#!/bin/bash
# Wrapper script for starting The Ur-Quan Masters

HTTPBASE="http://user.interface.org.nz/~lorne/uqm"

kill_uqm() {
  [ -d "/mnt/scratch/uqm" ] && rm -ir "/mnt/scratch/uqm"
}

run_uqm() {
  get_files
  echo "Running.." 
  echo "$BINPATH/uqm" --contentdir="$CONTENTPATH" "$@"
  "$BINPATH/uqm" --contentdir="$CONTENTPATH" "$@"
}

get_files() {
  CONTENT="$CONTENTPATH/packages/uqm-0.5.0-content.uqm" 
  BINARY="$BINPATH/uqm"
}

fetch_files() {
  get_files

  if [ ! -f "$CONTENT" ]; then
    CONTENTPATH="/mnt/scratch/uqm/share/uqm/content"
    get_files
    mkdir -p "$CONTENTPATH/packages"
    wget "$HTTPBASE/uqm-0.5.0-content.uqm" -O "$CONTENT"
    wget "$HTTPBASE/version" -O "$CONTENTPATH/version"
  fi

  if [ ! -f "$BINARY" ]; then
    echo $BINPATH
    BINPATH="/mnt/scratch/uqm/lib/uqm"
    get_files
    mkdir -p "$BINPATH"
    wget "$HTTPBASE/uqm" -O "$BINARY"
    chmod +x "$BINARY"
  fi
}

check_files() {
  echo Checking files

  [ -f "$CONTENT" ]  || echo "Content is missing ($CONTENT)"
  [ -f "$BINARY" ] || echo "Binary is missing ($BINARY)"
  [ ! -f "$BINARY" ] || [ ! -f "$CONTENT" ] && return -1

  expected_sum=$(mktemp uqm-sum.XXXXXX)
  m4  -DCONTENT="$CONTENT" -DBINARY="$BINARY"  > "$expected_sum" <<EOF
SHA1 (BINARY) = 6dd35542446b949b25ce8fa54edbd85e4d4131a2
SHA1 (CONTENT) = 68554522a3c084bd98366e15470fff8658cc16b0
EOF

  generated_sum=$(mktemp uqm-sum.XXXXXX)
  sha1 "$BINARY" "$CONTENT" > "$generated_sum"

  diff "$expected_sum" "$generated_sum" 2>&1 > /dev/null
  files_ok=$?

  if [ $files_ok -eq 0 ]; then
    echo "Files ok"
    result=0
  else
    echo "Files corrupt"
    result=-1

    echo "-- expected --"
    cat "$expected_sum"
    
    echo "-- actual --"
    cat "$generated_sum"
  fi

  rm "$expected_sum" "$generated_sum"
  return $result
}

find_uqm() {
  until [[ -z "$1" || ("$BINPATH" && "$CONTENTPATH") ]]; do
    if [[ -z "$BINPATH" && -x "$1/lib/uqm/uqm" ]]; then
      BINPATH="$1/lib/uqm"
    fi
    if [[ -z "$CONTENTPATH" && -d "$1/share/uqm/content" ]]; then
      CONTENTPATH="$1/share/uqm/content"
    fi
    shift
  done

  get_files
}


find_uqm "$HOME/.uqm" "/mnt/scratch/uqm"

case "$1" in
  fetch) fetch_files;;
  check) check_files;;
  run) check_files && run_uqm;;
  remove) kill_uqm;;
  voodoo) fetch_files && check_files && run_uqm && kill_uqm;;
  *) echo "$0 [ fetch | check | remove | run | voodoo ]";;
esac