#!/usr/bin/env python

# Install.py tool to download, unpack, and point to the Eigen library
# used to automate the steps described in the README file in this dir

from __future__ import print_function
import sys,os,re,glob,subprocess,shutil
sys.path.append('..')
from install_helpers import fullpath,geturl,checkmd5sum
from argparse import ArgumentParser

parser = ArgumentParser(prog='Install.py',
                        description="LAMMPS library build wrapper script")

# settings

version = '3.3.7'
tarball = "eigen.tar.gz"

# known checksums for different Eigen versions. used to validate the download.
checksums = { \
              '3.3.4' : '1a47e78efe365a97de0c022d127607c3', \
              '3.3.5' : 'ee48cafede2f51fe33984ff5c9f48026', \
              '3.3.6' : 'd1be14064b50310b0eb2b49e402c64d7', \
              '3.3.7' : 'f2a417d083fe8ca4b8ed2bc613d20f07' \
}

# help message

help = """
Syntax from src dir: make lib-smd args="-b"
                 or: make lib-smd args="-p /usr/include/eigen3"

Syntax from lib dir: python Install.py -b
                 or: python Install.py -p /usr/include/eigen3"
                 or: python Install.py -v 3.3.4 -b

Example:

make lib-smd args="-b"   # download/build in default lib/smd/eigen-eigen-*
make lib-smd args="-p /usr/include/eigen3" # use existing Eigen installation in /usr/include/eigen3
"""

pgroup = parser.add_mutually_exclusive_group()
pgroup.add_argument("-b", "--build", action="store_true",
                    help="download and build the Eigen3 library")
pgroup.add_argument("-p", "--path",
                    help="specify folder of existing Eigen installation")
parser.add_argument("-v", "--version", default=version,
                    help="set version of Eigen to download and build (default: %s)" % version)

args = parser.parse_args()

# print help message and exit, if neither build nor path options are given
if args.build == False and not args.path:
  parser.print_help()
  sys.exit(help)

homepath = fullpath(".")
eigenpath = "%s/eigen3" % homepath

buildflag = args.build
pathflag = args.path != None
version = args.version

if pathflag:
  eigenpath = args.path
  if not os.path.isdir(eigenpath): sys.exit("Eigen path %s does not exist" % eigenpath)
  eigenpath = fullpath(eigenpath)

# download and unpack Eigen tarball
# use glob to find name of dir it unpacks to

if buildflag:
  print("Downloading Eigen ...")
  url = "http://bitbucket.org/eigen/eigen/get/%s.tar.gz" % version
  geturl(url,"%s/%s" % (homepath,tarball))

  # verify downloaded archive integrity via md5 checksum, if known.
  if version in checksums:
    print("checking version %s\n" % version)
    if not checkmd5sum(checksums[version],'%s/%s' % (homepath,tarball)):
      sys.exit("Checksum for Eigen library does not match")


  print("Cleaning up old folders ...")
  edir = glob.glob("%s/eigen-eigen-*" % homepath)
  edir.append(eigenpath)
  for one in edir:
    if os.path.isdir(one):
      shutil.rmtree(one)

  print("Unpacking Eigen tarball ...")
  cmd = 'cd "%s"; tar -xzvf %s' % (homepath,tarball)
  subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)
  edir = glob.glob("%s/eigen-eigen-*" % homepath)
  os.rename(edir[0],eigenpath)
  os.remove(tarball)

# create link in lib/smd to Eigen src dir

print("Creating link to Eigen include folder")
if os.path.isfile("includelink") or os.path.islink("includelink"):
  os.remove("includelink")
linkdir = eigenpath
cmd = 'ln -s "%s" includelink' % linkdir
subprocess.check_output(cmd,stderr=subprocess.STDOUT,shell=True)