# Scenario:
#   print-cell can be used for printing into a trace
#   traces can run out of space
#   therefore, we need to gracefully handle insufficient space in 'out'
#     if we're printing something 3 bytes or less, just make sure it doesn't crash
#     if we're printing something longer than 3 bytes, try to fall back to ellipses (which are 3 bytes)
fn print-cell _in: (addr handle cell), out: (addr stream byte), trace: (addr trace) {
  check-stack
  trace-text trace, "print", "print"
  trace-lower trace
  var in/eax: (addr handle cell) <- copy _in
  var in-addr/eax: (addr cell) <- lookup *in
  {
    compare in-addr, 0
    break-if-!=
    var overflow?/eax: boolean <- try-write out, "NULL"
    compare overflow?, 0/false
    {
      break-if-=
      overflow? <- try-write out, "..."
      error trace, "print-cell: no space for 'NULL'"
    }
    trace-higher trace
    return
  }
  {
    var nil?/eax: boolean <- nil? in-addr
    compare nil?, 0/false
    break-if-=
    var overflow?/eax: boolean <- try-write out, "()"
    compare overflow?, 0/false
    {
      break-if-=
      error trace, "print-cell: no space for '()'"
    }
    trace-higher trace
    return
  }
  var in-type/ecx: (addr int) <- get in-addr, type
  compare *in-type, 0/pair
  {
    break-if-!=
    print-pair in-addr, out, trace
    trace-higher trace
    return
  }
  compare *in-type, 1/number
  {
    break-if-!=
    print-number in-addr, out, trace
    trace-higher trace
    return
  }
  compare *in-type, 2/symbol
  {
    break-if-!=
    print-symbol in-addr, out, trace
    trace-higher trace
    return
  }
  compare *in-type, 3/stream
  {
    break-if-!=
    print-stream in-addr, out, trace
    trace-higher trace
    return
  }
  compare *in-type, 4/primitive
  {
    break-if-!=
    var overflow?/eax: boolean <- try-write out, "{primitive}"
    compare overflow?, 0/false
    {
      break-if-=
      overflow? <- try-write out, "..."
      error trace, "print-cell: no space for primitive"
    }
    trace-higher trace
    return
  }
  compare *in-type, 5/screen
  {
    break-if-!=
    {
      var available-space/eax: int <- space-remaining-in-stream out
      compare available-space, 0x10
      break-if->=
      var dummy/eax: boolean <- try-write out, "..."
      error trace, "print-cell: no space for screen"
      return
    }
    write out, "{screen "
    var screen-ah/eax: (addr handle screen) <- get in-addr, screen-data
    var screen/eax: (addr screen) <- lookup *screen-ah
    var screen-addr/eax: int <- copy screen
    write-int32-hex out, screen-addr
    write out, "}"
    trace-higher trace
    return
  }
  compare *in-type, 6/keyboard
  {
    break-if-!=
    {
      var available-space/eax: int <- space-remaining-in-stream out
      compare available-space, 0x10
      break-if->=
      var dummy/eax: boolean <- try-write out, "..."
      error trace, "print-cell: no space for keyboard"
      return
    }
    write out, "{keyboard "
    var keyboard-ah/eax: (addr handle gap-buffer) <- get in-addr, keyboard-data
    var keyboard/eax: (addr gap-buffer) <- lookup *keyboard-ah
    var keyboard-addr/eax: int <- copy keyboard
    write-int32-hex out, keyboard-addr
    write out, "}"
    trace-higher trace
    return
  }
  compare *in-type, 7/array
  {
    break-if-!=
    {
      var overflow?/eax: boolean <- try-write out, "{array"
      compare overflow?, 0/false
      break-if-=
      return
    }
    var data-ah/eax: (addr handle array handle cell) <- get in-addr, array-data
    var _data/eax: (addr array handle cell) <- lookup *data-ah
    var data/esi: (addr array handle cell) <- copy _data
    var i/ecx: int <- copy 0
    var max/edx: int <- length data
    {
      compare i, max
      break-if->=
      {
        var available-space/eax: int <- space-remaining-in-stream out
        compare available-space, 0x10
        break-if->=
        var dummy/eax: boolean <- try-write out, "..."
        error trace, "print-cell: no space for array"
        return
      }
      var overflow?/eax: boolean <- try-write out " "
      compare overflow?, 0/false
      break-if-!=
      var curr-ah/eax: (addr handle cell) <- index data, i
      print-cell curr-ah, out, trace
      i <- increment
      loop
    }
    var dummy/eax: boolean <- try-write out, "}"
    trace-higher trace
    return
  }
}

# debug helper
fn dump-cell-at-top-right in-ah: (addr handle cell) {
  var stream-storage: (stream byte 0x1000)
  var stream/edx: (addr stream byte) <- address stream-storage
  var trace-storage: trace
  var trace/edi: (addr trace) <- address trace-storage
  initialize-trace trace, 1/only-errors, 0x10/capacity, 0/visible
  print-cell in-ah, stream, trace
  var d1/eax: int <- copy 0
  var d2/ecx: int <- copy 0
  d1, d2 <- draw-stream-wrapping-right-then-down 0/screen, stream, 0/xmin, 0/ymin, 0x80/xmax, 0x30/ymax, 0/x, 0/y, 7/fg, 0xc5/bg=blue-bg
}

fn dump-cell-from-cursor-over-full-screen in-ah: (addr handle cell), fg: int, bg: int {
  var stream-storage: (stream byte 0x200)
  var stream/edx: (addr stream byte) <- address stream-storage
  var trace-storage: trace
  var trace/edi: (addr trace) <- address trace-storage
  initialize-trace trace, 1/only-errors, 0x10/capacity, 0/visible
  print-cell in-ah, stream, trace
  draw-stream-wrapping-right-then-down-from-cursor-over-full-screen 0/screen, stream, fg, bg
}

fn print-symbol _in: (addr cell), out: (addr stream byte), trace: (addr trace) {
  trace-text trace, "print", "symbol"
  var in/esi: (addr cell) <- copy _in
  var data-ah/eax: (addr handle stream byte) <- get in, text-data
  var _data/eax: (addr stream byte) <- lookup *data-ah
  var data/esi: (addr stream byte) <- copy _data
  rewind-stream data
  var _required-space/eax: int <- stream-size data
  var required-space/ecx: int <- copy _required-space
  var available-space/eax: int <- space-remaining-in-stream out
  compare required-space, available-space
  {
    break-if-<=
    var dummy/eax: boolean <- try-write out, "..."
    error trace, "print-symbol: no space"
    return
  }
  write-stream-immutable out, data
  # trace
  var should-trace?/eax: boolean <- should-trace? trace
  compare should-trace?, 0/false
  break-if-=
  rewind-stream data
  var stream-storage: (stream byte 0x40)
  var stream/ecx: (addr stream byte) <- address stream-storage
  write stream, "=> symbol "
  write-stream stream, data
  trace trace, "print", stream
}

fn print-stream _in: (addr cell), out: (addr stream byte), trace: (addr trace) {
  trace-text trace, "print", "stream"
  var in/esi: (addr cell) <- copy _in
  var data-ah/eax: (addr handle stream byte) <- get in, text-data
  var _data/eax: (addr stream byte) <- lookup *data-ah
  var data/esi: (addr stream byte) <- copy _data
  var _required-space/eax: int <- stream-size data
  var required-space/ecx: int <- copy _required-space
  required-space <- add 2  # for []
  var available-space/eax: int <- space-remaining-in-stream out
  compare required-space, available-space
  {
    break-if-<=
    var dummy/eax: boolean <- try-write out, "..."
    error trace, "print-stream: no space"
    return
  }
  write out, "["
  write-stream-immutable out, data
  write out, "]"
  # trace
  var should-trace?/eax: boolean <- should-trace? trace
  compare should-trace?, 0/false
  break-if-=
  rewind-stream data
  var stream-storage: (stream byte 0x40)
  var stream/ecx: (addr stream byte) <- address stream-storage
  write stream, "=> stream "
  write-stream-immutable stream, data
  trace trace, "print", stream
}

fn print-number _in: (addr cell), out: (addr stream byte), trace: (addr trace) {
  var available-space/eax: int <- space-remaining-in-stream out
  compare available-space, 0x10
  {
    break-if->=
    var dummy/eax: boolean <- try-write out, "..."
    error trace, "print-number: no space"
    return
  }
  var in/esi: (addr cell) <- copy _in
  var val/eax: (addr float) <- get in, number-data
  write-float-decimal-approximate out, *val, 0x10/precision
  # trace
  {
    var should-trace?/eax: boolean <- should-trace? trace
    compare should-trace?, 0/false
    break-if-!=
    return
  }
  var stream-storage: (stream byte 0x40)
  var stream/ecx: (addr stream byte) <- address stream-storage
  write stream, "=> number "
  write-float-decimal-approximate stream, *val, 0x10/precision
  trace trace, "print", stream
}

fn print-pair _in: (addr cell), out: (addr stream byte), trace: (addr trace) {
  # if in starts with a quote, print the quote outside the expression
  var in/esi: (addr cell) <- copy _in
  var left-ah/eax: (addr handle cell) <- get in, left
  var _left/eax: (addr cell) <- lookup *left-ah
  var left/ecx: (addr cell) <- copy _left
  var is-quote?/eax: boolean <- symbol-equal? left, "'"
  compare is-quote?, 0/false
  {
    break-if-=
    var dummy/eax: boolean <- try-write out, "'"
    var right-ah/eax: (addr handle cell) <- get in, right
    print-cell right-ah, out, trace
    return
  }
  var is-backquote?/eax: boolean <- symbol-equal? left, "`"
  compare is-backquote?, 0/false
  {
    break-if-=
    var dummy/eax: boolean <- try-write out, "`"
    var right-ah/eax: (addr handle cell) <- get in, right
    print-cell right-ah, out, trace
    return
  }
  var is-unquote?/eax: boolean <- symbol-equal? left, ","
  compare is-unquote?, 0/false
  {
    break-if-=
    var dummy/eax: boolean <- try-write out, ","
    var right-ah/eax: (addr handle cell) <- get in, right
    print-cell right-ah, out, trace
    return
  }
  var is-unquote-splice?/eax: boolean <- symbol-equal? left, ",@"
  compare is-unquote-splice?, 0/false
  {
    break-if-=
    var dummy/eax: boolean <- try-write out, ",@"
    var right-ah/eax: (addr handle cell) <- get in, right
    print-cell right-ah, out, trace
    return
  }
  #
  var curr/esi: (addr cell) <- copy _in
  {
    var overflow?/eax: boolean <- try-write out, "("
    compare overflow?, 0/false
    break-if-=
    error trace, "print-pair: no space for '('"
    return
  }
  $print-pair:loop: {
    var left/ecx: (addr handle cell) <- get curr, left
    print-cell left, out, trace
    # errors? skip
    {
      var error?/eax: boolean <- has-errors? trace
      compare error?, 0/false
      break-if-=
      return
    }
    var right/ecx: (addr handle cell) <- get curr, right
    var right-addr/eax: (addr cell) <- lookup *right
    {
      compare right-addr, 0
      break-if-!=
      {
        var overflow?/eax: boolean <- try-write out, " ... NULL"
        compare overflow?, 0/false
        break-if-=
        error trace, "print-pair: no space for ' ... NULL'"
        return
      }
      return
    }
    {
      var right-nil?/eax: boolean <- nil? right-addr
      compare right-nil?, 0/false
      {
        break-if-=
        trace-text trace, "print", "right is nil"
        break $print-pair:loop
      }
    }
    {
      var overflow?/eax: boolean <- try-write out, " "
      compare overflow?, 0/false
      break-if-=
      error trace, "print-pair: no space"
      return
    }
    var right-type-addr/edx: (addr int) <- get right-addr, type
    {
      compare *right-type-addr, 0/pair
      break-if-=
      {
        var overflow?/eax: boolean <- try-write out, ". "
        compare overflow?, 0/false
        break-if-=
        error trace, "print-pair: no space"
        return
      }
      print-cell right, out, trace
      break $print-pair:loop
    }
    curr <- copy right-addr
    loop
  }
  {
    var overflow?/eax: boolean <- try-write out, ")"
    compare overflow?, 0/false
    break-if-=
    error trace, "print-pair: no space for ')'"
    return
  }
}

# Most lisps intern nil, but we don't really have globals yet, so we'll be
# less efficient for now.
fn nil? _in: (addr cell) -> _/eax: boolean {
  var in/esi: (addr cell) <- copy _in
  # if type != pair, return false
  var type/eax: (addr int) <- get in, type
  compare *type, 0/pair
  {
    break-if-=
    return 0/false
  }
  # if left != null, return false
  var left-ah/eax: (addr handle cell) <- get in, left
  var left/eax: (addr cell) <- lookup *left-ah
  compare left, 0
  {
    break-if-=
    return 0/false
  }
  # if right != null, return false
  var right-ah/eax: (addr handle cell) <- get in, right
  var right/eax: (addr cell) <- lookup *right-ah
  compare right, 0
  {
    break-if-=
    return 0/false
  }
  return 1/true
}

fn test-print-cell-zero {
  var num-storage: (handle cell)
  var num/esi: (addr handle cell) <- address num-storage
  new-integer num, 0
  var out-storage: (stream byte 0x40)
  var out/edi: (addr stream byte) <- address out-storage
  var trace-storage: trace
  var trace/edx: (addr trace) <- address trace-storage
  initialize-trace trace, 1/only-errors, 0x10/capacity, 0/visible
  print-cell num, out, trace
  check-stream-equal out, "0", "F - test-print-cell-zero"
}

fn test-print-cell-integer {
  var num-storage: (handle cell)
  var num/esi: (addr handle cell) <- address num-storage
  new-integer num, 1
  var out-storage: (stream byte 0x40)
  var out/edi: (addr stream byte) <- address out-storage
  var trace-storage: trace
  var trace/edx: (addr trace) <- address trace-storage
  initialize-trace trace, 1/only-errors, 0x10/capacity, 0/visible
  print-cell num, out, trace
  check-stream-equal out, "1", "F - test-print-cell-integer"
}

fn test-print-cell-integer-2 {
  var num-storage: (handle cell)
  var num/esi: (addr handle cell) <- address num-storage
  new-integer num, 0x30
  var out-storage: (stream byte 0x40)
  var out/edi: (addr stream byte) <- address out-storage
  var trace-storage: trace
  var trace/edx: (addr trace) <- address trace-storage
  initialize-trace trace, 1/only-errors, 0x10/capacity, 0/visible
  print-cell num, out, trace
  check-stream-equal out, "48", "F - test-print-cell-integer-2"
}

fn test-print-cell-fraction {
  var num-storage: (handle cell)
  var num/esi: (addr handle cell) <- address num-storage
  var val/xmm0: float <- rational 1, 2
  new-float num, val
  var out-storage: (stream byte 0x40)
  var out/edi: (addr stream byte) <- address out-storage
  var trace-storage: trace
  var trace/edx: (addr trace) <- address trace-storage
  initialize-trace trace, 1/only-errors, 0x10/capacity, 0/visible
  print-cell num, out, trace
  check-stream-equal out, "0.5", "F - test-print-cell-fraction"
}

fn test-print-cell-symbol {
  var sym-storage: (handle cell)
  var sym/esi: (addr handle cell) <- address sym-storage
  new-symbol sym, "abc"
  var out-storage: (stream byte 0x40)
  var out/edi: (addr stream byte) <- address out-storage
  var trace-storage: trace
  var trace/edx: (addr trace) <- address trace-storage
  initialize-trace trace, 1/only-errors, 0x10/capacity, 0/visible
  print-cell sym, out, trace
  check-stream-equal out, "abc", "F - test-print-cell-symbol"
}

fn test-print-cell-nil-list {
  var nil-storage: (handle cell)
  var nil/esi: (addr handle cell) <- address nil-storage
  allocate-pair nil
  var out-storage: (stream byte 0x40)
  var out/edi: (addr stream byte) <- address out-storage
  var trace-storage: trace
  var trace/edx: (addr trace) <- address trace-storage
  initialize-trace trace, 1/only-errors, 0x10/capacity, 0/visible
  print-cell nil, out, trace
  check-stream-equal out, "()", "F - test-print-cell-nil-list"
}

fn test-print-cell-singleton-list {
  # list
  var left-storage: (handle cell)
  var left/ecx: (addr handle cell) <- address left-storage
  new-symbol left, "abc"
  var nil-storage: (handle cell)
  var nil/edx: (addr handle cell) <- address nil-storage
  allocate-pair nil
  var list-storage: (handle cell)
  var list/esi: (addr handle cell) <- address list-storage
  new-pair list, *left, *nil
  #
  var out-storage: (stream byte 0x40)
  var out/edi: (addr stream byte) <- address out-storage
  var trace-storage: trace
  var trace/edx: (addr trace) <- address trace-storage
  initialize-trace trace, 1/only-errors, 0x10/capacity, 0/visible
  print-cell list, out, trace
  check-stream-equal out, "(abc)", "F - test-print-cell-singleton-list"
}

fn test-print-cell-list {
  # list = cons "abc", nil
  var left-storage: (handle cell)
  var left/ecx: (addr handle cell) <- address left-storage
  new-symbol left, "abc"
  var nil-storage: (handle cell)
  var nil/edx: (addr handle cell) <- address nil-storage
  allocate-pair nil
  var list-storage: (handle cell)
  var list/esi: (addr handle cell) <- address list-storage
  new-pair list, *left, *nil
  # list = cons 64, list
  new-integer left, 0x40
  new-pair list, *left, *list
  #
  var out-storage: (stream byte 0x40)
  var out/edi: (addr stream byte) <- address out-storage
  var trace-storage: trace
  var trace/edx: (addr trace) <- address trace-storage
  initialize-trace trace, 1/only-errors, 0x10/capacity, 0/visible
  print-cell list, out, trace
  check-stream-equal out, "(64 abc)", "F - test-print-cell-list"
}

fn test-print-cell-list-of-nil {
  # list = cons "abc", nil
  var left-storage: (handle cell)
  var left/ecx: (addr handle cell) <- address left-storage
  allocate-pair left
  var nil-storage: (handle cell)
  var nil/edx: (addr handle cell) <- address nil-storage
  allocate-pair nil
  var list-storage: (handle cell)
  var list/esi: (addr handle cell) <- address list-storage
  new-pair list, *left, *nil
  # list = cons 64, list
  new-integer left, 0x40
  new-pair list, *left, *list
  #
  var out-storage: (stream byte 0x40)
  var out/edi: (addr stream byte) <- address out-storage
  var trace-storage: trace
  var trace/edx: (addr trace) <- address trace-storage
  initialize-trace trace, 1/only-errors, 0x10/capacity, 0/visible
  print-cell list, out, trace
  check-stream-equal out, "(64 ())", "F - test-print-cell-list-nil"
}

fn test-print-dotted-list {
  # list = cons 64, "abc"
  var left-storage: (handle cell)
  var left/ecx: (addr handle cell) <- address left-storage
  new-symbol left, "abc"
  var right-storage: (handle cell)
  var right/edx: (addr handle cell) <- address right-storage
  new-integer right, 0x40
  var list-storage: (handle cell)
  var list/esi: (addr handle cell) <- address list-storage
  new-pair list, *left, *right
  #
  var out-storage: (stream byte 0x40)
  var out/edi: (addr stream byte) <- address out-storage
  var trace-storage: trace
  var trace/edx: (addr trace) <- address trace-storage
  initialize-trace trace, 1/only-errors, 0x10/capacity, 0/visible
  print-cell list, out, trace
  check-stream-equal out, "(abc . 64)", "F - test-print-dotted-list"
}

fn test-print-cell-interrupted {
  var sym-storage: (handle cell)
  var sym/esi: (addr handle cell) <- address sym-storage
  new-symbol sym, "abcd"  # requires 4 bytes
  var out-storage: (stream byte 3)  # space for just 3 bytes
  var out/edi: (addr stream byte) <- address out-storage
  var trace-storage: trace
  var trace/edx: (addr trace) <- address trace-storage
  initialize-trace trace, 1/only-errors, 0x10/capacity, 0/visible
  print-cell sym, out, trace
  # insufficient space to print out the symbol; print out ellipses if we can
  check-stream-equal out, "...", "F - test-print-cell-interrupted"
}

fn test-print-cell-impossible {
  var sym-storage: (handle cell)
  var sym/esi: (addr handle cell) <- address sym-storage
  new-symbol sym, "abcd"  # requires 4 bytes
  var out-storage: (stream byte 2)
  var out/edi: (addr stream byte) <- address out-storage
  var trace-storage: trace
  var trace/edx: (addr trace) <- address trace-storage
  initialize-trace trace, 1/only-errors, 0x10/capacity, 0/visible
  print-cell sym, out, trace
  # insufficient space even for ellipses; print nothing
  check-stream-equal out, "", "F - test-print-cell-impossible"
}

fn test-print-cell-interrupted-list {
  # list = (abcd) requires 6 bytes
  var left-storage: (handle cell)
  var left/ecx: (addr handle cell) <- address left-storage
  new-symbol left, "abcd"
  var nil-storage: (handle cell)
  var nil/edx: (addr handle cell) <- address nil-storage
  allocate-pair nil
  var list-storage: (handle cell)
  var list/esi: (addr handle cell) <- address list-storage
  new-pair list, *left, *nil
  #
  var out-storage: (stream byte 4)  # space for just 4 bytes
  var out/edi: (addr stream byte) <- address out-storage
  var trace-storage: trace
  var trace/edx: (addr trace) <- address trace-storage
  initialize-trace trace, 1/only-errors, 0x10/capacity, 0/visible
  print-cell list, out, trace
  check-stream-equal out, "(...", "F - test-print-cell-interrupted-list"
}