#include "physicaldisk.h"

#include "common/io/io.h"
#include "util/stringUtils.h"

#include <OS.h>
#include <StorageDefs.h>
#include <Drivers.h>
#include <sys/ioctl.h>

static const char* detectDisk(FFstrbuf* path, const char* diskType, FFlist* result)
{
    FF_AUTO_CLOSE_FD int rawfd = open(path->chars, O_RDONLY);
    if (rawfd < 0) return "detectDisk: open(rawfd) failed";

    device_geometry geometry;
    if (ioctl(rawfd, B_GET_GEOMETRY, &geometry, sizeof(geometry)) < 0)
        return "ioctl(B_GET_GEOMETRY) failed";

    char name[B_OS_NAME_LENGTH];
    if (ioctl(rawfd, B_GET_DEVICE_NAME, name, sizeof(name)) != 0)
    {
        // ioctl reports `not a tty` for NVME drives for some reason
        snprintf(name, sizeof(name), "Unknown %s drive", diskType);
    }

    FFPhysicalDiskResult* device = (FFPhysicalDiskResult*) ffListAdd(result);
    ffStrbufInitS(&device->name, name);
    ffStrbufInitCopy(&device->devPath, path);
    ffStrbufInit(&device->serial);
    ffStrbufInit(&device->revision);
    ffStrbufInitS(&device->interconnect, diskType);
    device->temperature = FF_PHYSICALDISK_TEMP_UNSET;
    device->type = FF_PHYSICALDISK_TYPE_NONE;
    device->type |= (geometry.read_only ? FF_PHYSICALDISK_TYPE_READONLY : FF_PHYSICALDISK_TYPE_READWRITE) |
        (geometry.removable ? FF_PHYSICALDISK_TYPE_REMOVABLE : FF_PHYSICALDISK_TYPE_FIXED);
    device->size = (uint64_t) geometry.cylinder_count * geometry.head_count * geometry.sectors_per_track * geometry.bytes_per_sector;

    return NULL;
}

static const char* searchRawDeviceFile(FFstrbuf* path, const char* diskType, FFlist* result)
{
    FF_AUTO_CLOSE_DIR DIR* dir = opendir(path->chars);
    if (!dir) return "detectDiskType: opendir() failed";
    uint32_t baseLen = path->length;

    struct dirent* entry;
    while((entry = readdir(dir)))
    {
        if (entry->d_name[0] == '.') continue;
        ffStrbufAppendC(path, '/');
        ffStrbufAppendS(path, entry->d_name);

        struct stat st;
        if (stat(path->chars, &st) != 0)
        {
            ffStrbufSubstrBefore(path, baseLen);
            continue;
        }

        if (S_ISDIR(st.st_mode))
            searchRawDeviceFile(path, diskType, result);
        else if (ffStrEquals(entry->d_name, "raw"))
            detectDisk(path, diskType, result);

        ffStrbufSubstrBefore(path, baseLen);
    }
    return NULL;
}

const char* ffDetectPhysicalDisk(FFlist* result, FF_MAYBE_UNUSED FFPhysicalDiskOptions* options)
{
    FF_AUTO_CLOSE_DIR DIR* dir = opendir("/dev/disk");
    if (!dir) return "opendir(/dev/disk) failed";

    FF_STRBUF_AUTO_DESTROY path = ffStrbufCreateA(64);
    ffStrbufAppendS(&path, "/dev/disk/");
    uint32_t baseLen = path.length;

    struct dirent* entry;
    while((entry = readdir(dir)))
    {
        if (entry->d_name[0] == '.' || ffStrEquals(entry->d_name, "virtual")) continue;
        ffStrbufAppendS(&path, entry->d_name);
        searchRawDeviceFile(&path, entry->d_name, result);
        ffStrbufSubstrBefore(&path, baseLen);
    }

    return NULL;
}
