# SPDX-License-Identifier: LSL-1.0
# Copyright (c) 2026 Markus Maiwald
# Stewardship: Self Sovereign Society Foundation
#
# This file is part of the Nexus Sovereign Core.
# See legal/LICENSE_SOVEREIGN.md for license terms.

## Nexus Membrane: Block I/O Client

# Membrane Block API (The Block Valve - Userland Side)
# Phase 37.2: Sovereign Storage Architecture
#
# This module provides raw sector access to userland filesystems.
# The kernel is just a valve - NO filesystem logic in kernel.

import libc

const
  SECTOR_SIZE* = 512
  
  # Block Valve Syscalls
  SYS_BLK_READ* = 0x220
  SYS_BLK_WRITE* = 0x221
  SYS_BLK_SYNC* = 0x222

proc blk_read*(sector: uint64, buf: pointer): int =
  ## Read a single 512-byte sector from disk
  ## Returns: bytes read (512) or negative error
  return syscall(SYS_BLK_READ, uint64(sector), cast[uint64](buf), 1'u64)

proc blk_write*(sector: uint64, buf: pointer): int =
  ## Write a single 512-byte sector to disk
  ## Returns: bytes written (512) or negative error
  return syscall(SYS_BLK_WRITE, uint64(sector), cast[uint64](buf), 1'u64)

proc blk_sync*(): int =
  ## Flush all pending writes to disk
  ## Returns: 0 on success, negative error
  return syscall(SYS_BLK_SYNC, 0'u64, 0'u64, 0'u64)

# --- Multi-Sector Helpers ---

proc blk_read_multi*(start_sector: uint64, buf: pointer, count: int): int =
  ## Read multiple contiguous sectors
  var total = 0
  for i in 0..<count:
    let offset = i * SECTOR_SIZE
    let res = blk_read(start_sector + uint64(i), 
                       cast[pointer](cast[int](buf) + offset))
    if res < 0: return res
    total += res
  return total

proc blk_write_multi*(start_sector: uint64, buf: pointer, count: int): int =
  ## Write multiple contiguous sectors
  var total = 0
  for i in 0..<count:
    let offset = i * SECTOR_SIZE
    let res = blk_write(start_sector + uint64(i),
                        cast[pointer](cast[int](buf) + offset))
    if res < 0: return res
    total += res
  return total