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

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

# --- SYSCALL PRIMITIVE ---

proc syscall*(nr: int, a0: int = 0, a1: int = 0, a2: int = 0): int {.inline.} =
  var res: int
  asm """
    mv a7, %1
    mv a0, %2
    mv a1, %3
    mv a2, %4
    ecall
    mv %0, a0
    : "=r"(`res`)
    : "r"(`nr`), "r"(`a0`), "r"(`a1`), "r"(`a2`)
    : "a0", "a7", "memory"
  """
  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.} =
  return recv_flow(int(fd), buf, int(count))

# --- 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):
      return -1
    else:
      console_write(buf, count)
      return int(count)

  let sys = cast[ptr SysTable](SYS_TABLE_ADDR)
  if sys.fn_vfs_write != nil:
    let f = cast[proc(fd: int32, buf: pointer, count: uint64): int64 {.cdecl.}](
        sys.fn_vfs_write)
    return int(f(int32(fd), buf, uint64(count)))

  if fd >= 100:
    return send_flow(int(fd), buf, int(count))

  # File Write (Syscall 0x204)
  return syscall(0x204, int(fd), cast[int](buf), int(count))

# Stdin buffer for input packets
var stdin_buf: array[128, byte]
var stdin_len: int = 0
var stdin_pos: int = 0

proc read*(fd: cint, buf: pointer, count: csize_t): int {.exportc, cdecl.} =
  if fd == 0:
    if stdin_pos < stdin_len:
      let remaining = stdin_len - stdin_pos
      let to_copy = if remaining > int(count): int(count) else: remaining
      copyMem(buf, addr stdin_buf[stdin_pos], to_copy)
      stdin_pos += to_copy
      if stdin_pos >= stdin_len:
        stdin_len = 0
        stdin_pos = 0
      return to_copy

    # Poll input ring
    var pkt: IonPacket
    if ion_user_input(addr pkt):
      let len = min(int(pkt.len), 128)
      copyMem(addr stdin_buf[0], pkt.data, len)
      stdin_len = len
      stdin_pos = 0
      ion_user_return(pkt.id)
      let to_copy = if stdin_len > int(count): int(count) else: stdin_len
      copyMem(buf, addr stdin_buf[0], to_copy)
      stdin_pos += to_copy
      return to_copy
    return 0

  if fd >= 100: return recv(fd, buf, count, 0)

  # Try SysTable first
  let sys = cast[ptr SysTable](SYS_TABLE_ADDR)
  if sys.fn_vfs_read != nil:
    let f = cast[proc(fd: int32, buf: pointer, count: uint64): int64 {.cdecl.}](
        sys.fn_vfs_read)
    return int(f(int32(fd), buf, uint64(count)))

  return syscall(0x203, int(fd), cast[int](buf), int(count))

proc exit*(status: cint) {.exportc, cdecl.} =
  discard syscall(0, 0)
  while true: discard

proc open*(pathname: cstring, flags: cint): cint {.exportc, cdecl.} =
  let sys = cast[ptr SysTable](SYS_TABLE_ADDR)
  if sys.fn_vfs_open != nil:
    return cint(sys.fn_vfs_open(pathname, int32(flags)))

  return cint(syscall(0x200, cast[int](pathname), int(flags)))

proc close*(fd: cint): cint {.exportc, cdecl.} =
  if fd >= 100: return 0
  # Try SysTable first
  let sys = cast[ptr SysTable](SYS_TABLE_ADDR)
  if sys.fn_vfs_close != nil:
    let f = cast[proc(fd: int32): int32 {.cdecl.}](sys.fn_vfs_close)
    return cint(f(int32(fd)))
  return cint(syscall(0x201, int(fd)))

proc nexus_list*(buf: pointer, len: int): int {.exportc, cdecl.} =
  let sys = cast[ptr SysTable](SYS_TABLE_ADDR)
  if sys.fn_vfs_list != nil:
    let f = cast[proc(buf: pointer, max_len: uint64): int64 {.cdecl.}](
        sys.fn_vfs_list)
    return int(f(buf, uint64(len)))
  return syscall(0x202, cast[int](buf), len)

# 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

# --- PHASE 29: WORKER MODEL (THE HIVE) ---

proc spawn*(entry: proc(arg: uint64) {.cdecl.}, arg: uint64 = 0): int {.exportc, cdecl.} =
  ## Spawn a new worker fiber
  ## Returns: Fiber ID on success, -1 on failure
  return syscall(0x500, cast[int](entry), int(arg))

proc join*(fid: int): int {.exportc, cdecl.} =
  ## Wait for worker fiber to complete
  ## Returns: 0 on success, -1 on failure
  return syscall(0x501, fid)

# --- PHASE 28: PLEDGE ---

proc pledge*(promises: uint64): int {.exportc, cdecl.} =
  ## Reduce capabilities (one-way ratchet)
  ## Returns: 0 on success, -1 on failure
  let sys = cast[ptr SysTable](SYS_TABLE_ADDR)
  if sys.fn_pledge != nil:
    return int(sys.fn_pledge(promises))
  return -1

# --- HIGH LEVEL HELPERS ---
import strutils, sequtils

proc get_vfs_listing*(): seq[string] =
  var buf = newString(4096)
  let n = nexus_list(addr buf[0], 4096)
  if n > 0:
    buf.setLen(n)
    return buf.splitLines().filterIt(it.strip().len > 0)
  return @[]