// Copyright (C) 2012-2013 Internet Systems Consortium, Inc. ("ISC")
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.

#include "config.h"

#include <dhcpsrv/dhcpsrv_log.h>
#include <dhcpsrv/lease_mgr_factory.h>
#include <dhcpsrv/memfile_lease_mgr.h>
#ifdef HAVE_MYSQL
#include <dhcpsrv/mysql_lease_mgr.h>
#endif
#ifdef HAVE_PGSQL
#include <dhcpsrv/pgsql_lease_mgr.h>
#endif

#include <boost/algorithm/string.hpp>
#include <boost/foreach.hpp>
#include <boost/scoped_ptr.hpp>

#include <algorithm>
#include <iostream>
#include <iterator>
#include <map>
#include <sstream>
#include <utility>

using namespace std;

namespace isc {
namespace dhcp {

boost::scoped_ptr<LeaseMgr>&
LeaseMgrFactory::getLeaseMgrPtr() {
    static boost::scoped_ptr<LeaseMgr> leaseMgrPtr;
    return (leaseMgrPtr);
}

LeaseMgr::ParameterMap
LeaseMgrFactory::parse(const std::string& dbaccess) {
    LeaseMgr::ParameterMap mapped_tokens;

    if (!dbaccess.empty()) {
        vector<string> tokens;

        // We need to pass a string to is_any_of, not just char*. Otherwise
        // there are cryptic warnings on Debian6 running g++ 4.4 in
        // /usr/include/c++/4.4/bits/stl_algo.h:2178 "array subscript is above
        // array bounds"
        boost::split(tokens, dbaccess, boost::is_any_of(string("\t ")));
        BOOST_FOREACH(std::string token, tokens) {
            size_t pos = token.find("=");
            if (pos != string::npos) {
                string name = token.substr(0, pos);
                string value = token.substr(pos + 1);
                mapped_tokens.insert(make_pair(name, value));
            } else {
                LOG_ERROR(dhcpsrv_logger, DHCPSRV_INVALID_ACCESS).arg(dbaccess);
                isc_throw(InvalidParameter, "Cannot parse " << token
                          << ", expected format is name=value");
            }
        }
    }

    return (mapped_tokens);
}

std::string
LeaseMgrFactory::redactedAccessString(const LeaseMgr::ParameterMap& parameters) {
    // Reconstruct the access string: start of with an empty string, then
    // work through all the parameters in the original string and add them.
    std::string access;
    for (LeaseMgr::ParameterMap::const_iterator i = parameters.begin();
         i != parameters.end(); ++i) {

        // Separate second and subsequent tokens are preceded by a space.
        if (!access.empty()) {
            access += " ";
        }

        // Append name of parameter...
        access += i->first;
        access += "=";

        // ... and the value, except in the case of the password, where a
        // redacted value is appended.
        if (i->first == std::string("password")) {
            access += "*****";
        } else {
            access += i->second;
        }
    }

    return (access);
}

void
LeaseMgrFactory::create(const std::string& dbaccess) {
    const std::string type = "type";

    // Parse the access string and create a redacted string for logging.
    LeaseMgr::ParameterMap parameters = parse(dbaccess);
    std::string redacted = redactedAccessString(parameters);

    // Is "type" present?
    if (parameters.find(type) == parameters.end()) {
        LOG_ERROR(dhcpsrv_logger, DHCPSRV_NOTYPE_DB).arg(dbaccess);
        isc_throw(InvalidParameter, "Database configuration parameters do not "
                  "contain the 'type' keyword");
    }


    // Yes, check what it is.
#ifdef HAVE_MYSQL
    if (parameters[type] == string("mysql")) {
        LOG_INFO(dhcpsrv_logger, DHCPSRV_MYSQL_DB).arg(redacted);
        getLeaseMgrPtr().reset(new MySqlLeaseMgr(parameters));
        return;
    }
#endif
#ifdef HAVE_PGSQL
    if (parameters[type] == string("postgresql")) {
        LOG_INFO(dhcpsrv_logger, DHCPSRV_PGSQL_DB).arg(redacted);
        getLeaseMgrPtr().reset(new PgSqlLeaseMgr(parameters));
        return;
    }
#endif
    if (parameters[type] == string("memfile")) {
        LOG_INFO(dhcpsrv_logger, DHCPSRV_MEMFILE_DB).arg(redacted);
        getLeaseMgrPtr().reset(new Memfile_LeaseMgr(parameters));
        return;
    }

    // Get here on no match
    LOG_ERROR(dhcpsrv_logger, DHCPSRV_UNKNOWN_DB).arg(parameters[type]);
    isc_throw(InvalidType, "Database access parameter 'type' does "
              "not specify a supported database backend");
}

void
LeaseMgrFactory::destroy() {
    // Destroy current lease manager.  This is a no-op if no lease manager
    // is available.
    if (getLeaseMgrPtr()) {
        LOG_DEBUG(dhcpsrv_logger, DHCPSRV_DBG_TRACE, DHCPSRV_CLOSE_DB)
            .arg(getLeaseMgrPtr()->getType());
    }
    getLeaseMgrPtr().reset();
}

LeaseMgr&
LeaseMgrFactory::instance() {
    LeaseMgr* lmptr = getLeaseMgrPtr().get();
    if (lmptr == NULL) {
        isc_throw(NoLeaseManager, "no current lease manager is available");
    }
    return (*lmptr);
}


}; // namespace dhcp
}; // namespace isc