#!/usr/bin/python

# Copyright (c) 2011 Christian Haselgrove
# BSD License: http://www.opensource.org/licenses/bsd-license.php

import sys
import os
import datetime
import dateutil.parser
import pyxnat

def command_line_error(msg):
    sys.stderr.write('%s: %s\n' % (progname, msg))
    sys.stderr.write('run %s with no arguments for usage\n' % progname)
    return

def write_rc(xnat_uri, resource_uri, files):
    fo = open('.xnat', 'w')
    fo.write('%s\n' % xnat_uri)
    fo.write('%s\n' % resource_uri)
    fo.write('%s\n' % datetime.datetime.now().strftime('%s'))
    for path in sorted(files):
        times = files[path]
        fo.write('%d %d %s\n' % (times['t_local'], times['t_remote'], path))
    fo.close()
    return

def read_rc():
    fo = open('.xnat')
    xnat_uri = fo.readline().strip()
    resource_uri = fo.readline().strip()
    last_updated = int(fo.readline().strip())
    files = {}
    for line in fo:
        (t_local, t_remote, path) = line.strip('\n').split(' ', 2)
        files[path] = {'t_remote': int(t_remote), 't_local': int(t_local)}
    fo.close()
    return (xnat_uri, resource_uri, last_updated, files)

def get_statuses(rc_files, resource):
    all_files = set(rc_files)
    remote_files = {}
    for f in resource.files():
        path = f.attributes()['path']
        t_remote = int(dateutil.parser.parse(f.last_modified()).strftime('%s'))
        remote_files[path] = t_remote
        all_files.add(path)
    local_files = {}
    for (dirpath, dirnames, filenames) in os.walk('.'):
        for filename in filenames:
            path = '%s/%s' % (dirpath, filename)
            # remote initial './'
            path = path[2:]
            if path == '.xnat':
                continue
            local_files[path] = int(os.stat(path).st_mtime)
            all_files.add(path)
    statuses = {}
    for path in sorted(all_files):
        if path not in rc_files:
            if path in local_files:
                local_code = 'N'
            else:
                local_code = ' '
        elif path not in local_files:
            local_code = 'D'
        elif local_files[path] == rc_files[path]['t_local']:
            local_code = 'U'
        elif local_files[path] > rc_files[path]['t_local']:
            local_code = 'M'
        else:
            local_code = '?'
        if path not in rc_files:
            if path in remote_files:
                remote_code = 'N'
            else:
                remote_code = ' '
        elif path not in remote_files:
            remote_code = 'D'
        elif remote_files[path] == rc_files[path]['t_remote']:
            remote_code = 'U'
        elif remote_files[path] > rc_files[path]['t_remote']:
            remote_code = 'M'
        else:
            remote_code = '?'
        statuses[path] = {'local': local_code, 'remote': remote_code}
    return statuses

def files_times(path, f):
    t_local = int(os.stat(path).st_mtime)
    t_remote = int(dateutil.parser.parse(f.last_modified()).strftime('%s'))
    return {'t_remote': t_remote, 't_local': t_local}

def connect(uri, user, password):
    if user is None:
        return pyxnat.Interface(uri, anonymous=True)
    return pyxnat.Interface(uri, user, password)

progname = os.path.basename(sys.argv.pop(0))

if not sys.argv:
    print
    print 'usage: %s [-s] command [command arguments ...]' % progname
    print
    print 'XNAT_USER and XNAT_PASSWORD must be defined in the environment'
    print
    print 'options are:'
    print
    print '    -s -- dry run (no actual changes)'
    print
    print 'commands and arguments are:'
    print
    print '    init [-c] <XNAT URI> <resource URI> -- associate with a resource'
    print '                                           use -c to create the resource'
    print
    print '    status -- give status since last sync'
    print
    print '    push [-f] -- (force) push changes to the server'
    print
    print '    pull [-f] -- (force) pull changes from the server'
    print
    print 'status lines are:'
    print
    print '    local_status remote_status path'
    print
    print 'status codes are:'
    print
    print '    N -- new'
    print '    U -- unchanged'
    print '    M -- modified'
    print '    D -- deleted'
    print '    ? -- unknown (modification time is before last sync)'
    print
    print 'pushes and pulls ignore files with exceptional conditions:'
    print
    print '    any "?" status'
    print '    N status matching U/M/D status'
    print '    no status matching any but N status'
    print
    print 'push/pull updates are performed as follows (source/dest/action):'
    print
    print '    N N update if forced'
    print '    N   update'
    print '    U M update if forced'
    print '    U D update if forced'
    print '    M U update'
    print '    M M update if forced'
    print '    M D update if forced'
    print '    D U update'
    print '    D M update if forced'
    print '    D D update'
    print
    sys.exit(1)

try:
    user = os.environ['XNAT_USER']
except KeyError:
    print 'XNAT_USER not set, using unauthenticated connection'
    user = None
    password = None
else:
    try:
        password = os.environ['XNAT_PASSWORD']
    except KeyError:
        print 'XNAT_PASSWORD not set, using unauthenticated connection'
        user = None
        password = None

dry_run_flag = False
if sys.argv[0] == '-s':
    dry_run_flag = True
    sys.argv.pop(0)

if not sys.argv:
    command_line_error('no command given')
    sys.exit(1)

command = sys.argv.pop(0)

if command == 'init':
    try:
        if sys.argv[0] == '-c':
            create_flag = True
            sys.argv.pop(0)
        else:
            create_flag = False
        xnat_uri = sys.argv.pop(0)
        resource_uri = sys.argv.pop(0)
    except IndexError:
        command_line_error('not enough arguments to init')
        sys.exit(1)
    if os.path.exists('.xnat'):
        sys.stderr.write('%s: .xnat exists, already a sync dir\n' % progname)
        sys.exit(1)
    i = connect(xnat_uri, user, password)
    resource = i.select(resource_uri)
    if create_flag:
        if resource.exists():
            sys.stderr.write('%s: resource exists\n' % progname)
            sys.exit(1)
        if dry_run_flag:
            print 'not creating resource'
        else:
            print 'creating resource'
            resource.create()
    else:
        if not resource.exists():
            sys.stderr.write("%s: can't find resource\n" % progname)
            sys.exit(1)
    files = {}
    if dry_run_flag:
        print 'not writing .xnat'
    else:
        print 'writing .xnat'
        write_rc(xnat_uri, resource_uri, files)
elif command == 'status':
    (xnat_uri, resource_uri, last_updated, rc_files) = read_rc()
    i = connect(xnat_uri, user, password)
    resource = i.select(resource_uri)
    if not resource.exists():
        sys.stderr.write("%s: can't find resource\n" % progname)
        sys.exit(1)
    statuses = get_statuses(rc_files, resource)
    for path in sorted(statuses):
        print '%s %s %s' % (statuses[path]['local'], 
                            statuses[path]['remote'], 
                            path)
elif command == 'push':
    if sys.argv and sys.argv[0] == '-f':
        force_flag = True
    else:
        force_flag = False
    (xnat_uri, resource_uri, last_updated, rc_files) = read_rc()
    i = connect(xnat_uri, user, password)
    resource = i.select(resource_uri)
    if not resource.exists():
        sys.stderr.write("%s: can't find resource\n" % progname)
        sys.exit(1)
    statuses = get_statuses(rc_files, resource)
    prunes = []
    for path in sorted(statuses):
        if statuses[path]['local'] == '?' or statuses[path]['remote'] == '?':
            print 'panic: %s' % path
            prunes.append(path)
        elif statuses[path]['local'] == 'N' and statuses[path]['remote'] != ' ':
            print 'panic: %s' % path
            prunes.append(path)
        elif statuses[path]['remote'] == 'N' and statuses[path]['local'] != ' ':
            print 'panic: %s' % path
            prunes.append(path)
        elif statuses[path]['local'] == ' ' and statuses[path]['remote'] != 'N':
            print 'panic: %s' % path
            prunes.append(path)
        elif statuses[path]['remote'] == ' ' and statuses[path]['local'] != 'N':
            print 'panic: %s' % path
            prunes.append(path)
    for path in prunes:
        del statuses[path]
    for path in sorted(statuses):
        if statuses[path]['local'] == 'N':
            if statuses[path]['remote'] == 'N':
                if force_flag:
                    if dry_run_flag:
                        print 'not updating %s' % path
                    else:
                        print 'updating %s' % path
                        f = resource.file(path)
                        f.put(path)
                        rc_files[path] = files_times(path, f)
            if statuses[path]['remote'] == ' ':
                if dry_run_flag:
                    print 'not updating %s' % path
                else:
                    print 'updating %s' % path
                    f = resource.file(path)
                    f.put(path)
                    rc_files[path] = files_times(path, f)
        if statuses[path]['local'] == 'D':
            if statuses[path]['remote'] == 'D':
                if dry_run_flag:
                    print 'not updating %s' % path
                else:
                    print 'updating %s' % path
                    f = resource.file(path)
                    f.delete()
                    del rc_files[path]
            if statuses[path]['remote'] == 'M':
                if force_flag:
                    if dry_run_flag:
                        print 'not updating %s' % path
                    else:
                        print 'updating %s' % path
                        f = resource.file(path)
                        f.delete()
                        del rc_files[path]
            if statuses[path]['remote'] == 'U':
                if dry_run_flag:
                    print 'not updating %s' % path
                else:
                    print 'updating %s' % path
                    f = resource.file(path)
                    f.delete()
                    del rc_files[path]
        if statuses[path]['local'] == 'M':
            if statuses[path]['remote'] == 'D':
                if force_flag:
                    if dry_run_flag:
                        print 'not updating %s' % path
                    else:
                        print 'updating %s' % path
                        f = resource.file(path)
                        f.put(path)
                        rc_files[path] = files_times(path, f)
            if statuses[path]['remote'] == 'M':
                if force_flag:
                    if dry_run_flag:
                        print 'not updating %s' % path
                    else:
                        print 'updating %s' % path
                        f = resource.file(path)
                        f.put(path)
                        rc_files[path] = files_times(path, f)
            if statuses[path]['remote'] == 'U':
                if dry_run_flag:
                    print 'not updating %s' % path
                else:
                    print 'updating %s' % path
                    f = resource.file(path)
                    f.put(path)
                    rc_files[path] = files_times(path, f)
        if statuses[path]['local'] == 'U':
            if statuses[path]['remote'] == 'D':
                if force_flag:
                    if dry_run_flag:
                        print 'not updating %s' % path
                    else:
                        print 'updating %s' % path
                        f = resource.file(path)
                        f.put(path)
                        rc_files[path] = files_times(path, f)
            if statuses[path]['remote'] == 'M':
                if force_flag:
                    if dry_run_flag:
                        print 'not updating %s' % path
                    else:
                        print 'updating %s' % path
                        f = resource.file(path)
                        f.put(path)
                        rc_files[path] = files_times(path, f)
    if not dry_run_flag:
        write_rc(xnat_uri, resource_uri, rc_files)
elif command == 'pull':
    if sys.argv and sys.argv[0] == '-f':
        force_flag = True
    else:
        force_flag = False
    (xnat_uri, resource_uri, last_updated, rc_files) = read_rc()
    i = connect(xnat_uri, user, password)
    resource = i.select(resource_uri)
    if not resource.exists():
        sys.stderr.write("%s: can't find resource\n" % progname)
        sys.exit(1)
    statuses = get_statuses(rc_files, resource)
    prunes = []
    for path in sorted(statuses):
        if statuses[path]['local'] == '?' or statuses[path]['remote'] == '?':
            print 'panic: %s' % path
            prunes.append(path)
        elif statuses[path]['local'] == 'N' and statuses[path]['remote'] != ' ':
            print 'panic: %s' % path
            prunes.append(path)
        elif statuses[path]['remote'] == 'N' and statuses[path]['local'] != ' ':
            print 'panic: %s' % path
            prunes.append(path)
        elif statuses[path]['local'] == ' ' and statuses[path]['remote'] != 'N':
            print 'panic: %s' % path
            prunes.append(path)
        elif statuses[path]['remote'] == ' ' and statuses[path]['local'] != 'N':
            print 'panic: %s' % path
            prunes.append(path)
    for path in prunes:
        del statuses[path]
    for path in sorted(statuses):
        if statuses[path]['remote'] == 'N':
            if statuses[path]['local'] == 'N':
                if force_flag:
                    if dry_run_flag:
                        print 'not updating %s' % path
                    else:
                        print 'updating %s' % path
                        f = resource.file(path)
                        f.get(path)
                        rc_files[path] = files_times(path, f)
            if statuses[path]['local'] == ' ':
                if dry_run_flag:
                    print 'not updating %s' % path
                else:
                    print 'updating %s' % path
                    f = resource.file(path)
                    f.get(path)
                    rc_files[path] = files_times(path, f)
        if statuses[path]['remote'] == 'D':
            if statuses[path]['local'] == 'D':
                if dry_run_flag:
                    print 'not updating %s' % path
                else:
                    print 'updating %s' % path
                    os.unlink(path)
                    del rc_files[path]
            if statuses[path]['local'] == 'M':
                if force_flag:
                    if dry_run_flag:
                        print 'not updating %s' % path
                    else:
                        print 'updating %s' % path
                        os.unlink(path)
                        del rc_files[path]
            if statuses[path]['local'] == 'U':
                if dry_run_flag:
                    print 'not updating %s' % path
                else:
                    print 'updating %s' % path
                    os.unlink(path)
                    del rc_files[path]
        if statuses[path]['remote'] == 'M':
            if statuses[path]['local'] == 'D':
                if force_flag:
                    if dry_run_flag:
                        print 'not updating %s' % path
                    else:
                        print 'updating %s' % path
                        f = resource.file(path)
                        f.get(path)
                        rc_files[path] = files_times(path, f)
            if statuses[path]['local'] == 'M':
                if force_flag:
                    if dry_run_flag:
                        print 'not updating %s' % path
                    else:
                        print 'updating %s' % path
                        f = resource.file(path)
                        f.get(path)
                        rc_files[path] = files_times(path, f)
            if statuses[path]['local'] == 'U':
                if dry_run_flag:
                    print 'not updating %s' % path
                else:
                    print 'updating %s' % path
                    f = resource.file(path)
                    f.get(path)
                    rc_files[path] = files_times(path, f)
        if statuses[path]['remote'] == 'U':
            if statuses[path]['local'] == 'D':
                if force_flag:
                    if dry_run_flag:
                        print 'not updating %s' % path
                    else:
                        print 'updating %s' % path
                        f = resource.file(path)
                        f.get(path)
                        rc_files[path] = files_times(path, f)
            if statuses[path]['local'] == 'M':
                if force_flag:
                    if dry_run_flag:
                        print 'not updating %s' % path
                    else:
                        print 'updating %s' % path
                        f = resource.file(path)
                        f.get(path)
                        rc_files[path] = files_times(path, f)
    if not dry_run_flag:
        write_rc(xnat_uri, resource_uri, rc_files)
else:
    command_line_error('unknown command "%s"' % command)
    sys.exit(1)

sys.exit(0)

# eof