#! /bin/sh

STORE_DIR=/nix/store
PRIORITY=75
 COMPRESSI
KEY=/nix/var/nix/keys/id_nix_remote

hostname=/run/current-system/sw/bin/
KEYNAME=$($hostname/hostname)

nix=/run/current-system/sw/bin/
xz=/run/current-system/sw/bin/
bzip2=/run/current-system/sw/bin/
sed=/run/current-system/sw/bin/
openssl=/run/current-system/sw/bin/

export NIX_REMOTE=daemon

header(){
 echo "Content-Type: text/plain; charset=utf-8"
 echo 
}

clean_path() {
 $sed/sed -re "s@^$STORE_DIR/?@@" | xargs
}

storeq(){
 $nix/nix-store -q "$@"
}

sign(){
 sha256sum | sed -e 's/ .*//' | $openssl/openssl rsautl -sign -inkey "$@" | base64 -w 0
}

case "$QUERY_STRING" in 
 "")
  header
  echo "Hello, this is a dynamically-generated Nix binary cache"
  ;;
 /nix-cache-info)
  header
  echo "StoreDir: $STORE_DIR"
  echo "WantMassQuery: 0"
  echo "Priority: $PRIORITY"
  ;;
 *.narinfo)
  hash=${QUERY_STRING%.narinfo}
  hash=${hash#/}
  path="$(echo "$STORE_DIR/$hash-"* )"
  if [ -n "$path" ] && [ -e "$path" ]; then
   header
   info="$(
   echo "StorePath: $path"
   echo "URL: $(basename "$path").nar.$COMPRESSION"
   echo "Compression: $COMPRESSION"
   echo "NarHash: $(storeq --hash "$path")"
   echo "NarSize: $(storeq --size "$path")"
   echo "References: $(storeq --references "$path" | tac | clean_path )"
   echo "Deriver: $(storeq --deriver "$path" | clean_path )"
   echo "System: x86_64-linux"
   )"
   signature="$(echo "$info" | sign "$KEY")"

   echo "$info"
   echo "Signature: 1;$KEYNAME;$signature"

  else
   exit 1
  fi
  ;;
 *.nar.xz)
  path="$STORE_DIR${QUERY_STRING%.nar.xz}"
  if [ -n "$path" ] && [ -e "$path" ]; then
   header
   $nix/nix-store --dump "$path" | $xz/xz | cat
  else
   exit 1
  fi
  ;;
 *.nar.bzip2)
  path="$STORE_DIR${QUERY_STRING%.nar.bzip2}"
  echo "$path" >&2;
  if [ -n "$path" ] && [ -e "$path" ]; then
   header
   $nix/nix-store --dump "$path" | $bzip2/bzip2 | cat
  else
   exit 1
  fi
  ;;
esac