import React, {Component} from 'react'
import PropTypes from 'prop-types'

const MAX_INT = 2147483647
const MIN_INT = -2147483648

const isNaturalNumber = input => {
	return typeof input === 'number' && input % 1 === 0 && Number.isInteger(input) && input >= 0 && 1 / input !== -Infinity
}

const isInteger = input => {
	if (!Number.isInteger(input)) {
		return false
	}

	if (typeof input !== 'number' || input !== Math.floor(input) || input === Infinity || isNaN(input)) {
		return false
	}

	if (input > MAX_INT || input < MIN_INT) {
		return false
	}
	return true
}

const isFloat = input => {
	if (typeof input !== 'number' || input !== parseFloat(input) || input === Infinity || isNaN(input)) {
		return false
	}

	if (input > MAX_INT || input < MIN_INT) {
		return false
	}
	return true
}

class InputGuard extends Component {
	constructor (props) {
		super(props)
		this.state = {
			currentValue: props.children.props.value,
			isFocused: false
		}
		this.handleChange = this.handleChange.bind(this, props.children.props.onChange)
		this.handleFocus = this.handleFocus.bind(this, props.children.props.onFocus)
		this.handleBlur = this.handleBlur.bind(this, props.children.props.onBlur)
	}

	handleChange (onChange, e) {
		if (this.props.type === 'string' || e.target.value === '') {
			this.setState({currentValue: e.target.value})
			if (typeof onChange === 'function') {
				return onChange(e)
			}
			return null
		} else if (this.props.type === 'int' && !isInteger(Number(e.target.value))) {
			return null
		} else if (this.props.type === 'float' && !isFloat(Number(e.target.value))) {
			return null
		} else if (this.props.type === 'naturalNumber' && !isNaturalNumber(Number(e.target.value))) {
			return null
		} else if (this.props.notZero === true && Number(e.target.value) === 0) {
			return null
		}

		const event = {...e, ...{target: {...e.target, value: Number(e.target.value)}}}
		this.setState({currentValue: event.target.value})
		if (typeof onChange === 'function') {
			return onChange(event)
		}
	}

	handleFocus (onFocus, e) {
		this.setState({isFocused: true})
		if (typeof onFocus === 'function') {
			onFocus(e)
		}
	}

	handleBlur (onBlur, e) {
		this.setState({isFocused: false})
		if (typeof onBlur === 'function') {
			onBlur(e)
		}
	}

	static getDerivedStateFromProps (nextProps, prevState) {
		if (nextProps.children.props.value !== prevState.currentValue && !prevState.isFocused) {
			return {currentValue: nextProps.children.props.value}
		}
		return null
	}

	render () {
		return React.cloneElement(this.props.children, {
			value: this.state.currentValue,
			onChange: this.handleChange,
			onFocus: this.handleFocus,
			onBlur: this.handleBlur
		})
	}
}

InputGuard.defaultProps = {
	type: 'string',
	notZero: false
}

InputGuard.propTypes = {
	children: PropTypes.element.isRequired,
	type: PropTypes.oneOf(['int', 'float', 'naturalNumber', 'string']),
	notZero: PropTypes.bool
}

export default InputGuard