SHELL = /bin/bash

REPOSITORY = https://github.com/pypa/virtualenv.git

check_env_vars:
ifdef OUTPUT_PATH
OUTPUT_PATH := ${OUTPUT_PATH}/python-virtualenv
else
	$(error OUTPUT_PATH is undefined)
endif

venv:
	python3 -m venv venv

venv-3.6:
	export PYENV_VERSION=3.6
	python3 -m venv venv

repository:
	git clone ${REPOSITORY} repository

20.25.0: check_env_vars venv repository
	source venv/bin/activate
	cd repository
	git checkout tags/$@
	pip install .[docs]
	cd docs
	mkdir --parents "${OUTPUT_PATH}"
	sphinx-build -b dirhtml . "${OUTPUT_PATH}/$@"

16.7.12: check_env_vars venv-3.6 repository
	source venv/bin/activate
	cd repository
	git checkout tags/$@
	pip install .[docs]
	cd docs
	mkdir --parents "${OUTPUT_PATH}"
	sphinx-build -b dirhtml . "${OUTPUT_PATH}/$@"

.ONESHELL:
.SUFFIXES:
.PHONY:
.DELETE_ON_ERROR: