# -*- coding: iso-8859-1 -*-

"""This modules defines func / methods for creating test repositories

:organization: Logilab

:copyright: 2001-2008 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr

"""

__docformat__ = "restructuredtext en"

from random import randint, choice

from copy import deepcopy

from mx.DateTime import DateTime, DateTimeDelta

from decimal import Decimal

from yams.constraints import (SizeConstraint, StaticVocabularyConstraint,

                              IntervalBoundConstraint)

from rql.utils import decompose_b26 as base_decompose_b26

from cubicweb import Binary

from cubicweb.schema import RQLConstraint

def decompose_b26(index, ascii=False):

    """return a letter (base-26) decomposition of index"""

    if ascii:

        return base_decompose_b26(index)

    return base_decompose_b26(index, u'�abcdefghijklmnopqrstuvwxyz')

def get_choices(eschema, attrname):

    """returns possible choices for 'attrname'

    if attrname doesn't have ChoiceConstraint, return None

    """

    for cst in eschema.constraints(attrname):

        if isinstance(cst, StaticVocabularyConstraint):

            return cst.vocabulary()

    return None

def get_max_length(eschema, attrname):

    """returns the maximum length allowed for 'attrname'"""

    for cst in eschema.constraints(attrname):

        if isinstance(cst, SizeConstraint) and cst.max:

            return cst.max

    return 300

    #raise AttributeError('No Size constraint on attribute "%s"' % attrname)

def get_bounds(eschema, attrname):

    for cst in eschema.constraints(attrname):

        if isinstance(cst, IntervalBoundConstraint):

            return cst.minvalue, cst.maxvalue

    return None, None

_GENERATED_VALUES = {}

class _ValueGenerator(object):

    """generates integers / dates / strings / etc. to fill a DB table"""

    def __init__(self, eschema, choice_func=None):

        """<choice_func> is a function that returns a list of possible

        choices for a given entity type and an attribute name. It should

        looks like :

            def values_for(etype, attrname):

                # some stuff ...

                return alist_of_acceptable_values # or None

        """

        self.e_schema = eschema

        self.choice_func = choice_func

    def _generate_value(self, attrname, index, **kwargs):

        if not self.e_schema.has_unique_values(attrname):

            return self.__generate_value(attrname, index, **kwargs)

        value = self.__generate_value(attrname, index, **kwargs)

        while value in _GENERATED_VALUES.get((self.e_schema.type, attrname), ()):

            index += 1

            value = self.__generate_value(attrname, index, **kwargs)

        _GENERATED_VALUES.setdefault((self.e_schema.type, attrname), set()).add(value)

        return value

    def __generate_value(self, attrname, index, **kwargs):

        """generates a consistent value for 'attrname'"""

        attrtype = str(self.e_schema.destination(attrname)).lower()

        # Before calling generate_%s functions, try to find values domain

        etype = self.e_schema.type

        if self.choice_func is not None:

            values_domain = self.choice_func(etype, attrname)

            if values_domain is not None:

                return choice(values_domain)

        gen_func = getattr(self, 'generate_%s_%s' % (self.e_schema.type, attrname), None)

        if gen_func is None:

            gen_func = getattr(self, 'generate_Any_%s' % attrname, None)

        if gen_func is not None:

            return gen_func(index, **kwargs)

        # If no specific values domain, then generate a dummy value

        gen_func = getattr(self, 'generate_%s' % (attrtype))

        return gen_func(attrname, index, **kwargs)

    def generate_choice(self, attrname, index):

        """generates a consistent value for 'attrname' if it's a choice"""

        choices = get_choices(self.e_schema, attrname)

        if choices is None:

            return None

        return unicode(choice(choices)) # FIXME

    def generate_string(self, attrname, index, format=None):

        """generates a consistent value for 'attrname' if it's a string"""

        # First try to get choices

        choosed = self.generate_choice(attrname, index)

        if choosed is not None:

            return choosed

        # All other case, generate a default string

        attrlength = get_max_length(self.e_schema, attrname)

        num_len = numlen(index)

        if num_len >= attrlength:

            ascii = self.e_schema.rproperty(attrname, 'internationalizable')

            return ('&'+decompose_b26(index, ascii))[:attrlength]

        # always use plain text when no format is specified

        attrprefix = attrname[:max(attrlength-num_len-1, 0)]

        if format == 'text/html':

            value = u'<span>�%s<b>%d</b></span>' % (attrprefix, index)

        elif format == 'text/rest':

            value = u"""

title

-----

* %s

* %d

* �&

""" % (attrprefix, index)

        else:

            value = u'�&%s%d' % (attrprefix, index)

        return value[:attrlength]

    def generate_password(self, attrname, index):

        """generates a consistent value for 'attrname' if it's a password"""

        return u'toto'

    def generate_integer(self, attrname, index):

        """generates a consistent value for 'attrname' if it's an integer"""

        choosed = self.generate_choice(attrname, index)

        if choosed is not None:

            return choosed

        minvalue, maxvalue = get_bounds(self.e_schema, attrname)

        if maxvalue is not None and maxvalue <= 0 and minvalue is None:

            minvalue = maxvalue - index # i.e. randint(-index, 0)

        else:

            maxvalue = maxvalue or index

        return randint(minvalue or 0, maxvalue)

    generate_int = generate_integer

    def generate_float(self, attrname, index):

        """generates a consistent value for 'attrname' if it's a float"""

        return float(randint(-index, index))

    def generate_decimal(self, attrname, index):

        """generates a consistent value for 'attrname' if it's a float"""

        return Decimal(str(self.generate_float(attrname, index)))

    def generate_date(self, attrname, index):

        """generates a random date (format is 'yyyy-mm-dd')"""

        return DateTime(randint(2000, 2004), randint(1, 12), randint(1, 28))

    def generate_time(self, attrname, index):

        """generates a random time (format is ' HH:MM')"""

        return DateTimeDelta(0, 11, index%60) #'11:%02d' % (index % 60)

    def generate_datetime(self, attrname, index):

        """generates a random date (format is 'yyyy-mm-dd HH:MM')"""

        return DateTime(randint(2000, 2004), randint(1, 12), randint(1, 28), 11, index%60)

    def generate_bytes(self, attrname, index, format=None):

        # modpython way

        fakefile = Binary("%s%s" % (attrname, index))

        fakefile.filename = "file_%s" % attrname

        fakefile.value = fakefile.getvalue()

        return fakefile

    def generate_boolean(self, attrname, index):

        """generates a consistent value for 'attrname' if it's a boolean"""

        return index % 2 == 0

    def generate_Any_data_format(self, index, **kwargs):

        # data_format attribute of Image/File has no vocabulary constraint, we

        # need this method else stupid values will be set which make mtconverter

        # raise exception

        return u'application/octet-stream'

    def generate_Any_content_format(self, index, **kwargs):

        # content_format attribute of EmailPart has no vocabulary constraint, we

        # need this method else stupid values will be set which make mtconverter

        # raise exception

        return u'text/plain'

    def generate_Image_data_format(self, index, **kwargs):

        # data_format attribute of Image/File has no vocabulary constraint, we

        # need this method else stupid values will be set which make mtconverter

        # raise exception

        return u'image/png'

class autoextend(type):

    def __new__(mcs, name, bases, classdict):

        for attrname, attrvalue in classdict.items():

            if callable(attrvalue):

                if attrname.startswith('generate_') and \

                       attrvalue.func_code.co_argcount < 2:

                    raise TypeError('generate_xxx must accept at least 1 argument')

                setattr(_ValueGenerator, attrname, attrvalue)

        return type.__new__(mcs, name, bases, classdict)

class ValueGenerator(_ValueGenerator):

    __metaclass__ = autoextend

def _default_choice_func(etype, attrname):

    """default choice_func for insert_entity_queries"""

    return None

def insert_entity_queries(etype, schema, vreg, entity_num,

                          choice_func=_default_choice_func):

    """returns a list of 'add entity' queries (couples query, args)

    :type etype: str

    :param etype: the entity's type

    :type schema: cubicweb.schema.Schema

    :param schema: the application schema

    :type entity_num: int

    :param entity_num: the number of entities to insert

    XXX FIXME: choice_func is here for *historical* reasons, it should

               probably replaced by a nicer way to specify choices

    :type choice_func: function

    :param choice_func: a function that takes an entity type, an attrname and

                        returns acceptable values for this attribute

    """

    # XXX HACK, remove or fix asap

    if etype in (('String', 'Int', 'Float', 'Boolean', 'Date', 'EGroup', 'EUser')):

        return []

    queries = []

    for index in xrange(entity_num):

        restrictions = []

        args = {}

        for attrname, value in make_entity(etype, schema, vreg, index, choice_func).items():

            restrictions.append('X %s %%(%s)s' % (attrname, attrname))

            args[attrname] = value

        if restrictions:

            queries.append(('INSERT %s X: %s' % (etype, ', '.join(restrictions)),

                            args))

            assert not 'eid' in args, args

        else:

            queries.append(('INSERT %s X' % etype, {}))        

    return queries

def make_entity(etype, schema, vreg, index=0, choice_func=_default_choice_func,

                form=False):

    """generates a random entity and returns it as a dict

    by default, generate an entity to be inserted in the repository

    elif form, generate an form dictionnary to be given to a web controller

    """

    eschema = schema.eschema(etype)

    valgen = ValueGenerator(eschema, choice_func)

    entity = {}

    # preprocessing to deal with _format fields

    attributes = []

    relatedfields = {}

    for rschema, attrschema in eschema.attribute_definitions():

        attrname = rschema.type

        if attrname == 'eid':

            # don't specify eids !

            continue

        if attrname.endswith('_format') and attrname[:-7] in eschema.subject_relations():

            relatedfields[attrname[:-7]] = attrschema

        else:

            attributes.append((attrname, attrschema))

    for attrname, attrschema in attributes:

        if attrname in relatedfields:

            # first generate a format and record it

            format = valgen._generate_value(attrname + '_format', index)

            entity[attrname + '_format'] = format

            # then a value coherent with this format

            value = valgen._generate_value(attrname, index, format=format)

        else:

            value = valgen._generate_value(attrname, index)

        if form: # need to encode values

            if attrschema.type == 'Bytes':

                # twisted way

                fakefile = value

                filename = value.filename

                value = (filename, u"text/plain", fakefile)

            elif attrschema.type == 'Date':

                value = value.strftime(vreg.property_value('ui.date-format'))

            elif attrschema.type == 'Datetime':

                value = value.strftime(vreg.property_value('ui.datetime-format'))

            elif attrschema.type == 'Time':

                value = value.strftime(vreg.property_value('ui.time-format'))

            elif attrschema.type == 'Float':

                fmt = vreg.property_value('ui.float-format')

                value = fmt % value

            else:

                value = unicode(value)

        entity[attrname] = value

    return entity

def select(constraints, cursor, selectvar='O'):

    """returns list of eids matching <constraints>

    <selectvar> should be either 'O' or 'S' to match schema definitions

    """

    try:

        rset = cursor.execute('Any %s WHERE %s' % (selectvar, constraints))

    except:

        print "could restrict eid_list with given constraints (%r)" % constraints

        return []

    return set(eid for eid, in rset.rows)

def make_relations_queries(schema, edict, cursor, ignored_relations=(),

                           existingrels=None):

    """returns a list of generated RQL queries for relations

    :param schema: The application schema

    :param e_dict: mapping between etypes and eids

    :param ignored_relations: list of relations to ignore (i.e. don't try

                              to generate insert queries for these relations)

    """

    gen = RelationsQueriesGenerator(schema, cursor, existingrels)

    return gen.compute_queries(edict, ignored_relations)

class RelationsQueriesGenerator(object):

    rql_tmpl = 'SET S %s O WHERE S eid %%(subjeid)s, O eid %%(objeid)s'

    def __init__(self, schema, cursor, existing=None):

        self.schema = schema

        self.cursor = cursor

        self.existingrels = existing or {}

    def compute_queries(self, edict, ignored_relations):

        queries = []

        #   1/ skip final relations and explictly ignored relations

        rels = [rschema for rschema in self.schema.relations()

                if not (rschema.is_final() or rschema in ignored_relations)]

        # for each relation

        #   2/ take each possible couple (subj, obj)

        #   3/ analyze cardinality of relation

        #      a/ if relation is mandatory, insert one relation

        #      b/ else insert N relations where N is the mininum

        #         of 20 and the number of existing targetable entities

        for rschema in rels:

            sym = set()

            sedict = deepcopy(edict)

            oedict = deepcopy(edict)

            delayed = []

            # for each couple (subjschema, objschema), insert relations

            for subj, obj in rschema.iter_rdefs():

                sym.add( (subj, obj) )

                if rschema.symetric and (obj, subj) in sym:

                    continue

                subjcard, objcard = rschema.rproperty(subj, obj, 'cardinality')

                # process mandatory relations first

                if subjcard in '1+' or objcard in '1+': 

                    queries += self.make_relation_queries(sedict, oedict,

                                                          rschema, subj, obj)

                else:

                    delayed.append( (subj, obj) )

            for subj, obj in delayed:

                queries += self.make_relation_queries(sedict, oedict, rschema,

                                                      subj, obj)

        return queries

    def qargs(self, subjeids, objeids, subjcard, objcard, subjeid, objeid):

        if subjcard in '?1':

            subjeids.remove(subjeid)

        if objcard in '?1':

            objeids.remove(objeid)

        return {'subjeid' : subjeid, 'objeid' : objeid}

    def make_relation_queries(self, sedict, oedict, rschema, subj, obj):

        subjcard, objcard = rschema.rproperty(subj, obj, 'cardinality')

        subjeids = sedict.get(subj, frozenset())

        used = self.existingrels[rschema.type]

        preexisting_subjrels = set(subj for subj, obj in used)

        preexisting_objrels = set(obj for subj, obj in used)

        # if there are constraints, only select appropriate objeids

        q = self.rql_tmpl % rschema.type

        constraints = [c for c in rschema.rproperty(subj, obj, 'constraints')

                       if isinstance(c, RQLConstraint)]