const std = @import("std");
const uefi = std.os.uefi;
const Status = uefi.Status;

pub const EfiBlockMedia = extern struct {
    /// The current media ID. If the media changes, this value is changed.
    media_id: u32,

    /// `true` if the media is removable; otherwise, `false`.
    removable_media: bool,
    /// `true` if there is a media currently present in the device
    media_present: bool,
    /// `true` if the `BlockIoProtocol` was produced to abstract
    /// partition structures on the disk. `false` if the `BlockIoProtocol` was
    /// produced to abstract the logical blocks on a hardware device.
    logical_partition: bool,
    /// `true` if the media is marked read-only otherwise, `false`. This field
    /// shows the read-only status as of the most recent `WriteBlocks()`
    read_only: bool,
    /// `true` if the WriteBlocks() function caches write data.
    write_caching: bool,

    /// The intrinsic block size of the device. If the media changes, then this
    // field is updated. Returns the number of bytes per logical block.

    block_size: u32,
    /// Supplies the alignment requirement for any buffer used in a data
    /// transfer. IoAlign values of 0 and 1 mean that the buffer can be
    /// placed anywhere in memory. Otherwise, IoAlign must be a power of
    /// 2, and the requirement is that the start address of a buffer must be
    /// evenly divisible by IoAlign with no remainder.
    io_align: u32,
    /// The last LBA on the device. If the media changes, then this field is updated.
    last_block: u64,

    // Revision 2

    lowest_aligned_lba: u64,
    logical_blocks_per_physical_block: u32,
    optimal_transfer_length_granularity: u32,
};

pub const BlockIoProtocol = extern struct {
    const Self = @This();

    revision: u64,
    media: *EfiBlockMedia,

    _reset: *const fn (*BlockIoProtocol, extended_verification: bool) callconv(.C) Status,
    _read_blocks: *const fn (*BlockIoProtocol, media_id: u32, lba: u64, buffer_size: usize, buf: [*]u8) callconv(.C) Status,
    _write_blocks: *const fn (*BlockIoProtocol, media_id: u32, lba: u64, buffer_size: usize, buf: [*]u8) callconv(.C) Status,
    _flush_blocks: *const fn (*BlockIoProtocol) callconv(.C) Status,

    /// Resets the block device hardware.
    pub fn reset(self: *Self, extended_verification: bool) Status {
        return self._reset(self, extended_verification);
    }

    /// Reads the number of requested blocks from the device.
    pub fn readBlocks(self: *Self, media_id: u32, lba: u64, buffer_size: usize, buf: [*]u8) Status {
        return self._read_blocks(self, media_id, lba, buffer_size, buf);
    }

    /// Writes a specified number of blocks to the device.
    pub fn writeBlocks(self: *Self, media_id: u32, lba: u64, buffer_size: usize, buf: [*]u8) Status {
        return self._write_blocks(self, media_id, lba, buffer_size, buf);
    }

    /// Flushes all modified data to a physical block device.
    pub fn flushBlocks(self: *Self) Status {
        return self._flush_blocks(self);
    }

    pub const guid align(8) = uefi.Guid{
        .time_low = 0x964e5b21,
        .time_mid = 0x6459,
        .time_high_and_version = 0x11d2,
        .clock_seq_high_and_reserved = 0x8e,
        .clock_seq_low = 0x39,
        .node = [_]u8{ 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b },
    };
};