<?php

class ReCaptcha extends SimpleCaptcha {
	// reCAPTHCA error code returned from recaptcha_check_answer
	private $recaptcha_error = null;

	/**
	 * Displays the reCAPTCHA widget.
	 * If $this->recaptcha_error is set, it will display an error in the widget.
	 * @param OutputPage $out
	 */
	function getForm( OutputPage $out, $tabIndex = 1 ) {
		global $wgReCaptchaPublicKey, $wgReCaptchaTheme;

		$useHttps = ( isset( $_SERVER['HTTPS'] ) && $_SERVER['HTTPS'] == 'on' );
		$js = 'var RecaptchaOptions = ' . Xml::encodeJsVar(
			array( 'theme' => $wgReCaptchaTheme, 'tabindex' => $tabIndex )
		);

		return Html::inlineScript(
			$js
		) . recaptcha_get_html( $wgReCaptchaPublicKey, $this->recaptcha_error, $useHttps );
	}

	/**
	 * Calls the library function recaptcha_check_answer to verify the users input.
	 * Sets $this->recaptcha_error if the user is incorrect.
	 * @return boolean
	 *
	 */
	function passCaptcha() {
		global $wgReCaptchaPrivateKey, $wgRequest;

		// API is hardwired to return wpCaptchaId and wpCaptchaWord,
		// so use that if the standard two are empty
		$challenge = $wgRequest->getVal(
			'recaptcha_challenge_field', $wgRequest->getVal( 'wpCaptchaId' )
		);
		$response = $wgRequest->getVal(
			'recaptcha_response_field', $wgRequest->getVal( 'wpCaptchaWord' )
		);

		if ( $response === null ) {
			// new captcha session
			return false;
		}

		$ip = $wgRequest->getIP();

		$recaptcha_response = recaptcha_check_answer(
			$wgReCaptchaPrivateKey,
			$ip,
			$challenge,
			$response
		);

		if ( !$recaptcha_response->is_valid ) {
			$this->recaptcha_error = $recaptcha_response->error;
			return false;
		}

		$recaptcha_error = null;

		return true;

	}

	function addCaptchaAPI( &$resultArr ) {
		global $wgReCaptchaPublicKey;

		$resultArr['captcha']['type'] = 'recaptcha';
		$resultArr['captcha']['mime'] = 'image/png';
		$resultArr['captcha']['key'] = $wgReCaptchaPublicKey;
		$resultArr['captcha']['error'] = $this->recaptcha_error;
	}

	/**
	 * Show a message asking the user to enter a captcha on edit
	 * The result will be treated as wiki text
	 *
	 * @param $action string Action being performed
	 * @return string
	 */
	function getMessage( $action ) {
		$name = 'recaptcha-' . $action;
		$text = wfMessage( $name )->text();

		# Obtain a more tailored message, if possible, otherwise, fall back to
		# the default for edits
		return wfMessage( $name, $text )->isDisabled() ? wfMessage( 'recaptcha-edit' )->text() : $text;
	}

	public function APIGetAllowedParams( &$module, &$params, $flags ) {
		if ( $flags && $this->isAPICaptchaModule( $module ) ) {
			if ( defined( 'ApiBase::PARAM_HELP_MSG' ) ) {
				$params['recaptcha_challenge_field'] = array(
					ApiBase::PARAM_HELP_MSG => 'recaptcha-apihelp-param-recaptcha_challenge_field',
				);
				$params['recaptcha_response_field'] = array(
					ApiBase::PARAM_HELP_MSG => 'recaptcha-apihelp-param-recaptcha_response_field',
				);
			} else {
				// @todo: Remove this branch when support for MediaWiki < 1.25 is dropped
				$params['recaptcha_challenge_field'] = null;
				$params['recaptcha_response_field'] = null;
			}
		}

		return true;
	}

	/**
	 * @deprecated since MediaWiki 1.25
	 */
	public function APIGetParamDescription( &$module, &$desc ) {
		if ( $this->isAPICaptchaModule( $module ) ) {
			$desc['recaptcha_challenge_field'] = 'Field from the ReCaptcha widget';
			$desc['recaptcha_response_field'] = 'Field from the ReCaptcha widget';
		}

		return true;
	}
}