Dirty little script

localsync

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

from paver.easy import sh
import os
import sys

clear_flag = '--clear'

def local_sync():
    _check_dependencies()

    associations = _get_sources_targets_associations()

    should_clear = _should_clear()

    _confirm_execution(associations, should_clear)

    if should_clear:
        _run_clear(associations)

    _run_associations(associations)


def _check_dependencies():
    programs = ['unison']
    missing_programs = []
    for program in programs:
        command = 'command -v ' + program
        output = sh(command, capture=True, ignore_error=True)
        if program not in output:
            missing_programs.append(program)

        if missing_programs:
            error = 'Missing programs : ' + ', '.join(missing_programs)
            if 'unison' in missing_programs:
                error += "\n" + \
                         'if brew install unison raises problems on ' \
                         'execution, you should check ' \
                         'https://github.com/bcpierce00/unison/issues/79'
            raise Exception(error)


def _get_sources_targets_associations():
    targets_env_variable_prefix = 'LOCAL_SYNC_'

    associations = [
        _get_association_from_env_variable(value)
            for env_variable, value in os.environ.iteritems()
                if env_variable.find(targets_env_variable_prefix) == 0
    ]

    if not associations:
        error = 'We are unable to find any variable prefixed ' + \
                targets_env_variable_prefix + '. Syntax: ' + \
            '"export ' + targets_env_variable_prefix + 'S0M3N4ME="path1:path2"'
        raise Exception(error)

    filters = sys.argv[1:]

    if clear_flag in filters:
        del filters[filters.index(clear_flag)]

    if filters:
        pattern = filters.pop()
        associations = [
            association for association in associations
            if pattern in '|'.join(association)
        ]
        if not associations:
            raise Exception('No more association after filter: ' + pattern)

    return associations


def _get_association_from_env_variable(env_variable):
    association_items = env_variable.split(':')
    if len(association_items) != 2:
        raise Exception('Unable to parse ' + env_variable)

    for association_item in association_items:
        if not os.path.exists(association_item):
            raise Exception(association_item + ' does not seem to exist')

    return association_items
    
    
def _should_clear():
    return clear_flag in sys.argv


def _confirm_execution(associations, clear=None):
    if clear is None:
        clear = False

    message = ''
    clear_lines = []

    if clear:
        clear_lines = [' ==> '.join(association)
                        for association in associations]
        clear_lines_as_string = "\n".join(clear_lines)
        message = ('=' * 40) + "\n" + \
            'Beware you are about to force a clean up: ' + \
            "\n" + ('=' * 40) + "\n" + "\n" + \
            clear_lines_as_string + "\n\n"

    associations_lines = [' <--> '.join(association)
                          for association in associations]
    associations_as_string = "\n".join(associations_lines)
    message += associations_as_string

    print(message)
    user_instruction = raw_input('Shall we proceed? 🤔 [y/n]')
    if user_instruction != 'y':
        sys.exit(0)


def _run_clear(associations):
    command = ''
    for association in associations:
        from_path = association[0]
        to_path = association[1]
        #command += 'rm -rf ' + to_path + ' && ' +\
        command += '' +\
            'rsync -av --exclude=".git" --exclude="node_modules" ' +\
            '--exclude=".idea" --exclude="vendor" '+ \
            '--exclude=".paver_targets" ' +\
            from_path + '/ ' + to_path + ' && '
    command += ' echo "copy done"'

    sh(command)


def _run_associations(associations):
    command = ''
    for association in associations:
        command += 'unison ' + '"' + '" "'.join(association) + '" ' + \
                   '-ignore "Name .git" -ignore "Name node_modules" ' + \
                   '-ignore "Name vendor" -ignore "Name .idea" ' + \
                   '-ignore "Name .paver_targets" -repeat watch & '

    if not command: #empty string
        raise Exception('No unison sync to run')

    command += 'wait'
    sh(command)


if __name__ == "__main__":
    local_sync()