<?php
/**
 * key=value parsing.
 *
 * @package Adminkeep
 */

namespace Adminkeep\Cli;

defined( 'ABSPATH' ) || exit;

/**
 * Turns the text a shell hands over into the typed value a settings schema expects.
 *
 * Strict on purpose. The settings form falls back to a default when a value is unusable, which is
 * right for a form; a script that made a typo needs to be told.
 */
class ValueParser {

	/**
	 * Words accepted for a bool.
	 */
	const BOOLS = array(
		'true'  => true,
		'1'     => true,
		'yes'   => true,
		'on'    => true,
		'false' => false,
		'0'     => false,
		'no'    => false,
		'off'   => false,
	);

	/**
	 * Split "key=value" on the first "=".
	 *
	 * @param string $pair Argument as typed.
	 * @return array|\WP_Error Key and value, or why not.
	 */
	public static function split( $pair ) {
		$pair = (string) $pair;
		$at   = strpos( $pair, '=' );

		if ( false === $at || 0 === $at ) {
			return new \WP_Error( 'adminkeep_cli_pair', sprintf( '"%s" is not a key=value pair.', $pair ) );
		}

		return array( substr( $pair, 0, $at ), (string) substr( $pair, $at + 1 ) );
	}

	/**
	 * Parse one value against its schema entry.
	 *
	 * @param string $raw  Value as typed.
	 * @param array  $spec Schema entry.
	 * @return mixed|\WP_Error Typed value, or why not.
	 */
	public static function parse( $raw, array $spec ) {
		$raw  = (string) $raw;
		$type = isset( $spec['type'] ) ? $spec['type'] : 'string';

		switch ( $type ) {
			case 'bool':
				$word = strtolower( trim( $raw ) );

				if ( ! array_key_exists( $word, self::BOOLS ) ) {
					return new \WP_Error( 'adminkeep_cli_value', sprintf( '"%s" is not a yes/no value. Use true or false.', $raw ) );
				}

				return self::BOOLS[ $word ];

			case 'int':
				if ( ! preg_match( '/^-?\d+$/', trim( $raw ) ) ) {
					return new \WP_Error( 'adminkeep_cli_value', sprintf( '"%s" is not a whole number.', $raw ) );
				}

				return (int) trim( $raw );

			case 'array':
				return array_values( array_filter( array_map( 'trim', explode( ',', $raw ) ), 'strlen' ) );

			case 'string':
			default:
				if ( isset( $spec['choices'] ) && is_array( $spec['choices'] ) && ! in_array( $raw, $spec['choices'], true ) ) {
					return new \WP_Error( 'adminkeep_cli_value', sprintf( '"%s" is not allowed. Choose one of: %s.', $raw, implode( ', ', $spec['choices'] ) ) );
				}

				return $raw;
		}
	}
}