<?php

/**
 * Cookie storage object
 */

namespace WpOrg\Requests;

use WpOrg\Requests\Exception\InvalidArgument;
use WpOrg\Requests\Response\Headers;
use WpOrg\Requests\Utility\CaseInsensitiveDictionary;
use WpOrg\Requests\Utility\InputValidator;

/**
 * Cookie storage object
 */
class Cookie
{
    /**
     * Cookie name.
     *
     * @var string
     */
    public $name;

    /**
     * Cookie value.
     *
     * @var string
     */
    public $value;

    /**
     * Cookie attributes
     *
     * Valid keys are (currently) path, domain, expires, max-age, secure and
     * httponly.
     *
     * @var \WpOrg\Requests\Utility\CaseInsensitiveDictionary|array Array-like object
     */
    public $attributes = [];

    /**
     * Cookie flags
     *
     * Valid keys are (currently) creation, last-access, persistent and
     * host-only.
     *
     * @var array
     */
    public $flags = [];

    /**
     * Reference time for relative calculations
     *
     * This is used in place of `time()` when calculating Max-Age expiration and
     * checking time validity.
     *
     * @var int
     */
    public $reference_time = 0;

    /**
     * Create a new cookie object
     *
     * @param  string  $name
     * @param  string  $value
     * @param  array|\WpOrg\Requests\Utility\CaseInsensitiveDictionary  $attributes  Associative array of attribute data
     * @param  array  $flags
     * @param  int|null  $reference_time
     *
     * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed $name argument is not a string.
     * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed $value argument is not a string.
     * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed $attributes argument is not an array or iterable object with array access.
     * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed $flags argument is not an array.
     * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed $reference_time argument is not an integer or null.
     */
    public function __construct($name, $value, $attributes = [], $flags = [], $reference_time = null)
    {
        if (is_string($name) === false) {
            throw InvalidArgument::create(1, '$name', 'string', gettype($name));
        }

        if (is_string($value) === false) {
            throw InvalidArgument::create(2, '$value', 'string', gettype($value));
        }

        if (InputValidator::has_array_access($attributes) === false || InputValidator::is_iterable($attributes) === false) {
            throw InvalidArgument::create(3, '$attributes', 'array|ArrayAccess&Traversable', gettype($attributes));
        }

        if (is_array($flags) === false) {
            throw InvalidArgument::create(4, '$flags', 'array', gettype($flags));
        }

        if ($reference_time !== null && is_int($reference_time) === false) {
            throw InvalidArgument::create(5, '$reference_time', 'integer|null', gettype($reference_time));
        }

        $this->name = $name;
        $this->value = $value;
        $this->attributes = $attributes;
        $default_flags = [
            'creation' => time(),
            'last-access' => time(),
            'persistent' => false,
            'host-only' => true,
        ];
        $this->flags = array_merge($default_flags, $flags);

        $this->reference_time = time();
        if ($reference_time !== null) {
            $this->reference_time = $reference_time;
        }

        $this->normalize();
    }

    /**
     * Get the cookie value
     *
     * Attributes and other data can be accessed via methods.
     */
    public function __toString()
    {
        return $this->value;
    }

    /**
     * Check if a cookie is expired.
     *
     * Checks the age against $this->reference_time to determine if the cookie
     * is expired.
     *
     * @return bool True if expired, false if time is valid.
     */
    public function is_expired()
    {
        // RFC6265, s. 4.1.2.2:
        // If a cookie has both the Max-Age and the Expires attribute, the Max-
        // Age attribute has precedence and controls the expiration date of the
        // cookie.
        if (isset($this->attributes['max-age'])) {
            $max_age = $this->attributes['max-age'];

            return $max_age < $this->reference_time;
        }

        if (isset($this->attributes['expires'])) {
            $expires = $this->attributes['expires'];

            return $expires < $this->reference_time;
        }

        return false;
    }

    /**
     * Check if a cookie is valid for a given URI
     *
     * @param  \WpOrg\Requests\Iri  $uri  URI to check
     * @return bool Whether the cookie is valid for the given URI
     */
    public function uri_matches(Iri $uri)
    {
        if (! $this->domain_matches($uri->host)) {
            return false;
        }

        if (! $this->path_matches($uri->path)) {
            return false;
        }

        return empty($this->attributes['secure']) || $uri->scheme === 'https';
    }

    /**
     * Check if a cookie is valid for a given domain
     *
     * @param  string  $domain  Domain to check
     * @return bool Whether the cookie is valid for the given domain
     */
    public function domain_matches($domain)
    {
        if (is_string($domain) === false) {
            return false;
        }

        if (! isset($this->attributes['domain'])) {
            // Cookies created manually; cookies created by Requests will set
            // the domain to the requested domain
            return true;
        }

        $cookie_domain = $this->attributes['domain'];
        if ($cookie_domain === $domain) {
            // The cookie domain and the passed domain are identical.
            return true;
        }

        // If the cookie is marked as host-only and we don't have an exact
        // match, reject the cookie
        if ($this->flags['host-only'] === true) {
            return false;
        }

        if (strlen($domain) <= strlen($cookie_domain)) {
            // For obvious reasons, the cookie domain cannot be a suffix if the passed domain
            // is shorter than the cookie domain
            return false;
        }

        if (substr($domain, -1 * strlen($cookie_domain)) !== $cookie_domain) {
            // The cookie domain should be a suffix of the passed domain.
            return false;
        }

        $prefix = substr($domain, 0, strlen($domain) - strlen($cookie_domain));
        if (substr($prefix, -1) !== '.') {
            // The last character of the passed domain that is not included in the
            // domain string should be a %x2E (".") character.
            return false;
        }

        // The passed domain should be a host name (i.e., not an IP address).
        return ! preg_match('#^(.+\.)\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$#', $domain);
    }

    /**
     * Check if a cookie is valid for a given path
     *
     * From the path-match check in RFC 6265 section 5.1.4
     *
     * @param  string  $request_path  Path to check
     * @return bool Whether the cookie is valid for the given path
     */
    public function path_matches($request_path)
    {
        if (empty($request_path)) {
            // Normalize empty path to root
            $request_path = '/';
        }

        if (! isset($this->attributes['path'])) {
            // Cookies created manually; cookies created by Requests will set
            // the path to the requested path
            return true;
        }

        if (is_scalar($request_path) === false) {
            return false;
        }

        $cookie_path = $this->attributes['path'];

        if ($cookie_path === $request_path) {
            // The cookie-path and the request-path are identical.
            return true;
        }

        if (strlen($request_path) > strlen($cookie_path) && substr($request_path, 0, strlen($cookie_path)) === $cookie_path) {
            if (substr($cookie_path, -1) === '/') {
                // The cookie-path is a prefix of the request-path, and the last
                // character of the cookie-path is %x2F ("/").
                return true;
            }

            if (substr($request_path, strlen($cookie_path), 1) === '/') {
                // The cookie-path is a prefix of the request-path, and the
                // first character of the request-path that is not included in
                // the cookie-path is a %x2F ("/") character.
                return true;
            }
        }

        return false;
    }

    /**
     * Normalize cookie and attributes
     *
     * @return bool Whether the cookie was successfully normalized
     */
    public function normalize()
    {
        foreach ($this->attributes as $key => $value) {
            $orig_value = $value;
            $value = $this->normalize_attribute($key, $value);
            if ($value === null) {
                unset($this->attributes[$key]);

                continue;
            }

            if ($value !== $orig_value) {
                $this->attributes[$key] = $value;
            }
        }

        return true;
    }

    /**
     * Parse an individual cookie attribute
     *
     * Handles parsing individual attributes from the cookie values.
     *
     * @param  string  $name  Attribute name
     * @param  string|bool  $value  Attribute value (string value, or true if empty/flag)
     * @return mixed Value if available, or null if the attribute value is invalid (and should be skipped)
     */
    protected function normalize_attribute($name, $value)
    {
        switch (strtolower($name)) {
            case 'expires':
                // Expiration parsing, as per RFC 6265 section 5.2.1
                if (is_int($value)) {
                    return $value;
                }

                $expiry_time = strtotime($value);
                if ($expiry_time === false) {
                    return null;
                }

                return $expiry_time;

            case 'max-age':
                // Expiration parsing, as per RFC 6265 section 5.2.2
                if (is_int($value)) {
                    return $value;
                }

                // Check that we have a valid age
                if (! preg_match('/^-?\d+$/', $value)) {
                    return null;
                }

                $delta_seconds = (int) $value;
                if ($delta_seconds <= 0) {
                    $expiry_time = 0;
                } else {
                    $expiry_time = $this->reference_time + $delta_seconds;
                }

                return $expiry_time;

            case 'domain':
                // Domains are not required as per RFC 6265 section 5.2.3
                if (empty($value)) {
                    return null;
                }

                // Domain normalization, as per RFC 6265 section 5.2.3
                if ($value[0] === '.') {
                    $value = substr($value, 1);
                }

                return $value;

            default:
                return $value;
        }
    }

    /**
     * Format a cookie for a Cookie header
     *
     * This is used when sending cookies to a server.
     *
     * @return string Cookie formatted for Cookie header
     */
    public function format_for_header()
    {
        return sprintf('%s=%s', $this->name, $this->value);
    }

    /**
     * Format a cookie for a Set-Cookie header
     *
     * This is used when sending cookies to clients. This isn't really
     * applicable to client-side usage, but might be handy for debugging.
     *
     * @return string Cookie formatted for Set-Cookie header
     */
    public function format_for_set_cookie()
    {
        $header_value = $this->format_for_header();
        if (! empty($this->attributes)) {
            $parts = [];
            foreach ($this->attributes as $key => $value) {
                // Ignore non-associative attributes
                if (is_numeric($key)) {
                    $parts[] = $value;
                } else {
                    $parts[] = sprintf('%s=%s', $key, $value);
                }
            }

            $header_value .= '; '.implode('; ', $parts);
        }

        return $header_value;
    }

    /**
     * Parse a cookie string into a cookie object
     *
     * Based on Mozilla's parsing code in Firefox and related projects, which
     * is an intentional deviation from RFC 2109 and RFC 2616. RFC 6265
     * specifies some of this handling, but not in a thorough manner.
     *
     * @param  string  $cookie_header  Cookie header value (from a Set-Cookie header)
     * @param  string  $name
     * @param  int|null  $reference_time
     * @return \WpOrg\Requests\Cookie Parsed cookie object
     *
     * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed $cookie_header argument is not a string.
     * @throws \WpOrg\Requests\Exception\InvalidArgument When the passed $name argument is not a string.
     */
    public static function parse($cookie_header, $name = '', $reference_time = null)
    {
        if (is_string($cookie_header) === false) {
            throw InvalidArgument::create(1, '$cookie_header', 'string', gettype($cookie_header));
        }

        if (is_string($name) === false) {
            throw InvalidArgument::create(2, '$name', 'string', gettype($name));
        }

        $parts = explode(';', $cookie_header);
        $kvparts = array_shift($parts);

        if (! empty($name)) {
            $value = $cookie_header;
        } elseif (strpos($kvparts, '=') === false) {
            // Some sites might only have a value without the equals separator.
            // Deviate from RFC 6265 and pretend it was actually a blank name
            // (`=foo`)
            //
            // https://bugzilla.mozilla.org/show_bug.cgi?id=169091
            $name = '';
            $value = $kvparts;
        } else {
            [$name, $value] = explode('=', $kvparts, 2);
        }

        $name = trim($name);
        $value = trim($value);

        // Attribute keys are handled case-insensitively
        $attributes = new CaseInsensitiveDictionary;

        if (! empty($parts)) {
            foreach ($parts as $part) {
                if (strpos($part, '=') === false) {
                    $part_key = $part;
                    $part_value = true;
                } else {
                    [$part_key, $part_value] = explode('=', $part, 2);
                    $part_value = trim($part_value);
                }

                $part_key = trim($part_key);
                $attributes[$part_key] = $part_value;
            }
        }

        return new static($name, $value, $attributes, [], $reference_time);
    }

    /**
     * Parse all Set-Cookie headers from request headers
     *
     * @param  \WpOrg\Requests\Response\Headers  $headers  Headers to parse from
     * @param  \WpOrg\Requests\Iri|null  $origin  URI for comparing cookie origins
     * @param  int|null  $time  Reference time for expiration calculation
     * @return array
     */
    public static function parse_from_headers(Headers $headers, ?Iri $origin = null, $time = null)
    {
        $cookie_headers = $headers->getValues('Set-Cookie');
        if (empty($cookie_headers)) {
            return [];
        }

        $cookies = [];
        foreach ($cookie_headers as $header) {
            $parsed = self::parse($header, '', $time);

            // Default domain/path attributes
            if (empty($parsed->attributes['domain']) && ! empty($origin)) {
                $parsed->attributes['domain'] = $origin->host;
                $parsed->flags['host-only'] = true;
            } else {
                $parsed->flags['host-only'] = false;
            }

            $path_is_valid = (! empty($parsed->attributes['path']) && $parsed->attributes['path'][0] === '/');
            if (! $path_is_valid && ! empty($origin)) {
                $path = $origin->path;

                // Default path normalization as per RFC 6265 section 5.1.4
                if (substr($path, 0, 1) !== '/') {
                    // If the uri-path is empty or if the first character of
                    // the uri-path is not a %x2F ("/") character, output
                    // %x2F ("/") and skip the remaining steps.
                    $path = '/';
                } elseif (substr_count($path, '/') === 1) {
                    // If the uri-path contains no more than one %x2F ("/")
                    // character, output %x2F ("/") and skip the remaining
                    // step.
                    $path = '/';
                } else {
                    // Output the characters of the uri-path from the first
                    // character up to, but not including, the right-most
                    // %x2F ("/").
                    $path = substr($path, 0, strrpos($path, '/'));
                }

                $parsed->attributes['path'] = $path;
            }

            // Reject invalid cookie domains
            if (! empty($origin) && ! $parsed->domain_matches($origin->host)) {
                continue;
            }

            $cookies[$parsed->name] = $parsed;
        }

        return $cookies;
    }
}
