#!/usr/local/plan9/bin/rc
# 2017/08/06 update
# 2021/07/13 update, added -e option

# edit might be useless for the OS except MacOS
# TextEdit.app of MacOS is too annoying
# so I must execute
#	xattr -c file
# in prior to open the file


rfork e
PATH=/usr/local/plan9/bin:$PATH

usage='usage: edit [-e editor] [file]'
# on Mac use "open" for editor if you don't want EDITOR value below

wd=`{pwd}
os=`{uname}

fn  owner {
   ls -l $1 | awk '{print $4}'
}

fn med {a=(){
  # usage: med file
  a=`{xattr $1}	# extended attribute
  if(~ $a ?*)
    xattr -c $1 # maybe better
    #xattr -d $a $1
  open -a $EDITOR $1 || echo $usage
  # back ground job. don't rm $1
}}

fn med2 {a=(){
  # usage: med2 file
  $EDITOR $1 &
}}

fn netcp {
  # to be used for copy back
  u=uuidgen
  cp $1 $2-$u
  if(~ $status ?*){
    echo 'could not cp from',$1,'to',$2-$u
    exit
  }
  mv $2-$u $1
  if(~ $status ?*){
    echo 'netcp failed',$1,$2
    exit
  }
}

fn ided {b=() d=(){ # indirect edit in $T
  # usage: ided file
  # the file is absolute path
  b=`{basename $1}
  d=`{basename -d $1}
  if(! test -e $T$d)
    mkdir -p $T$d
  cp -X $1 $T$1
  # -X is Mac special, which means "Do not copy Extended Attributes"
  $EDIT $T$1
}}

fn dir1 { echo $1 | awk -F / '{print $2}' }
  # usage: dir1 path
  # dir1 returns the first element of absolute path
  # dir1 /aaa/bbb --> aaa
  # dir1 aaa/bbb --> bbb

fn confirm {a=(){
  echo $1'?(y/n)' >[1=2]
  while(! ~ $a y n)
    a=`{read}
  echo $a
}}

T=$home/tmp/edit # working directory for edit.
# $T is automatically created, if absent, with chmod 0700
if(! test -d $T){
  mkdir -p $T
  chmod 0700 $T
}

switch($os){
case Darwin
  atom = /Applications/Atom.app
  texshop=/Applications/TeX/TeXShop.app/Contents/MacOS/TeXShop
  itext=/Applications/'iText Express.app'
  textedit=/Applications/TextEdit.app	# too restrictive, but simple
  mi=/Applications/mi.app
  xcode=/Applications/Xcode.app	# too big!
  EDITORLIST=(textedit atom mi itext texshop xcode) # used for usage
  EDITOR=mi
  EDIT=med	# med is defined in this file
case Linux FreeBSD
  # nano is preinstalled
  EDITORLIST=(nano jove)
  EDITOR=jove	# small editor with emacs like key binding
  EDIT=med2
case *
  echo unsuppoted OS
  exit
}

while(~ $1 -*){
switch($1){
case -e
  shift
  EDITOR=$1
  shift
case -*
  echo $usage
  exit
}}

if(! ~ $EDITOR $EDITORLIST){
  echo 'select from:' $EDITORLIST
  exit
}

if(~ $#* 0){
  # usage1: edit
  # usage2: command | edit
  # second case will work only for GUI based editor such as TextEdit.app
  t=$pid # identifier
  f=$T/$t
  if(u test -t 0) # input is a tty not a pipe
    touch $f
  if not
    cat > $f
  p=`{echo -n NXNAXAMXMEXE | tr X '\010'}
  if(grep -s $p $f){ # we guess man output
    cat $f | col -b  > $f^m
    mv $f^m $f
  }
  $EDIT $f
  #rm $f
  exit
}

if(! test -e $1){
  a=`{confirm create}
  if(~ $a y Y)
    touch $1
  if not
    exit
}

e=$1
if(! ~ $e /*)
  e=$wd/$e
ifs='
' e=`{cleanname $e}
# NB: then $e is the absolute path of $1
# $T/$e is wrong. use $T$e

# we assume names for server begins with /n
# maybe better: if(! ~ `{owner $e} `{whoami})

if(~ `{dir1 $e} n || ~ `{owner $e} root){
  ided $e
  a=`{confirm save}
  if(~ $a y Y){
    if(~ `{dir1 $e} n)
      cp -X $T$e $e
    if not
      sudo cp -X $T$e $e
  }
  exit
}

$EDIT $e