<?php

namespace WellRESTed\Message;

use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Message\StreamInterface;
use Psr\Http\Message\UploadedFileInterface;
use Psr\Http\Message\UriInterface;
use InvalidArgumentException;

/**
 * Representation of an incoming, server-side HTTP request.
 *
 * Per the HTTP specification, this interface includes properties for
 * each of the following:
 *
 * - Protocol version
 * - HTTP method
 * - URI
 * - Headers
 * - Message body
 *
 * Additionally, it encapsulates all data as it has arrived to the
 * application from the CGI and/or PHP environment, including:
 *
 * - The values represented in $_SERVER.
 * - Any cookies provided (generally via $_COOKIE)
 * - Query string arguments (generally via $_GET, or as parsed via parse_str())
 * - Upload files, if any (as represented by $_FILES)
 * - Deserialized body parameters (generally from $_POST)
 *
 * $_SERVER values MUST be treated as immutable, as they represent application
 * state at the time of request; as such, no methods are provided to allow
 * modification of those values. The other values provide such methods, as they
 * can be restored from $_SERVER or the request body, and may need treatment
 * during the application (e.g., body parameters may be deserialized based on
 * content type).
 */
class ServerRequest extends Request implements ServerRequestInterface
{
    /** @var array */
    private $attributes;
    /** @var array */
    private $cookieParams;
    /** @var mixed */
    private $parsedBody;
    /** @var array */
    private $queryParams;
    /** @var array */
    private $serverParams;
    /** @var array */
    private $uploadedFiles;

    // ------------------------------------------------------------------------

    /**
     * Creates a new, empty representation of a server-side HTTP request.
     *
     * To obtain a ServerRequest representing the request sent to the server
     * instantiating the request, use the factory method
     * ServerRequest::getServerRequest
     *
     * @see ServerRequest::getServerRequest
     */
    public function __construct()
    {
        parent::__construct();
        $this->attributes = [];
        $this->cookieParams = [];
        $this->queryParams = [];
        $this->serverParams = [];
        $this->uploadedFiles = [];
    }

    public function __clone()
    {
        if (is_object($this->parsedBody)) {
            $this->parsedBody = clone $this->parsedBody;
        }
        parent::__clone();
    }

    // ------------------------------------------------------------------------
    // Psr\Http\Message\ServerRequestInterface

    /**
     * Retrieve server parameters.
     *
     * Retrieves data related to the incoming request environment,
     * typically derived from PHP's $_SERVER superglobal. The data IS NOT
     * REQUIRED to originate from $_SERVER.
     *
     * @return array
     */
    public function getServerParams()
    {
        return $this->serverParams;
    }

    /**
     * Retrieve cookies.
     *
     * Retrieves cookies sent by the client to the server.
     *
     * @return array
     */
    public function getCookieParams()
    {
        return $this->cookieParams;
    }

    /**
     * Create a new instance with the specified cookies.
     *
     * The data IS NOT REQUIRED to come from the $_COOKIE superglobal, but MUST
     * be compatible with the structure of $_COOKIE. Typically, this data will
     * be injected at instantiation.
     *
     * @param array $cookies Array of key/value pairs representing cookies.
     * @return static
     */
    public function withCookieParams(array $cookies)
    {
        $request = clone $this;
        $request->cookieParams = $cookies;
        return $request;
    }

    /**
     * Retrieve query string arguments.
     *
     * Retrieves the deserialized query string arguments, if any.
     *
     * Note: the query params might not be in sync with the URI or server
     * params. If you need to ensure you are only getting the original
     * values, you may need to parse the query string from `getUri()->getQuery()`
     * or from the `QUERY_STRING` server param.
     *
     * @return array
     */
    public function getQueryParams()
    {
        return $this->queryParams;
    }

    /**
     * Create a new instance with the specified query string arguments.
     *
     * These values SHOULD remain immutable over the course of the incoming
     * request. They MAY be injected during instantiation, such as from PHP's
     * $_GET superglobal, or MAY be derived from some other value such as the
     * URI. In cases where the arguments are parsed from the URI, the data
     * MUST be compatible with what PHP's parse_str() would return for
     * purposes of how duplicate query parameters are handled, and how nested
     * sets are handled.
     *
     * Setting query string arguments MUST NOT change the URL stored by the
     * request, nor the values in the server params.
     *
     * @param array $query Array of query string arguments, typically from
     *     $_GET.
     * @return static
     */
    public function withQueryParams(array $query)
    {
        $request = clone $this;
        $request->queryParams = $query;
        return $request;
    }

    /**
     * Retrieve normalized file upload data.
     *
     * This method returns upload metadata in a normalized tree, with each leaf
     * an instance of Psr\Http\Message\UploadedFileInterface.
     *
     * These values MAY be prepared from $_FILES or the message body during
     * instantiation, or MAY be injected via withUploadedFiles().
     *
     * @return array An array tree of UploadedFileInterface instances; an empty
     *     array will be returned if no data is present.
     */
    public function getUploadedFiles()
    {
        return $this->uploadedFiles;
    }

    /**
     * Create a new instance with the specified uploaded files.
     *
     * @param array $uploadedFiles An array tree of UploadedFileInterface instances.
     * @return static
     * @throws InvalidArgumentException if an invalid structure is provided.
     */
    public function withUploadedFiles(array $uploadedFiles)
    {
        if (!$this->isValidUploadedFilesTree($uploadedFiles)) {
            throw new InvalidArgumentException(
                'withUploadedFiles expects an array tree with UploadedFileInterface leaves.'
            );
        }

        $request = clone $this;
        $request->uploadedFiles = $uploadedFiles;
        return $request;
    }

    /**
     * Retrieve any parameters provided in the request body.
     *
     * If the request Content-Type is either application/x-www-form-urlencoded
     * or multipart/form-data, and the request method is POST, this method will
     * return the contents of $_POST.
     *
     * Otherwise, this method may return any results of deserializing
     * the request body content; as parsing returns structured content, the
     * potential types MUST be arrays or objects only. A null value indicates
     * the absence of body content.
     *
     * @return null|array|object The deserialized body parameters, if any.
     *     These will typically be an array or object.
     */
    public function getParsedBody()
    {
        return $this->parsedBody;
    }

    /**
     * Create a new instance with the specified body parameters.
     *
     * These MAY be injected during instantiation.
     *
     * If the request Content-Type is either application/x-www-form-urlencoded
     * or multipart/form-data, and the request method is POST, use this method
     * ONLY to inject the contents of $_POST.
     *
     * The data IS NOT REQUIRED to come from $_POST, but MUST be the results of
     * deserializing the request body content. Deserialization/parsing returns
     * structured data, and, as such, this method ONLY accepts arrays or objects,
     * or a null value if nothing was available to parse.
     *
     * As an example, if content negotiation determines that the request data
     * is a JSON payload, this method could be used to create a request
     * instance with the deserialized parameters.
     *
     * @param null|array|object $data The deserialized body data. This will
     *     typically be in an array or object.
     * @return static
     */
    public function withParsedBody($data)
    {
        if (!(is_null($data) || is_array($data) || is_object($data))) {
            throw new InvalidArgumentException('Parsed body must be null, array, or object.');
        }

        $request = clone $this;
        $request->parsedBody = $data;
        return $request;
    }

    /**
     * Retrieve attributes derived from the request.
     *
     * The request "attributes" may be used to allow injection of any
     * parameters derived from the request: e.g., the results of path
     * match operations; the results of decrypting cookies; the results of
     * deserializing non-form-encoded message bodies; etc. Attributes
     * will be application and request specific, and CAN be mutable.
     *
     * @return array Attributes derived from the request.
     */
    public function getAttributes()
    {
        return $this->attributes;
    }

    /**
     * Retrieve a single derived request attribute.
     *
     * Retrieves a single derived request attribute as described in
     * getAttributes(). If the attribute has not been previously set, returns
     * the default value as provided.
     *
     * This method obviates the need for a hasAttribute() method, as it allows
     * specifying a default value to return if the attribute is not found.
     *
     * @see getAttributes()
     * @param string $name The attribute name.
     * @param mixed $default Default value to return if the attribute does not exist.
     * @return mixed
     */
    public function getAttribute($name, $default = null)
    {
        if (isset($this->attributes[$name])) {
            return $this->attributes[$name];
        }
        return $default;
    }

    /**
     * Create a new instance with the specified derived request attribute.
     *
     * This method allows setting a single derived request attribute as
     * described in getAttributes().
     *
     * @see getAttributes()
     * @param string $name The attribute name.
     * @param mixed $value The value of the attribute.
     * @return static
     */
    public function withAttribute($name, $value)
    {
        $request = clone $this;
        $request->attributes[$name] = $value;
        return $request;
    }

    /**
     * Create a new instance that removes the specified derived request
     * attribute.
     *
     * This method allows removing a single derived request attribute as
     * described in getAttributes().
     *
     * This method MUST be implemented in such a way as to retain the
     * immutability of the message, and MUST return a new instance that removes
     * the attribute.
     *
     * @see getAttributes()
     * @param string $name The attribute name.
     * @return static
     */
    public function withoutAttribute($name)
    {
        $request = clone $this;
        unset($request->attributes[$name]);
        return $request;
    }

    // ------------------------------------------------------------------------

    /**
     * @param array $attributes
     * @return void
     */
    protected function readFromServerRequest(array $attributes = [])
    {
        $this->attributes = $attributes;
        $this->serverParams = $_SERVER;
        $this->cookieParams = $_COOKIE;
        $this->readUploadedFiles($_FILES);
        $this->queryParams = [];
        $this->uri = $this->readUri();
        if (isset($_SERVER['QUERY_STRING'])) {
            parse_str($_SERVER['QUERY_STRING'], $this->queryParams);
        }
        if (isset($_SERVER['SERVER_PROTOCOL']) && $_SERVER['SERVER_PROTOCOL'] === 'HTTP/1.0') {
            // The default is 1.1, so only update if 1.0
            $this->protocolVersion = '1.0';
        }
        if (isset($_SERVER['REQUEST_METHOD'])) {
            $this->method = $_SERVER['REQUEST_METHOD'];
        }
        $headers = $this->getServerRequestHeaders();
        foreach ($headers as $key => $value) {
            $this->headers[$key] = $value;
        }
        $this->body = $this->getStreamForBody();

        $contentType = $this->getHeaderLine('Content-type');
        if (strpos($contentType, 'application/x-www-form-urlencoded') !== false
            || strpos($contentType, 'multipart/form-data') !== false) {
            $this->parsedBody = $_POST;
        }
    }

    protected function readUploadedFiles(array $input): void
    {
        $uploadedFiles = [];
        foreach ($input as $name => $value) {
            $this->addUploadedFilesToBranch($uploadedFiles, $name, $value);
        }
        $this->uploadedFiles = $uploadedFiles;
    }

    protected function addUploadedFilesToBranch(
        array &$branch,
        string $name,
        array $value
    ): void {
        // Check for each of the expected keys.
        if (isset($value['name'], $value['type'], $value['tmp_name'], $value['error'], $value['size'])) {
            // This is a file. It may be a single file, or a list of files.

            // Check if these items are arrays.
            if (is_array($value['name'])
                && is_array($value['type'])
                && is_array($value['tmp_name'])
                && is_array($value['error'])
                && is_array($value['size'])
            ) {
                // Each item is an array. This is a list of uploaded files.
                $files = [];
                $keys = array_keys($value['name']);
                foreach ($keys as $key) {
                    $files[$key] = new UploadedFile(
                        $value['name'][$key],
                        $value['type'][$key],
                        $value['size'][$key],
                        $value['tmp_name'][$key],
                        $value['error'][$key]
                    );
                }
                $branch[$name] = $files;
            } else {
                // All expected keys are present and are not arrays. This is an uploaded file.
                $uploadedFile = new UploadedFile(
                    $value['name'],
                    $value['type'],
                    $value['size'],
                    $value['tmp_name'],
                    $value['error']
                );
                $branch[$name] = $uploadedFile;
            }
        } else {
            // Add another branch
            $nextBranch = [];
            foreach ($value as $nextName => $nextValue) {
                $this->addUploadedFilesToBranch($nextBranch, $nextName, $nextValue);
            }
            $branch[$name] = $nextBranch;
        }
    }

    protected function readUri(): UriInterface
    {
        $uri = '';

        $scheme = 'http';
        if (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] && $_SERVER['HTTPS'] !== 'off') {
            $scheme = 'https';
        }

        if (isset($_SERVER['HTTP_HOST'])) {
            $authority = $_SERVER['HTTP_HOST'];
            $uri .= "$scheme://$authority";
        }

        // Path and query string
        if (isset($_SERVER['REQUEST_URI'])) {
            $uri .= $_SERVER['REQUEST_URI'];
        }

        return new Uri($uri);
    }

    /**
     * Return a reference to the singleton instance of the Request derived
     * from the server's information about the request sent to the server.
     *
     * @param array $attributes Key-value pairs to add to the request.
     * @return static
     * @static
     */
    public static function getServerRequest(array $attributes = [])
    {
        $request = new static();
        $request->readFromServerRequest($attributes);
        return $request;
    }

    /**
     * Return a stream representing the request's body.
     *
     * Override this method to use a specific StreamInterface implementation.
     *
     * @return StreamInterface
     */
    protected function getStreamForBody()
    {
        $input = fopen('php://input', 'rb');
        $temp = fopen('php://temp', 'wb+');
        stream_copy_to_stream($input, $temp);
        rewind($temp);
        return new Stream($temp);
    }

    /**
     * Read and return all request headers from the request issued to the server.
     *
     * @return array Associative array of headers
     */
    protected function getServerRequestHeaders()
    {
        // http://www.php.net/manual/en/function.getallheaders.php#84262
        $headers = [];
        foreach ($_SERVER as $name => $value) {
            if (substr($name, 0, 5) === 'HTTP_') {
                $name = $this->normalizeHeaderName(substr($name, 5));
                $headers[$name] = trim($value);
            } elseif ($this->isContentHeader($name) && !empty(trim($value))) {
                $name = $this->normalizeHeaderName($name);
                $headers[$name] = trim($value);
            }
        }
        return $headers;
    }

    private function isContentHeader(string $name): bool
    {
        return ($name === 'CONTENT_LENGTH' || $name === 'CONTENT_TYPE');
    }

    /**
     * @param string $name
     * @return string
     */
    private function normalizeHeaderName($name)
    {
        $name = ucwords(strtolower(str_replace('_', ' ', $name)));
        return str_replace(' ', '-', $name);
    }

    /**
     * @param array $root
     * @return bool
     */
    private function isValidUploadedFilesTree(array $root)
    {
        // Allow empty array.
        if (count($root) === 0) {
            return true;
        }

        // If not empty, the array MUST have all string keys.
        $keys = array_keys($root);
        if (count($keys) !== count(array_filter($keys, 'is_string'))) {
            return false;
        }

        // Valid if each child branch is valid.
        foreach ($root as $branch) {
            if (!$this->isValidUploadedFilesBranch($branch)) {
                return false;
            }
        }
        return true;
    }

    /**
     * @param UploadedFileInterface|array $branch
     * @return bool
     */
    private function isValidUploadedFilesBranch($branch): bool
    {
        if (is_array($branch)) {
            // Branch.
            foreach ($branch as $child) {
                if (!$this->isValidUploadedFilesBranch($child)) {
                    return false;
                }
            }
            return true;
        } else {
            // Leaf. Valid only if this is an UploadedFileInterface.
            return $branch instanceof UploadedFileInterface;
        }
    }
}