##############################################################################
#
# Copyright (c) 2002 Zope Corporation and Contributors. All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
"""WebDAV support - lock item.

$Id: LockItem.py 40218 2005-11-18 14:39:19Z andreasjung $
"""

import time

from AccessControl import ClassSecurityInfo
from AccessControl.Owned import ownerInfo
from Globals import Persistent
from zope.interface import implements

from common import generateLockToken
from interfaces import ILockItem
from WriteLockInterface import LockItemInterface

MAXTIMEOUT = (2L**32)-1                 # Maximum timeout time
DEFAULTTIMEOUT = 12 * 60L               # Default timeout

def validateTimeout(timeout):
    # Timeout *should* be in the form "Seconds-XXX" or "Infinite"
    errors = []
    try:
        t =str(timeout).split('-')[-1]
        if t.lower() == 'infinite':
            timeout = DEFAULTTIMEOUT # Default to 1800 secods for infinite
        else:                       # requests
            timeout = long(t)
    except ValueError:
        errors.append("Bad timeout value")
    if timeout > MAXTIMEOUT:
        errors.append("Timeout request is greater than %s" % MAXTIMEOUT)
    return timeout, errors


class LockItem(Persistent):

    implements(ILockItem)
    __implements__ = (LockItemInterface,)

    # Use the Zope 2.3 declarative security to manage access
    security = ClassSecurityInfo()
    security.declarePublic('getOwner', 'getLockToken', 'getDepth',
                           'getTimeout', 'getTimeoutString',
                           'getModifiedTime', 'isValid', 'getLockScope',
                           'getLockType')
    security.declareProtected('Change Lock Information',
                              'setTimeout', 'refresh')
    security.declareProtected('Access contents information',
                              'getCreator', 'getCreatorPath')

    def __init__(self, creator, owner='', depth=0, timeout='Infinite',
                 locktype='write', lockscope='exclusive', token=None):
        errors = []
        # First check the values and raise value errors if outside of contract
        if not getattr(creator, 'getUserName', None):
            errors.append("Creator not a user object")
        if str(depth).lower() not in ('0', 'infinity'):
            errors.append("Depth must be 0 or infinity")
        if locktype.lower() != 'write':
            errors.append("Lock type '%s' not supported" % locktype)
        if lockscope.lower() != 'exclusive':
            errors.append("Lock scope '%s' not supported" % lockscope)

        timeout, e = validateTimeout(timeout)
        errors = errors + e

        # Finally, if there were errors, report them ALL to on high
        if errors:
            raise ValueError, errors

        # AccessControl.Owned.ownerInfo returns the id of the creator
        # and the path to the UserFolder they're defined in
        self._creator = ownerInfo(creator)

        self._owner = owner
        self._depth = depth
        self._timeout = timeout
        self._locktype = locktype
        self._lockscope = lockscope
        self._modifiedtime = time.time()

        if token is None:
            self._token = generateLockToken()
        else:
            self._token = token

    def getCreator(self):
        return self._creator

    def getCreatorPath(self):
        db, name = self._creator
        path = '/'.join(db)
        return "/%s/%s" % (path, name)

    def getOwner(self):
        return self._owner

    def getLockToken(self):
        return self._token

    def getDepth(self):
        return self._depth

    def getTimeout(self):
        return self._timeout

    def getTimeoutString(self):
        t = str(self._timeout)
        if t[-1] == 'L': t = t[:-1]     # lob off Long signifier
        return "Second-%s" % t

    def setTimeout(self, newtimeout):
        timeout, errors = validateTimeout(newtimeout)
        if errors:
            raise ValueError, errors
        else:
            self._timeout = timeout
            self._modifiedtime = time.time() # reset modified

    def getModifiedTime(self):
        return self._modifiedtime

    def refresh(self):
        self._modifiedtime = time.time()

    def isValid(self):
        now = time.time()
        modified = self._modifiedtime
        timeout = self._timeout

        return (modified + timeout) > now

    def getLockType(self):
        return self._locktype

    def getLockScope(self):
        return self._lockscope

    def asLockDiscoveryProperty(self, ns='d',fake=0):

        if fake: token = 'this-is-a-faked-no-permission-token'
        else:    token = self._token
        s = (' <%(ns)s:activelock>\n'
             '  <%(ns)s:locktype><%(ns)s:%(locktype)s/></%(ns)s:locktype>\n'
             '  <%(ns)s:lockscope><%(ns)s:%(lockscope)s/></%(ns)s:lockscope>\n'
             '  <%(ns)s:depth>%(depth)s</%(ns)s:depth>\n'
             '  <%(ns)s:owner>%(owner)s</%(ns)s:owner>\n'
             '  <%(ns)s:timeout>%(timeout)s</%(ns)s:timeout>\n'
             '  <%(ns)s:locktoken>\n'
             '   <%(ns)s:href>opaquelocktoken:%(locktoken)s</%(ns)s:href>\n'
             '  </%(ns)s:locktoken>\n'
             ' </%(ns)s:activelock>\n'
             ) % {
               'ns': ns,
               'locktype': self._locktype,
               'lockscope': self._lockscope,
               'depth': self._depth,
               'owner': self._owner,
               'timeout': self.getTimeoutString(),
               'locktoken': token,
               }
        return s

    def asXML(self):

        s = """<?xml version="1.0" encoding="utf-8" ?>
<d:prop xmlns:d="DAV:">
 <d:lockdiscovery>
  %s
 </d:lockdiscovery>
</d:prop>""" % self.asLockDiscoveryProperty(ns="d")
        return s