import socket
import ../../core/ion/memory
import ion_client

proc console_write(p: pointer, len: csize_t) {.importc, cdecl.}

# --- SYSCALL PRIMITIVE ---

proc nexus_syscall*(nr: int, arg: int): int {.exportc, cdecl.} =
  var res: int
  asm """
    mv a7, %1
    mv a0, %2
    ecall
    mv %0, a0
    : "=r"(`res`)
    : "r"(`nr`), "r"(`arg`)
    : "a0", "a7"
  """
  return res

# --- POSIX SOCKET API SHIMS ---

type
  SockAddrIn = object
    sin_family: uint16
    sin_port: uint16
    sin_addr: uint32
    sin_zero: array[8, char]

proc socket*(domain, sock_type, protocol: int): int {.exportc, cdecl.} =
  return new_socket()

proc connect*(fd: int, sock_addr: pointer, len: int): int {.exportc, cdecl.} =
  if sock_addr == nil: return -1
  let sin = cast[ptr SockAddrIn](sock_addr)
  return connect_flow(fd, sin.sin_addr, sin.sin_port)

proc send*(fd: cint, buf: pointer, count: csize_t, flags: cint): int {.exportc, cdecl.} =
  return send_flow(int(fd), buf, int(count))

proc recv*(fd: cint, buf: pointer, count: csize_t, flags: cint): int {.exportc, cdecl.} =
  # TODO: Implement RX buffering in socket.nim
  return 0

# --- LIBC IO SHIMS ---

proc write*(fd: cint, buf: pointer, count: csize_t): int {.exportc, cdecl.} =
  if fd == 1 or fd == 2:
    when defined(is_kernel):
      # Not used here
      return -1
    else:
      # Direct UART for Phase 7
      console_write(buf, count)
      return int(count)

  return send_flow(int(fd), buf, int(count))

proc read*(fd: cint, buf: pointer, count: csize_t): int {.exportc, cdecl.} =
  if fd == 0:
    # UART Input unimplemented
    return 0
  return recv(fd, buf, count, 0)

proc exit*(status: cint) {.exportc, cdecl.} =
  while true:
    # Exit loop - yield forever or shutdown
    discard nexus_syscall(0, 0)

proc open*(pathname: cstring, flags: cint): cint {.exportc, cdecl.} =
  # Filesystem not active yet
  return -1

proc close*(fd: cint): cint {.exportc, cdecl.} =
  # TODO: Close socket
  return 0

# moved to top

proc sleep*(seconds: uint32) {.exportc, cdecl.} =
  var i: int = 0
  let limit = int(seconds) * 50_000_000
  while i < limit:
    i += 1