configure

#!/usr/bin/env bash
#
# Copyright (c) nexB Inc. and others. All rights reserved.
# SPDX-License-Identifier: Apache-2.0
# See http://www.apache.org/licenses/LICENSE-2.0 for the license text.
# See https://github.com/nexB/ for support or download.
# See https://aboutcode.org for more information about nexB OSS projects.
#

set -e
#set -x

################################
# A configuration script to set things up: 
# create a virtualenv and install or update thirdparty packages.
# Source this script for initial configuration
# Use configure --help for details
#
# This script will search for a virtualenv.pyz app in etc/thirdparty/virtualenv.pyz
# Otherwise it will download the latest from the VIRTUALENV_PYZ_URL default
################################
CLI_ARGS=$1

################################
# Defaults. Change these variables to customize this script
################################

# Requirement arguments passed to pip and used by default or with --dev.
REQUIREMENTS="--editable . --constraint requirements.txt"
DEV_REQUIREMENTS="--editable .[dev] --editable .[packages] --constraint requirements.txt --constraint requirements-dev.txt"

# where we create a virtualenv
VIRTUALENV_DIR=.

# Cleanable files and directories to delete with the --clean option
CLEANABLE="
    build
    bin
    lib
    lib64
    include
    tcl
    local
    .Python
    .eggs
    pip-selfcheck.json
    src/scancode_toolkit.egg-info
    src/scancode_toolkit_mini.egg-info
    SCANCODE_DEV_MODE
    man
    Scripts"


# extra  arguments passed to pip
PIP_EXTRA_ARGS=" "

# the URL to download virtualenv.pyz if needed
VIRTUALENV_PYZ_URL=https://bootstrap.pypa.io/virtualenv.pyz
################################


################################
# Current directory where this script lives
CFG_ROOT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
CFG_BIN_DIR=$CFG_ROOT_DIR/$VIRTUALENV_DIR/bin


################################
# scancode-specific: Thirdparty package locations and index handling
if [[ "$PYPI_LINKS" == "" ]]; then
    # Do we have thirdparty/files? use the mit.LICENSE as a proxy
    if [[ -f "$CFG_ROOT_DIR/thirdparty/mit.LICENSE" ]]; then
        LINKS=$CFG_ROOT_DIR/thirdparty
    else
        LINKS=https://thirdparty.aboutcode.org/pypi
    fi
else
    LINKS=$PYPI_LINKS
fi

PIP_EXTRA_ARGS="--no-index --find-links $LINKS"
################################


################################
# Set the quiet flag to empty if not defined 
if [[ "$CFG_QUIET" == "" ]]; then
    CFG_QUIET=" "
fi


################################
# find a proper Python to run
# Use environment variables or a file if available.
# Otherwise the latest Python by default.
if [[ "$PYTHON_EXECUTABLE" == "" ]]; then
    # check for a file named PYTHON_EXECUTABLE 
    if [ -f "$CFG_ROOT_DIR/PYTHON_EXECUTABLE" ]; then
        PYTHON_EXECUTABLE=$(cat "$CFG_ROOT_DIR/PYTHON_EXECUTABLE")
    else
        PYTHON_EXECUTABLE=python3
    fi
fi


################################
cli_help() {
    echo An initial configuration script
    echo "  usage: ./configure [options]"
    echo
    echo The default is to configure for regular use. Use --dev for development.
    echo
    echo The options are:
    echo " --clean: clean built and installed files and exit."
    echo " --dev:   configure the environment for development."
    echo " --help:  display this help message and exit."
    echo
    echo By default, the python interpreter version found in the path is used.
    echo Alternatively, the PYTHON_EXECUTABLE environment variable can be set to
    echo configure another Python executable interpreter to use. If this is not
    echo set, a file named PYTHON_EXECUTABLE containing a single line with the
    echo path of the Python executable to use will be checked last.
    set +e
    exit
}


clean() {
    # Remove cleanable file and directories and files from the root dir.
    echo "* Cleaning ..."
    for cln in $CLEANABLE;
        do rm -rf "${CFG_ROOT_DIR:?}/${cln:?}";
    done
    set +e
    exit
}


create_virtualenv() {
    # create a virtualenv for Python
    # Note: we do not use the bundled Python 3 "venv" because its behavior and
    # presence is not consistent across Linux distro and sometimes pip is not
    # included either by default. The virtualenv.pyz app cures all these issues.

    VENV_DIR="$1"
    if [ ! -f "$CFG_BIN_DIR/python" ]; then

        mkdir -p "$CFG_ROOT_DIR/$VENV_DIR"

        if [ -f "$CFG_ROOT_DIR/etc/thirdparty/virtualenv.pyz" ]; then
            VIRTUALENV_PYZ="$CFG_ROOT_DIR/etc/thirdparty/virtualenv.pyz"
        else
            VIRTUALENV_PYZ="$CFG_ROOT_DIR/$VENV_DIR/virtualenv.pyz"
            wget -O "$VIRTUALENV_PYZ" "$VIRTUALENV_PYZ_URL"
        fi

        $PYTHON_EXECUTABLE "$VIRTUALENV_PYZ" \
            --wheel embed --pip embed --setuptools embed \
            --seeder pip \
            --never-download \
            --no-periodic-update \
            --no-vcs-ignore \
            $CFG_QUIET \
            "$CFG_ROOT_DIR/$VENV_DIR"
    fi
}


install_packages() {
    # install requirements in virtualenv
    # note: --no-build-isolation means that pip/wheel/setuptools will not
    # be reinstalled a second time and reused from the virtualenv and this
    # speeds up the installation.
    # We always have the PEP517 build dependencies installed already.

    "$CFG_BIN_DIR/pip" install \
        --upgrade \
        --no-build-isolation \
        $CFG_QUIET \
        $PIP_EXTRA_ARGS \
        $1
}


################################
# Main command line entry point
CFG_DEV_MODE=0
CFG_REQUIREMENTS=$REQUIREMENTS

case "$CLI_ARGS" in
    --help)    cli_help;;
    --clean)   clean;;
    --dev)     CFG_REQUIREMENTS="$DEV_REQUIREMENTS" && CFG_DEV_MODE=1;;
esac

create_virtualenv "$VIRTUALENV_DIR"
install_packages "$CFG_REQUIREMENTS"
. "$CFG_BIN_DIR/activate"

################################
# scancode-specific: Setup development mode

if [[ "$CFG_DEV_MODE" == 1 ]]; then
    # Add development tag file to auto-regen license index on file changes
    touch "$CFG_ROOT_DIR/SCANCODE_DEV_MODE"
fi

set +e