#!/usr/bin/python
# -*- coding: utf-8 -*-

# Orthanc - A Lightweight, RESTful DICOM Store
# Copyright (C) 2012-2014 Medical Physics Department, CHU of Liege,
# Belgium
#
# This program is free software: you can redistribute it and/or
# modify it under the terms of the GNU 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
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.


import argparse
import time
import os
import os.path
import RestToolbox

parser = argparse.ArgumentParser(
    description = 'Automated classification of DICOM files from Orthanc.',
    formatter_class = argparse.ArgumentDefaultsHelpFormatter)

parser.add_argument('--host', default = 'localhost',
                    help = 'The host address that runs Orthanc')
parser.add_argument('--port', type = int, default = '8042',
                    help = 'The port number to which Orthanc is listening for the REST API')
parser.add_argument('--target', default = 'OrthancFiles',
                    help = 'The target directory where to store the DICOM files')
parser.add_argument('--all', action = 'store_true',
                    help = 'Replay the entire history on startup (disabled by default)')
parser.set_defaults(all = False)
parser.add_argument('--remove', action = 'store_true',
                    help = 'Remove DICOM files from Orthanc once classified (disabled by default)')
parser.set_defaults(remove = False)


# Parse the arguments
args = parser.parse_args()
URL = 'http://%s:%d' % (args.host, args.port)
print 'Connecting to Orthanc on address: %s' % URL

# Compute the starting point for the changes loop
if args.all:
    current = 0
else:
    current = RestToolbox.DoGet(URL + '/changes?last')['Last']

# Polling loop using the "changes" API of Orthanc, waiting for the
# incoming of new DICOM files
while True:
    r = RestToolbox.DoGet(URL + '/changes', {
            'since' : current,
            'limit' : 4   # Retrieve at most 4 changes at once
            })

    for change in r['Changes']:
        # We are only interested interested in the arrival of new instances
        if change['ChangeType'] == 'NewInstance':
            # Extract the patient, study, series and instance information
            instance = RestToolbox.DoGet('%s/instances/%s' % (URL, change['ID']))
            series = RestToolbox.DoGet('%s/series/%s' % (URL, instance['ParentSeries']))
            study = RestToolbox.DoGet('%s/studies/%s' % (URL, series['ParentStudy']))
            patient = RestToolbox.DoGet('%s/patients/%s' % (URL, study['ParentPatient']))

            # Construct a target path
            a = '%s - %s' % (patient['MainDicomTags']['PatientID'], 
                             patient['MainDicomTags']['PatientName'])
            b = study['MainDicomTags']['StudyDescription']
            c = '%s - %s' % (series['MainDicomTags']['Modality'],
                             series['MainDicomTags']['SeriesDescription'])
            d = '%s.dcm' % instance['MainDicomTags']['SOPInstanceUID']

            p = os.path.join(
                args.target,
                a.encode('ascii', 'ignore'),
                b.encode('ascii', 'ignore'),
                c.encode('ascii', 'ignore')
                )

            f = os.path.join(p, d.encode('ascii', 'ignore'))
                             

            # Copy the DICOM file to the target path
            print('Writing new DICOM file: %s' % f)

            try:
                os.makedirs(p)
            except:
                # Already existing directory, ignore the error
                pass

            dcm = RestToolbox.DoGet('%s/instances/%s/file' % (URL, change['ID']))
            with open(f, 'wb') as g:
                g.write(dcm)
            
            # If requested, remove the instance once it has been copied
            if args.remove:
                RestToolbox.DoDelete('%s/instances/%s' % (URL, change['ID']))

    current = r['Last']

    if r['Done']:
        print "Everything has been processed: Waiting..."
        time.sleep(1)