#!/usr/bin/env python2


import os
import random
import sys
import yaml

import bottle
import cliapp

import distixapi



class AuthenticationPlugin(object):

    name = 'AuthenticationPlugin'

    def __init__(self, users):
        self._users = users

    def apply(self, callback, route):
        def authorize(*args, **kwargs):
            try:
                scopes = distixapi.get_scopes(self._users, bottle.request)
            except distixapi.AuthenticationError:
                return bottle.abort(401, 'Unauthorized')
            if route['method'].lower() not in scopes:
                return bottle.abort(401, 'Unauthorized')
            return callback(*args, **kwargs)
        return authorize


class API(object):

    def __init__(self, users):
        self.app = bottle.Bottle()
        self.app.install(AuthenticationPlugin(users))
        self.app.route('/version', method='GET', callback=self.version)

    def run(self, port):
        self.app.run(port=port)

    def version(self):
        return { 'version': '1.0' }


class DistixBackend(cliapp.Application):

    def add_settings(self):
        self.settings.integer(
            ['port'],
            'listen on PORT',
            metavar='PORT')

        self.settings.string(
            ['port-file'],
            'pick random ports, write to FILE',
            metavar='FILE')

        self.settings.string(
            ['pid-file'],
            'write pid to FILE',
            metavar='FILE')

        self.settings.string(
            ['users-file'],
            'read users list from FILE',
            metavar='FILE')

    def process_args(self, args):
        users = self.read_user_file()
        if self.settings['port']:
            port = self.settings['port']
        else:
            port = self.pick_random_port()
        self.write_pid_file()
        api = API(users)
        api.run(port)

    def read_user_file(self):
        filename = self.settings['users-file']
        if os.path.exists(filename):
            with open(filename) as f:
                return yaml.safe_load(f)

    def pick_random_port(self):
        port = random.randint(1025, 32767)
        with open(self.settings['port-file'], 'w') as f:
            f.write('{}\n'.format(port))
        return port

    def write_pid_file(self):
        filename = self.settings['pid-file']
        if filename:
            with open(filename, 'w') as f:
                f.write('{}\n'.format(os.getpid()))


DistixBackend(version=distixapi.__version__).run()