<?php

/**
 * League.Uri (https://uri.thephpleague.com)
 *
 * (c) Ignace Nyamagana Butera <nyamsprod@gmail.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
declare (strict_types=1);
namespace WP_Ultimo\Dependencies\League\Uri\UriTemplate;

use WP_Ultimo\Dependencies\League\Uri\Encoder;
use WP_Ultimo\Dependencies\League\Uri\Exceptions\SyntaxError;
use Stringable;
use function implode;
use function is_array;
use function preg_match;
use function rawurlencode;
use function str_contains;
use function substr;
/**
 * Processing behavior according to the expression type operator.
 *
 * @internal The class exposes the internal representation of an Operator and its usage
 *
 * @link https://www.rfc-editor.org/rfc/rfc6570#section-2.2
 * @link https://tools.ietf.org/html/rfc6570#appendix-A
 */
enum Operator : string
{
    /**
     * Expression regular expression pattern.
     *
     * @link https://tools.ietf.org/html/rfc6570#section-2.2
     */
    private const REGEXP_EXPRESSION = '/^\\{(?:(?<operator>[\\.\\/;\\?&\\=,\\!@\\|\\+#])?(?<variables>[^\\}]*))\\}$/';
    /**
     * Reserved Operator characters.
     *
     * @link https://tools.ietf.org/html/rfc6570#section-2.2
     */
    private const RESERVED_OPERATOR = '=,!@|';
    case None = '';
    case ReservedChars = '+';
    case Label = '.';
    case Path = '/';
    case PathParam = ';';
    case Query = '?';
    case QueryPair = '&';
    case Fragment = '#';
    public function first() : string
    {
        return match ($this) {
            self::None, self::ReservedChars => '',
            default => $this->value,
        };
    }
    public function separator() : string
    {
        return match ($this) {
            self::None, self::ReservedChars, self::Fragment => ',',
            self::Query, self::QueryPair => '&',
            default => $this->value,
        };
    }
    public function isNamed() : bool
    {
        return match ($this) {
            self::Query, self::PathParam, self::QueryPair => \true,
            default => \false,
        };
    }
    /**
     * Removes percent encoding on reserved characters (used with + and # modifiers).
     */
    public function decode(string $var) : string
    {
        return match ($this) {
            Operator::ReservedChars, Operator::Fragment => (string) Encoder::encodeQueryOrFragment($var),
            default => rawurlencode($var),
        };
    }
    /**
     * @throws SyntaxError if the expression is invalid
     * @throws SyntaxError if the operator used in the expression is invalid
     * @throws SyntaxError if the contained variable specifiers are invalid
     *
     * @return array{operator:Operator, variables:string}
     */
    public static function parseExpression(Stringable|string $expression) : array
    {
        $expression = (string) $expression;
        if (1 !== preg_match(self::REGEXP_EXPRESSION, $expression, $parts)) {
            throw new SyntaxError('The expression "' . $expression . '" is invalid.');
        }
        /** @var array{operator:string, variables:string} $parts */
        $parts = $parts + ['operator' => ''];
        if ('' !== $parts['operator'] && str_contains(self::RESERVED_OPERATOR, $parts['operator'])) {
            throw new SyntaxError('The operator used in the expression "' . $expression . '" is reserved.');
        }
        return ['operator' => self::from($parts['operator']), 'variables' => $parts['variables']];
    }
    /**
     * Replaces an expression with the given variables.
     *
     * @throws TemplateCanNotBeExpanded if the variables is an array and a ":" modifier needs to be applied
     * @throws TemplateCanNotBeExpanded if the variables contains nested array values
     */
    public function expand(VarSpecifier $varSpecifier, VariableBag $variables) : string
    {
        $value = $variables->fetch($varSpecifier->name);
        if (null === $value) {
            return '';
        }
        [$expanded, $actualQuery] = $this->inject($value, $varSpecifier);
        if (!$actualQuery) {
            return $expanded;
        }
        if ('&' !== $this->separator() && '' === $expanded) {
            return $varSpecifier->name;
        }
        return $varSpecifier->name . '=' . $expanded;
    }
    /**
     * @param string|array<string> $value
     *
     * @return array{0:string, 1:bool}
     */
    private function inject(array|string $value, VarSpecifier $varSpec) : array
    {
        if (is_array($value)) {
            return $this->replaceList($value, $varSpec);
        }
        if (':' === $varSpec->modifier) {
            $value = substr($value, 0, $varSpec->position);
        }
        return [$this->decode($value), $this->isNamed()];
    }
    /**
     * Expands an expression using a list of values.
     *
     * @param array<string> $value
     *
     * @throws TemplateCanNotBeExpanded if the variables is an array and a ":" modifier needs to be applied
     *
     * @return array{0:string, 1:bool}
     */
    private function replaceList(array $value, VarSpecifier $varSpec) : array
    {
        if (':' === $varSpec->modifier) {
            throw TemplateCanNotBeExpanded::dueToUnableToProcessValueListWithPrefix($varSpec->name);
        }
        if ([] === $value) {
            return ['', \false];
        }
        $pairs = [];
        $isList = \array_is_list($value);
        $useQuery = $this->isNamed();
        foreach ($value as $key => $var) {
            if (!$isList) {
                $key = rawurlencode((string) $key);
            }
            $var = $this->decode($var);
            if ('*' === $varSpec->modifier) {
                if (!$isList) {
                    $var = $key . '=' . $var;
                } elseif ($key > 0 && $useQuery) {
                    $var = $varSpec->name . '=' . $var;
                }
            }
            $pairs[$key] = $var;
        }
        if ('*' === $varSpec->modifier) {
            if (!$isList) {
                // Don't prepend the value name when using the `explode` modifier with an associative array.
                $useQuery = \false;
            }
            return [implode($this->separator(), $pairs), $useQuery];
        }
        if (!$isList) {
            // When an associative array is encountered and the `explode` modifier is not set, then
            // the result must be a comma separated list of keys followed by their respective values.
            $retVal = [];
            foreach ($pairs as $offset => $data) {
                $retVal[$offset] = $offset . ',' . $data;
            }
            $pairs = $retVal;
        }
        return [implode(',', $pairs), $useQuery];
    }
}
