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

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

"""

__docformat__ = "restructuredtext en"

from random import randint, choice

from copy import deepcopy

from datetime import datetime, date, time, timedelta

from decimal import Decimal

from logilab.common import attrdict

from yams.constraints import (SizeConstraint, StaticVocabularyConstraint,

                              IntervalBoundConstraint, BoundConstraint,

                              Attribute, actual_value)

from rql.utils import decompose_b26 as base_decompose_b26

from cubicweb import Binary

from cubicweb.schema import RQLConstraint

def custom_range(start, stop, step):

    while start < stop:

        yield start

        start += step

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_max_length(eschema, attrname):

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

    for cst in eschema.rdef(attrname).constraints:

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

            return cst.max

    return 300

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

_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.choice_func = choice_func

        self.eschema = eschema

    def generate_attribute_value(self, entity, attrname, index=1, **kwargs):

        if attrname in entity:

            return entity[attrname]

        eschema = self.eschema

        if not eschema.has_unique_values(attrname):

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

        else:

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

            while value in _GENERATED_VALUES.get((eschema, attrname), ()):

                index += 1

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

            _GENERATED_VALUES.setdefault((eschema, attrname), set()).add(value)

        entity[attrname] = value

        return value

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

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

        eschema = self.eschema

        attrtype = str(eschema.destination(attrname)).lower()

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

        if self.choice_func is not None:

            values_domain = self.choice_func(eschema, attrname)

            if values_domain is not None:

                return choice(values_domain)

        gen_func = getattr(self, 'generate_%s_%s' % (eschema, attrname),

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

        if gen_func is not None:

            return gen_func(entity, index, **kwargs)

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

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

        return gen_func(entity, attrname, index, **kwargs)

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

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

        # First try to get choices

        choosed = self.get_choice(entity, attrname)

        if choosed is not None:

            return choosed

        # All other case, generate a default string

        attrlength = get_max_length(self.eschema, attrname)

        num_len = numlen(index)

        if num_len >= attrlength:

            ascii = self.eschema.rdef(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, entity, attrname, index):

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

        return u'toto'

    def generate_integer(self, entity, attrname, index):

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

        return self._constrained_generate(entity, attrname, 0, 1, index)

    generate_int = generate_integer

    def generate_float(self, entity, attrname, index):

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

        return self._constrained_generate(entity, attrname, 0.0, 1.0, index)

    def generate_decimal(self, entity, attrname, index):

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

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

    def generate_datetime(self, entity, attrname, index):

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

        base = datetime(randint(2000, 2004), randint(1, 12), randint(1, 28), 11, index%60)

        return self._constrained_generate(entity, attrname, base, timedelta(hours=1), index)

    def generate_date(self, entity, attrname, index):

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

        base = date(randint(2000, 2010), 1, 1) + timedelta(randint(1, 365))

        return self._constrained_generate(entity, attrname, base, timedelta(days=1), index)

    def generate_time(self, entity, attrname, index):

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

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

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

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

        fakefile.filename = u"file_%s" % attrname

        return fakefile

    def generate_boolean(self, entity, attrname, index):

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

        return index % 2 == 0

    def _constrained_generate(self, entity, attrname, base, step, index):

        choosed = self.get_choice(entity, attrname)

        if choosed is not None:

            return choosed

        # ensure index > 0

        index += 1

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

        if maxvalue is None:

            if minvalue is not None:

                base = max(minvalue, base)

            maxvalue = base + index * step

        if minvalue is None:

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

        return choice(list(custom_range(minvalue, maxvalue, step)))

    def _actual_boundary(self, entity, boundary):

        if isinstance(boundary, Attribute):

            # ensure we've a value for this attribute

            self.generate_attribute_value(entity, boundary.attr)

            boundary = actual_value(boundary, entity)

        return boundary

    def get_bounds(self, entity, attrname):

        minvalue = maxvalue = None

        for cst in self.eschema.rdef(attrname).constraints:

            if isinstance(cst, IntervalBoundConstraint):

                minvalue = self._actual_boundary(entity, cst.minvalue)

                maxvalue = self._actual_boundary(entity, cst.maxvalue)

            elif isinstance(cst, BoundConstraint):

                if cst.operator[0] == '<':

                    maxvalue = self._actual_boundary(entity, cst.boundary)

                else:

                    minvalue = self._actual_boundary(entity, cst.boundary)

        return minvalue, maxvalue

    def get_choice(self, entity, attrname):

        """generates a consistent value for 'attrname' if it has some static

        vocabulary set, else return None.

        """

        for cst in self.eschema.rdef(attrname).constraints:

            if isinstance(cst, StaticVocabularyConstraint):

                return unicode(choice(cst.vocabulary()))

        return None

    # XXX nothing to do here

    def generate_Any_data_format(self, entity, 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, entity, 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, entity, 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 instance 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 set(('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 = attrdict()

    # 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_attribute_value(entity, attrname + '_format', index)

            # then a value coherent with this format

            value = valgen.generate_attribute_value(entity, attrname, index, format=format)

        else:

            value = valgen.generate_attribute_value(entity, 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)

    return entity

def select(constraints, cursor, selectvar='O', objtype=None):

    """returns list of eids matching <constraints>

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

    """

    try:

        rql = 'Any %s WHERE %s' % (selectvar, constraints)

        if objtype:

            rql += ', %s is %s' % (selectvar, objtype)

        rset = cursor.execute(rql)

    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 instance 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)

def composite_relation(rschema):

    for obj in rschema.objects():

        if obj.rdef(rschema, 'object').composite == 'subject':

            return True

    for obj in rschema.subjects():

        if obj.rdef(rschema, 'subject').composite == 'object':

            return True