<?php


class Zrt_Db_Document_Adapter_Couch
    {

    /**
     * @var Zend_Http_Client HTTP client used for accessing server
     */
    protected $_client;
    protected $_config = array(
        'db' => null ,
        'host' => '127.0.0.1' ,
        'port' => 5984 ,
        'ssl' => false ,
        'username' => null ,
        'password' => null
    );
    // The base URI for this connection.
    protected $_baseUri = null;
    // Whether the connection information has changed.
    protected $_dirty = false;


    public function __construct( $config = array( ) )
        {
        if ( null !== $config )
            {
            if ( is_array( $config ) )
                {
                $this->setFromArray( $config );
                }
            elseif ( $config instanceof Zend_Config )
                {
                $this->setFromConfig( $config );
                }
            elseif ( is_string( $config ) )
                {
                $this->setDb( $config );
                }
            }


        }


    public function setFromArray( array $options )
        {
        foreach ( $options as $key => $value )
            {
            $method = 'set' . ucfirst( $key );
            if ( method_exists( $this , $method ) )
                {
                $this->$method( $value );
                }
            }
        return $this;


        }


    public function setFromConfig( Zend_Config $config )
        {
        return $this->setFromArray( $config->toArray() );


        }


    /**
     * Set Database on which to perform operations
     *
     * @param  string $db
     * @return Zrt_Db_Document_Adapter_Couch
     */
    public function setDb( $db )
        {
        if ( !preg_match( '/^[a-z][a-z0-9_$()+-\/]+$/' , $db ) )
            {
            throw new Zrt_Exception( sprintf( 'Invalid database specified: "%s"' ,
                                              htmlentities( $db ) ) );
            }
        $this->_config['db'] = $db;
        $this->_dirty = true;
        return $this;


        }


    /**
     * Retrieve current database name
     *
     * @return string|null
     */
    public function getDb()
        {
        return $this->_config['db'];


        }


    /**
     * Sets whether to use SSL.
     *
     * @param bool $ssl
     */
    public function setSsl( $ssl )
        {
        $this->_config['ssl'] = !!$ssl;
        $this->_dirty = true;
        return $this;


        }


    /**
     * Retrieve SSL settings.
     *
     * @return bool
     */
    public function getSsl()
        {
        return $this->_config['ssl'];


        }


    /**
     * Sets username to use.
     *
     * @param string $username
     */
    public function setUsername( $username )
        {
        $this->_config['username'] = $username;
        $this->_dirty = true;
        return $this;


        }


    /**
     * Retrieve username.
     *
     * @return string
     */
    public function getUsername()
        {
        return $this->_config['username'];


        }


    /**
     * Sets whether to use a password.
     *
     * @param string $password
     */
    public function setPassword( $password )
        {
        $this->_config['password'] = $password;
        $this->_dirty = true;
        return $this;


        }


    /**
     * Retrieve password.
     *
     * @return string
     */
    public function getPassword()
        {
        return $this->_config['password'];


        }


    /**
     * Set database host
     *
     * @param  string $host
     * @return Zrt_Db_Document_Adapter_Couch
     */
    public function setHost( $host )
        {
        $this->_config['host'] = $host;
        $this->_dirty = true;
        return $this;


        }


    /**
     * Retrieve database host
     *
     * @return string
     */
    public function getHost()
        {
        return $this->_config['host'];


        }


    /**
     * Set database host port
     *
     * @param  int $port
     * @return Zrt_Db_Document_Adapter_Couch
     */
    public function setPort( $port )
        {
        $this->_config['port'] = ( int ) $port;
        $this->_dirty = true;
        return $this;


        }


    /**
     * Retrieve database host port
     *
     * @return int
     */
    public function getPort()
        {
        return $this->_config['port'];


        }


    /**
     * Queries a view.
     *
     * @param Zrt_Db_Document_View
     * @return Zrt_Db_Document_CouchSet
     */
    public function view( Zrt_Db_Document_View $view )
        {
        $db = $this->getDb();
        $designDocument = $view->getDesignDocument();
        $name = $view->getName();
        $parameters = $view->getParameters();
        $response = $this->_prepare( "/$db/_design/$designDocument/_view/$name" ,
                                     $parameters )->_execute();

        $status = $response->getStatus();
        switch ( $status )
            {
            case Zrt_Http::OK:
                return new Zrt_Db_Document_CouchSet( array(
                            'adapter' => $this ,
                            'data' => $response->getBody()
                        ) );
                break;

            case Zrt_Http::NOT_FOUND:
                throw new Zrt_Exception( "$name is not a valid view in the $designDocument document." );
                break;

            case Zrt_Http::BAD_REQUEST:
                // Usually a JSON formatting error.
                throw new Zrt_Exception( "Request was poorly formatted" );
                break;

            default:
                throw new Zrt_Exception( "Response code $status not handled." );
                break;
            }


        }


    /**
     * Retrieves documents from the database based on IDs, or null if nothing is found.
     *
     * @param string|array $id
     * @throws Zrt_Exception
     * @return Zrt_Db_Document_CouchSet
     */
    public function find( $identifiers )
        {
        $db = $this->getDb();
        if ( !is_array( $identifiers ) )
            {
            $identifiers = array( $identifiers );
            }
        $postData = new stdClass();
        $postData->keys = $identifiers;
        $parameters = array(
            'include_docs' => true
        );

        $this->getHttpClient()->setRawData( Zend_Json::encode( $postData ) );
        $response = $this->_prepare( "/$db/_all_docs" , $parameters )->_execute( Zend_Http_Client::POST );

        $status = $response->getStatus();
        switch ( $status )
            {
            case Zrt_Http::OK:
                return new Zrt_Db_Document_CouchSet( array(
                            'adapter' => $this ,
                            'data' => $response->getBody()
                        ) );
                break;

            case Zrt_Http::NOT_FOUND:
                return null;
                break;

            case Zrt_Http::UNAUTHORISED:
                throw new Zrt_Exception( "Database username and password were incorrect" );
                break;

            case Zrt_Http::BAD_REQUEST:
                throw new Zrt_Exception( "Error in call: " . $response->getBody() );
                break;

            case Zrt_Http::UNSUPPORTED_MEDIA_TYPE:
                throw new Zrt_Exception( "Content type must be application/json" );
                break;

            default:
                throw new Zrt_Exception( "Response code $status not handled." );
                break;
            }


        }


    /**
     * Saves a document, either by creating or updating it.
     *
     * @param Zrt_Db_Document_Couch $document
     * @param string $method
     * @throws Zrt_Exception
     */
    public function save( Zrt_Db_Document_Couch $document ,
                          $method = Zend_Http_Client::PUT )
        {
        $db = $this->getDb();
        $id = $document->getId();

        // Set the raw data to be saved.
        $this->getHttpClient()->setRawData( $document->toJson() );
        $response = $this->_prepare( "/$db/$id" )->_execute( $method );

        $status = $response->getStatus();
        switch ( $status )
            {
            case Zrt_Http::OK:
            case Zrt_Http::CREATED:

                $decodedResponse = Zend_Json::decode( $response->getBody() );
                $revision = $decodedResponse['rev'];
                break;

            case Zrt_Http::PRECONDITION_FAILED:
                throw new Zrt_Exception( "A document with the ID $id already exists" );
                break;

            case Zrt_Http::CONFLICT:
                throw new Zrt_Exception( "There was a conflict updating the database" );
                break;

            case Zrt_Http::UNAUTHORISED:
                throw new Zrt_Exception( "Database username and password were incorrect" );
                break;

            case Zrt_Http::BAD_REQUEST:
                throw new Zrt_Exception( "Error in call: " . $response->getBody() );
                break;

            case Zrt_Http::UNSUPPORTED_MEDIA_TYPE:
                throw new Zrt_Exception( "Content type must be application/json" );
                break;

            default:
                throw new Zrt_Exception( "Response code $status not handled." . $response->getBody() );
                break;
            }
        return $revision;


        }


    protected function _getBaseUri()
        {
        if ( !$this->_dirty )
            {
            return $this->_baseUri;
            }
        $portNumber = $this->getPort();
        if ( $this->_config['ssl'] )
            {
            $s = 's';
            $port = (443 != $portNumber) ? ":$portNumber" : '';
            }
        else
            {
            $s = '';
            $port = (80 != $portNumber) ? ":$portNumber" : '';
            }

        $username = $this->getUsername();
        if ( $username )
            {
            $password = $this->getPassword();
            if ( !$password )
                {
                throw new Zrt_Exception( "Must specify both a username and password for authentication." );
                }
            $credentials = "$username:$password@";
            }
        else
            {
            $credentials = '';
            }

        // Save the constructed base URI and mark it clean so we don't regenerate next time.
        $this->_baseUri = "http$s://" . $credentials . $this->getHost() . $port;
        $this->_dirty = false;

        return $this->_baseUri;


        }


    public function ping()
        {
        return $this->_prepare( '/' )->_execute()->getBody();


        }


    public function _prepare( $path , $parameters = null )
        {
        $client = $this->getHttpClient();
        $client->setHeaders( 'Content-Type' , 'application/json' );
        $base = $this->_getBaseUri();
        $path = ltrim( $path , '/' );
        $client->setUri( "$base/$path" );
        if ( null !== $parameters )
            {
            foreach ( $parameters as $key => $value )
                {
                $parameters[$key] = Zend_Json::encode( $value );
                }
            $client->setParameterGet( $parameters );
            }
        return $this;


        }


    protected function _execute( $method = Zend_Http_Client::GET )
        {
        $client = $this->getHttpClient();
        $response = $client->request( $method );
        $client->resetParameters();
        return $response;


        }


    /**
     * Get current HTTP client
     *
     * @return Zend_Http_Client
     */
    public function getHttpClient()
        {
        if ( null === $this->_client )
            {
            $this->_client = new Zend_Http_Client();
            }
        return $this->_client;


        }


    }