#include <bh/internal/file.h>

static const bh_io_table_t bh_file_table = {
    (int (*)(struct bh_io_s *, int)) bh_file_open_base,
    (void (*)(struct bh_io_s *)) bh_file_close_base,
    (int (*)(struct bh_io_s *)) bh_file_is_open_base,
    (size_t (*)(struct bh_io_s *, char *, size_t)) bh_file_read_base,
    (size_t (*)(struct bh_io_s *, const char *, size_t)) bh_file_write_base,
    (void (*)(struct bh_io_s *)) bh_file_flush_base,
    (int (*)(struct bh_io_s *, bh_off_t, int)) bh_file_seek_base,
    (bh_off_t (*)(struct bh_io_s *)) bh_file_size_base,
    (bh_off_t (*)(struct bh_io_s *)) bh_file_tell_base,
    (bh_off_t (*)(struct bh_io_s *)) bh_file_available_base,
    (void (*)(struct bh_io_s *)) bh_file_clear_base,
    (void (*)(struct bh_io_s *)) bh_file_destroy
};

bh_file_t *bh_file_new(const char *path)
{
    bh_file_t *result;

    result = malloc(sizeof(*result));
    if (result && bh_file_init(result, path))
    {
        free(result);
        result = NULL;
    }

    return result;
}

void bh_file_free(bh_file_t *file)
{
    bh_file_destroy(file);
    free(file);
}

int bh_file_init(bh_file_t *file,
                 const char *path)
{
    if (!path)
        return BH_INVALID;

    file->handle = INVALID_HANDLE_VALUE;
    file->mode = 0;
    file->path = strdup(path);
    file->base.table = &bh_file_table;

    return BH_OK;
}

int bh_file_open_base(bh_file_t *file,
                      int mode)
{
    DWORD access = 0, how = 0;

    if (mode & BH_IO_READ)
        access |= GENERIC_READ;
    if (mode & BH_IO_WRITE)
        access |= GENERIC_WRITE;

    switch (mode & BH_IO_MASK)
    {
    case BH_IO_OPEN:    how = OPEN_EXISTING;    break;
    case BH_IO_CREATE:  how = CREATE_ALWAYS;    break;
    case BH_IO_APPEND:  how = OPEN_ALWAYS;      break;

    default:
    case BH_IO_TRUNCATE:
        return BH_NO_IMPL;
    }

    file->mode = mode;
    file->handle = CreateFileA(file->path, access, FILE_SHARE_READ, NULL, how, FILE_ATTRIBUTE_NORMAL, NULL);

    if (file->handle == INVALID_HANDLE_VALUE)
    {
        /* Error handling */
        switch (GetLastError())
        {
        case ERROR_FILE_EXISTS:     return BH_FOUND;
        case ERROR_FILE_NOT_FOUND:  return BH_NOT_FOUND;
        default:                    return BH_ERROR;
        }
    }

    return BH_OK;
}

void bh_file_close_base(bh_file_t *file)
{
    if (file->handle != INVALID_HANDLE_VALUE)
        CloseHandle(file->handle);

    file->handle = INVALID_HANDLE_VALUE;
}

int bh_file_is_open_base(bh_file_t *file)
{
    return file->handle != INVALID_HANDLE_VALUE;
}

void bh_file_destroy(bh_file_t *file)
{
    bh_file_close(file);
    free(file->path);
}

size_t bh_file_read_base(bh_file_t *file,
                         char *data,
                         size_t size)
{
    DWORD readed;

    if (!ReadFile(file->handle, data, (DWORD)size, &readed, NULL))
    {
        file->base.flags |= BH_IO_ERROR;
        return 0;
    }

    if (!readed)
        file->base.flags |= BH_IO_EOF;
    else
        file->base.flags &= ~BH_IO_EOF;

    return readed;
}

size_t bh_file_write_base(bh_file_t *file,
                          const char *data,
                          size_t size)
{
    DWORD written;

    if ((file->mode & BH_IO_MASK) == BH_IO_APPEND)
        bh_file_seek(file, 0, BH_IO_END);

    if (!WriteFile(file->handle, data, (DWORD)size, &written, NULL))
    {
        file->base.flags |= BH_IO_ERROR;
        return 0;
    }

    if (!written)
        file->base.flags |= BH_IO_EOF;
    else
        file->base.flags &= ~BH_IO_EOF;

    return written;
}

void bh_file_flush_base(bh_file_t *file)
{
    FlushFileBuffers(file->handle);
}

int bh_file_seek_base(bh_file_t *file,
                      bh_off_t pos,
                      int dir)
{
    LARGE_INTEGER position;

    position.QuadPart = pos;
    if (SetFilePointerEx(file->handle, position, NULL, dir))
        return BH_OK;

    return BH_ERROR;
}

bh_off_t bh_file_size_base(bh_file_t *file)
{
    return -1;
}

bh_off_t bh_file_tell_base(bh_file_t *file)
{
    LARGE_INTEGER dummy, position;

    dummy.QuadPart = 0;

    if (SetFilePointerEx(file->handle, dummy, &position, BH_IO_CURRENT))
        return position.QuadPart;

    return -1;
}

bh_off_t bh_file_available_base(bh_file_t *file)
{
    return 0;
}

void bh_file_clear_base(bh_file_t *file)
{
    file->base.flags &= ~BH_IO_ERROR;
}