import React, { FC, useReducer } from 'react';
import CurrencyInput, { formatValue } from '../index';

type Field = {
  value: number | undefined;
  validationClass: string;
  errorMessage: string;
};

type ExampleState = {
  field1: Field;
  field2: Field;
};

type Action = {
  fieldName: string;
  value: Field;
};

function reducer(state: ExampleState, { fieldName, value }: Action): ExampleState {
  return {
    ...state,
    [fieldName]: value,
  };
}

const initialState: ExampleState = {
  field1: {
    value: 100,
    validationClass: '',
    errorMessage: '',
  },
  field2: {
    value: 200,
    validationClass: '',
    errorMessage: '',
  },
};

export const Example4: FC = () => {
  const prefix = '£';
  const [state, dispatch] = useReducer(reducer, initialState);

  const handleOnValueChange = (_value: string | undefined, fieldName: string | undefined): void => {
    if (!fieldName) {
      return;
    }

    if (!_value) {
      return dispatch({
        fieldName,
        value: {
          value: undefined,
          validationClass: '',
          errorMessage: '',
        },
      });
    }

    const value = Number(_value);

    if (!Number.isNaN(value)) {
      dispatch({
        fieldName,
        value: {
          value,
          validationClass: 'is-valid',
          errorMessage: '',
        },
      });
    } else {
      dispatch({
        fieldName,
        value: {
          value,
          validationClass: 'is-invalid',
          errorMessage: 'Please enter a valid number',
        },
      });
    }
  };

  const total = (state.field1.value || 0) + (state.field2.value || 0);

  return (
    <div className="row">
      <div className="col-12 mb-4">
        <a
          href="https://github.com/cchanxzy/react-currency-input-field/blob/main/src/examples/Example4.tsx"
          target="_blank"
          rel="noreferrer"
        >
          <h2>Example 4</h2>
        </a>
        <ul>
          <li>Add two values together</li>
          <li>Format the total value</li>
        </ul>

        <form className="needs-validation">
          <div className="row">
            <div className="col">
              <label htmlFor="validation-example-3-field1">Value 1</label>
              <CurrencyInput
                id="validation-example-3-field1"
                name="field1"
                className={`form-control ${state.field1.validationClass}`}
                value={state.field1.value}
                onValueChange={handleOnValueChange}
                prefix={prefix}
              />
              <div className="invalid-feedback">{state.field1.errorMessage}</div>
            </div>

            <div className="col">
              <label htmlFor="validation-example-3-field2">Value 2</label>
              <CurrencyInput
                id="validation-example-3-field2"
                name="field2"
                className={`form-control ${state.field2.validationClass}`}
                value={state.field2.value}
                onValueChange={handleOnValueChange}
                prefix={prefix}
              />
              <div className="invalid-feedback">{state.field1.errorMessage}</div>
            </div>

            <div className="col">
              <div className="">
                <label>Total:</label>
                <div className="h3">{formatValue({ prefix, value: String(total) })}</div>
              </div>
            </div>
          </div>
        </form>
      </div>
    </div>
  );
};

export default Example4;