/******************************************************************************
 * ventoy_windows.c 
 *
 * Copyright (c) 2020, longpanda <admin@ventoy.net>
 *
 * 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 3 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 <http://www.gnu.org/licenses/>.
 *
 */

#include <grub/types.h>
#include <grub/misc.h>
#include <grub/mm.h>
#include <grub/err.h>
#include <grub/dl.h>
#include <grub/disk.h>
#include <grub/device.h>
#include <grub/term.h>
#include <grub/partition.h>
#include <grub/file.h>
#include <grub/normal.h>
#include <grub/extcmd.h>
#include <grub/datetime.h>
#include <grub/i18n.h>
#include <grub/net.h>
#include <grub/time.h>
#include <grub/crypto.h>
#include <grub/ventoy.h>
#include "ventoy_def.h"

GRUB_MOD_LICENSE ("GPLv3+");

wim_hash g_old_hash;
wim_tail g_wim_data;

static wim_lookup_entry *g_replace_look = NULL;

grub_ssize_t lzx_decompress ( const void *data, grub_size_t len, void *buf );

static int wim_name_cmp(const char *search, grub_uint16_t *name, grub_uint16_t namelen)
{
    char c1 = vtoy_to_upper(*search);
    char c2 = vtoy_to_upper(*name);

    while (namelen > 0 && (c1 == c2))
    {
        search++;
        name++;
        namelen--;
        
        c1 = vtoy_to_upper(*search);
        c2 = vtoy_to_upper(*name);
    }

    if (namelen == 0 && *search == 0)
    {
        return 0;
    }

    return 1;
}

static int ventoy_is_pe64(grub_uint8_t *buffer)
{
    grub_uint32_t pe_off;

    if (buffer[0] != 'M' || buffer[1] != 'Z')
    {
        return 0;
    }
    
    pe_off = *(grub_uint32_t *)(buffer + 60);

    if (buffer[pe_off] != 'P' || buffer[pe_off + 1] != 'E')
    {
        return 0;
    }

    if (*(grub_uint16_t *)(buffer + pe_off + 24) == 0x020b)
    {
        return 1;
    }

    return 0;
}

grub_err_t ventoy_cmd_wimdows_reset(grub_extcmd_context_t ctxt, int argc, char **args)
{
    (void)ctxt;
    (void)argc;
    (void)args;
    
    check_free(g_wim_data.jump_bin_data, grub_free);
    check_free(g_wim_data.new_meta_data, grub_free);
    check_free(g_wim_data.new_lookup_data, grub_free);

    grub_memset(&g_wim_data, 0, sizeof(g_wim_data));

    return 0;
}

static int ventoy_load_jump_exe(const char *path, grub_uint8_t **data, grub_uint32_t *size, wim_hash *hash)
{
    grub_uint32_t i;
    grub_uint32_t align;
    grub_file_t file;

    debug("windows load jump %s\n", path);
    
    file = ventoy_grub_file_open(VENTOY_FILE_TYPE, "%s", path);
    if (!file)
    {
        debug("Can't open file %s\n", path); 
        return 1;
    }

    align = ventoy_align((int)file->size, 2048);

    debug("file %s size:%d align:%u\n", path, (int)file->size, align);

    *size = (grub_uint32_t)file->size;
    *data = (grub_uint8_t *)grub_malloc(align);
    if ((*data) == NULL)
    {
        debug("Failed to alloc memory size %u\n", align);
        goto end;
    }

    grub_file_read(file, (*data), file->size);

    if (hash)
    {
        grub_crypto_hash(GRUB_MD_SHA1, hash->sha1, (*data), file->size);

        if (g_ventoy_debug)
        {
            debug("%s", "jump bin 64 hash: ");
            for (i = 0; i < sizeof(hash->sha1); i++)
            {
                ventoy_debug("%02x ", hash->sha1[i]);
            }
            ventoy_debug("\n");
        }
    }

end:

    grub_file_close(file);
    return 0;
}

static int ventoy_get_override_info(grub_file_t file)
{
    grub_uint32_t start_block;
    grub_uint64_t file_offset;
    grub_uint64_t override_offset;
    grub_uint32_t override_len;
    grub_uint64_t fe_entry_size_offset;
    
    if (grub_strcmp(file->fs->name, "iso9660") == 0)
    {
        g_wim_data.iso_type = 0;
        override_len = sizeof(ventoy_iso9660_override);
        override_offset = grub_iso9660_get_last_file_dirent_pos(file) + 2;

        grub_file_read(file, &start_block, 1); // just read for hook trigger
        file_offset = grub_iso9660_get_last_read_pos(file);

        debug("iso9660 wim size:%llu override_offset:%llu file_offset:%llu\n", 
            (ulonglong)file->size, (ulonglong)override_offset, (ulonglong)file_offset);
    }
    else
    {
        g_wim_data.iso_type = 1;    
        override_len = sizeof(ventoy_udf_override);
        override_offset = grub_udf_get_last_file_attr_offset(file, &start_block, &fe_entry_size_offset);
        
        file_offset = grub_udf_get_file_offset(file);

        debug("UDF wim size:%llu override_offset:%llu file_offset:%llu start_block=%u\n", 
            (ulonglong)file->size, (ulonglong)override_offset, (ulonglong)file_offset, start_block);
    }

    g_wim_data.file_offset = file_offset;
    g_wim_data.udf_start_block = start_block;
    g_wim_data.fe_entry_size_offset = fe_entry_size_offset;
    g_wim_data.override_offset = override_offset;
    g_wim_data.override_len = override_len;

    return 0;
}

static int ventoy_read_resource(grub_file_t fp, wim_resource_header *head, void **buffer)
{
    int decompress_len = 0;
    int total_decompress = 0;
    grub_uint32_t i = 0;
    grub_uint32_t chunk_num = 0;
    grub_uint32_t chunk_size = 0;
    grub_uint32_t last_chunk_size = 0;
    grub_uint32_t last_decompress_size = 0;
    grub_uint32_t cur_offset = 0;
    grub_uint8_t *cur_dst = NULL;
    grub_uint8_t *buffer_compress = NULL;
    grub_uint8_t *buffer_decompress = NULL;
    grub_uint32_t *chunk_offset = NULL;

    buffer_decompress = (grub_uint8_t *)grub_malloc(head->raw_size + head->size_in_wim);
    if (NULL == buffer_decompress)
    {
        return 0;
    }

    grub_file_seek(fp, head->offset);

    if (head->size_in_wim == head->raw_size)
    {
        grub_file_read(fp, buffer_decompress, head->size_in_wim);
        *buffer = buffer_decompress;
        return 0;
    }

    buffer_compress = buffer_decompress + head->raw_size;
    grub_file_read(fp, buffer_compress, head->size_in_wim);

    chunk_num = (head->raw_size + WIM_CHUNK_LEN - 1) / WIM_CHUNK_LEN;
    cur_offset = (chunk_num - 1) * 4;
    chunk_offset = (grub_uint32_t *)buffer_compress;
    
    cur_dst = buffer_decompress;
    
    for (i = 0; i < chunk_num - 1; i++)
    {
        chunk_size = (i == 0) ? chunk_offset[i] : chunk_offset[i] - chunk_offset[i - 1];

        if (WIM_CHUNK_LEN == chunk_size)
        {
            grub_memcpy(cur_dst, buffer_compress + cur_offset, chunk_size);
            decompress_len = (int)chunk_size; 
        }
        else
        {
            decompress_len = (int)lzx_decompress(buffer_compress + cur_offset, chunk_size, cur_dst);
        }

        //debug("chunk_size:%u decompresslen:%d\n", chunk_size, decompress_len);
        
        total_decompress += decompress_len;
        cur_dst += decompress_len;
        cur_offset += chunk_size;
    }

    /* last chunk */
    last_chunk_size = (grub_uint32_t)(head->size_in_wim - cur_offset);
    last_decompress_size = head->raw_size - total_decompress;
    
    if (last_chunk_size < WIM_CHUNK_LEN && last_chunk_size == last_decompress_size)
    {
        debug("Last chunk %u uncompressed\n", last_chunk_size);
        grub_memcpy(cur_dst, buffer_compress + cur_offset, last_chunk_size);
        decompress_len = (int)last_chunk_size; 
    }
    else
    {
        decompress_len = (int)lzx_decompress(buffer_compress + cur_offset, head->size_in_wim - cur_offset, cur_dst);            
    }
    
    cur_dst += decompress_len;
    total_decompress += decompress_len;

    if (cur_dst != buffer_decompress + head->raw_size)
    {
        debug("head->size_in_wim:%llu head->raw_size:%llu cur_dst:%p buffer_decompress:%p total_decompress:%d\n", 
            (ulonglong)head->size_in_wim, (ulonglong)head->raw_size, cur_dst, buffer_decompress, total_decompress);
        grub_free(buffer_decompress);
        return 1;
    }
    
    *buffer = buffer_decompress;
    return 0;
}


static wim_directory_entry * search_wim_dirent(wim_directory_entry *dir, const char *search_name)
{
    do 
    {
        if (dir->len && dir->name_len)
        {
            if (wim_name_cmp(search_name, (grub_uint16_t *)(dir + 1), dir->name_len / 2) == 0)
            {
                return dir;
            }
        }
        dir = (wim_directory_entry *)((grub_uint8_t *)dir + dir->len);
    } while(dir->len);
        
    return NULL;
}

static wim_directory_entry * search_full_wim_dirent
(
    void *meta_data, 
    wim_directory_entry *dir,
    const char **path    
)
{
    wim_directory_entry *subdir = NULL;
    wim_directory_entry *search = dir;

    while (*path)
    {
        subdir = (wim_directory_entry *)((char *)meta_data + search->subdir);
        search = search_wim_dirent(subdir, *path);
        if (!search)
        {
            debug("%s search failed\n", *path);
        }

        path++;
    }
    return search;
}

static wim_directory_entry * search_replace_wim_dirent(void *meta_data, wim_directory_entry *dir)
{
    wim_directory_entry *wim_dirent = NULL;
    const char *winpeshl_path[] = { "Windows", "System32", "winpeshl.exe", NULL };
    const char *pecmd_path[] = { "Windows", "System32", "PECMD.exe", NULL };

    wim_dirent = search_full_wim_dirent(meta_data, dir, winpeshl_path);
    if (wim_dirent)
    {
        return wim_dirent;
    }
    
    wim_dirent = search_full_wim_dirent(meta_data, dir, pecmd_path);
    if (wim_dirent)
    {
        return wim_dirent;
    }

    return NULL;
}


static wim_lookup_entry * ventoy_find_look_entry(wim_header *header, wim_lookup_entry *lookup, wim_hash *hash)
{
    grub_uint32_t i = 0;
    
    for (i = 0; i < (grub_uint32_t)header->lookup.raw_size / sizeof(wim_lookup_entry); i++)
    {
        if (grub_memcmp(&lookup[i].hash, hash, sizeof(wim_hash)) == 0)
        {
            return lookup + i;
        }
    }

    return NULL;
}

static wim_lookup_entry * ventoy_find_meta_entry(wim_header *header, wim_lookup_entry *lookup)
{
    grub_uint32_t i = 0;
    grub_uint32_t index = 0;;

    if ((header == NULL) || (lookup == NULL))
    {
        return NULL;
    }
    
    for (i = 0; i < (grub_uint32_t)header->lookup.raw_size / sizeof(wim_lookup_entry); i++)
    {
        if (lookup[i].resource.flags & RESHDR_FLAG_METADATA)
        {
            index++;
            if (index == header->boot_index)
            {
                return lookup + i;
            }
        }
    }

    return NULL;
}

static int ventoy_update_all_hash(void *meta_data, wim_directory_entry *dir)
{
    if ((meta_data == NULL) || (dir == NULL))
    {
        return 0;
    }

    if (dir->len == 0)
    {
        return 0;
    }

    do
    {
        if (dir->subdir == 0 && grub_memcmp(dir->hash.sha1, g_old_hash.sha1, sizeof(wim_hash)) == 0)
        {
            debug("find target file, name_len:%u upadte hash\n", dir->name_len);
            grub_memcpy(dir->hash.sha1, &(g_wim_data.bin_hash), sizeof(wim_hash));
        }
        
        if (dir->subdir)
        {
            ventoy_update_all_hash(meta_data, (wim_directory_entry *)((char *)meta_data + dir->subdir));
        }
    
        dir = (wim_directory_entry *)((char *)dir + dir->len);
    } while (dir->len);

    return 0;
}

static int ventoy_cat_exe_file_data(grub_uint32_t exe_len, grub_uint8_t *exe_data)
{
    int pe64 = 0;
    char file[256];
    grub_uint32_t jump_len = 0;
    grub_uint32_t jump_align = 0;
    grub_uint8_t *jump_data = NULL;

    pe64 = ventoy_is_pe64(exe_data);
    
    grub_snprintf(file, sizeof(file), "%s/vtoyjump%d.exe", grub_env_get("vtoy_path"), pe64 ? 64 : 32);
    ventoy_load_jump_exe(file, &jump_data, &jump_len, NULL);
    jump_align = ventoy_align(jump_len, 16);
    
    g_wim_data.jump_exe_len = jump_len;
    g_wim_data.bin_raw_len = jump_align + sizeof(ventoy_os_param) + exe_len;
    g_wim_data.bin_align_len = ventoy_align(g_wim_data.bin_raw_len, 2048);
    
    g_wim_data.jump_bin_data = grub_malloc(g_wim_data.bin_align_len);
    if (g_wim_data.jump_bin_data)
    {
        grub_memcpy(g_wim_data.jump_bin_data, jump_data, jump_len);
        grub_memcpy(g_wim_data.jump_bin_data + jump_align + sizeof(ventoy_os_param), exe_data, exe_len);
    }

    debug("jump_exe_len:%u bin_raw_len:%u bin_align_len:%u\n", 
        g_wim_data.jump_exe_len, g_wim_data.bin_raw_len, g_wim_data.bin_align_len);
    
    return 0;
}

static int ventoy_update_before_chain(ventoy_os_param *param)
{
    grub_uint32_t jump_align = 0;
    wim_lookup_entry *meta_look = NULL;
    wim_security_header *security = NULL;
    wim_directory_entry *rootdir = NULL;
    wim_header *head = &(g_wim_data.wim_header);    
    wim_lookup_entry *lookup = (wim_lookup_entry *)g_wim_data.new_lookup_data;

    jump_align = ventoy_align(g_wim_data.jump_exe_len, 16);
    if (g_wim_data.jump_bin_data)
    {
        grub_memcpy(g_wim_data.jump_bin_data + jump_align, param, sizeof(ventoy_os_param));        
    }

    grub_crypto_hash(GRUB_MD_SHA1, g_wim_data.bin_hash.sha1, g_wim_data.jump_bin_data, g_wim_data.bin_raw_len);

    security = (wim_security_header *)g_wim_data.new_meta_data;
    rootdir = (wim_directory_entry *)(g_wim_data.new_meta_data + ((security->len + 7) & 0xFFFFFFF8U));

    /* update all winpeshl.exe dirent entry's hash */
    ventoy_update_all_hash(g_wim_data.new_meta_data, rootdir);

    /* update winpeshl.exe lookup entry data (hash/offset/length) */
    if (g_replace_look)
    {
        debug("update replace lookup entry_id:%ld\n", ((long)g_replace_look - (long)lookup) / sizeof(wim_lookup_entry));
        g_replace_look->resource.raw_size = g_wim_data.bin_raw_len;
        g_replace_look->resource.size_in_wim = g_wim_data.bin_raw_len;
        g_replace_look->resource.flags = 0;
        g_replace_look->resource.offset = g_wim_data.wim_align_size;

        grub_memcpy(g_replace_look->hash.sha1, g_wim_data.bin_hash.sha1, sizeof(wim_hash));
    }

    /* update metadata's hash */
    meta_look = ventoy_find_meta_entry(head, lookup);
    if (meta_look)
    {
        debug("find meta lookup entry_id:%ld\n", ((long)meta_look - (long)lookup) / sizeof(wim_lookup_entry));
        grub_memcpy(&meta_look->resource, &head->metadata, sizeof(wim_resource_header));
        grub_crypto_hash(GRUB_MD_SHA1, meta_look->hash.sha1, g_wim_data.new_meta_data, g_wim_data.new_meta_len);
    }

    return 0;
}

grub_err_t ventoy_cmd_wimdows_locate_wim(grub_extcmd_context_t ctxt, int argc, char **args)
{
    int rc;
    grub_file_t file;
    grub_uint32_t exe_len;
    grub_uint8_t *exe_data = NULL;
    grub_uint8_t *decompress_data = NULL;
    wim_lookup_entry *lookup = NULL;
    wim_security_header *security = NULL;
    wim_directory_entry *rootdir = NULL;
    wim_directory_entry *search = NULL;
    wim_header *head = &(g_wim_data.wim_header);    
    
    (void)ctxt;
    (void)argc;

    debug("windows locate wim start %s\n", args[0]);
    
    file = ventoy_grub_file_open(VENTOY_FILE_TYPE, "%s", args[0]);
    if (!file)
    {
        return grub_error(GRUB_ERR_BAD_ARGUMENT, "Can't open file %s\n", args[0]); 
    }

    ventoy_get_override_info(file);

    grub_file_seek(file, 0);
    grub_file_read(file, head, sizeof(wim_header));

    if (grub_memcmp(head->signature, WIM_HEAD_SIGNATURE, sizeof(head->signature)))
    {
        debug("Not a valid wim file %s\n", (char *)head->signature);
        grub_file_close(file);
        return 1;
    }

    if (head->flags & FLAG_HEADER_COMPRESS_XPRESS)
    {
        debug("Xpress compress is not supported 0x%x\n", head->flags);
        grub_file_close(file);
        return 1;
    }

    rc = ventoy_read_resource(file, &head->metadata, (void **)&decompress_data);
    if (rc)
    {
        grub_printf("failed to read meta data %d\n", rc);
        grub_file_close(file);
        return 1;
    }

    security = (wim_security_header *)decompress_data;
    rootdir = (wim_directory_entry *)(decompress_data + ((security->len + 7) & 0xFFFFFFF8U));

    /* search winpeshl.exe dirent entry */
    search = search_replace_wim_dirent(decompress_data, rootdir);
    if (!search)
    {
        debug("Failed to find replace file %p\n", search);
        grub_file_close(file);
        return 1;
    }
    
    debug("find replace file at %p\n", search);

    grub_memcpy(&g_old_hash, search->hash.sha1, sizeof(wim_hash));

    debug("read lookup offset:%llu size:%llu\n", (ulonglong)head->lookup.offset, (ulonglong)head->lookup.raw_size);
    lookup = grub_malloc(head->lookup.raw_size);
    grub_file_seek(file, head->lookup.offset);
    grub_file_read(file, lookup, head->lookup.raw_size);

    /* find and extact winpeshl.exe */
    g_replace_look = ventoy_find_look_entry(head, lookup, &g_old_hash);
    if (g_replace_look)
    {
        exe_len = (grub_uint32_t)g_replace_look->resource.raw_size;
        debug("find replace lookup entry_id:%ld raw_size:%u\n", 
            ((long)g_replace_look - (long)lookup) / sizeof(wim_lookup_entry), exe_len);

        if (0 == ventoy_read_resource(file, &(g_replace_look->resource), (void **)&(exe_data)))
        {
            ventoy_cat_exe_file_data(exe_len, exe_data);
            grub_free(exe_data);
        }
        else
        {
            debug("failed to read replace file meta data %u\n", exe_len);
        }
    }
    else
    {
        debug("failed to find lookup entry for replace file 0x%02x 0x%02x\n", g_old_hash.sha1[0], g_old_hash.sha1[1]);
    }

    g_wim_data.wim_raw_size = (grub_uint32_t)file->size;
    g_wim_data.wim_align_size = ventoy_align(g_wim_data.wim_raw_size, 2048);
    
    check_free(g_wim_data.new_meta_data, grub_free);
    g_wim_data.new_meta_data = decompress_data;
    g_wim_data.new_meta_len = head->metadata.raw_size;
    g_wim_data.new_meta_align_len = ventoy_align(g_wim_data.new_meta_len, 2048);
    
    check_free(g_wim_data.new_lookup_data, grub_free);
    g_wim_data.new_lookup_data = (grub_uint8_t *)lookup;
    g_wim_data.new_lookup_len = (grub_uint32_t)head->lookup.raw_size;
    g_wim_data.new_lookup_align_len = ventoy_align(g_wim_data.new_lookup_len, 2048);

    head->metadata.flags = RESHDR_FLAG_METADATA;
    head->metadata.offset = g_wim_data.wim_align_size + g_wim_data.bin_align_len;
    head->metadata.size_in_wim = g_wim_data.new_meta_len;
    head->metadata.raw_size = g_wim_data.new_meta_len;

    head->lookup.flags = 0;
    head->lookup.offset = head->metadata.offset + g_wim_data.new_meta_align_len;
    head->lookup.size_in_wim = g_wim_data.new_lookup_len;
    head->lookup.raw_size = g_wim_data.new_lookup_len;

    grub_file_close(file);

    debug("%s", "windows locate wim finish\n");
    VENTOY_CMD_RETURN(GRUB_ERR_NONE);
}

static grub_uint32_t ventoy_get_override_chunk_num(void)
{
    /* 1: block count in Partition Descriptor */
    /* 2: file_size in file_entry or extend_file_entry */
    /* 3: data_size and position in extend data short ad */
    /* 4: new wim file header */
    return 4;
}

static void ventoy_windows_fill_override_data(    grub_uint64_t isosize, void *override)
{
    grub_uint32_t data32;
    grub_uint64_t data64;
    grub_uint64_t sector;
    grub_uint32_t new_wim_size;
    ventoy_override_chunk *cur;

    sector = (isosize + 2047) / 2048;

    cur = (ventoy_override_chunk *)override;

    new_wim_size = g_wim_data.wim_align_size + g_wim_data.bin_align_len + 
        g_wim_data.new_meta_align_len + g_wim_data.new_lookup_align_len;

    if (g_wim_data.iso_type == 0)
    {
        ventoy_iso9660_override *dirent = (ventoy_iso9660_override *)g_wim_data.override_data;

        dirent->first_sector    = (grub_uint32_t)sector;
        dirent->size            = new_wim_size;
        dirent->first_sector_be = grub_swap_bytes32(dirent->first_sector);
        dirent->size_be         = grub_swap_bytes32(dirent->size);
    }
    else
    {
        ventoy_udf_override *udf = (ventoy_udf_override *)g_wim_data.override_data;
        udf->length   = new_wim_size;
        udf->position = (grub_uint32_t)sector - g_wim_data.udf_start_block;
    }

    //override 1: sector number in pd data 
    cur->img_offset = grub_udf_get_last_pd_size_offset();
    cur->override_size = 4;
    data32 = sector - g_wim_data.udf_start_block + (new_wim_size / 2048);
    grub_memcpy(cur->override_data, &(data32), 4);

    //override 2: filesize in file_entry
    cur++;
    cur->img_offset = g_wim_data.fe_entry_size_offset;
    cur->override_size = 8;
    data64 = new_wim_size;
    grub_memcpy(cur->override_data, &(data64), 8);

    /* override 3: position and length in extend data */
    cur++;
    cur->img_offset = g_wim_data.override_offset;
    cur->override_size = g_wim_data.override_len;
    grub_memcpy(cur->override_data, g_wim_data.override_data, cur->override_size);

    /* override 4: new wim file header */
    cur++;
    cur->img_offset = g_wim_data.file_offset;
    cur->override_size = sizeof(wim_header);
    grub_memcpy(cur->override_data, &(g_wim_data.wim_header), cur->override_size);

    return;
}

static void ventoy_windows_fill_virt_data(    grub_uint64_t isosize, ventoy_chain_head *chain)
{
    grub_uint64_t sector;
    grub_uint32_t offset;
    grub_uint32_t wim_secs;
    grub_uint32_t mem_secs;
    char *override = NULL;
    ventoy_virt_chunk *cur = NULL;

    sector = (isosize + 2047) / 2048;
    offset = sizeof(ventoy_virt_chunk);
    
    wim_secs = g_wim_data.wim_align_size / 2048;
    mem_secs = (g_wim_data.bin_align_len + g_wim_data.new_meta_align_len + g_wim_data.new_lookup_align_len) / 2048;

    override = (char *)chain + chain->virt_chunk_offset;
    cur = (ventoy_virt_chunk *)override;

    cur->remap_sector_start = sector;
    cur->remap_sector_end   = cur->remap_sector_start + wim_secs;
    cur->org_sector_start   = (grub_uint32_t)(g_wim_data.file_offset / 2048);
    
    cur->mem_sector_start   = cur->remap_sector_end;
    cur->mem_sector_end     = cur->mem_sector_start + mem_secs;
    cur->mem_sector_offset  = offset;

    grub_memcpy(override + offset, g_wim_data.jump_bin_data, g_wim_data.bin_raw_len);
    offset += g_wim_data.bin_align_len;

    grub_memcpy(override + offset, g_wim_data.new_meta_data, g_wim_data.new_meta_len);
    offset += g_wim_data.new_meta_align_len;
    
    grub_memcpy(override + offset, g_wim_data.new_lookup_data, g_wim_data.new_lookup_len);
    offset += g_wim_data.new_lookup_align_len;

    chain->virt_img_size_in_bytes += g_wim_data.wim_align_size + 
                                     g_wim_data.bin_align_len + 
                                     g_wim_data.new_meta_align_len + 
                                     g_wim_data.new_lookup_align_len;
    return;
}

static int ventoy_windows_drive_map(ventoy_chain_head *chain)
{
    grub_disk_t disk;
        
    debug("drive map begin <%p> ...\n", chain);

    if (chain->disk_drive == 0x80)
    {
        disk = grub_disk_open("hd1");
        if (disk)
        {
            grub_disk_close(disk);
            debug("drive map needed %p\n", disk);
            chain->drive_map = 0x81;
        }
        else
        {
            debug("failed to open disk %s\n", "hd1");
        }
    }
    else
    {
        debug("no need to map 0x%x\n", chain->disk_drive);
    }

    return 0;
}

grub_err_t ventoy_cmd_windows_chain_data(grub_extcmd_context_t ctxt, int argc, char **args)
{
    int unknown_image = 0;
    int ventoy_compatible = 0;
    grub_uint32_t size = 0;
    grub_uint64_t isosize = 0;
    grub_uint32_t boot_catlog = 0;
    grub_uint32_t img_chunk_size = 0;
    grub_uint32_t override_size = 0;
    grub_uint32_t virt_chunk_size = 0;
    grub_file_t file;
    grub_disk_t disk;
    const char *pLastChain = NULL;
    const char *compatible;
    ventoy_chain_head *chain;
    char envbuf[64];
    
    (void)ctxt;
    (void)argc;

    debug("chain data begin <%s> ...\n", args[0]);

    compatible = grub_env_get("ventoy_compatible");
    if (compatible && compatible[0] == 'Y')
    {
        ventoy_compatible = 1;
    }

    if (NULL == g_img_chunk_list.chunk)
    {
        grub_printf("ventoy not ready\n");
        return 1;
    }

    if (0 == ventoy_compatible && g_wim_data.new_meta_data == NULL)
    {
        unknown_image = 1;
        debug("Warning: %s was not recognized by Ventoy\n", args[0]);
    }

    file = ventoy_grub_file_open(VENTOY_FILE_TYPE, "%s", args[0]);
    if (!file)
    {
        return 1;
    }

    isosize = file->size;

    boot_catlog = ventoy_get_iso_boot_catlog(file);
    if (boot_catlog)
    {
        if (ventoy_is_efi_os() && (!ventoy_has_efi_eltorito(file, boot_catlog)))
        {
            grub_env_set("LoadIsoEfiDriver", "on");
        }
    }
    else
    {
        if (ventoy_is_efi_os())
        {
            grub_env_set("LoadIsoEfiDriver", "on");
        }
        else
        {
            return grub_error(GRUB_ERR_BAD_ARGUMENT, "File %s is not bootable", args[0]);
        }
    }

    img_chunk_size = g_img_chunk_list.cur_chunk * sizeof(ventoy_img_chunk);
    
    if (ventoy_compatible || unknown_image)
    {
        size = sizeof(ventoy_chain_head) + img_chunk_size;
    }
    else
    {
        override_size = ventoy_get_override_chunk_num() * sizeof(ventoy_override_chunk);
        virt_chunk_size = sizeof(ventoy_virt_chunk) + g_wim_data.bin_align_len + 
            g_wim_data.new_meta_align_len + g_wim_data.new_lookup_align_len;;
        size = sizeof(ventoy_chain_head) + img_chunk_size + override_size + virt_chunk_size;
    }

    pLastChain = grub_env_get("vtoy_chain_mem_addr");
    if (pLastChain)
    {
        chain = (ventoy_chain_head *)grub_strtoul(pLastChain, NULL, 16);
        if (chain)
        {
            debug("free last chain memory %p\n", chain);
            grub_free(chain);
        }
    }

    chain = grub_malloc(size);
    if (!chain)
    {
        grub_printf("Failed to alloc chain memory size %u\n", size);
        grub_file_close(file);
        return 1;
    }

    grub_snprintf(envbuf, sizeof(envbuf), "0x%lx", (unsigned long)chain);
    grub_env_set("vtoy_chain_mem_addr", envbuf);
    grub_snprintf(envbuf, sizeof(envbuf), "%u", size);
    grub_env_set("vtoy_chain_mem_size", envbuf);

    grub_memset(chain, 0, sizeof(ventoy_chain_head));

    /* part 1: os parameter */
    ventoy_fill_os_param(file, &(chain->os_param));

    if (g_wim_data.jump_bin_data && g_wim_data.new_meta_data)
    {
        ventoy_update_before_chain(&(chain->os_param));
    }

    /* part 2: chain head */
    disk = file->device->disk;
    chain->disk_drive = disk->id;
    chain->disk_sector_size = (1 << disk->log_sector_size);
    chain->real_img_size_in_bytes = file->size;
    chain->virt_img_size_in_bytes = (file->size + 2047) / 2048 * 2048;
    chain->boot_catalog = boot_catlog;

    if (!ventoy_is_efi_os())
    {
        grub_file_seek(file, boot_catlog * 2048);
        grub_file_read(file, chain->boot_catalog_sector, sizeof(chain->boot_catalog_sector));
    }

    /* part 3: image chunk */
    chain->img_chunk_offset = sizeof(ventoy_chain_head);
    chain->img_chunk_num = g_img_chunk_list.cur_chunk;
    grub_memcpy((char *)chain + chain->img_chunk_offset, g_img_chunk_list.chunk, img_chunk_size);

    if (ventoy_compatible || unknown_image)
    {
        return 0;
    }

    if (g_wim_data.new_meta_data == NULL)
    {
        return 0;
    }

    /* part 4: override chunk */
    chain->override_chunk_offset = chain->img_chunk_offset + img_chunk_size;
    chain->override_chunk_num = ventoy_get_override_chunk_num();
    ventoy_windows_fill_override_data(isosize, (char *)chain + chain->override_chunk_offset);

    /* part 5: virt chunk */
    chain->virt_chunk_offset = chain->override_chunk_offset + override_size;
    chain->virt_chunk_num = 1;
    ventoy_windows_fill_virt_data(isosize, chain);

    if (ventoy_is_efi_os() == 0)
    {
        ventoy_windows_drive_map(chain);        
    }

    VENTOY_CMD_RETURN(GRUB_ERR_NONE);
}