/**
 * External dependencies
 */
import { utils } from '@rjsf/core';

/**
 * WordPress dependencies
 */
import { SelectControl } from '@wordpress/components';

const { asNumber, guessType } = utils;
const nums = new Set( [ 'number', 'integer' ] );

/**
 * This is a silly limitation in the DOM where option change event values are
 * always retrieved as strings.
 *
 * @param {Object} schema
 * @param {string} schema.type
 * @param {Array} schema.enum
 * @param {*} value
 *
 * @return {*}
 */
function processValue( schema, value ) {
	// "enum" is a reserved word, so only "type" and "items" can be destructured
	const { type, items } = schema;
	if ( value === '' ) {
		return undefined;
	} else if ( type === 'array' && items && nums.has( items.type ) ) {
		return value.map( asNumber );
	} else if ( type === 'boolean' ) {
		return value === 'true';
	} else if ( type === 'number' ) {
		return asNumber( value );
	}

	// If type is undefined, but an enum is present, try and infer the type from
	// the enum values
	if ( schema.enum ) {
		if ( schema.enum.every( ( x ) => guessType( x ) === 'number' ) ) {
			return asNumber( value );
		} else if ( schema.enum.every( ( x ) => guessType( x ) === 'boolean' ) ) {
			return value === 'true';
		}
	}

	return value;
}

function getValue( event, multiple ) {
	if ( multiple ) {
		return [].slice
			.call( event.target.options )
			.filter( ( o ) => o.selected )
			.map( ( o ) => o.value );
	}
	return event.target.value;
}

function SelectWidget( props ) {
	const {
		schema,
		uiSchema = {},
		id,
		options,
		value,
		label,
		required,
		disabled,
		readonly,
		multiple,
		onChange,
		onBlur,
		onFocus,
		placeholder,
	} = props;
	const { enumOptions, enumDisabled } = options;
	const emptyValue = multiple ? [] : '';

	const optionsList = [];

	if ( ! multiple && schema.default === undefined ) {
		optionsList.push( { value: '', label: placeholder } );
	}

	for ( const option of enumOptions ) {
		optionsList.push( {
			...option,
			disabled: enumDisabled && enumDisabled.includes( option.value ),
		} );
	}

	return (
		<SelectControl
			id={ id }
			multiple={ multiple }
			options={ optionsList }
			value={ typeof value === 'undefined' ? emptyValue : value }
			label={ label }
			help={ uiSchema[ 'ui:description' ] || schema.description }
			required={ required }
			disabled={ disabled }
			readOnly={ readonly }
			onChange={ ( newValue ) => onChange( processValue( schema, newValue ) ) }
			onBlur={ onBlur && ( ( e ) => onBlur( id, processValue( schema, getValue( e, multiple ) ) ) ) }
			onFocus={ onFocus && ( ( e ) => onFocus( id, processValue( schema, getValue( e, multiple ) ) ) ) }
		/>
	);
}

export default SelectWidget;
