##############################################################################
#
# Copyright (c) 2001 Zope Corporation and Contributors. All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.0 (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
#
#############################################################################

__version__ = '$Id: util.py,v 1.10 2002/08/14 22:19:34 mj Exp $'


import re
from types import StringType,ListType,TupleType,DictType,InstanceType
from DateTime import DateTime

SequenceTypes = (TupleType, ListType)

class parseIndexRequest:
    """
    This class provides functionality to hide the internals of a request
    send from the Catalog/ZCatalog to an index._apply_index() method.

    The class understands the following type of parameters:

    - old-style parameters where the query for an index as value inside
      the request directory where the index name is the name of the key.
      Additional parameters for an index could be passed as index+"_usage" ...


    - dictionary-style parameters specify a query for an index as
      an entry in the request dictionary where the key corresponds to the
      name of the index and the key is a dictionary with the parameters
      passed to the index.

      Allowed keys of the parameter dictionary:

      'query'  - contains the query (either string, list or tuple) (required)

      other parameters depend on the the index


   - record-style parameters specify a query for an index as instance of the
     Record class. This happens usually when parameters from a web form use
     the "record" type e.g. <input type="text" name="path.query:record:string">.
     All restrictions of the dictionary-style parameters apply to the record-style
     parameters

    """


    ParserException = 'IndexRequestParseError'

    def __init__(self, request, iid, options=[]):
        """ parse a request  from the ZPublisher and return a uniform
        datastructure back to the _apply_index() method of the index

          request -- the request dictionary send from the ZPublisher
          iid     -- Id of index
          options -- a list of options the index is interested in
        """

        self.id = iid

        if not request.has_key(iid):
            self.keys = None
            return

        # We keep this for backward compatility
        usage_param = iid + '_usage'
        if request.has_key(usage_param):
            self.usage = request[usage_param]

        param = request[iid]
        keys = None
        t = type(param)

        if t is InstanceType and not isinstance(param, DateTime):
            """ query is of type record """

            record = param

            if not hasattr(record, 'query'):
                raise self.ParserException, (
                    "record for '%s' *must* contain a "
                    "'query' attribute" % self.id)
            keys = record.query

            if type(keys) is StringType:
                keys = [keys.strip()]

            for op in options:
                if op == "query": continue

                if hasattr(record, op):
                    setattr(self, op, getattr(record, op))

        elif t is DictType:
            """ query is a dictionary containing all parameters """

            query = param.get("query", ())
            if type(query) in SequenceTypes:
                keys = query
            else:
                keys = [ query ]

            for op in options:
                if op == "query": continue

                if param.has_key(op):
                    setattr(self, op, param[op])

        else:
            """ query is tuple, list, string, number, or something else """

            if t in SequenceTypes:
                keys = param
            else:
                keys = [param]

            for op in options:
                field = iid + "_" + op
                if request.has_key(field):
                    setattr(self, op, request[field])

        if not keys:
            keys = None

        self.keys = keys


    def get(self,k,default_v=None):

        if hasattr(self,k):
            v = getattr(self,k)
            if v: return v
            else: return default_v
        else:
            return default_v

def test():

    r  = parseIndexRequest({'path':{'query':"","level":2,"operator":'and'}},'path',['query',"level","operator"])
    for k in dir(r):
        print k,getattr(r,k)

if __name__=="__main__":
    test()
