import React, { useState, useEffect } from 'react';
import { useFieldArray, useForm } from 'react-hook-form';
import { z } from 'zod';
import { zodResolver } from '@hookform/resolvers/zod';

// Zod Schema for validation
const schema = z.object({
  activityName: z.string().min(1, { message: "Activity name is required" }),
  unitOfMeasurement: z.string().min(1, { message: "Measurement is required" }),
  checkList: z
    .array(z.string().min(1, { message: "Checklist item cannot be empty" }))
    .optional(),
} );

// for demo data
let initialData = {
  activityName: "Item",
  unitOfMeasurement: "Item-2",
  checkList: [
    'item 3',
    'Item 4'
  ]
}
const EditActivity = ({onClose}) => {
  const [isLoading, setIsLoading] = useState(false);

  const {
    register,
    handleSubmit,
    control,
    setValue,
    clearErrors,
    setError,
    getValues,
    reset,
    formState: { errors },
  } = useForm({
    resolver: zodResolver(schema),
    defaultValues: {
      activityName: '',
      unitOfMeasurement: '',
      checkList: [],
    },
  });

  // Setting up field array for checkList (dynamic fields)
  const {
    fields: checkListItems,
    append,
    remove,
  } = useFieldArray({
    control,
    name: 'checkList',
  });

  // Pre-populating the form with initial data when component mounts or initialData changes
  useEffect(() => {
    if (initialData) {
      reset({
        activityName: initialData.activityName,
        unitOfMeasurement: initialData.unitOfMeasurement,
        checkList: initialData.checkList || [],
      });
    }
  }, [initialData, reset]);

  // Form submission handler
  const onSubmit = (data) => {
    console.log('Submitted:', data);
  };

  // Add a new checklist item
  const addChecklistItem = () => {
    const values = getValues('checkList');
    const lastIndex = checkListItems.length - 1;

    // Prevent adding new input if the last one is empty
    if (checkListItems.length > 0 && (!values?.[lastIndex] || values[lastIndex].trim() === '')) {
      setError(`checkList.${lastIndex}`, {
        type: 'manual',
        message: 'Please fill this checklist item before adding another.',
      });
      return;
    }

    clearErrors(`checkList.${lastIndex}`); // Clear the error if the input is filled.
    append(''); // Add a new empty checklist input
  };

  // Remove a checklist item
  const removeChecklistItem = (index) => {
    remove(index); // Remove the checklist item from the field array
  };

  // Handle checklist item input change
  const handleChecklistChange = (index, value) => {
    setValue(`checkList.${index}`, value); // Update the value of the checklist item
  };

  const handleCLose = () =>
  {
    () => reset()
    onClose()
  }
  return (
    <form onSubmit={handleSubmit(onSubmit)}>
      <div className="row">
        <div className="col-6">
          <label className="form-label">Activity</label>
          <input
            type="text"
            {...register('activityName')}
            className={`form-control form-control-sm ${errors.activityName ? 'is-invalid' : ''}`}
          />
          {errors.activityName && <p className="danger-text">{errors.activityName.message}</p>}
        </div>

        <div className="col-6">
          <label className="form-label">Measurement</label>
          <input
            type="text"
            {...register('unitOfMeasurement')}
            className={`form-control form-control-sm ${errors.unitOfMeasurement ? 'is-invalid' : ''}`}
          />
          {errors.unitOfMeasurement && (
            <p className="danger-text">{errors.unitOfMeasurement.message}</p>
          )}
        </div>

        <div className="col-md-6 text-start">
          {/* Dynamic checklist items */}
          {checkListItems.map((item, index) => (
            <div key={item.id} className="d-flex align-items-center gap-2 my-1">
              <input
                {...register(`checkList.${index}`)}
                className="form-control form-control-sm"
                placeholder={`Checklist item ${index + 1}`}
                onChange={(e) => handleChecklistChange(index, e.target.value)} // Handle input change
              />
              <button
                type="button"
                onClick={() => removeChecklistItem(index)}   // Remove button
                className="btn btn-xs btn-icon btn-text-secondary"
              >
                <span className="icon-base bx bx-x"/>
              </button>
              {errors.checkList?.[index] && (
                <p className="danger-text">{errors.checkList[index]?.message}</p>
              )}
            </div>
          ))}
          {/* Add new checklist item */}
          <button type="button" className="btn btn-sm btn-primary mt-2" onClick={addChecklistItem}>
            + Add Checklist Item
          </button>
        </div>

        <div className="col-12 text-center mt-3">
          <button type="submit" className="btn btn-sm btn-primary me-3">
            Submit
          </button>
          <button
            type="reset"
            className="btn btn-sm btn-label-secondary"
            onClick={handleCLose}
          >
            Cancel
          </button>
        </div>
      </div>
    </form>
  );
};

export default EditActivity;