#!/bin/bash

set -e

msg() {
  >&2 echo "garlicd: $@"
} 

if [ -z "$1" ]; then
  >&2 echo "usage: garlicd <bscpkgs directory>"
  exit 1
fi

export PATH="@extraPath@:$PATH"

bscpkgsdir=$(readlink -f "$1")

garlic_sandbox=$(nix show-config |\
  grep extra-sandbox-paths |\
  grep -o '/garlic=[^ ]*' || true)

if [ -z "$garlic_sandbox" ]; then
  msg "Missing extra-sandbox-paths /garlic mountpoint"
  msg "Check the ~/.config/nix/nix.conf file"
  exit 1
fi

mountdir_rel=$(echo "$garlic_sandbox" | sed 's@^/garlic=@@g')
mountdir=$(readlink -f "$mountdir_rel")
run="$mountdir/run"
completed="$mountdir/completed"

for fifo in "$run" "$completed"; do
  if [ ! -e "$fifo" ]; then
    mkfifo "$fifo"
    # FIXME: Use more resctrictive permissions
    chmod 666 "$fifo"
  fi
done

cd "$bscpkgsdir"

while true; do
  msg "Waiting for experiments ..."
  read -r tre < "$run"

  msg "Attempting to run: $tre"
  msg "Copying files to MN4..."
  # It fails if the user doesn't have nix-store, but is already copied
  # with the post build hook
  nix copy --to ssh://mn1 $tre || true

  msg "Launching the experiment..."
  garlic -R "$tre"

  msg "Fetching results..."
  results=$(garlic -Fv "$tre")

  msg "results=\"$results\""
  
  msg "Searching drv..."
  drv=$(nix-store -q --deriver $results)

  msg "drv = \"$drv\""
  if [ -z "$drv" ]; then
    msg "Something failed, drv is empty. Check the logs."
    exit 1
  fi

  echo -n "$drv" >> "$completed"
  msg "execution completed :-)"
done