<?php

class ParTCP_Outgoing_Message {

	public $data = [];
	public $recipientPubKey;
	private $crypto; // an object providing crypto functions
	private $keyRetrievalFunction; // callback for retrieving public key of an identity


	public function __construct( $cryptoObject, $keyRetrievalFunction = NULL ){
		$this->crypto = $cryptoObject;
		$this->keyRetrievalFunction = $keyRetrievalFunction;
		if ( $this->crypto->identity ){
			$this->set( 'From', $this->crypto->identity );
		}
	}


	private function get_recipient_key( $forCrypto = FALSE ){
		if ( is_null( $this->recipientPubKey ) ){
			if ( ! empty( $this->data['To'] ) && $this->keyRetrievalFunction ){
				$this->recipientPubKey = call_user_func( $this->keyRetrievalFunction, $this->data['To'] );
			}
			else {
				$this->recipientPubKey = FALSE;
			}
		}
		if ( ! $this->recipientPubKey ){
			return FALSE;
		}
		return $this->recipientPubKey;
	}


	public function set( $name, $value = NULL, $encrypted = FALSE ){
		if ( is_null( $value ) ){
			unset( $this->data[ $name ] );
			return;
		}
		if ( $encrypted ){
			$key = $this->get_recipient_key( TRUE );
			if ( $key ){
				$this->set( $name, NULL );
				$name .= '~';
				$value = $this->crypto->encrypt( $value, $key );
			}
		}
		$this->data[ $name ] = $value;
	}


	public function multiset( $namesAndValues, $encrypted = FALSE ){
		foreach ( $namesAndValues as $name => $value ){
			$this->set( $name, $value, $encrypted );
		}
	}
	

	public function set_date( $time = NULL ){
		$this->set( 'Date', date( 'c', $time ?? time() ) );
	}
	
	
	public function set_recipient( $id, $pubKey = NULL ){
		$this->set( 'To', $id );
		if ( $pubKey ){
			$this->recipientPubKey = $pubKey;
		}
	}
	
	
	public function set_public_key(){
		$pubKey = $this->crypto->get_local_pubkey();
		if ( $pubKey ){
			$this->set( 'Public-Key', $pubKey );
		}
	}


	public function dump(){
		return yaml_emit( $this->data );
	}

	
	public function dump_signed(){
		$rawMessage = $this->dump();
		$signature = $this->crypto->generate_signature( $rawMessage );
		return "Signature: {$signature}\n{$rawMessage}";
	}

}

// end of file outgoing_message.class.php