#! /bin/sh
set -euf


# TODO Cache-Control [RFC 2616, Section 14.9]
# TODO Accept-Encoding: gzip,deflate
# TODO Keep-Alive: 300
# TODO Connection: keep-alive

Server='htgen'
Request="$(sed 's/\r$//;/^$/q')"
date="`date '+%Y-%m-%d %H:%M:%S'`"

##
## Parse request.
##
Request_Line=
eval "$(echo "$Request" | sed -rn '
  1{s^([a-zA-Z]+) ([a-zA-Z0-9?&+*/.-]+) HTTP/([0-9]+\.[0-9]+)$\
      Request_Line="&"\
      Method="\1"\
      Request_URI="\2"\
      HTTP_Version="\3"\
    p;t;i\
      Request_Line= # invalid request
    q
  }
  s/^Host: ([a-zA-Z0-9?+&/:.-]+)$/Host="\1"/p
')"

##
## Log request.
##
# TODO real logging
cat>&2<<EOF

## $date, $TCPREMOTEIP:$TCPREMOTEPORT $Request_Line
$Request
EOF

##
## Handle request.
##
if test -z "$Request_Line" ; then
  echo "# FAIL"
  exit -23
fi >&2
  
# TODO Date: `date --utc`

case "$Host" in
  src.mine.nu:42380|src.mine.nu|vix|vix:42380|localhost:42380)
    case "${Method-Invalid-Request}" in
      GET|HEAD)
        case "$Request_URI" in
          /style5.css)
            body_type=file
            body=~/public_html$Request_URI
            cat<<EOF
HTTP/1.0 200 OK
Connection: close
Content-Length: `du -b $body | cut -f1`
Content-Type: text/css
Server: $Server

EOF
          ;;
          /favicon5.png|/favicon2.png)
            body_type=file
            body=~/public_html$Request_URI
            cat<<EOF
HTTP/1.0 200 OK
Connection: close
Content-Length: `du -b $body | cut -f1`
Content-Type: image/png
Server: $Server
Cache-Control: public

EOF
          ;;
          /|/index.html)
          # TODO 304 Not Modified
          # TODO better max-age(?)
          # TODO may we use more than one Cache-Control?
            body_type=file
            body=~/public_html/index.html
            cat<<EOF
HTTP/1.0 200 OK
Content-Type: text/html; charset=UTF-8
Server: $Server
Connection: close
Content-Length: `du -b $body | cut -f1`
Cache-Control: max-age=60

EOF
          ;;
          *)
            body_type=string
            body="404 Not found: $Request_URI"
            cat<<EOF
HTTP/1.0 404 Not Found
Content-Type: text/plain; charset=UTF-8
Server: $Server
Connection: close
Content-Length: ${#body}

EOF
          ;;
        esac
      ;;
      *) # Method
        body_type=string
        body="501 Not Implemented: $Method"
        cat<<EOF
HTTP/1.0 501 Not Implemented
Content-Type: text/plain; charset=UTF-8
Server: $Server
Connection: close
Content-Length: ${#body}
Cache-Control: public

EOF
      ;;
    esac
  ;;
  *) # Host
    body_type=string
    body="403 Forbidden"
    cat<<EOF
HTTP/1.1 403 Forbidden
Content-Type: text/plain; charset=UTF-8
Connection: close
Content-Length: ${#body}
Cache-Control: public

EOF
  ;;
esac

##
## Print message-body.
##
case "$Method" in
  GET)
    case "$body_type" in
      file) cat "$body" ;;
      string) echo -n "$body" ;;
    esac
  ;;
esac


# Success (mod transfer)
echo "# OK" >&2
exit