# -*- coding: utf-8 -*-
#
# Copyright (C) 2007 Edgewall Software
# Copyright (C) 2005-2007 Christopher Lenz <cmlenz@gmx.de>
# All rights reserved.
#
# This software is licensed as described in the file COPYING, which
# you should have received as part of this distribution. The terms
# are also available at http://bitten.edgewall.org/wiki/License.

"""Implementation of the build slave."""

from datetime import datetime
import urllib2
import logging
import os
import platform
try:
    set
except NameError:
    from sets import Set as set
import shutil
import tempfile
import time
import urlparse

from bitten.build import BuildError
from bitten.build.config import Configuration
from bitten.recipe import Recipe, InvalidRecipeError
from bitten.util import xmlio

log = logging.getLogger('bitten.slave')


class SaneHTTPErrorProcessor(urllib2.HTTPErrorProcessor):
    "The HTTPErrorProcessor defined in urllib needs some love."

    def http_response(self, request, response):
        code, msg, hdrs = response.code, response.msg, response.info()
        if code >= 300:
            response = self.parent.error(
                'http', request, response, code, msg, hdrs)
        return response


class BuildSlave(object):
    """BEEP initiator implementation for the build slave."""

    def __init__(self, url, name=None, config=None, dry_run=False,
                 work_dir=None, keep_files=False, single_build=False,
                 username=None, password=None):
        """Create the build slave instance.
        
        @param url: The URL of the build master
        @param port: TCP port number of the build master to connect to
        @param name: The name with which this slave should identify itself
        @param config: The slave configuration
        @param dry_run: Whether the build outcome should not be reported back
            to the master
        @param work_dir: The working directory to use for build execution
        @param keep_files: Whether files and directories created for build
            execution should be kept when done
        @param single_build: Whether this slave should exit after completing a 
            single build, or continue processing builds forever
        @param username: the username to use when authentication against the
            build master is requested
        @param password: the password to use when authentication is needed
        """
        self.url = url
        if name is None:
            name = platform.node().split('.', 1)[0].lower()
        self.name = name
        self.config = Configuration(config)
        self.dry_run = dry_run
        if not work_dir:
            work_dir = tempfile.mkdtemp(prefix='bitten')
        elif not os.path.exists(work_dir):
            os.makedirs(work_dir)
        self.work_dir = work_dir
        self.keep_files = keep_files
        self.single_build = single_build

        self.opener = urllib2.build_opener(SaneHTTPErrorProcessor)
        password_mgr = urllib2.HTTPPasswordMgrWithDefaultRealm()
        if username and password:
            password_mgr.add_password(None, url, username, password)
        self.opener.add_handler(urllib2.HTTPBasicAuthHandler(password_mgr))
        self.opener.add_handler(urllib2.HTTPDigestAuthHandler(password_mgr))

    def request(self, method, url, body=None, headers=None):
        log.debug('Sending %s request to %r', body and 'POST' or 'GET', url)
        req = urllib2.Request(url, body, headers or {})
        try:
            return self.opener.open(req)
        except urllib2.HTTPError, e:
            if e.code >= 300:
                log.warn('Server returned error %d: %s', e.code, e.msg)
                raise
            return e

    def run(self):
        while True:
            try:
                try:
                    self._create_build()
                except urllib2.URLError, e:
                    log.error(e)
                    raise ExitSlave()
            except ExitSlave:
                break
            time.sleep(30)

    def quit(self):
        log.info('Shutting down')
        raise ExitSlave()

    def _create_build(self):
        xml = xmlio.Element('slave', name=self.name)[
            xmlio.Element('platform', processor=self.config['processor'])[
                self.config['machine']
            ],
            xmlio.Element('os', family=self.config['family'],
                                version=self.config['version'])[
                self.config['os']
            ],
        ]

        log.debug('Configured packages: %s', self.config.packages)
        for package, properties in self.config.packages.items():
            xml.append(xmlio.Element('package', name=package, **properties))

        body = str(xml)
        log.debug('Sending slave configuration: %s', body)
        resp = self.request('POST', self.url, body, {
            'Content-Length': len(body),
            'Content-Type': 'application/x-bitten+xml'
        })

        if resp.code == 201:
            self._initiate_build(resp.info().get('location'))
        elif resp.code == 204:
            log.info(resp.read())
        else:
            log.error('Unexpected response (%d %s)', resp.code, resp.msg)
            raise ExitSlave()

    def _initiate_build(self, build_url):
        build_id = int(build_url.split('/')[-1])
        log.info('Build %s pending at %s', build_id, build_url)
        resp = self.request('GET', build_url)
        if resp.code == 200:
            xml = xmlio.parse(resp)
            basedir = os.path.join(self.work_dir, 'build_%d' % build_id)
            if not os.path.exists(basedir):
                os.mkdir(basedir)
            try:
                recipe = Recipe(xml, basedir, self.config)
                self._execute_build(build_url, recipe)
            finally:
                if not self.keep_files:
                    log.debug('Removing build directory %s' % basedir)
                    shutil.rmtree(basedir)
                if self.single_build:
                    log.info('Exiting after single build completed.')
                    raise ExitSlave()
        else:
            log.error('Unexpected response (%d): %s', resp.code, resp.msg)
            raise ExitSlave()

    def _execute_build(self, build_url, recipe):
        for step in recipe:
            log.info('Executing build step %r', step.id)
            if not self._execute_step(build_url, recipe, step):
                log.warning('Stopping build due to failure')
                break
        else:
            log.warning('Build completed')

    def _execute_step(self, build_url, recipe, step):
        failed = False
        started = datetime.utcnow()
        xml = xmlio.Element('result', step=step.id, time=started.isoformat())
        try:
            for type, category, generator, output in \
                    step.execute(recipe.ctxt):
                if type == Recipe.ERROR:
                    failed = True
                xml.append(xmlio.Element(type, category=category,
                                         generator=generator)[
                    output
                ])
        except BuildError, e:
            log.error('Build step %r failed (%s)', step.id, e)
            failed = True
        except Exception, e:
            log.error('Internal error in build step %r', step.id, exc_info=True)
            failed = True
        xml.attr['duration'] = (datetime.utcnow() - started).seconds
        if failed:
            xml.attr['status'] = 'failure'
            log.warning('Build step %r failed', step.id)
        else:
            xml.attr['status'] = 'success'
            log.info('Build step %s completed successfully', step.id)

        resp = self.request('POST', build_url + '/steps/', str(xml), {
            'Content-Type': 'application/x-bitten+xml'
        })
        if resp.code != 201:
            log.error('Unexpected response (%d): %s', resp.code, resp.msg)

        return not failed or step.onerror != 'fail'


class ExitSlave(Exception):
    """Exception used internally by the slave to signal that the slave process
    should be stopped."""


def main():
    """Main entry point for running the build slave."""
    from bitten import __version__ as VERSION
    from optparse import OptionParser

    parser = OptionParser(usage='usage: %prog [options] url',
                          version='%%prog %s' % VERSION)
    parser.add_option('--name', action='store', dest='name',
                      help='name of this slave (defaults to host name)')
    parser.add_option('-f', '--config', action='store', dest='config',
                      metavar='FILE', help='path to configuration file')
    parser.add_option('-d', '--work-dir', action='store', dest='work_dir',
                      metavar='DIR', help='working directory for builds')
    parser.add_option('-k', '--keep-files', action='store_true',
                      dest='keep_files', 
                      help='don\'t delete files after builds')
    parser.add_option('-l', '--log', dest='logfile', metavar='FILENAME',
                      help='write log messages to FILENAME')
    parser.add_option('-n', '--dry-run', action='store_true', dest='dry_run',
                      help='don\'t report results back to master')
    parser.add_option('--debug', action='store_const', dest='loglevel',
                      const=logging.DEBUG, help='enable debugging output')
    parser.add_option('-v', '--verbose', action='store_const', dest='loglevel',
                      const=logging.INFO, help='print as much as possible')
    parser.add_option('-q', '--quiet', action='store_const', dest='loglevel',
                      const=logging.ERROR, help='print as little as possible')
    parser.add_option('-s', '--single', action='store_true',
                      dest='single_build',
                      help='exit after completing a single build')
    parser.add_option('-u', '--user', dest='username',
                      help='the username to use for authentication')
    parser.add_option('-p', '--password', dest='password',
                      help='the password to use when authenticating')
    parser.set_defaults(dry_run=False, keep_files=False,
                        loglevel=logging.WARNING, single_build=False)
    options, args = parser.parse_args()

    if len(args) < 1:
        parser.error('incorrect number of arguments')
    url = args[0]

    logger = logging.getLogger('bitten')
    logger.setLevel(options.loglevel)
    handler = logging.StreamHandler()
    handler.setLevel(options.loglevel)
    formatter = logging.Formatter('[%(levelname)-8s] %(message)s')
    handler.setFormatter(formatter)
    logger.addHandler(handler)
    if options.logfile:
        handler = logging.FileHandler(options.logfile)
        handler.setLevel(options.loglevel)
        formatter = logging.Formatter('%(asctime)s [%(name)s] %(levelname)s: '
                                      '%(message)s')
        handler.setFormatter(formatter)
        logger.addHandler(handler)

    slave = BuildSlave(url, name=options.name, config=options.config,
                       dry_run=options.dry_run, work_dir=options.work_dir,
                       keep_files=options.keep_files,
                       single_build=options.single_build,
                       username=options.username, password=options.password)
    try:
        try:
            slave.run()
        except KeyboardInterrupt:
            slave.quit()
    except ExitSlave:
        pass

    if not options.work_dir:
        log.debug('Removing temporary directory %s' % slave.work_dir)
        shutil.rmtree(slave.work_dir)

if __name__ == '__main__':
    main()