/** @file
 *  @brief Postlists for remote databases
 */
/* Copyright (C) 2007 Lemur Consulting Ltd
 * Copyright (C) 2007,2008,2009,2011,2012,2013,2015,2019 Olly Betts
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see
 * <https://www.gnu.org/licenses/>.
 */

#include <config.h>

#include "net_postlist.h"

#include "omassert.h"
#include "pack.h"
#include "unicode/description_append.h"

using namespace std;

Xapian::docid
NetworkPostList::get_docid() const
{
    return lastdocid;
}

Xapian::termcount
NetworkPostList::get_wdf() const
{
    return lastwdf;
}

PositionList *
NetworkPostList::open_position_list() const
{
    return db->open_position_list(lastdocid, term);
}

PostList *
NetworkPostList::next(double)
{
    if (!started) {
        started = true;
        pos = postings.data();
        pos_end = pos + postings.size();
        lastdocid = 0;
    }

    if (pos == pos_end) {
        pos = NULL;
    } else {
        Xapian::docid inc;
        if (!unpack_uint(&pos, pos_end, &inc) ||
            !unpack_uint(&pos, pos_end, &lastwdf)) {
            unpack_throw_serialisation_error(pos);
        }
        lastdocid += inc + 1;
    }

    return NULL;
}

PostList *
NetworkPostList::skip_to(Xapian::docid did, double min_weight)
{
    if (!started)
        next(min_weight);
    while (pos && lastdocid < did)
        next(min_weight);
    return NULL;
}

bool
NetworkPostList::at_end() const
{
    return (pos == NULL && started);
}

Xapian::termcount
NetworkPostList::get_wdf_upper_bound() const
{
    // This is only called when setting weights on PostList objects before
    // a match, which shouldn't happen to NetworkPostList objects (as remote
    // matching happens like a local match on the server).
    Assert(false);
    return 0;
}

string
NetworkPostList::get_description() const
{
    string desc = "NetworkPostList(";
    description_append(desc, term);
    desc += ')';
    return desc;
}
