#!/usr/bin/env bash
#
# Summary: Create a Python virtualenv using the pyenv-virtualenv plugin
#
# Usage: pyenv virtualenv [-v|--verbose] [VIRTUALENV_OPTIONS] <version> <virtualenv-name>
#
#   -v/--verbose     Verbose mode: print compilation status to stdout
#

PYENV_VIRTUALENV_VERSION="20130218"

set -e
[ -n "$PYENV_DEBUG" ] && set -x

# Provide pyenv completions
if [ "$1" = "--complete" ]; then
  exec pyenv-versions --bare
fi

if [ -z "$PYENV_ROOT" ]; then
  PYENV_ROOT="${HOME}/.pyenv"
fi

# Define library functions
parse_options() {
  OPTIONS=()
  ARGUMENTS=()
  local arg option index

  for arg in "$@"; do
    if [ "${arg:0:1}" = "-" ]; then
      if [ "${arg:1:1}" = "-" ]; then
        OPTIONS[${#OPTIONS[*]}]="${arg:2}"
      else
        index=1
        while option="${arg:$index:1}"; do
          [ -n "$option" ] || break
          OPTIONS[${#OPTIONS[*]}]="$option"
          index=$(($index+1))
        done
      fi
    else
      ARGUMENTS[${#ARGUMENTS[*]}]="$arg"
    fi
  done
}

resolve_link() {
  $(type -p greadlink readlink | head -1) "$1"
}

abs_dirname() {
  local cwd="$(pwd)"
  local path="$1"

  while [ -n "$path" ]; do
    cd "${path%/*}"
    local name="${path##*/}"
    path="$(resolve_link "$name" || true)"
  done

  pwd
  cd "$cwd"
}

version() {
  echo "pyenv-virtualenv ${PYENV_VIRTUALENV_VERSION}"
}

usage() {
  # We can remove the sed fallback once pyenv 0.2.0 is widely available.
  pyenv-help virtualenv 2>/dev/null || sed -ne '/^#/!q;s/.//;s/.//;1,4d;p' < "$0"
  [ -z "$1" ] || exit "$1"
}

unset VERBOSE
PYENV_VIRTUALENV_ROOT="$(abs_dirname "$0")/.."
VIRTUALENV_OPTIONS=()

parse_options "$@"
for option in "${OPTIONS[@]}"; do
  case "$option" in
  "h" | "help" )
    usage 0
    ;;
  "v" | "verbose" )
    VERBOSE="-v"
    ;;
  "version" )
    version
    exit 0
    ;;
  * )
    VIRTUALENV_OPTIONS[${#VIRTUALENV_OPTIONS[*]}]="--$option"
    ;;
  esac
done

VERSION_NAME="${ARGUMENTS[0]}"
[ -n "$VERSION_NAME" ] || usage 1

for script in $(pyenv-hooks virtualenv); do
  source "$script"
done

PYTHON_BIN=$(PYENV_VERSION="${VERSION_NAME}" pyenv-which python)
if [ ! -x "${PYTHON_BIN}" ]; then
  echo "pyenv-virtualenv: could not obtain python executable: ${PYTHON_BIN}" >&2
  exit 1
fi

# find canonical name of python executable.
# virtualenv will create "bin/python" executable as same name as its bootstraped python.
if [ -L "${PYTHON_BIN}" ]; then
  while [ -L "${PYTHON_BIN}" ]; do # retrieve symlinks
    PYTHON_BIN="$(dirname "${PYTHON_BIN}")/$(resolve_link "${PYTHON_BIN}")"
  done
else
# python 2.6 and older don't have "bin/python" as symlink.
# so we must traverse files like "bin/python*" to obtain canonical name.
  for python in ${PYENV_ROOT}/versions/${VERSION_NAME}/bin/python*; do
    if ( basename "$python" | grep '^python[0-9][0-9]*\.[0-9][0-9]*$' && cmp "$PYTHON_BIN" "$python" ) >/dev/null; then
      PYTHON_BIN="${python}"
      break
    fi
  done
fi

VIRTUALENV_NAME="${ARGUMENTS[1]##*/}"
VIRTUALENV_PATH="${PYENV_ROOT}/versions/${VIRTUALENV_NAME}"

# create virtualenv
VIRTUALENV="${PYENV_VIRTUALENV_ROOT}/libexec/pyenv-virtualenv/virtualenv.py"
[ -f "${VIRTUALENV}" ] || VIRTUALENV="${PYENV_VIRTUALENV_ROOT}/python-libexec/virtualenv.py" # backward compatibility before v20130218
[ -f "${VIRTUALENV}" ] || VIRTUALENV="${PYENV_VIRTUALENV_ROOT}/libexec/virtualenv.py"
"${PYTHON_BIN}" "${VIRTUALENV}" "${VIRTUALENV_OPTIONS[@]}" "${VIRTUALENV_PATH}"

# create symlink of `python' bound for actual executable
if [ ! -f "$VIRTUALENV_PYTHON_BIN" ]; then
  if [ -f "${VIRTUALENV_PATH}/bin/$(basename "${PYTHON_BIN}")" ]; then
    {
      cd ${VIRTUALENV_PATH}/bin
      ln -fs "$(basename "${PYTHON_BIN}")" python
    }
  fi
fi

pyenv-rehash