// Copyright (c) Vitaliy Filippov, 2019+
// License: VNPL-1.1 (see README.md for details)

#include "disk_tool.h"
#include "rw_blocking.h"
#include "osd_id.h"

int disk_tool_t::process_meta(std::function<void(blockstore_meta_header_v2_t *)> hdr_fn,
    std::function<void(uint64_t, clean_disk_entry*, uint8_t*)> record_fn)
{
    if (dsk.meta_block_size % DIRECT_IO_ALIGNMENT)
    {
        fprintf(stderr, "Invalid metadata block size: is not a multiple of %d\n", DIRECT_IO_ALIGNMENT);
        return 1;
    }
    dsk.meta_fd = open(dsk.meta_device.c_str(), O_DIRECT|O_RDONLY);
    if (dsk.meta_fd < 0)
    {
        fprintf(stderr, "Failed to open metadata device %s: %s\n", dsk.meta_device.c_str(), strerror(errno));
        return 1;
    }
    int buf_size = 1024*1024;
    if (buf_size % dsk.meta_block_size)
        buf_size = 8*dsk.meta_block_size;
    if (buf_size > dsk.meta_len)
        buf_size = dsk.meta_len;
    void *data = memalign_or_die(MEM_ALIGNMENT, buf_size);
    lseek64(dsk.meta_fd, dsk.meta_offset, 0);
    read_blocking(dsk.meta_fd, data, dsk.meta_block_size);
    // Check superblock
    blockstore_meta_header_v2_t *hdr = (blockstore_meta_header_v2_t *)data;
    if (hdr->zero == 0 && hdr->magic == BLOCKSTORE_META_MAGIC_V1)
    {
        if (hdr->version == BLOCKSTORE_META_FORMAT_V1)
        {
            // Vitastor 0.6-0.8 - static array of clean_disk_entry with bitmaps
            hdr->data_csum_type = 0;
            hdr->csum_block_size = 0;
            hdr->header_csum = 0;
        }
        else if (hdr->version == BLOCKSTORE_META_FORMAT_V2)
        {
            // Vitastor 0.9 - static array of clean_disk_entry with bitmaps and checksums
            if (hdr->data_csum_type != 0 &&
                hdr->data_csum_type != BLOCKSTORE_CSUM_CRC32C)
            {
                fprintf(stderr, "I don't know checksum format %u, the only supported format is crc32c = %u.\n", hdr->data_csum_type, BLOCKSTORE_CSUM_CRC32C);
                free(data);
                close(dsk.meta_fd);
                dsk.meta_fd = -1;
                return 1;
            }
        }
        else
        {
            // Unsupported version
            fprintf(stderr, "Metadata format is too new for me (stored version is %ju, max supported %u).\n", hdr->version, BLOCKSTORE_META_FORMAT_V2);
            free(data);
            close(dsk.meta_fd);
            dsk.meta_fd = -1;
            return 1;
        }
        if (hdr->meta_block_size != dsk.meta_block_size)
        {
            fprintf(stderr, "Using block size of %u bytes based on information from the superblock\n", hdr->meta_block_size);
            dsk.meta_block_size = hdr->meta_block_size;
            if (buf_size % dsk.meta_block_size)
            {
                buf_size = 8*dsk.meta_block_size;
                void *new_data = memalign_or_die(MEM_ALIGNMENT, buf_size);
                memcpy(new_data, data, dsk.meta_block_size);
                free(data);
                data = new_data;
                hdr = (blockstore_meta_header_v2_t *)data;
            }
        }
        dsk.meta_format = hdr->version;
        dsk.data_block_size = hdr->data_block_size;
        dsk.csum_block_size = hdr->csum_block_size;
        dsk.data_csum_type = hdr->data_csum_type;
        dsk.bitmap_granularity = hdr->bitmap_granularity;
        dsk.clean_entry_bitmap_size = (hdr->data_block_size / hdr->bitmap_granularity + 7) / 8;
        dsk.clean_entry_size = sizeof(clean_disk_entry) + 2*dsk.clean_entry_bitmap_size
            + (hdr->data_csum_type
                ? ((hdr->data_block_size+hdr->csum_block_size-1)/hdr->csum_block_size
                    *(hdr->data_csum_type & 0xff))
                : 0)
            + (dsk.meta_format == BLOCKSTORE_META_FORMAT_V2 ? 4 /*entry_csum*/ : 0);
        uint64_t block_num = 0;
        hdr_fn(hdr);
        hdr = NULL;
        meta_pos = dsk.meta_block_size;
        lseek64(dsk.meta_fd, dsk.meta_offset+meta_pos, 0);
        while (meta_pos < dsk.meta_len)
        {
            uint64_t read_len = buf_size < dsk.meta_len-meta_pos ? buf_size : dsk.meta_len-meta_pos;
            read_blocking(dsk.meta_fd, data, read_len);
            meta_pos += read_len;
            for (uint64_t blk = 0; blk < read_len; blk += dsk.meta_block_size)
            {
                for (uint64_t ioff = 0; ioff <= dsk.meta_block_size-dsk.clean_entry_size; ioff += dsk.clean_entry_size, block_num++)
                {
                    clean_disk_entry *entry = (clean_disk_entry*)((uint8_t*)data + blk + ioff);
                    if (entry->oid.inode)
                    {
                        if (dsk.data_csum_type)
                        {
                            uint32_t *entry_csum = (uint32_t*)((uint8_t*)entry + dsk.clean_entry_size - 4);
                            if (*entry_csum != crc32c(0, entry, dsk.clean_entry_size - 4))
                            {
                                fprintf(stderr, "Metadata entry %ju is corrupt (checksum mismatch), skipping\n", block_num);
                                continue;
                            }
                        }
                        record_fn(block_num, entry, entry->bitmap);
                    }
                }
            }
        }
    }
    else
    {
        // Vitastor 0.4-0.5 - static array of clean_disk_entry
        dsk.clean_entry_bitmap_size = 0;
        dsk.clean_entry_size = sizeof(clean_disk_entry);
        uint64_t block_num = 0;
        hdr_fn(NULL);
        while (meta_pos < dsk.meta_len)
        {
            uint64_t read_len = buf_size < dsk.meta_len-meta_pos ? buf_size : dsk.meta_len-meta_pos;
            read_blocking(dsk.meta_fd, data, read_len);
            meta_pos += read_len;
            for (uint64_t blk = 0; blk < read_len; blk += dsk.meta_block_size)
            {
                for (uint64_t ioff = 0; ioff < dsk.meta_block_size-dsk.clean_entry_size; ioff += dsk.clean_entry_size, block_num++)
                {
                    clean_disk_entry *entry = (clean_disk_entry*)((uint8_t*)data + blk + ioff);
                    if (entry->oid.inode)
                    {
                        record_fn(block_num, entry, NULL);
                    }
                }
            }
        }
    }
    free(data);
    close(dsk.meta_fd);
    dsk.meta_fd = -1;
    return 0;
}

int disk_tool_t::dump_meta()
{
    int r = process_meta(
        [this](blockstore_meta_header_v2_t *hdr) { dump_meta_header(hdr); },
        [this](uint64_t block_num, clean_disk_entry *entry, uint8_t *bitmap) { dump_meta_entry(block_num, entry, bitmap); }
    );
    if (r == 0)
        printf("\n]}\n");
    return r;
}

void disk_tool_t::dump_meta_header(blockstore_meta_header_v2_t *hdr)
{
    if (hdr)
    {
        if (hdr->version == BLOCKSTORE_META_FORMAT_V1)
        {
            printf(
                "{\"version\":\"0.6\",\"meta_block_size\":%u,\"data_block_size\":%u,\"bitmap_granularity\":%u,"
                "\"entries\":[\n",
                hdr->meta_block_size, hdr->data_block_size, hdr->bitmap_granularity
            );
        }
        else if (hdr->version == BLOCKSTORE_META_FORMAT_V2)
        {
            printf(
                "{\"version\":\"0.9\",\"meta_block_size\":%u,\"data_block_size\":%u,\"bitmap_granularity\":%u,"
                "\"data_csum_type\":%s,\"csum_block_size\":%u,\"entries\":[\n",
                hdr->meta_block_size, hdr->data_block_size, hdr->bitmap_granularity,
                csum_type_str(hdr->data_csum_type).c_str(), hdr->csum_block_size
            );
        }
    }
    else
    {
        printf("{\"version\":\"0.5\",\"meta_block_size\":%ju,\"entries\":[\n", dsk.meta_block_size);
    }
    first_entry = true;
}

void disk_tool_t::dump_meta_entry(uint64_t block_num, clean_disk_entry *entry, uint8_t *bitmap)
{
    printf(
#define ENTRY_FMT "{\"block\":%ju,\"pool\":%u,\"inode\":\"0x%jx\",\"stripe\":\"0x%jx\",\"version\":%ju"
        (first_entry ? ENTRY_FMT : (",\n" ENTRY_FMT)),
#undef ENTRY_FMT
        block_num, INODE_POOL(entry->oid.inode), INODE_NO_POOL(entry->oid.inode),
        entry->oid.stripe, entry->version
    );
    if (bitmap)
    {
        printf(",\"bitmap\":\"");
        for (uint64_t i = 0; i < dsk.clean_entry_bitmap_size; i++)
        {
            printf("%02x", bitmap[i]);
        }
        printf("\",\"ext_bitmap\":\"");
        for (uint64_t i = 0; i < dsk.clean_entry_bitmap_size; i++)
        {
            printf("%02x", bitmap[dsk.clean_entry_bitmap_size + i]);
        }
        if (dsk.csum_block_size && dsk.data_csum_type)
        {
            uint8_t *csums = bitmap + dsk.clean_entry_bitmap_size*2;
            printf("\",\"block_csums\":\"");
            for (uint64_t i = 0; i < (dsk.data_block_size+dsk.csum_block_size-1)/dsk.csum_block_size*(dsk.data_csum_type & 0xFF); i++)
            {
                printf("%02x", csums[i]);
            }
        }
        printf("\"}");
    }
    else
    {
        printf("}");
    }
    first_entry = false;
}

int disk_tool_t::write_json_meta(json11::Json meta)
{
    new_meta_buf = (uint8_t*)memalign_or_die(MEM_ALIGNMENT, new_meta_len);
    memset(new_meta_buf, 0, new_meta_len);
    blockstore_meta_header_v2_t *new_hdr = (blockstore_meta_header_v2_t *)new_meta_buf;
    new_hdr->zero = 0;
    new_hdr->magic = BLOCKSTORE_META_MAGIC_V1;
    new_hdr->version = meta["version"].uint64_value() == BLOCKSTORE_META_FORMAT_V1
        ? BLOCKSTORE_META_FORMAT_V1 : BLOCKSTORE_META_FORMAT_V2;
    new_hdr->meta_block_size = meta["meta_block_size"].uint64_value()
        ? meta["meta_block_size"].uint64_value() : 4096;
    new_hdr->data_block_size = meta["data_block_size"].uint64_value()
        ? meta["data_block_size"].uint64_value() : 131072;
    new_hdr->bitmap_granularity = meta["bitmap_granularity"].uint64_value()
        ? meta["bitmap_granularity"].uint64_value() : 4096;
    new_hdr->data_csum_type = meta["data_csum_type"].is_number()
        ? meta["data_csum_type"].uint64_value()
        : (meta["data_csum_type"].string_value() == "crc32c"
            ? BLOCKSTORE_CSUM_CRC32C
            : BLOCKSTORE_CSUM_NONE);
    new_hdr->csum_block_size = meta["csum_block_size"].uint64_value();
    uint32_t new_clean_entry_header_size = (new_hdr->version == BLOCKSTORE_META_FORMAT_V1
        ? sizeof(clean_disk_entry) : sizeof(clean_disk_entry) + 4 /*entry_csum*/);
    new_clean_entry_bitmap_size = (new_hdr->data_block_size / new_hdr->bitmap_granularity + 7) / 8;
    new_data_csum_size = (new_hdr->data_csum_type
        ? ((new_hdr->data_block_size+new_hdr->csum_block_size-1)/new_hdr->csum_block_size*(new_hdr->data_csum_type & 0xFF))
        : 0);
    new_clean_entry_size = new_clean_entry_header_size + 2*new_clean_entry_bitmap_size + new_data_csum_size;
    new_entries_per_block = new_hdr->meta_block_size / new_clean_entry_size;
    for (const auto & e: meta["entries"].array_items())
    {
        uint64_t data_block = e["block"].uint64_value();
        uint64_t mb = 1 + data_block/new_entries_per_block;
        if (mb >= new_meta_len/new_hdr->meta_block_size)
        {
            free(new_meta_buf);
            new_meta_buf = NULL;
            fprintf(stderr, "Metadata (data block %ju) doesn't fit into the new area\n", data_block);
            return 1;
        }
        clean_disk_entry *new_entry = (clean_disk_entry*)(new_meta_buf +
            new_hdr->meta_block_size*mb +
            new_clean_entry_size*(data_block % new_entries_per_block));
        new_entry->oid.inode = (sscanf_json(NULL, e["pool"]) << (64-POOL_ID_BITS)) | sscanf_json(NULL, e["inode"]);
        new_entry->oid.stripe = sscanf_json(NULL, e["stripe"]);
        new_entry->version = sscanf_json(NULL, e["version"]);
        fromhexstr(e["bitmap"].string_value(), new_clean_entry_bitmap_size,
            ((uint8_t*)new_entry) + sizeof(clean_disk_entry));
        fromhexstr(e["ext_bitmap"].string_value(), new_clean_entry_bitmap_size,
            ((uint8_t*)new_entry) + sizeof(clean_disk_entry) + new_clean_entry_bitmap_size);
        if (new_hdr->version == BLOCKSTORE_META_FORMAT_V2)
        {
            if (new_hdr->data_csum_type != 0)
            {
                fromhexstr(e["data_csum"].string_value(), new_data_csum_size,
                    ((uint8_t*)new_entry) + sizeof(clean_disk_entry) + 2*new_clean_entry_bitmap_size);
            }
            uint32_t *new_entry_csum = (uint32_t*)(((uint8_t*)new_entry) + sizeof(clean_disk_entry) +
                2*new_clean_entry_bitmap_size + new_data_csum_size);
            *new_entry_csum = crc32c(0, new_entry, new_clean_entry_size - 4);
        }
    }
    int r = resize_write_new_meta();
    free(new_meta_buf);
    new_meta_buf = NULL;
    return r;
}