#
#  Copyright (c) 2007 Helmut Merz helmutm@cy55.de
#
#  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; either version 2 of the License, or
#  (at your option) any later version.
#
#  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#

"""
Transporter base classes.

$Id$
"""

from base64 import b64encode
from twisted.internet import reactor
from twisted.internet.defer import Deferred, DeferredList, fail
from twisted.web.client import getPage
from zope.interface import implements

from loops.agent.interfaces import ITransporter, ITransportJob
from loops.agent.schedule import Job


class TransportJob(Job):

    implements(ITransportJob)

    def __init__(self, transporter):
        super(TransportJob, self).__init__()
        self.transporter = transporter

    def execute(self):
        result = self.params.get('result')
        if result is None:
            return fail('No data available.')
        transfers = []
        for resource in result:
            d = self.transporter.transfer(resource)
            transfers.append(d)
            d.addCallback(self.logTransfer)
            d.addErrback(self.logError)
        return DeferredList(transfers)

    def logTransfer(self, result, err=None):
        # TODO: logging
        # self.transporter.agent.logger.log(...)
        pass

    def logError(self, error):
        print '*** error on transfer', self.transporter.serverURL, error


class Transporter(object):

    implements(ITransporter)

    jobFactory = TransportJob

    serverURL = 'http://localhost:8080'
    method = 'PUT'
    machineName = 'unknown'
    userName = 'nobody'
    password = 'secret'

    def __init__(self, agent, **params):
        self.agent = agent
        for k, v in params.items():
            setattr(self, k ,v)

    def createJob(self):
        return self.jobFactory(self)

    def transfer(self, resource):
        data = resource.data
        if type(data) is file:
            text = data.read()
            data.close()
        else:
            text = data
        # TODO: encode text (?)
        # TODO: set headers: Content-Type, Authorization, User-Agent
        path = resource.path
        app = resource.application
        deferreds = []
        metadata = resource.metadata
        auth = b64encode(':'.join((self.userName, self.password)))
        headers = {'Authorization': 'Basic ' + auth}
        if metadata is not None:
            url = self.makePath('.meta', app, path, 'xml')
            deferreds.append(getPage(url, method=self.method, headers=headers,
                                     postdata=metadata.asXML()))
        url = self.makePath('.data', app, path)
        deferreds.append(getPage(url, method=self.method, headers=headers,
                                 postdata=text))
        return DeferredList(deferreds, fireOnOneErrback=True)

    def makePath(self, infoType, app, path, extension=None):
        if path.startswith('/'):
            path = path[1:]
        url = self.serverURL
        if url.endswith('/'):
            url = url[:-1]
        fullPath = '/'.join((url, infoType,
                             self.machineName, self.userName, app, path))
        if extension:
            fullPath += '.' + extension
        return fullPath