/* -------------------------------------------------------------------------- */
/* Copyright 2002-2012, OpenNebula Project Leads (OpenNebula.org)             */
/*                                                                            */
/* 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.                                             */
/* -------------------------------------------------------------------------- */

#ifndef AUTH_MANAGER_H_
#define AUTH_MANAGER_H_

#include <time.h>

#include "MadManager.h"
#include "ActionManager.h"
#include "SSLTools.h"

#include "AuthManagerDriver.h"
#include "PoolObjectSQL.h"
#include "PoolObjectAuth.h"

using namespace std;

//Forward definitions
class AuthRequest;
class PoolObjectAuth;

/* -------------------------------------------------------------------------- */
/* -------------------------------------------------------------------------- */

extern "C" void * authm_action_loop(void *arg);

class AuthManager : public MadManager, public ActionListener
{
public:

    AuthManager(
        time_t                      timer,
        time_t                      __time_out,
        vector<const Attribute*>&   _mads):
            MadManager(_mads), timer_period(timer)
    {
        _time_out = __time_out;

        am.addListener(this);

        pthread_mutex_init(&mutex,0);
    };

    ~AuthManager(){};

    enum Actions
    {
        AUTHENTICATE,
        AUTHORIZE,
        FINALIZE
    };

    /**
     *  Triggers specific actions to the Auth Manager. This function
     *  wraps the ActionManager trigger function.
     *    @param action the Auth Manager action
     *    @param request an auth request
     */
    void trigger(
        Actions       action,
        AuthRequest*  request);

    /**
     *  This functions starts the associated listener thread, and creates a
     *  new thread for the AuthManager. This thread will wait in
     *  an action loop till it receives ACTION_FINALIZE.
     *    @return 0 on success.
     */
    int start();

    /**
     *  Loads Virtual Machine Manager Mads defined in configuration file
     *   @param uid of the user executing the driver. When uid is 0 the nebula
     *   identity will be used. Otherwise the Mad will be loaded through the
     *   sudo application.
     */
    void load_mads(int uid);

    /**
     *  Gets the thread identification.
     *    @return pthread_t for the manager thread (that in the action loop).
     */
    pthread_t get_thread_id() const
    {
        return authm_thread;
    };

    /**
     *  Notify the result of an auth request
     */
    void notify_request(int auth_id, bool result, const string& message);

    /**
     *  Discards a pending request. Call this before freeing not notified or
     *  timeout requests.
     */
    void discard_request(int auth_id)
    {
        lock();

        auth_requests.erase(auth_id);

        unlock();
    }

    /**
     *  Gets default timeout for Auth requests
     */
    static time_t  time_out()
    {
        return _time_out;
    }

private:
    /**
     *  Thread id for the Transfer Manager
     */
    pthread_t               authm_thread;

    /**
     *  Action engine for the Manager
     */
    ActionManager           am;

    /**
     *  List of pending requests
     */
    map<int, AuthRequest *> auth_requests;

    /**
     *  Mutex to access the auth_requests
     */
    pthread_mutex_t         mutex;

    /**
     *  Default timeout for Auth requests
     */
    static time_t           _time_out;

    /**
     *  Timer for the Manager (periocally triggers timer action)
     */
    time_t                  timer_period;

    /**
     *  Generic name for the Auth driver
     */
     static const char *  auth_driver_name;

    /**
     *  Returns a pointer to a Auth Manager driver.
     *    @param name of an attribute of the driver (e.g. its type)
     *    @param value of the attribute
     *    @return the Auth driver with attribute name equal to value
     *    or 0 in not found
     */
    const AuthManagerDriver * get(
        const string&   name,
        const string&   value)
    {
        return static_cast<const AuthManagerDriver *>
               (MadManager::get(0,name,value));
    };

    /**
     *  Returns a pointer to a Auth Manager driver. The driver is
     *  searched by its name.
     *    @param name the name of the driver
     *    @return the TM driver owned by uid with attribute name equal to value
     *    or 0 in not found
     */
    const AuthManagerDriver * get()
    {
        string name("NAME");

        return static_cast<const AuthManagerDriver *>
               (MadManager::get(0,name,auth_driver_name));
    };

    /**
     *  Function to execute the Manager action loop method within a new pthread
     * (requires C linkage)
     */
    friend void * authm_action_loop(void *arg);

    /**
     *  The action function executed when an action is triggered.
     *    @param action the name of the action
     *    @param arg arguments for the action function
     */
    void do_action(
        const string &  action,
        void *          arg);

    /**
     *  This function authenticates a user
     */
    void authenticate_action(AuthRequest * ar);

    /**
     *  This function authorizes a user request
     */
    void authorize_action(AuthRequest * ar);

    /**
     *  This function is periodically executed to check time_outs on requests
     */
    void timer_action();

    /**
     *  Function to lock the pool
     */
    void lock()
    {
        pthread_mutex_lock(&mutex);
    };

    /**
     *  Function to unlock the pool
     */
    void unlock()
    {
        pthread_mutex_unlock(&mutex);
    };

    /**
     *  Add a new request to the Request map
     *    @param ar pointer to the AuthRequest
     *    @return the id for the request
     */
    int add_request(AuthRequest *ar);

    /**
     *  Gets request from the Request map
     *    @param id for the request
     *    @return pointer to the AuthRequest
     */
    AuthRequest * get_request(int id);
};

/* -------------------------------------------------------------------------- */
/* -------------------------------------------------------------------------- */

/**
 *  The AuthRequest class is used to pass an Authorization or Authentication
 *  request to the AuthManager. The result of the request will be stored
 *  in the result and message attributes of this class.
 */
class AuthRequest : public ActionListener
{
public:
    AuthRequest(int _uid, int _gid):
        result(false),
        timeout(false),
        uid(_uid),
        gid(_gid),
        time_out(0),
        self_authorize(true)
    {
        am.addListener(this);
    };

    ~AuthRequest(){};

    /**
     *  Authorization Request Type
     */
    enum Operation
    {
        USE    = 0x1LL,  /**< Auth. to use an object                   */
        MANAGE = 0x2LL,  /**< Auth. to perform management actions      */
        ADMIN  = 0x4LL,  /**< Auth. to perform administrative actions  */
        CREATE = 0x8LL   /**< Auth. to create an object                */
    };

    static string operation_to_str(Operation op)
    {
        switch (op)
        {
            case USE:    return "USE";
            case MANAGE: return "MANAGE";
            case ADMIN:  return "ADMIN";
            case CREATE: return "CREATE";
            default:     return "";
        }
    };


    /**
     *  Sets the challenge to authenticate an user
     *  @param challenge a driver specific authentication challenge
     */
    void add_authenticate(const string &_driver,
                          const string &_username,
                          const string &_password,
                          const string &_session)
    {
        username = _username;
        password = _password;
        session  = _session;
        
        driver   = _driver;
    }

    /**
     *  Adds a CREATE authorization request.
     * 
     *        OBJECT:<-1|OBJECT_TMPL_XML64>:CREATE:UID:AUTH
     *      
     *    @param type of the object to be created
     *    @param template (base64 encoded) of the new object
     */
     void add_create_auth(PoolObjectSQL::ObjectType type, const string& txml_64)
     {
         PoolObjectAuth perms; //oid & gid set to -1
         
         perms.uid      = uid;
         perms.obj_type = type;

         add_auth(AuthRequest::CREATE, perms, txml_64);
     }

    /**
     *  Adds a new authorization item to this request
     *
     *        OBJECT:OBJECT_ID:ACTION:OWNER:AUTH
     *
     * @param op the operation to be authorized
     * @param ob_perms object's permission attributes
     */
    void add_auth(Operation             op,
                  const PoolObjectAuth& ob_perms)
    {
        add_auth(op, ob_perms, "");
    }

    /**
     *  Gets the authorization requests in a single string
     *  @return a space separated list of auth requests, or an empty string if
     *          no auth requests were added
     */
    string get_auths()
    {
        ostringstream oss;
        unsigned int  i;

        if ( auths.empty() )
        {
            return string();
        }

        for (i=0; i<auths.size()-1; i++)
        {
            oss << auths[i] << " ";
        }

        oss << auths[i];

        return oss.str();
    };

    /**
     *  Notify client that we have an answer for the request
     */
    void notify()
    {
        am.trigger(ActionListener::ACTION_FINALIZE,0);
    };

    /**
     *  Wait for the AuthRequest to be completed
     */
    void wait()
    {
        time_out = time(0) + AuthManager::time_out();

        am.loop(0,0);
    };

    bool core_authorize()
    {
        return ( uid == 0 || self_authorize );
    }

    bool core_authenticate()
    {
        string sha1_session = SSLTools::sha1_digest(session);

        return (password == sha1_session);
    }

    /**
     *  The result of the request, true if authorized or authenticated
     */
    bool            result;

    /**
     *  Error message for negative results
     */
    string          message;

    /**
     *  Time out
     */
    bool            timeout;

    /**
     *  Identification of this request
     */
    int             id;

private:

    friend class AuthManager;

    /**
     *  The ActionManager that will be notify when the request is ready.
     */
    ActionManager am;

    /**
     *  The user id for this request
     */
    int uid;

    /**
     *  The user group ID
     */
    int gid;

    /**
     *  Timeout for this request
     */
    time_t time_out;

    /**
     *  Username to authenticate the user
     */
    string username;

    /**
     *  User password to authenticate the user
     */
    string password;

    /**
     *  Authentication token as sent in the XML-RPC call (user:session)
     */
    string session;

    /**
     *  Authentication driver to be used with this request
     */
    string driver;

    /**
     *  A list of authorization requests
     */
    vector<string> auths;

    /**
     *  Plain authorization for the request
     */
    bool self_authorize;

    /**
     *  No actions defined for the Auth request, just FINALIZE when done
     */
    void do_action(const string &name, void *args){};

    /**
     *  Adds a new authorization item to this request, with a template for
     *  a new object
     *
     *        OBJECT:<OBJECT_ID|OBJECT_TMPL_XML64>:ACTION:OWNER:AUTH
     *
     * @param op the operation to be authorized
     * @param ob_perms object's permission attributes
     * @param ob_template new object's template. If it is empty,
     * it will be ignored
     */
    void add_auth(Operation             op,
                  const PoolObjectAuth& ob_perms,
                  string                ob_template);
};

#endif /*AUTH_MANAGER_H*/