#!/usr/bin/python
usage="""\
This script installs spack in a new prefix.
To use: cd to the prefix and execute this script.
"""
import os
import sys
import getpass
from subprocess import check_call

def escape(s):
    """Returns a TTY escape code if stdout is a tty, otherwise empty string"""
    if sys.stdout.isatty():
        return "\033[{}m".format(s)
    return ''

def bold(n):
    return escape("1;{}".format(n))

blue   = bold(34)
red    = bold(31)
white  = bold(39)
reset  = escape(0)

def msg(msg):
    print "{}==>{} {}{}".format(blue, white, str(msg), reset)

def error(msg):
    print "{}==> ERROR: {} {}{}".format(red, white, str(msg), reset)
    sys.exit(1)


user = getpass.getuser()
if not user:
    error("Couldn't determine username!")

spack_repo  = "https://%s@lc.llnl.gov/stash/scm/SCALE/spack.git" % user
msg("Fetching spack from %s" % spack_repo)

prefix = os.getcwd()

if os.path.exists(".git"):
    error("There already seems to be a git repository here.")
if os.listdir("."):
    error("There is already something in this directory.")

msg("This script will install:")
print "    %s/bin/spack" % prefix
print "    %s/lib/spack/..." % prefix

check_call(["git", "init", "--shared", "-q"])
check_call(["git", "remote", "add", "origin", spack_repo])
check_call(["git", "fetch", "origin", "master:refs/remotes/origin/master", "-n", "-q"])
check_call(["git", "reset", "--hard", "origin/master", "-q"])

msg("Successfully installed spack in %s" % prefix)