#define C_KINO_INDEXFILENAMES
#include "KinoSearch/Util/ToolSet.h"

#include "KinoSearch/Util/IndexFileNames.h"
#include "KinoSearch/Store/DirHandle.h"
#include "KinoSearch/Store/Folder.h"
#include "KinoSearch/Util/StringHelper.h"

CharBuf*
IxFileNames_latest_snapshot(Folder *folder)
{
    DirHandle *dh = Folder_Open_Dir(folder, NULL);
    CharBuf   *entry = dh ? DH_Get_Entry(dh) : NULL;
    CharBuf   *retval   = NULL;
    uint64_t   latest_gen = 0;

    if (!dh) { RETHROW(INCREF(Err_get_error())); }

    while (DH_Next(dh)) {
        if (   CB_Starts_With_Str(entry, "snapshot_", 9)
            && CB_Ends_With_Str(entry, ".json", 5)
        ) {
            uint64_t gen = IxFileNames_extract_gen(entry);
            if (gen > latest_gen) {
                latest_gen = gen;
                if (!retval) retval = CB_Clone(entry);
                else CB_Mimic(retval, (Obj*)entry);
            }
        }
    }

    DECREF(dh);
    return retval;
}

uint64_t
IxFileNames_extract_gen(const CharBuf *name)
{
    ZombieCharBuf *num_string = ZCB_WRAP(name);

    // Advance past first underscore.  Bail if we run out of string or if we
    // encounter a NULL.
    while (1) {
        uint32_t code_point = ZCB_Nip_One(num_string);
        if (code_point == 0) { return 0; }
        else if (code_point == '_') { break; }
    }

    return (uint64_t)ZCB_BaseX_To_I64(num_string, 36);
}

ZombieCharBuf*
IxFileNames_local_part(const CharBuf *path, ZombieCharBuf *target)
{
    ZombieCharBuf *scratch = ZCB_WRAP(path);
    size_t local_part_start = CB_Length(path);
    uint32_t code_point;

    ZCB_Assign(target, path);

    // Trim trailing slash. 
    while (ZCB_Code_Point_From(target, 1) == '/') {
        ZCB_Chop(target, 1);
        ZCB_Chop(scratch, 1);
        local_part_start--;
    }

    // Substring should start after last slash. 
    while (0 != (code_point = ZCB_Code_Point_From(scratch, 1))) {
        if (code_point == '/') {
            ZCB_Nip(target, local_part_start);
            break;
        }
        ZCB_Chop(scratch, 1);
        local_part_start--;
    }

    return target;
}

/* Copyright 2006-2011 Marvin Humphrey
 *
 * This program is free software; you can redistribute it and/or modify
 * under the same terms as Perl itself.
 */