(selectedRoleDefaults);

    if (prev !== next) {
      formStateRef.current = selectedRoleDefaults;
      reset({ selectedRole: selectedRoleDefaults });
    }
  }, [selectedRoleDefaults, reset]);

  const onSubmit = async (formData) => {
    // setIsLoading(true);

    const updates = [];
    const selected = formData.selectedRole;

    for (const [roleId, isChecked] of Object.entries(selected)) {
      const existing = employeeRoles.find((r) => r.roleId === roleId);
      const wasChecked = !!existing?.isEnabled;

      if (isChecked !== wasChecked) {
        updates.push({
          id: existing?.id || "00000000-0000-0000-0000-000000000000",
          employeeId,
          roleId,
          isEnabled: isChecked,
        });
      }
    }

    if (updates.length === 0) {
      showToast("No changes made", "info");
      // setIsLoading(false);
      return;
    }

    // try {
    //   await RolesRepository.createEmployeeRoles(updates);
    //   showToast("Roles updated successfully", "success");
    //   reset();
    //   onClosed();
    // } catch (err) {
    //   const message =
    //     err?.response?.data?.message || err?.message || "Error occurred while updating roles";
    //   showToast(message, "error");
    // } finally {
    //   setIsLoading(false);
    // }
    updateRoles(updates);
  };

  const isLoadingData = roleLoading || empLoading;

  return (
            <form onSubmit={handleSubmit(onSubmit)}>
              <div className="text-start mb-3">
                <p className="lead">Select Roles</p>
              </div>

              {isLoadingData ? (
                <p>Loading...</p>
              ) : (
                <div
                  className="d-flex flex-wrap justify-content-between pb-4"
                  style={{ maxHeight: "70vh", overflowY: "auto" }}
                >
                  {roles.map((role) => (
                    <div className="col-md-6 col-lg-4 mb-3" key={role.id}>
                      <div className="form-check ms-2 text-start">
                        <input
                          className="form-check-input"
                          type="checkbox"
                          id={role.id}
                          {...register(`selectedRole.${role.id}`)}
                        />
                        <label className="form-check-label" htmlFor={role.id}>
                          <small>{role.role || "--"}</small>
                        </label>
                      </div>
                    </div>
                  ))}
                </div>
              )}

              {errors.selectedRole && (
                <div className="text-danger text-center">
                  {errors.selectedRole.message}
                </div>
              )}

              <div className="text-center mt-3">
                <button type="submit" className="btn btn-sm btn-primary me-3" disabled={isLoading}>
                  {isLoading ? "Please Wait..." : "Submit"}
                </button>
                <button
                  type="reset"
                  className="btn btn-sm btn-label-secondary"
                  data-bs-dismiss="modal"
                  aria-label="Close"
                >
                  Cancel
                </button>
              </div>
            </form>
  );
};

export default ManageRole;