<?php
/*
* Copyright 2018 Google LLC
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
namespace Google\ApiCore;
use Google\ApiCore\ResourceTemplate\AbsoluteResourceTemplate;
use Google\Protobuf\Internal\Message;
use GuzzleHttp\Psr7\Request;
use GuzzleHttp\Psr7\Utils;
use Psr\Http\Message\RequestInterface;
use Psr\Http\Message\UriInterface;
/**
* Builds a PSR-7 request from a set of request information.
*
* @internal
*/
class RequestBuilder
{
use ArrayTrait;
use UriTrait;
use ValidationTrait;
private $baseUri;
private $restConfig;
/**
* @param string $baseUri
* @param string $restConfigPath
* @throws ValidationException
*/
public function __construct($baseUri, $restConfigPath)
{
self::validateFileExists($restConfigPath);
$this->baseUri = $baseUri;
$this->restConfig = require($restConfigPath);
}
/**
* @param string $path
* @param Message $message
* @param array $headers
* @return RequestInterface
* @throws ValidationException
*/
public function build($path, Message $message, array $headers = [])
{
list($interface, $method) = explode('/', $path);
if (!isset($this->restConfig['interfaces'][$interface][$method])) {
throw new ValidationException(
"Failed to build request, as the provided path ($path) was not found in the configuration."
);
}
$methodConfig = $this->restConfig['interfaces'][$interface][$method] + [
'placeholders' => [],
'body' => null,
'additionalBindings' => null,
];
$bindings = $this->buildBindings($methodConfig['placeholders'], $message);
$uriTemplateConfigs = $this->getConfigsForUriTemplates($methodConfig);
foreach ($uriTemplateConfigs as $config) {
$pathTemplate = $this->tryRenderPathTemplate($config['uriTemplate'], $bindings);
if ($pathTemplate) {
// We found a valid uriTemplate - now build and return the Request
list($body, $queryParams) = $this->constructBodyAndQueryParameters($message, $config);
$uri = $this->buildUri($pathTemplate, $queryParams);
return new Request(
$config['method'],
$uri,
['Content-Type' => 'application/json'] + $headers,
$body
);
}
}
// No valid uriTemplate found - construct an exception
$uriTemplates = [];
foreach ($uriTemplateConfigs as $config) {
$uriTemplates[] = $config['uriTemplate'];
}
throw new ValidationException("Could not map bindings for $path to any Uri template.\n" .
"Bindings: " . print_r($bindings, true) .
"UriTemplates: " . print_r($uriTemplates, true));
}
/**
* Create a list of all possible configs using the additionalBindings
*
* @param array $config
* @return array[] An array of configs
*/
private function getConfigsForUriTemplates($config)
{
$configs = [$config];
if ($config['additionalBindings']) {
foreach ($config['additionalBindings'] as $additionalBinding) {
$configs[] = $additionalBinding + $config;
}
}
return $configs;
}
/**
* @param $message
* @param $config
* @return array Tuple [$body, $queryParams]
*/
private function constructBodyAndQueryParameters(Message $message, $config)
{
$messageDataJson = $message->serializeToJsonString();
if ($config['body'] === '*') {
return [$messageDataJson, []];
}
$body = null;
$queryParams = [];
$messageData = json_decode($messageDataJson, true);
foreach ($messageData as $name => $value) {
if (array_key_exists($name, $config['placeholders'])) {
continue;
}
if (Serializer::toSnakeCase($name) === $config['body']) {
if (($bodyMessage = $message->{"get$name"}()) instanceof Message) {
$body = $bodyMessage->serializeToJsonString();
} else {
$body = json_encode($value);
}
continue;
}
if (is_array($value) && $this->isAssoc($value)) {
foreach ($value as $key => $value2) {
$queryParams[$name . '.' . $key] = $value2;
}
} else {
$queryParams[$name] = $value;
}
}
// Ensures required query params with default values are always sent
// over the wire.
if (isset($config['queryParams'])) {
foreach ($config['queryParams'] as $requiredQueryParam) {
$requiredQueryParam = Serializer::toCamelCase($requiredQueryParam);
if (!array_key_exists($requiredQueryParam, $queryParams)) {
$getter = Serializer::getGetter($requiredQueryParam);
$queryParams[$requiredQueryParam] = $message->$getter();
}
}
}
return [$body, $queryParams];
}
/**
* @param array $placeholders
* @param Message $message
* @return array Bindings from path template fields to values from message
*/
private function buildBindings(array $placeholders, Message $message)
{
$bindings = [];
foreach ($placeholders as $placeholder => $metadata) {
$value = array_reduce(
$metadata['getters'],
function (Message $result = null, $getter) {
if ($result) {
return $result->$getter();
}
},
$message
);
$bindings[$placeholder] = $value;
}
return $bindings;
}
/**
* Try to render the resource name. The rendered resource name will always contain a leading '/'
*
* @param $uriTemplate
* @param array $bindings
* @return null|string
* @throws ValidationException
*/
private function tryRenderPathTemplate($uriTemplate, array $bindings)
{
$template = new AbsoluteResourceTemplate($uriTemplate);
try {
return $template->render($bindings);
} catch (ValidationException $e) {
return null;
}
}
/**
* @param $path
* @param $queryParams
* @return UriInterface
*/
private function buildUri($path, $queryParams)
{
$uri = Utils::uriFor(
sprintf(
'https://%s%s',
$this->baseUri,
$path
)
);
if ($queryParams) {
$uri = $this->buildUriWithQuery(
$uri,
$queryParams
);
}
return $uri;
}
}