Ext.define('saas.model.Session', {
    extend: 'Ext.data.Model',

    fields: [
        { name: 'token', type: 'string' },
        { name: 'expire', type: 'number' },
        { name: 'timestamp', type: 'number' },
        { name: 'span', type: 'number' },
        { name: 'account' }
    ],

    statics: {
        login: function(username, password) {
            return new Ext.Promise(function (resolve, reject) {
				Ext.Ajax.request({
                    url: '/api/operation/auth/authorize',
                    params: {
                        username: username,
                        password: password
                    },
                    method: 'POST',
                    success: function (response) {
                        var res = Ext.decode(response.responseText);
                        if (res.success) {
                            var session = saas.model.Session.loadData(res.data.token), 
                                account = res.data.account, companyId = res.data.companyId;
                            account.companyId = companyId;
                            session.set('account', account);
                            // 服务端与本地存在时间差
                            session.set('span', session.get('timestamp') - new Date().getTime());
                            if (!session.isValid()) {
                                reject({
                                    message: '登录失败，无效身份令牌'
                                });
                            } else {
                                resolve(session);
                            }
                        } else {
                            Ext.log.error('request failure with code: ', res.code, ', message: ', res.message);
                            reject(res);
                        }
                    },
                    failure: function (response) {
                        Ext.log.error('server-side failure with status code: ', response.status);
                        reject(response);
                    }
                });
            });
        }
    },

    isValid: function() {
        return !Ext.isEmpty(this.get('token')) && this.get('token').length > 128
            && this.get('timestamp') + this.get('expire') * 1000 > new Date().getTime() + this.get('span');
    },
    
    logout: function() {
        return new Ext.Promise(function (resolve, reject) {
            resolve({});
        });
    }
});