#! /bin/sh
# vim:set fdm=marker:
set -euf

Server=htgen

## htgen --serve {{{
case $# in
  (1)
    case "$1" in
      (--serve)
        HTGEN_HOST=${HTGEN_HOST-0.0.0.0}
        HTGEN_PORT=${HTGEN_PORT-42380}
        HTGEN_SCRIPT=${HTGEN_SCRIPT-:}
        TCPSERVER_OPTS='-c 423 -t 2 -D'
        echo "#### $Server $HTGEN_HOST:$HTGEN_PORT" >&2
        exec tcpserver $TCPSERVER_OPTS "$HTGEN_HOST" "$HTGEN_PORT" "$0"
    esac
esac
## }}}

## reply_404 {{{
reply_404() {
  cat<<EOF
HTTP/1.0 404 Not Found
Content-Type: text/plain; charset=UTF-8
Server: $Server
Connection: close
Content-Length: 0

EOF
}
## }}}

## date. {{{
#date=`date --rfc-3339=ns`
date="`date '+%Y-%m-%d %H:%M:%S'`"
cat>&2<<EOF

# ${TCPREMOTEHOST-}[$TCPREMOTEIP]:$TCPREMOTEPORT connected at $date over $PROTO
EOF
## }}}
## Parse Request-Line. {{{
read Request_Line
eval "$(echo "$Request_Line" | sed -rn '
  s^([a-zA-Z]+) ([a-zA-Z0-9?&+*/.-]+) HTTP/([0-9]+\.[0-9]+)\r$\
     Request_Line="&"\
     Method="\1"\
     Request_URI="\2"\
     HTTP_Version="\3"\
   p;t;i\
     Request_Line= # invalid request
')"
#echo "Request-Line: $Request_Line" >&2
# cat>&2<<EOF
# Request_Line='$Request_Line'
# Method='$Method'
# Request_URI='$Request_URI'
# HTTP_Version='$HTTP_Version'
# EOF

## debug
cat>&2<<EOF
$Method $Request_URI HTTP/$HTTP_Version
EOF
## }}}
## Parse HTTP-Headers. {{{
# TODO support https://tools.ietf.org/html/rfc7230#section-3.2.4, obs-fold?
# TODO allow headers to appear multiple times
k=
v=
while read -r line; do
  line=${line%
}
  case $line in
    '')
      break
      ;;
    [A-Za-z][0-9A-Za-z-]*:*)
      k=${line%%:*}
      k=${k//-/_}
      k=${k,,}
      k=req_$k
      v=${line#*: }
      v=${v## }
      printf '%s=%s\n' "$k" "$v" >&2
      export "$k=$v"
      ;;
  esac
done
unset k v

echo >&2
## }}}

eval "$HTGEN_SCRIPT"

reply_404