#!/usr/bin/env python3

# vim: ft=python
# -*- mode: python -*-

import json
import os
import sys
import subprocess

help_str = ('A config file `sync.json` has been created in {}. '
           'Please specify the remote host and destination directory in this '
           'config file and then run the sync script again.').format(os.path.join(os.getcwd(), '.config'))
config_filename = os.path.join('.config', 'sync.json')
rsync_path = os.getenv('RSYNC_PATH', default = 'rsync')


def in_source_tree():
    return os.path.isfile('tools/socks.sync')


def create_sample_config():
    if not os.path.isdir('.config'):
        os.mkdir('.config')
    
    config_file = open(config_filename, mode='w')
    data = {
        'targets': {
            'example': {
                'host': 'Hostname',
                'user': 'User to connect to the remote host as (optional)',
                'path': 'Destination directory on remote host'
            }
        },

        'default_target': 'example'
    }

    json.dump(data, config_file, indent=4)


def read_config():
    config_file = None
    try:
        config_file = open(config_filename)
    except (OSError, FileNotFoundError):
        create_sample_config()
        print(help_str)
        exit(0)

    return json.load(config_file)


def check_config(cfg):
    if not 'targets' in cfg:
        print('No targets specified in config file')
        exit(-1)


def make_full_target(target):
    path = target['path'].replace('\\', '/')
    if path[-1] != '/':
        path += '/'

    out = '{}:{}'.format(target['host'], path)

    if 'user' in target:
        out = '{}@{}'.format(target['user'], out)

    return out


def print_available_targets(targets):
    print('Available targets:')

    for name, target in targets.items():
        print('  * {} ({})'.format(name, make_full_target(target)))


if not in_source_tree():
    print('This script must be executed from the root of the Socks source tree')
    exit(-1)

config = read_config()
check_config(config);
targets = config['targets']

if len(sys.argv) < 2:
    print('No mode specified. Available modes:')
    print('  * pull: Update the local source tree to match the remote source tree')
    print('  * push: Upload the remote source tree to match the local source tree')
    exit(0)

mode = sys.argv[1]
if mode != 'pull' and mode != 'push':
    print('Invalid sync mode "{}"'.format(mode))
    exit(-1)

target_name = ''

if len(sys.argv) < 3:
    if 'default_target' in config:
        target_name = config['default_target']
        print('No target specified. Using default target "{}"'.format(target_name))
    else:
        print('No target specified (and no default target configured)')
        print_available_targets(config['targets'])
        exit(0)

if target_name not in targets:
    print('Unknown target "{}"'.format(target_name))
    print_available_targets(config['targets'])
    exit(-1)

target = targets[target_name]

print('Syncing source tree with {} ({})'.format(make_full_target(target), mode))
rsync_args = [
    rsync_path,
    '-azhP',
    '--exclude',
    'build/'
]

if mode == 'pull':
    rsync_args += [ make_full_target(target), '.' ]
else:
    rsync_args += [ '.', make_full_target(target) ]


rsync = subprocess.Popen(rsync_args)
rsync.communicate()

if rsync.returncode == 0:
    print('** Sync completed successfully')
else:
    print('** Sync failed (error {})'.format(rsync.errorcode))

exit(rsync.returncode)