# Copyright (C) 2014-2016  Codethink Limited
#
# 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; version 2 of the License.
#
# 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, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.


import logging

import bottle

import lorrycontroller


class GiveMeJob(lorrycontroller.LorryControllerRoute):

    http_method = 'POST'
    path = '/1.0/give-me-job'

    def run(self, **kwargs):
        logging.info('%s %s called', self.http_method, self.path)

        statedb = self.open_statedb()
        with statedb:
            if statedb.get_running_queue() and not self.max_jobs_reached(statedb):
                lorry_infos = statedb.get_all_lorries_info()
                now = statedb.get_current_time()
                for lorry_info in lorry_infos:
                    if self.ready_to_run(lorry_info, now):
                        metadata = self.get_repo_metadata(statedb, lorry_info)
                        downstream_type = lorrycontroller.downstream_types[
                            self.app_settings['git-server-type']]
                        downstream_type(self.app_settings) \
                            .prepare_repo(lorry_info['path'], metadata)

                        self.give_job_to_minion(statedb, lorry_info, now)
                        logging.info(
                            'Giving job %s to lorry %s to MINION %s:%s',
                            lorry_info['job_id'],
                            lorry_info['path'],
                            bottle.request.forms.host,
                            bottle.request.forms.pid)
                        return lorry_info

        logging.info('No job to give MINION')
        return { 'job_id': None }

    def max_jobs_reached(self, statedb):
        max_jobs = statedb.get_max_jobs()
        if max_jobs is None:
            return False
        running_jobs = statedb.get_running_jobs()
        return len(running_jobs) >= max_jobs

    def ready_to_run(self, lorry_info, now):
        due = lorry_info['last_run'] + lorry_info['interval']
        return (lorry_info['running_job'] is None and due <= now)

    def get_repo_metadata(self, statedb, lorry_info):
        '''Get repository head and description.'''

        if not lorry_info['from_host']:
            return {}

        assert lorry_info['from_path']

        try:
            host_info = statedb.get_host_info(lorry_info['from_host'])
        except lorrycontroller.HostNotFoundError:
            # XXX We don't know whether upstream is Trove.  It should be
            # possible to set host type for single repositories.
            host_info = {
                'host':        lorry_info['from_host'],
                'protocol':    'ssh',
                'username':    None,
                'password':    None,
                'type':        'trove',
                'type_params': {},
            }

        metadata = lorrycontroller.get_upstream_host(host_info) \
                                  .get_repo_metadata(lorry_info['from_path'])
        if 'description' in metadata:
            # Prepend Upstream Host name
            metadata['description'] = '{host}: {desc}'.format(
                host=lorry_info['from_host'],
                desc=metadata['description'])
        return metadata

    def give_job_to_minion(self, statedb, lorry_info, now):
        path = lorry_info['path']
        minion_host = bottle.request.forms.host
        minion_pid = bottle.request.forms.pid
        running_job = statedb.get_next_job_id()
        statedb.set_running_job(path, running_job)
        statedb.add_new_job(
            running_job, minion_host, minion_pid, path, int(now))
        lorry_info['job_id'] = running_job
        return lorry_info