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

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

:organization: Logilab

:copyright: 2001-2009 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.

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

:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses

"""

__docformat__ = "restructuredtext en"

from random import randint, choice

from copy import deepcopy

from datetime import datetime, date, timedelta

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 date(randint(2000, 2004), randint(1, 12), randint(1, 28))

    def generate_time(self, attrname, index):

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

        return timedelta(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', 'CWGroup', 'CWUser')):

        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)