import os

from twisted.internet import defer
from buildbot.process.build import Build


LOGS_ROOT = '/var/log/buildbot/builds'


class LogSaverBuild(Build):
    @defer.inlineCallbacks
    def saveLogToFile(self):
        logs_folder = '%s/%s' % (LOGS_ROOT, self.builder.name)
        if not os.path.exists(logs_folder):
            os.makedirs(logs_folder)

        log_path = '%s/%d.log' % (logs_folder, self.buildid)
        with open(log_path, 'w') as log_f:
            for step in self.executedSteps:
                log_data = yield self.master.data.get(('steps', step.stepid, 'logs', 'stdio', 'raw'))
                if not log_data:
                    continue
                log_f.write(log_data['raw'])

    @defer.inlineCallbacks
    def buildFinished(self, text, results):
        res = yield Build.buildFinished(self, text, results)
        self.saveLogToFile()
        defer.returnValue(res)


# example usage in config file

from buildbot.config import BuilderConfig
from buildbot.process.factory import BuildFactory

build_factory = BuildFactory()  # also add steps to factory as usual

build_factory.buildClass = LogSaverBuild    # setting custom build type

# and setup builder as usual
builder = BuilderConfig(
    name='builder_name',
    workernames=['worker1', 'worker2'],
    factory=build_factory
)