source $BIN_DIR/utils

PYTHON_VERSION=''
if [ -f runtime.txt ]; then
  PYTHON_VERSION=$(cat runtime.txt)
fi
PYTHON_VERSION=$($BUILDPACK_PATH/bin/steps/libs/version.rb $BUILDPACK_PATH/manifest.yml $PYTHON_VERSION)
PYTHON_DIR=$DEPS_DIR/$DEPS_IDX/python

# Install Python.
if [ -f $CACHE_DIR/python-stack ]; then
  if [ ! $(cat $CACHE_DIR/python-stack) = $CF_STACK ]; then
    rm -fr $PYTHON_DIR $CACHE_DIR/python-version $CACHE_DIR/python-stack $CACHE_DIR/vendor
    unset SKIP_INSTALL
  fi
fi
if [ -f $CACHE_DIR/python-version ]; then
  if [ ! $(cat $CACHE_DIR/python-version) = $PYTHON_VERSION ]; then
    puts-step "Found $(cat $CACHE_DIR/python-version), removing"
    rm -fr $PYTHON_DIR $CACHE_DIR/python-version $CACHE_DIR/python-stack $CACHE_DIR/vendor
  else
    SKIP_INSTALL=1
  fi
fi

if [ -z "${SKIP_INSTALL:-}" ]; then
  puts-step "Installing $PYTHON_VERSION"

  # Prepare destination directory.
  mkdir $PYTHON_DIR

  exit_code=0
  SHORT_PYTHON_VERSION=$(echo $PYTHON_VERSION | sed "s|python-||")
  filtered_url=$($BUILDPACK_PATH/compile-extensions/bin/download_dependency_by_name python $SHORT_PYTHON_VERSION /tmp/python.tar.gz) || exit_code=$?
  if [ $exit_code -ne 0 ]; then
    $BUILDPACK_PATH/compile-extensions/bin/recommend_dependency_by_name python $SHORT_PYTHON_VERSION
    exit 1
  fi
  $BUILDPACK_PATH/compile-extensions/bin/warn_if_newer_patch_by_name python $SHORT_PYTHON_VERSION

  tar zxvf /tmp/python.tar.gz -C $PYTHON_DIR &> /dev/null
  echo "Downloaded [$filtered_url]"
  FRESH_PYTHON=true
fi

# Link
pushd $DEPS_DIR/$DEPS_IDX/bin >/dev/null
  ln -s ../python/bin/* .
popd >/dev/null

pushd $DEPS_DIR/$DEPS_IDX/lib >/dev/null
  ln -s ../python/lib/* .
popd >/dev/null

# Record for future reference.
echo $PYTHON_VERSION > "$CACHE_DIR/python-version"
echo $CF_STACK > "$CACHE_DIR/python-stack"

hash -r

PIP_VERSION=$($BUILDPACK_PATH/compile-extensions/bin/default_version_for $BUILDPACK_PATH/manifest.yml pip)
SETUPTOOLS_VERSION=$($BUILDPACK_PATH/compile-extensions/bin/default_version_for $BUILDPACK_PATH/manifest.yml setuptools)

# If Pip isn't up to date:
if [ -n "${FRESH_PYTHON:-}" ] || [[ ! $(pip --version) == *$PIP_VERSION* ]]; then
  TMPTARDIR=$(mktemp -d)

  # Prepare it for the real world
  puts-step "Installing Setuptools ($SETUPTOOLS_VERSION)"
  filtered_url=$($BUILDPACK_PATH/compile-extensions/bin/download_dependency_by_name setuptools $SETUPTOOLS_VERSION /tmp/setuptools.tgz)
  echo "Downloaded [$filtered_url]"

  tar zxf /tmp/setuptools.tgz -C $TMPTARDIR

  pushd $TMPTARDIR/setuptools-$SETUPTOOLS_VERSION/ >/dev/null
    python setup.py install --prefix=$DEPS_DIR/$DEPS_IDX/python &> /dev/null
  popd >/dev/null

  puts-step "Installing Pip ($PIP_VERSION)"
  filtered_url=$($BUILDPACK_PATH/compile-extensions/bin/download_dependency_by_name pip $PIP_VERSION /tmp/pip.tgz)
  echo "Downloaded [$filtered_url]"
  tar zxf /tmp/pip.tgz -C $TMPTARDIR

  pushd $TMPTARDIR/pip-$PIP_VERSION/ >/dev/null
    python setup.py install --prefix=$DEPS_DIR/$DEPS_IDX/python &> /dev/null
  popd >/dev/null

  pushd $DEPS_DIR/$DEPS_IDX/bin >/dev/null
    ln -sf ../python/bin/* .
  popd >/dev/null

  pushd $DEPS_DIR/$DEPS_IDX/lib >/dev/null
    ln -sf ../python/lib/* .
  popd >/dev/null
fi

pushd $DEPS_DIR/$DEPS_IDX/include >/dev/null
  ln -sf ../python/include/* .
popd >/dev/null
pushd $DEPS_DIR/$DEPS_IDX/pkgconfig >/dev/null
  ln -sf ../python/lib/pkgconfig/* .
popd >/dev/null

hash -r