#!/bin/bash
#
# Simple installation shell script for Python packages.
#
# Usage:
#   pkginstall PAKPREFIX [PYPACKAGE]
#
# PAKPREFIX: prefix of the package as distributed in the tarball.
#
# PYPACKAGE: name of the Python package as it will end up installed.  If not
# given, it defaults to PAKPREFIX.
#

#-----------------------------------------------------------------------------
# Process command-line args
#
PAKPREFIX=$1
PYPACKAGE=${2:-$PAKPREFIX}

#-----------------------------------------------------------------------------
# Configure main variables
#
# Defaults for variables that the .cfg file may override.
PYTHON_DEFAULT=python
PREFIX_DEFAULT=$HOME/usr/local

# Read config file which may declare user values for these variables.
source ./pkginstall.cfg

# Set the variables we'll actually use, either from the config file or from our
# defaults.
PYTHON=${PYTHON-${PYTHON_DEFAULT}}
PREFIX=${PREFIX-${PREFIX_DEFAULT}}

#-----------------------------------------------------------------------------
# 'Main' code begins
#

# Find the actual python executable path
PYTHONX=$(which $PYTHON)
if [[ ! -x $PYTHONX ]]; then
    echo "ERROR: no python executable found at given path: $PYTHON"
    echo "Aborting."
    exit 1
fi    

# Python version information.  PYTHONV holds a versioned string used to build
# the site-packages path for the actual Python version we'll use.
PYVER=$($PYTHONX -ESV 2>&1)
PYVER_MINOR=${PYVER#Python }
PYVER_MAJOR=${PYVER_MINOR:0:3}
PYTHONV=python${PYVER_MAJOR}

# Set prefixes and other variables for the installation path.
SITEPKG=${PREFIX}/lib/${PYTHONV}/site-packages
SITEPKG64=${PREFIX}/lib64/${PYTHONV}/site-packages

# User diagnostics of current config
echo "Configuration:"
echo "  PYTHON   : $PYTHON"
echo "  PYTHONX  : $PYTHONX"
echo "  PREFIX   : $PREFIX"
echo "  SITEPKG  : $SITEPKG"
echo "  SITEPKG64: $SITEPKG64"

# Find tarball
tarball=$(ls *$PAKPREFIX*.tar.*)

if [[ -z $tarball ]]; then
    echo "ERROR: tarball not found for $PYPACKAGE"
    exit 1
fi

# Figure out the name of the directory and compression format to use to unpack
pakdir=$(echo $tarball | awk -F '.tar.' '{print $1}')
tarfmt=$(echo $tarball | awk -F '.tar.' '{print $2}')

if [[ $tarfmt == "gz" ]]; then
    tarflag="z"
else
    tarflag="j"
fi

# Unpack the tarball if needed
if [[ ! -d $pakdir ]]; then
    echo "Unpacking tarball: $tarball"
    tar -x -${tarflag} -f $tarball

        if [[ ! -d $pakdir ]]; then
	echo "Tarball $tarball unpacked to unexpected path, aborting"
	exit 1
    fi
fi

# Remove existing ${PYPACKAGE} to make sure the build doesn't pick up spurious
# things.  We don't touch the bin/ dir or anything else because it's hard to
# know what goes there in advance.  But this should prevent most serious
# problems.
rm -rf $SITEPKG/${PYPACKAGE}
rm -rf $SITEPKG/${PYPACKAGE}*.egg
rm -rf $SITEPKG/${PYPACKAGE}*.egg-info

rm -rf $SITEPKG64/${PYPACKAGE}
rm -rf $SITEPKG64/${PYPACKAGE}*.egg
rm -rf $SITEPKG64/${PYPACKAGE}*.egg-info

# Make/install phase

# Set python search path correctly
export PYTHONPATH=$SITEPKG:$SITEPKG64:$PYTHONPATH

# Ensure install dirs exist
mkdir -p $SITEPKG
mkdir -p $SITEPKG64

cd ${pakdir}
rm -rf build dist
$PYTHONX setup.py clean
time $PYTHONX setup.py install --prefix=$PREFIX