/**
 * Copyright 2005-2013 Restlet S.A.S.
 * 
 * The contents of this file are subject to the terms of one of the following
 * open source licenses: Apache 2.0 or LGPL 3.0 or LGPL 2.1 or CDDL 1.0 or EPL
 * 1.0 (the "Licenses"). You can select the license that you prefer but you may
 * not use this file except in compliance with one of these Licenses.
 * 
 * You can obtain a copy of the Apache 2.0 license at
 * http://www.opensource.org/licenses/apache-2.0
 * 
 * You can obtain a copy of the LGPL 3.0 license at
 * http://www.opensource.org/licenses/lgpl-3.0
 * 
 * You can obtain a copy of the LGPL 2.1 license at
 * http://www.opensource.org/licenses/lgpl-2.1
 * 
 * You can obtain a copy of the CDDL 1.0 license at
 * http://www.opensource.org/licenses/cddl1
 * 
 * You can obtain a copy of the EPL 1.0 license at
 * http://www.opensource.org/licenses/eclipse-1.0
 * 
 * See the Licenses for the specific language governing permissions and
 * limitations under the Licenses.
 * 
 * Alternatively, you can obtain a royalty free commercial license with less
 * limitations, transferable or non-transferable, directly at
 * http://www.restlet.com/products/restlet-framework
 * 
 * Restlet is a registered trademark of Restlet S.A.S.
 */

package org.restlet.ext.oauth;

import org.restlet.Context;
import org.restlet.data.Form;
import org.restlet.ext.oauth.internal.CookieCopyClientResource;
import org.restlet.ext.oauth.internal.Scopes;
import org.restlet.representation.Representation;
import org.restlet.resource.ClientResource;

/**
 * Enum that lets clients retrieve tokens using different OAuth2 flows.
 * Currently this class enables use of the NONE (Autonomous) flow and the
 * PASSWORD flow. It also supports a client to refresh a token.
 * 
 * The class defines one function doFlow that wraps the above specified ways of
 * retrieving a token from an authorization server.
 * 
 * Example:
 * 
 * <pre>
 * {
 *     &#064;code
 *     OAuthParameters params = new OAuthParameters(&quot;clientId&quot;, &quot;clientSecret&quot;);
 *     Flow f = Flow.NONE;
 *     User u = f.execute(params, null, null, null, null, null);
 * 
 *     f = Flow.PASSWORD;
 *     u = f.execute(params, null, null, &quot;username&quot;, &quot;password&quot;, null);
 * 
 * }
 * </pre>
 * 
 * @see <a
 *      href="http://tools.ietf.org/html/draft-ietf-oauth-v2-10#section-1.4.2">User
 *      Agent Flow</a>
 * 
 * @see <a
 *      href="http://tools.ietf.org/html/draft-ietf-oauth-v2-10#section-1.4.4"
 *      >Autonomous Flow</a>
 * @see <a
 *      href="http://tools.ietf.org/html/draft-ietf-oauth-v2-10#section-1.4.3"
 *      >Password Flow (Native Application)</a>
 * 
 * @author Martin Svensson
 * @author Kristoffer Gronowski
 */
public enum Flow {
    NONE, PASSWORD, REFRESH;

    /*
     * public static OAuthUser userAgent(OAuthParameters params, String
     * callbackUri, String state, org.restlet.Client c) { OAuthUser result =
     * null;
     * 
     * Form form = new Form(); form.add(OAuthServerResource.RESPONSE_TYPE,
     * OAuthServerResource.ResponseType.token.name());
     * form.add(OAuthServerResource.CLIENT_ID, params.getClientId());
     * form.add(OAuthServerResource.REDIR_URI, callbackUri);
     * 
     * if (params.getRoles() != null && params.getRoles().size() > 0) {
     * form.add(OAuthServerResource.SCOPE, Scopes.toScope(params.getRoles())); }
     * 
     * if (state != null && state.length() > 0) {
     * form.add(OAuthServerResource.STATE, state); }
     * 
     * String q = form.getQueryString(); Reference redirRef = new
     * Reference(params.getBaseRef(), params.getAuthorizePath(), q, null);
     * ClientResource authResource = new CookieCopyClientResource(
     * redirRef.toUri()); authResource.setNext(c);
     * authResource.setFollowingRedirects(false); // token is in a 3xx
     * Representation r = authResource.get();
     * 
     * int maxRedirCnt = 10; // Stop the maddness if out of hand... int cnt = 0;
     * 
     * while (authResource.getStatus().isRedirection()) { String fragment =
     * authResource.getLocationRef().getFragment(); if (fragment != null &&
     * fragment.length() > 0) { Form f = new Form(fragment);
     * 
     * String accessToken = f .getFirstValue(OAuthServerResource.ACCESS_TOKEN);
     * 
     * String refreshToken = f
     * .getFirstValue(OAuthServerResource.REFRESH_TOKEN);
     * 
     * long expiresIn = 0; String exp =
     * f.getFirstValue(OAuthServerResource.EXPIRES_IN);
     * 
     * if (exp != null && exp.length() > 0) { expiresIn = Long.parseLong(exp); }
     * 
     * if (accessToken != null && accessToken.length() > 0) {
     * Context.getCurrentLogger().info(
     * "Successful UserAgent flow : AccessToken = " + accessToken +
     * " RefreshToken = " + refreshToken + " ExpiresIn = " + expiresIn); result
     * = new OAuthUser(null, accessToken, refreshToken, expiresIn);
     * result.setState(f.getFirstValue(OAuthServerResource.STATE)); break; }
     * else { // String error = // f.getFirstValue(OAuthResource.ACCESS_TOKEN);
     * // TODO throw exception.... } }
     * 
     * if (++cnt >= maxRedirCnt) break;
     * 
     * Context.getCurrentLogger().info( "Redir to = " +
     * authResource.getLocationRef());
     * authResource.setReference(authResource.getLocationRef());
     * 
     * // FOR TESTING!!!! if (cnt == 1) {
     * 
     * for (CookieSetting cs : authResource.getCookieSettings()) {
     * 
     * authResource.getCookies().add(cs.getName(), cs.getValue()); } }
     * 
     * r = authResource.get(); // Check if it is a OpenID form forward try { r =
     * OpenIdFormFrowarder.handleFormRedirect(r, authResource); } catch
     * (IOException e) { Context.getCurrentLogger().log(Level.WARNING,
     * "Failed in OpenID FW", e); } }
     * 
     * r.release(); authResource.release();
     * 
     * return result; }
     */
    private static OAuthUser noneFlow(OAuthParameters params,
            org.restlet.Client c) {
        OAuthUser result = null;

        Form form = new Form();
        form.add(OAuthServerResource.GRANT_TYPE,
                GrantType.none.name());
        form.add(OAuthServerResource.CLIENT_ID, params.getClientId());
        form.add(OAuthServerResource.CLIENT_SECRET, params.getClientSecret());

        if (params.getRoles() != null && params.getRoles().size() > 0) {
            form.add(OAuthServerResource.SCOPE,
                    Scopes.toScope(params.getRoles()));
        }

        ClientResource tokenResource = new CookieCopyClientResource(
                params.getBaseRef() + params.getAccessTokenPath());
        tokenResource.setNext(c);
        Context.getCurrentLogger().fine(
                "Sending NoneFlow form : " + form.getQueryString());

        Representation body = tokenResource.post(form.getWebRepresentation());

        if (tokenResource.getStatus().isSuccess()) {
            result = OAuthUser.createJson(body);
        }

        body.release();
        tokenResource.release();

        return result;
    }

    /**
     * Checks the credentials and returns a completed OAuth user.
     * 
     * @param params
     *            The authentication parameters.
     * @param username
     *            The username to check.
     * @param password
     *            The password to check.
     * @param c
     *            The client connector.
     * @return A completed OAuth user.
     */
    // TODO password should be passed as a char[]
    private static OAuthUser passwordFlow(OAuthParameters params,
            String username, String password, org.restlet.Client c) {
        OAuthUser result = null;
        Form form = new Form();
        form.add(OAuthServerResource.GRANT_TYPE,
                GrantType.password.name());
        form.add(OAuthServerResource.CLIENT_ID, params.getClientId());
        form.add(OAuthServerResource.CLIENT_SECRET, params.getClientSecret());
        form.add(OAuthServerResource.USERNAME, username);
        form.add(OAuthServerResource.PASSWORD, password);

        ClientResource tokenResource = new CookieCopyClientResource(
                params.getBaseRef() + params.getAccessTokenPath());
        tokenResource.setNext(c);

        Context.getCurrentLogger().fine(
                "Sending PasswordFlow form : " + form.getQueryString());
        Representation body = null;

        try {
            body = tokenResource.post(form.getWebRepresentation());

            if (tokenResource.getStatus().isSuccess()) {
                result = OAuthUser.createJson(body);
            }
        } finally {
            if (body != null)
                body.release();
            tokenResource.release();
        }

        return result;
    }

    /**
     * Checks the credentials, refresh the current OAuth token and returns a
     * completed OAuth user.
     * 
     * @param params
     *            The authentication parameters.
     * @param refreshToken
     *            The token to refresh.
     * @param c
     *            The client connector.
     * @return A completed OAuth user.
     */
    private static OAuthUser refreshToken(OAuthParameters params,
            String refreshToken, org.restlet.Client c) {

        OAuthUser result = null;

        ClientResource tokenResource = new CookieCopyClientResource(
                params.getBaseRef() + params.getAccessTokenPath());
        tokenResource.setNext(c);
        Form form = new Form();
        form.add(OAuthServerResource.GRANT_TYPE,
                GrantType.refresh_token.name());
        form.add(OAuthServerResource.CLIENT_ID, params.getClientId());
        form.add(OAuthServerResource.CLIENT_SECRET, params.getClientSecret());
        form.add(OAuthServerResource.REFRESH_TOKEN, refreshToken);

        Context.getCurrentLogger().fine(
                "Sending refresh form : " + form.getQueryString());

        Representation body = tokenResource.post(form.getWebRepresentation());

        if (tokenResource.getStatus().isSuccess()) {
            result = OAuthUser.createJson(body);
        }

        body.release();
        tokenResource.release();

        return result;
    }

    /**
     * Executes a specific OAuth Flow (including token refresh). Based on the
     * chosen flow some of the parameters need to be set (see description). Upon
     * successful authorization returns a new OAuthUser containing an access
     * token that can be used for getting protected resources.
     * 
     * @param params
     *            parameters specifying (clientId, clientSecret, scope etc).
     *            Used for all flows
     * @param callbackUri
     *            callbackUri used for the userAgent flow. The server
     * @param state
     *            used in the userAgent flow
     * @param username
     *            used in the password flow
     * @param password
     *            used in the password flow
     * @param refreshToken
     *            the token to refresh, used in the refresh flow
     * @return OAuthUser containing a token that can be used for access
     */
    public OAuthUser execute(OAuthParameters params, String callbackUri,
            String state, String username, String password, String refreshToken) {

        return execute(params, callbackUri, state, username, password,
                refreshToken, null);
    }

    /**
     * Executes a specific OAuth Flow (including token refresh). Based on the
     * chosen flow some of the parameters need to be set (see description). Upon
     * successful authorization returns a new OAuthUser containing an access
     * token that can be used for getting protected resources.
     * 
     * @param params
     *            parameters specifying OAuth end point. Used for all flows.
     * @param callbackUri
     *            callbackUri used for the userAgent flow.
     * @param state
     *            state that should be returned by the Authorization server.
     *            Used in UserAgent flow.
     * @param username
     *            used in the password flow.
     * @param password
     *            used in the password flow.
     * @param refreshToken
     *            the token to refresh, used in the refresh flow
     * @param client
     *            provided client
     * @return OAuthUser containing a token that can be used for access.
     */
    public OAuthUser execute(OAuthParameters params, String callbackUri,
            String state, String username, String password,
            String refreshToken, org.restlet.Client client) {
        if (this == Flow.PASSWORD) {
            return passwordFlow(params, username, password, client);
        } else if (this == Flow.NONE) {
            return noneFlow(params, client);
            // } else if (this == Flow.USERAGENT) {
            // return userAgent(params, callbackUri, state, c);
        } else if (this == Flow.REFRESH) {
            return refreshToken(params, refreshToken, client);
        }
        return null;
    }

}