<?php
namespace Dropbox;

/**
 * The base class for the two auth options.
 */
class WebAuthBase extends AuthBase
{
    protected function _getAuthorizeUrl($redirectUri, $state)
    {
        return RequestUtil::buildUrlForGetOrPut(
            $this->userLocale,
            $this->appInfo->getHost()->getWeb(),
            "1/oauth2/authorize",
            array(
                "client_id" => $this->appInfo->getKey(),
                "response_type" => "code",
                "redirect_uri" => $redirectUri,
                "state" => $state,
            ));
    }

    protected function _finish($code, $originalRedirectUri)
    {
        // This endpoint requires "Basic" auth.
        $clientCredentials = $this->appInfo->getKey().":".$this->appInfo->getSecret();
        $authHeaderValue = "Basic ".base64_encode($clientCredentials);

        $response = RequestUtil::doPostWithSpecificAuth(
            $this->clientIdentifier, $authHeaderValue, $this->userLocale,
            $this->appInfo->getHost()->getApi(),
            "1/oauth2/token",
            array(
                "grant_type" => "authorization_code",
                "code" => $code,
                "redirect_uri" => $originalRedirectUri,
            ));

        if ($response->statusCode !== 200) throw RequestUtil::unexpectedStatus($response);

        $parts = RequestUtil::parseResponseJson($response->body);

        if (!array_key_exists('token_type', $parts) || !is_string($parts['token_type'])) {
            throw new Exception_BadResponse("Missing \"token_type\" field.");
        }
        $tokenType = $parts['token_type'];
        if (!array_key_exists('access_token', $parts) || !is_string($parts['access_token'])) {
            throw new Exception_BadResponse("Missing \"access_token\" field.");
        }
        $accessToken = $parts['access_token'];
        if (!array_key_exists('uid', $parts) || !is_string($parts['uid'])) {
            throw new Exception_BadResponse("Missing \"uid\" string field.");
        }
        $userId = $parts['uid'];

        if ($tokenType !== "Bearer" && $tokenType !== "bearer") {
            throw new Exception_BadResponse("Unknown \"token_type\"; expecting \"Bearer\", got  "
                                            .Util::q($tokenType));
        }

        return array($accessToken, $userId);
    }
}
