<?php

namespace Duplicator\Package;

use Exception;

class InputValidator
{
    /** @var array<string,string> $patterns */
    private static $patterns                  = [
        'fdir'    => '/^([a-zA-Z]:[\\\\\/]|\/|\\\\\\\\|\/\/)[^<>\0]+$/',
        'fdirwc'  => '/^[\s\t]*?(#.*|[a-zA-Z]:[\\\\\/]|\/|\\\\\\\\|\/\/)[^<>\0]*$/',
        'ffile'   => '/^([a-zA-Z]:[\\\\\/]|\/|\\\\\\\\|\/\/)[^<>\0]+$/',
        'ffilewc' => '/^[\s\t]*?(#.*|[a-zA-Z]:[\\\\\/]|\/|\\\\\\\\|\/\/)[^<>\0]*$/',
        'fext'    => '/^\.?[^\\\\\/*:<>\0?"|\s\.]+$/',
        'email'   =>
        '/^[a-zA-Z0-9.!#$%&\'*+\/=?^_\`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/',
        'empty'   => '/^$/',
        'nempty'  => '/^.+$/',
    ];
    const FILTER_VALIDATE_IS_EMPTY            = 'empty';
    const FILTER_VALIDATE_NOT_EMPTY           = 'nempty';
    const FILTER_VALIDATE_FILE                = 'ffile';
    const FILTER_VALIDATE_FILE_WITH_COMMENT   = 'ffilewc';
    const FILTER_VALIDATE_FOLDER              = 'fdir';
    const FILTER_VALIDATE_FOLDER_WITH_COMMENT = 'fdirwc';
    const FILTER_VALIDATE_FILE_EXT            = 'fext';
    const FILTER_VALIDATE_EMAIL               = 'email';

    /** @var array<array{key:string,msg:string}> */
    private $errors = [];

    /**
     * Class contructor
     */
    public function __construct()
    {
        $this->errors = [];
    }

    /**
     * @return void
     */
    public function reset(): void
    {
        $this->errors = [];
    }

    /**
     *
     * @return bool
     */
    public function isSuccess(): bool
    {
        return empty($this->errors);
    }

    /**
     * Return errors
     *
     * @return array<array{key:string,msg:string}>
     */
    public function getErrors(): array
    {
        return $this->errors;
    }

    /**
     * Return errors messages
     *
     * @return string[]
     */
    public function getErrorsMsg(): array
    {
        $result = [];
        foreach ($this->errors as $err) {
            $result[] = $err['msg'];
        }
        return $result;
    }

    /**
     *
     * @param string $format printf format message where %s is the variable content default "%s\n"
     * @param bool   $echo   if false return string
     *
     * @return string if $echo is true return empty string, otherwise return the errors as a string
     */
    public function getErrorsFormat(string $format = "%s\n", bool $echo = true): string
    {
        $msgs = $this->getErrorsMsg();
        ob_start();
        foreach ($msgs as $msg) {
            printf($format, esc_html($msg)); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
        }

        if ($echo) {
            ob_end_flush();
            return '';
        } else {
            return ob_get_clean();
        }
    }

    /**
     * @param string $key field key
     * @param string $msg error message
     *
     * @return void
     */
    public function addError(string $key, string $msg): void
    {
        $this->errors[] = [
            'key' => $key,
            'msg' => $msg,
        ];
    }

    /**
     * filter_var function wrapper see http://php.net/manual/en/function.filter-var.php
     *
     * additional options
     * valkey => key of field
     * errmsg => error message; % s will be replaced with the contents of the variable  es. "<b>%s</b> isn't a valid field"
     * acc_vals => array of accepted values that skip validation
     *
     * @param mixed               $variable variable to validate
     * @param int                 $filter   filter name
     * @param array<string,mixed> $options  additional options for filter_var
     *
     * @return mixed
     */
    public function filterVar($variable, int $filter = FILTER_DEFAULT, array $options = [])
    {
        $success = true;
        $result  = null;
        if (isset($options['acc_vals']) && in_array($variable, $options['acc_vals'])) {
            return $variable;
        }

        if ($filter === FILTER_VALIDATE_BOOLEAN) {
            $options['flags'] = FILTER_NULL_ON_FAILURE;
            /** @var null|bool */
            $result = is_bool($variable) ? $variable : filter_var($variable, $filter, $options);
            if (is_null($result)) {
                $success = false;
            }
        } else {
            $result = filter_var($variable, $filter, $options);
            if ($result === false) {
                $success = false;
            }
        }

        if (!$success) {
            $key = $options['valkey'] ?? '';
            if (isset($options['errmsg'])) {
                $msg = sprintf($options['errmsg'], esc_html($variable));
            } else {
                $msg = sprintf('%1$s isn\'t a valid value', $variable);
            }

            $this->addError($key, $msg);
        }

        return $result;
    }

    /**
     * Validation of predefined regular expressions
     *
     * @param mixed               $variable variable to validate
     * @param string              $filter   filter name
     * @param array<string,mixed> $options  additional options for filter_var
     *
     * @return mixed
     */
    public function filterCustom($variable, string $filter, array $options = [])
    {
        if (!isset(self::$patterns[$filter])) {
            throw new Exception('Filter not valid');
        }

        $options = array_merge($options, [
            'options' => [
                'regexp' => self::$patterns[$filter],
            ],
        ]);
        //$options['regexp'] = self::$patterns[$filter];

        return $this->filterVar($variable, FILTER_VALIDATE_REGEXP, $options);
    }

    /**
     * it explodes a string with a delimiter and validates every element of the array
     *
     * @param string               $variable  string to explode
     * @param string               $delimiter delimiter
     * @param string               $filter    filter name
     * @param array<string, mixed> $options   additional options for filter_var
     *
     * @return mixed[]
     */
    public function explodeFilterCustom(
        string $variable,
        string $delimiter,
        string $filter,
        array $options = []
    ): array {
        if (empty($variable)) {
            return [];
        }

        if (strlen($delimiter) == 0) {
            throw new Exception('Delimiter can\'t be empty');
        }

        $vals = explode($delimiter, trim($variable, $delimiter));
        $res  = [];
        foreach ($vals as $val) {
            $res[] = $this->filterCustom($val, $filter, $options);
        }

        return $res;
    }
}