;; Copyright 2016
;; Kaz Kylheku <kaz@kylheku.com>
;; Vancouver, Canada
;; All rights reserved.
;;
;; Redistribution of this software in source and binary forms, with or without
;; modification, is permitted provided that the following two conditions are met.
;;
;; Use of this software in any manner constitutes agreement with the disclaimer
;; which follows the two conditions.
;;
;; 1. Redistributions of source code must retain the above copyright
;;    notice, this list of conditions and the following disclaimer.
;; 2. Redistributions in binary form must reproduce the above copyright
;;    notice, this list of conditions and the following disclaimer in
;;    the documentation and/or other materials provided with the
;;    distribution.
;;
;; THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
;; WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
;; MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL THE
;; COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DAMAGES, HOWEVER CAUSED,
;; AND UNDER ANY THEORY OF LIABILITY, ARISING IN ANY WAY OUT OF THE USE OF THIS
;; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

(defstruct sockaddr nil)

(defstruct sockaddr-in sockaddr
  (addr 0) (port 0))

(defstruct sockaddr-in6 sockaddr
  (addr 0) (port 0) (flow-info 0) (scope-id 0))

(defstruct sockaddr-un sockaddr
  path)

(defstruct addrinfo nil
  (flags 0)
  (family 0)
  (socktype 0)
  (protocol 0)
  (canonname 0))

(defvarl shut-rd 0)
(defvarl shut-wr 1)
(defvarl shut-rdwr 2)

(defun str-inaddr (addr : port)
  (let ((d (logand addr #xFF))
        (c (logand (ash addr -8) #xFF))
        (b (logand (ash addr -16) #xFF))
        (a         (ash addr -24))
        (p (if port `:@port` "")))
    (if (or (> a 255) (minusp a))
      (throwf 'eval-error "str-inaddr: ~a out of range for IPv4 address" addr)
      `@a.@b.@c.@d@p`)))

(defun sys:in6addr-condensed-text (numeric-pieces)
  (let* ((notyet t)
         (texts (window-mappend
                  1 nil
                  (lambda (pre chunk post)
                    (cond
                      ((and notyet (zerop (car chunk)) (cdr chunk))
                       (zap notyet)
                       (if (and post pre) '("") '(":")))
                      (t (mapcar (op format nil "~x") chunk))))
                  [partition-by zerop numeric-pieces])))
    `@{texts ":"}`))

(defun str-in6addr (addr : port)
  (let ((str (if (and (<= (width addr) 48)
                      (= (ash addr -32) #xFFFF))
               `::ffff:@(str-inaddr (logtrunc addr 32))`
               (let* ((pieces (let ((count 8))
                                (nexpand-left (lambda (val)
                                                (if (minusp (dec count))
                                                  (unless (zerop val)
                                                    (throwf 'eval-error
                                                            "str-in6addr: \
                                                            \ ~a out of range \
                                                            \ for IPv6 address"
                                                            addr))
                                                  (cons (logand val #xFFFF)
                                                        (ash val -16))))
                                              addr))))
                 (sys:in6addr-condensed-text pieces)))))
    (if port
      `[@str]:@port`
      str)))

(defun sys:str-inaddr-net-impl (addr wextra : weff)
  (let ((mask addr))
    (set mask (logior mask (ash mask 1)))
    (set mask (logior mask (ash mask 2)))
    (set mask (logior mask (ash mask 4)))
    (set mask (logior mask (ash mask 8)))
    (set mask (logior mask (ash mask 16)))
    (let ((w (- 32 (width (lognot mask 32))))
          (d (logand addr #xFF))
          (c (logand (ash addr -8) #xFF))
          (b (logand (ash addr -16) #xFF))
          (a         (ash addr -24))
          (we (or weff (+ w wextra))))
      (cond
        ((or (> a 255) (minusp a))
         (throwf 'eval-error "str-inaddr-net: ~a out of range for IPv4 address"
                 addr))
        ((> w 24) `@a.@b.@c.@d/@we`)
        ((> w 16) `@a.@b.@c/@we`)
        ((> w 8) `@a.@b/@we`)
        (t `@a/@we`)))))

(defun str-inaddr-net (addr : width)
  (sys:str-inaddr-net-impl addr 0 width))

(defun str-in6addr-net (addr : width)
  (if (and (<= (width addr) 48)
           (= (ash addr -32) #xFFFF))
    `::ffff:@(sys:str-inaddr-net-impl (logtrunc addr 32) 96 width)`
    (let ((mask addr))
      (set mask (logior mask (ash mask 1)))
      (set mask (logior mask (ash mask 2)))
      (set mask (logior mask (ash mask 4)))
      (set mask (logior mask (ash mask 8)))
      (set mask (logior mask (ash mask 16)))
      (set mask (logior mask (ash mask 32)))
      (set mask (logior mask (ash mask 64)))
      (let* ((w (- 128 (width (lognot mask 128))))
             (pieces (let ((count 8))
                       (nexpand-left (lambda (val)
                                       (if (minusp (dec count))
                                         (unless (zerop val)
                                           (throwf 'eval-error
                                                   "str-in6addr-net: \
                                                   \ ~a out of range \
                                                   \ for IPv6 address"
                                                   addr))
                                           (cons (logand val #xFFFF)
                                                 (ash val -16))))
                                       addr)))
             (cand-prefix [pieces 0..(trunc (+ w 15) 16)])
             (prefix (if (search cand-prefix '(0 0)) pieces cand-prefix)))
        `@(sys:in6addr-condensed-text prefix)/@(or width w)`))))

(defplace (sock-peer sock) body
  (getter setter
    ^(macrolet ((,getter () ^(sock-peer ',',sock))
                (,setter (val) ^(sock-set-peer ,',sock ,val)))
       ,body)))