# -*- makefile -*-
## -----------------------------------------------------------------------
# Copyright 2017-2023 Open Networking Foundation (ONF) and the ONF Contributors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
## -----------------------------------------------------------------------

$(if $(DEBUG),$(warning ENTER))

##-------------------##
##---]  GLOBALS  [---##
##-------------------##
.PHONY: venv

##------------------##
##---]  LOCALS  [---##
##------------------##
venv-name            ?= .venv#                            # default install directory
venv-abs-path        := $(PWD)/$(venv-name)

venv-activate-script := $(venv-name)/bin/activate#        # dependency

# Intent: activate= is a macro for accessing the virtualenv activation script#
#  Usage: $(activate) && python
activate             ?= set +u && source $(venv-activate-script) && set -u

## -----------------------------------------------------------------------
## Intent: Activate script path dependency
## Usage:
##    o place on the right side of colon as a target dependency
##    o When the script does not exist install the virtual env and display.
## -----------------------------------------------------------------------
$(venv-activate-script):
	@echo
	@echo "============================="
	@echo "Installing python virtual env"
	@echo "============================="
	virtualenv -p python3 $(venv-name)
	$(activate) && python -m pip install --upgrade pip
	$(activate) && pip install --upgrade setuptools
	$(activate) && { [[ -r requirements.txt ]] && python -m pip install -r requirements.txt; }
	$(activate) && python --version

## -----------------------------------------------------------------------
## Intent: Explicit named installer target w/o dependencies.
##         Makefile targets should depend on venv-activate-script.
## -----------------------------------------------------------------------
venv: $(venv-activate-script)

## -----------------------------------------------------------------------
## Intent: Revert installation to a clean checkout
## -----------------------------------------------------------------------
sterile :: clean
	$(RM) -r "$(venv-abs-path)"

## -----------------------------------------------------------------------
## -----------------------------------------------------------------------
help ::
	@echo
	@echo '[VIRTUAL ENV]'
	@echo '  venv                Create a python virtual environment'
	@echo '    venv-name=        Subdir name for virtualenv install'
	@echo '  venv-activate-script         make macro name'
	@echo '      $$(target) dependency    install python virtualenv'
	@echo '      source $$(macro) && cmd  configure env and run cmd'

$(if $(DEBUG),$(warning LEAVE))

# [EOF]