#!/usr/bin/env bash
shopt -s extglob
shopt -s nullglob

# This is necessary since this script is sometimes sourced from
# subshells that don't have the variables from bin/compile.
# Remove this once we no longer wrap all the things in `sub_env`.
BIN_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
ROOT_DIR=$(dirname "${BIN_DIR}")
# shellcheck source=vendor/buildpack-stdlib_v8.sh
source "${ROOT_DIR}/vendor/buildpack-stdlib_v8.sh"

if [ "$(uname)" == Darwin ]; then
    sed() { command sed -l "$@"; }
else
    sed() { command sed -u "$@"; }
fi

# Syntax sugar.
indent() {
  sed "s/^/       /"
}


# Clean up pip output
cleanup() {
  sed -e 's/\.\.\.\+/.../g' | sed -e '/already satisfied/Id' | sed -e '/No files were found to uninstall/Id' | sed -e '/Overwriting/Id' | sed -e '/python executable/Id' | sed -e '/no previously-included files/Id'
}

# Buildpack Steps.
puts-step() {
  echo "-----> $*"
}

# Buildpack Warnings.
puts-warn() {
  echo " !     $*"
}

# Does some serious copying.
deep-cp() {
  declare source="$1" target="$2"

  mkdir -p "$target"

  # cp doesn't like being called without source params,
  # so make sure they expand to something first.
  # subshell to avoid surprising caller with shopts.
  (
    shopt -s nullglob dotglob
    set -- "$source"/!(tmp|.|..)
    [[ $# == 0 ]] || cp -a "$@" "$target"
  )
}


# Measure the size of the Python installation.
measure-size() {
  echo "$(du -s .heroku/python 2>/dev/null || echo 0) | awk '{print $1}')"
}

# Python version operator >
version_gt() {
  test "$(printf '%s\n' "$@" | sort -V | head -n 1)" != "$1";
}

# Python verison operator >=
version_gte() {
  if [ "$1" == "$2" ]; then
    return 0
  fi

  version_gt "$1" "$2"
}

# Check if Python 2
python2_check() {
  VERSION="$1"

  version_gte "$VERSION" "python-2.7.0" && version_gt "python-3.0.0" "$VERSION"
}

# Check if Python 3
python3_check() {
  VERSION="$1"

  version_gte "$VERSION" "python-3.0.0" && version_gt "python-4.0.0" "$VERSION"
}

# Check if Python version needs to install SQLite3
python_sqlite3_check() {
  VERSION="$1"
  MIN_PYTHON_3="python-3.5.6"
  MIN_PYTHON_2="python-2.7.15"

  ( python2_check "$VERSION" && version_gte "$VERSION" "$MIN_PYTHON_2" ) \
    || ( python3_check "$VERSION" && version_gte "$VERSION" "$MIN_PYTHON_3" )
}

is_module_available() {
  # Returns 0 is the specified module exists, otherwise returns 1.
  # Uses pkgutil rather than pkg_resources or pip's CLI, since pkgutil exists
  # in the stdlib, and doesn't depend on the choice of package manager.
  local module_name="${1}"
  python -c "import sys, pkgutil; sys.exit(0 if pkgutil.find_loader('${module_name}') else 1)"
}