#!/usr/bin/env python

import sys
import os
import os.path
import signal
import resource
import subprocess

hackenv = os.path.join(os.path.realpath(os.environ['HACKENV']), '')
hackenv_hg = os.path.join(hackenv, '.hg', '')
hackenv_tmp = os.path.join(hackenv, 'tmp', '')
url = sys.argv[1]
output = None

if not url:
    sys.stdout.write('Usage:  fetch URL  or  fetch OUTPUT_FILE URL  (no spaces or quoting in OUTPUT_FILE)')
    sys.exit(1)

parts = url.split(None, 1)
if len(parts) == 2:
    output, url = parts

cmd = ['wget', '-nv']
if output is not None:
    if output.startswith('/hackenv/'):
        output = os.path.join(hackenv, output[9:])
    else:
        output = os.path.join(hackenv_tmp, output)
    real_output = os.path.realpath(output)
    if (os.path.commonprefix([hackenv, real_output]) != hackenv
        or os.path.commonprefix([hackenv_hg, real_output]) == hackenv_hg):
        sys.stdout.write('In another world: ' + output)
        sys.exit(1)
    if os.path.isdir(real_output):
        sys.stdout.write("That's a directory: " + output)
        sys.exit(1)
    cmd.extend(['-O', real_output])
cmd.extend(['--', url])

resource.setrlimit(resource.RLIMIT_FSIZE, (10*1024*1024, 10*1024*1024))
signal.alarm(30)
status = subprocess.Popen(
    cmd,
    stdout=subprocess.PIPE,
    stderr=subprocess.STDOUT,
    cwd=hackenv_tmp).communicate()[0]
if output is not None:
    status = status.replace(hackenv, '/hackenv/', 1)
sys.stdout.write(status)