#!/bin/sh

BASE_DIR="/var/nex"

send_error() {
  code="$1"
  message="$2"
  printf "HTTP/1.0 %s %s\r\nContent-Type: text/plain\r\nConnection: close\r\n\r\n%s %s\n" "$code" "$message" "$code" "$message"
  exit 0
}

IFS=' ' read -r method fullpath _
path="${fullpath%%[\?#]*}"
path_noslash="${path#/}"

CR=$(printf '\r')
while IFS= read -r line; do
  [ "$line" = "" ] || [ "$line" = "$CR" ] && break
done

[ "$method" != "GET" ] && send_error 405 "Method Not Allowed"
case "$path_noslash" in
  *..*) send_error 400 "Bad Request" ;;
esac

[ -z "$path_noslash" ] && path_noslash="index.html"
FILE="$BASE_DIR/$path_noslash"

case "$path" in
  */) FILE="${FILE%/}" ;;
esac

[ -f "$FILE" ] || send_error 404 "Not Found"

case "$path_noslash" in
  favicon.ico) mime="image/x-icon" ;;
  index.html) mime="text/html" ;;
  *) mime="text/plain" ;;
esac

printf "HTTP/1.0 200 OK\r\nContent-Type: %s\r\nConnection: close\r\n\r\n" "$mime"
cat "$FILE"
exit 0