/**
 * Licensed to the University Corporation for Advanced Internet
 * Development, Inc. (UCAID) under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for
 * additional information regarding copyright ownership.
 *
 * UCAID licenses this file to you 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.
 */

/**
 * @file shibsp/attribute/resolver/AttributeResolver.h
 *
 * A service that transforms or resolves additional attributes for a
 * particular subject.
 */

#ifndef __shibsp_resolver_h__
#define __shibsp_resolver_h__

#include <shibsp/base.h>

#include <string>
#include <vector>
#include <xmltooling/Lockable.h>

namespace opensaml {
    class SAML_API Assertion;
    namespace saml2 {
        class SAML_API NameID;
    };
    namespace saml2md {
        class SAML_API EntityDescriptor;
    };
};

namespace shibsp {

    class SHIBSP_API Application;
    class SHIBSP_API Attribute;
    class SHIBSP_API Session;
    class SHIBSP_API ResolutionContext;

#if defined (_MSC_VER)
    #pragma warning( push )
    #pragma warning( disable : 4250 4251 )
#endif

    /**
     * The service that resolves the attributes for a particular subject.
     */
    class SHIBSP_API AttributeResolver : public virtual xmltooling::Lockable
    {
        MAKE_NONCOPYABLE(AttributeResolver);
    protected:
        AttributeResolver();
    public:
        virtual ~AttributeResolver();

        /**
         * Creates a ResolutionContext based on session bootstrap material.
         *
         * <p>This enables resolution to occur ahead of session creation so that
         * Attributes can be supplied while creating the session.
         *
         * @param application       reference to Application that owns the eventual Session
         * @param issuer            issuing metadata of assertion issuer, if known
         * @param protocol          protocol used to establish Session
         * @param nameid            principal identifier, normalized to SAML 2, if any
         * @param authncontext_class    method/category of authentication event, if known
         * @param authncontext_decl specifics of authentication event, if known
         * @param tokens            assertions initiating the Session, if any
         * @param attributes        array of previously resolved attributes, if any
         * @return  newly created ResolutionContext, owned by caller
         */
        virtual ResolutionContext* createResolutionContext(
            const Application& application,
            const opensaml::saml2md::EntityDescriptor* issuer,
            const XMLCh* protocol,
            const opensaml::saml2::NameID* nameid=nullptr,
            const XMLCh* authncontext_class=nullptr,
            const XMLCh* authncontext_decl=nullptr,
            const std::vector<const opensaml::Assertion*>* tokens=nullptr,
            const std::vector<Attribute*>* attributes=nullptr
            ) const=0;

        /**
         * Creates a ResolutionContext for an existing Session.
         *
         * @param application   reference to Application that owns the Session
         * @param session       reference to Session
         * @return  newly created ResolutionContext, owned by caller
         */
        virtual ResolutionContext* createResolutionContext(const Application& application, const Session& session) const=0;


        /**
         * Resolves attributes for a given subject and returns them in the supplied context.
         *
         * @param ctx           resolution context to use to resolve attributes
         *
         * @throws AttributeResolutionException thrown if there is a problem resolving the attributes for the subject
         */
        virtual void resolveAttributes(ResolutionContext& ctx) const=0;

        /**
         * Populates an array with the set of Attribute IDs that might be generated.
         *
         * @param attributes    array to populate
         */
        virtual void getAttributeIds(std::vector<std::string>& attributes) const=0;
    };

#if defined (_MSC_VER)
    #pragma warning( pop )
#endif

    /**
     * Registers AttributeResolver classes into the runtime.
     */
    void SHIBSP_API registerAttributeResolvers();

    /** AttributeResolver based on SAML queries to an IdP during SSO. */
    #define QUERY_ATTRIBUTE_RESOLVER "Query"

    /** AttributeResolver based on free-standing SAML queries to additional AAs. */
    #define SIMPLEAGGREGATION_ATTRIBUTE_RESOLVER "SimpleAggregation"

    /** AttributeResolver based on chaining together other resolvers. */
    #define CHAINING_ATTRIBUTE_RESOLVER "Chaining"
};

#endif /* __shibsp_resolver_h__ */
