# OCCAM - Digital Computational Archive and Curation Service
# Copyright (C) 2014-2016 wilkie
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# This is the init process for x86-64 linux environments running in Docker.

import sys
import json
import subprocess
import os

# Load object.json (the task manifest)

f = open("/home/occam/task/objects/0/task.json")
task = json.load(f)
f.close()

processes = []

i = 0
for process in task.get('running', []):
  # For each process, determine the environment and run the object
  for obj in process.get('process', []):
    i = i + 1
    if 'init' in obj:
      # Read run command if there is one
      pass

    if 'run' in obj and i == len(process.get('process', [])):
      # Read the environment variables and run the command
      env = obj['run'].get('env', {})
      command = obj['run'].get('command')

      # Link mounted items
      for link in obj['run'].get('link', []):
        dest = link.get('name')
        src = link.get('target')

        if not (src is None or dest is None):
          # Create intermediate paths
          try:
            os.makedirs(os.path.dirname(dest))
          except:
            pass

          # Create the symlink
          if not os.path.exists(dest):
            os.symlink(src, dest)

      if not command is None:
        if not isinstance(command, list):
          command = [command]

        if not command[0].strip().startswith("/"):
          # Make it refer to the volume of the object if a relative path
          command[0] = os.path.join(obj.get('paths', {}).get('volume'), command[0].strip())

        env["OCCAM_INDEX"] = str(obj.get('index'))

        if not "PATH" in env:
          env["PATH"] = "/usr/bin"
        else:
          env["PATH"] = "%s:/usr/bin" % env["PATH"]

        # this is the main running process, wait for it
        cwd = (obj.get('paths', {}).get('cwd'))
        try:
          p = subprocess.Popen(command, env = env, cwd = cwd)
          p.communicate()
        except OSError as e:
          if e.errno == 2:
            print >> sys.stderr, "Error %s: No such file or directory: %s" % (str(e.errno), " ".join(command))
          else:
            print >> sys.stderr, "OS Error %s" % (e.errno)