<?php
/*

<  * Copyright 2018 MongoDB, Inc.



>  * Copyright 2018-present MongoDB, Inc.


 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *

<  *   http://www.apache.org/licenses/LICENSE-2.0



>  *   https://www.apache.org/licenses/LICENSE-2.0


 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

namespace MongoDB\Operation;

use MongoDB\Driver\Command;

> use MongoDB\Driver\Exception\RuntimeException as DriverRuntimeException;


use MongoDB\Driver\ReadPreference;
use MongoDB\Driver\Server;
use MongoDB\Driver\Session;
use MongoDB\Exception\InvalidArgumentException;
use MongoDB\Exception\UnsupportedException;

> 


use function current;
use function is_array;
use function is_string;
use function MongoDB\server_supports_feature;

/**
 * Operation for the explain command.
 *
 * @api
 * @see \MongoDB\Collection::explain()

<  * @see http://docs.mongodb.org/manual/reference/command/explain/



>  * @see https://mongodb.com/docs/manual/reference/command/explain/


 */
class Explain implements Executable
{

<     const VERBOSITY_ALL_PLANS = 'allPlansExecution';
<     const VERBOSITY_EXEC_STATS = 'executionStats';
<     const VERBOSITY_QUERY = 'queryPlanner';
< 
<     /** @var integer */
<     private static $wireVersionForDistinct = 4;



>     public const VERBOSITY_ALL_PLANS = 'allPlansExecution';
>     public const VERBOSITY_EXEC_STATS = 'executionStats';
>     public const VERBOSITY_QUERY = 'queryPlanner';



    /** @var integer */

<     private static $wireVersionForFindAndModify = 4;



>     private static $wireVersionForAggregate = 7;



    /** @var string */
    private $databaseName;

    /** @var Explainable */
    private $explainable;

    /** @var array */
    private $options;

    /**
     * Constructs an explain command for explainable operations.
     *
     * Supported options:
     *

>      *  * comment (mixed): BSON value to attach as a comment to this command.
     *  * readPreference (MongoDB\Driver\ReadPreference): Read preference.
>      *
     *
>      *    This is not supported for servers versions < 4.4.
     *  * session (MongoDB\Driver\Session): Client session.
>      *


     *
     *  * typeMap (array): Type map for BSON deserialization. This will be used
     *    used for the returned command result document.
     *
     *  * verbosity (string): The mode in which the explain command will be run.
     *
     * @param string      $databaseName Database name
     * @param Explainable $explainable  Operation to explain
     * @param array       $options      Command options
     * @throws InvalidArgumentException for parameter/option parsing errors
     */

<     public function __construct($databaseName, Explainable $explainable, array $options = [])



>     public function __construct(string $databaseName, Explainable $explainable, array $options = [])


    {
        if (isset($options['readPreference']) && ! $options['readPreference'] instanceof ReadPreference) {
            throw InvalidArgumentException::invalidType('"readPreference" option', $options['readPreference'], ReadPreference::class);
        }

        if (isset($options['session']) && ! $options['session'] instanceof Session) {
            throw InvalidArgumentException::invalidType('"session" option', $options['session'], Session::class);
        }

        if (isset($options['typeMap']) && ! is_array($options['typeMap'])) {
            throw InvalidArgumentException::invalidType('"typeMap" option', $options['typeMap'], 'array');
        }

        if (isset($options['verbosity']) && ! is_string($options['verbosity'])) {
            throw InvalidArgumentException::invalidType('"verbosity" option', $options['verbosity'], 'string');
        }

        $this->databaseName = $databaseName;
        $this->explainable = $explainable;
        $this->options = $options;
    }


>     /**
    public function execute(Server $server)
>      * Execute the operation.
    {
>      *
        if ($this->explainable instanceof Distinct && ! server_supports_feature($server, self::$wireVersionForDistinct)) {
>      * @see Executable::execute()
            throw UnsupportedException::explainNotSupported();
>      * @return array|object
        }
>      * @throws UnsupportedException if the server does not support explaining the operation

>      * @throws DriverRuntimeException for other driver errors (e.g. connection errors)
        if ($this->isFindAndModify($this->explainable) && ! server_supports_feature($server, self::$wireVersionForFindAndModify)) {
>      */



<         if ($this->explainable instanceof Distinct && ! server_supports_feature($server, self::$wireVersionForDistinct)) {



>         if ($this->explainable instanceof Aggregate && ! server_supports_feature($server, self::$wireVersionForAggregate)) {



<         if ($this->isFindAndModify($this->explainable) && ! server_supports_feature($server, self::$wireVersionForFindAndModify)) {
<             throw UnsupportedException::explainNotSupported();
<         }



>         $cursor = $server->executeCommand($this->databaseName, $this->createCommand($server), $this->createOptions());



<         $cmd = ['explain' => $this->explainable->getCommandDocument($server)];



>         if (isset($this->options['typeMap'])) {
>             $cursor->setTypeMap($this->options['typeMap']);
>         }



<         if (isset($this->options['verbosity'])) {
<             $cmd['verbosity'] = $this->options['verbosity'];



>         return current($cursor->toArray());


        }


<         $cursor = $server->executeCommand($this->databaseName, new Command($cmd), $this->createOptions());



>     /**
>      * Create the explain command.
>      */
>     private function createCommand(Server $server): Command
>     {
>         $cmd = ['explain' => $this->explainable->getCommandDocument($server)];




<         if (isset($this->options['typeMap'])) {
<             $cursor->setTypeMap($this->options['typeMap']);



>         foreach (['comment', 'verbosity'] as $option) {
>             if (isset($this->options[$option])) {
>                 $cmd[$option] = $this->options[$option];
>             }


        }


<         return current($cursor->toArray());



>         return new Command($cmd);


    }

    /**
     * Create options for executing the command.
     *

<      * @see http://php.net/manual/en/mongodb-driver-server.executecommand.php
<      * @return array



>      * @see https://php.net/manual/en/mongodb-driver-server.executecommand.php


     */

<     private function createOptions()



>     private function createOptions(): array


    {
        $options = [];

        if (isset($this->options['readPreference'])) {
            $options['readPreference'] = $this->options['readPreference'];
        }

        if (isset($this->options['session'])) {
            $options['session'] = $this->options['session'];
        }

        return $options;
    }


<     private function isFindAndModify($explainable)



>     private function isFindAndModify(Explainable $explainable): bool


    {
        if ($explainable instanceof FindAndModify || $explainable instanceof FindOneAndDelete || $explainable instanceof FindOneAndReplace || $explainable instanceof FindOneAndUpdate) {
            return true;
        }

        return false;
    }
}