/*
 *  Copyright 2016 Red Hat, Inc. and/or its affiliates
 *  and other contributors as indicated by the @author tags.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */

var KeycloakAuthorization = function (keycloak, options) {
    var _instance = this;
    this.rpt = null;

    var resolve = function () {};
    var reject = function () {};

    // detects if browser supports promises
    if (typeof Promise !== "undefined" && Promise.toString().indexOf("[native code]") !== -1) {
        this.ready = new Promise(function (res, rej) {
            resolve = res;
            reject = rej;
        });
    }

    this.init = function () {
        var request = new XMLHttpRequest();

        request.open('GET', keycloak.authServerUrl + '/realms/' + keycloak.realm + '/.well-known/uma2-configuration');
        request.onreadystatechange = function () {
            if (request.readyState == 4) {
                if (request.status == 200) {
                    _instance.config = JSON.parse(request.responseText);
                    resolve();
                } else {
                    console.error('Could not obtain configuration from server.');
                    reject();
                }
            }
        }

        request.send(null);
    };

    /**
     * This method enables client applications to better integrate with resource servers protected by a Keycloak
     * policy enforcer using UMA protocol.
     *
     * The authorization request must be provided with a ticket.
     */
    this.authorize = function (authorizationRequest) {
        this.then = function (onGrant, onDeny, onError) {
            if (authorizationRequest && authorizationRequest.ticket) {
                var request = new XMLHttpRequest();

                request.open('POST', _instance.config.token_endpoint, true);
                request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
                request.setRequestHeader('Authorization', 'Bearer ' + keycloak.token);

                request.onreadystatechange = function () {
                    if (request.readyState == 4) {
                        var status = request.status;

                        if (status >= 200 && status < 300) {
                            var rpt = JSON.parse(request.responseText).access_token;
                            _instance.rpt = rpt;
                            onGrant(rpt);
                        } else if (status == 403) {
                            if (onDeny) {
                                onDeny();
                            } else {
                                console.error('Authorization request was denied by the server.');
                            }
                        } else {
                            if (onError) {
                                onError();
                            } else {
                                console.error('Could not obtain authorization data from server.');
                            }
                        }
                    }
                };

                var params = "grant_type=urn:ietf:params:oauth:grant-type:uma-ticket&client_id=" + keycloak.clientId + "&ticket=" + authorizationRequest.ticket;

                if (authorizationRequest.submitRequest != undefined) {
                    params += "&submit_request=" + authorizationRequest.submitRequest;
                }

                var metadata = authorizationRequest.metadata;

                if (metadata) {
                    if (metadata.responseIncludeResourceName) {
                        params += "&response_include_resource_name=" + metadata.responseIncludeResourceName;
                    }
                    if (metadata.responsePermissionsLimit) {
                        params += "&response_permissions_limit=" + metadata.responsePermissionsLimit;
                    }
                }

                if (_instance.rpt && (authorizationRequest.incrementalAuthorization == undefined || authorizationRequest.incrementalAuthorization)) {
                    params += "&rpt=" + _instance.rpt;
                }

                request.send(params);
            }
        };

        return this;
    };

    /**
     * Obtains all entitlements from a Keycloak Server based on a given resourceServerId.
     */
    this.entitlement = function (resourceServerId, authorizationRequest) {
        this.then = function (onGrant, onDeny, onError) {
            var request = new XMLHttpRequest();

            request.open('POST', _instance.config.token_endpoint, true);
            request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
            request.setRequestHeader('Authorization', 'Bearer ' + keycloak.token);

            request.onreadystatechange = function () {
                if (request.readyState == 4) {
                    var status = request.status;

                    if (status >= 200 && status < 300) {
                        var rpt = JSON.parse(request.responseText).access_token;
                        _instance.rpt = rpt;
                        onGrant(rpt);
                    } else if (status == 403) {
                        if (onDeny) {
                            onDeny();
                        } else {
                            console.error('Authorization request was denied by the server.');
                        }
                    } else {
                        if (onError) {
                            onError();
                        } else {
                            console.error('Could not obtain authorization data from server.');
                        }
                    }
                }
            };

            if (!authorizationRequest) {
                authorizationRequest = {};
            }

            var params = "grant_type=urn:ietf:params:oauth:grant-type:uma-ticket&client_id=" + keycloak.clientId;

            if (authorizationRequest.claimToken) {
                params += "&claim_token=" + authorizationRequest.claimToken;

                if (authorizationRequest.claimTokenFormat) {
                    params += "&claim_token_format=" + authorizationRequest.claimTokenFormat;
                }
            }

            params += "&audience=" + resourceServerId;

            var permissions = authorizationRequest.permissions;

            if (!permissions) {
                permissions = [];
            }

            for (var i = 0; i < permissions.length; i++) {
                var resource = permissions[i];
                var permission = resource.id;

                if (resource.scopes && resource.scopes.length > 0) {
                    permission += "#";
                    for (var j = 0; j < resource.scopes.length; j++) {
                        var scope = resource.scopes[j];
                        if (permission.indexOf('#') != permission.length - 1) {
                            permission += ",";
                        }
                        permission += scope;
                    }
                }

                params += "&permission=" + permission;
            }

            var metadata = authorizationRequest.metadata;

            if (metadata) {
                if (metadata.responseIncludeResourceName) {
                    params += "&response_include_resource_name=" + metadata.responseIncludeResourceName;
                }
                if (metadata.responsePermissionsLimit) {
                    params += "&response_permissions_limit=" + metadata.responsePermissionsLimit;
                }
            }

            if (_instance.rpt) {
                params += "&rpt=" + _instance.rpt;
            }

            request.send(params);
        };

        return this;
    };

    this.init(this);

    return this;
};

export default KeycloakAuthorization;
