## $Id: vocabularies.py 9211 2012-09-21 08:19:35Z uli $
##
## Copyright (C) 2011 Uli Fouquet & Henrik Bettermann
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, write to the Free Software
## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
##
"""Vocabularies and sources for the student section.
"""
from zope.component import getUtility, queryUtility
from zope.catalog.interfaces import ICatalog
from zope.interface import implements, directlyProvides
from zope.schema.interfaces import ISource, IContextSourceBinder
from zope.schema.interfaces import ValidationError
from zc.sourcefactory.basic import BasicSourceFactory
from zc.sourcefactory.contextual import BasicContextualSourceFactory
from waeup.kofa.interfaces import SimpleKofaVocabulary
from waeup.kofa.interfaces import MessageFactory as _
from waeup.kofa.utils.helpers import get_sorted_preferred
from waeup.kofa.utils.countries import COUNTRIES
from waeup.kofa.university.vocabularies import course_levels


#: a tuple of tuples (<COUNTRY-NAME>, <ISO-CODE>) with Nigeria first.
COUNTRIES = get_sorted_preferred(COUNTRIES, ['NG'])
nats_vocab = SimpleKofaVocabulary(*COUNTRIES)

def study_levels(studycourse):
    if studycourse.certificate is not None:
        start_level = int(studycourse.certificate.start_level)
        end_level = int(studycourse.certificate.end_level)
        if start_level == 999 or end_level == 999:
            levels = [999]
        elif start_level == 10:
            levels = [10,] + [level for level in range(100,end_level+200,10)
                if level % 100 < 30]
        else:
            levels = [level for level in range(start_level,end_level+200,10)
                if level % 100 < 30]
    else:
        # default level range
        levels = [level for level in range(100,1000,10) if level % 100 < 30]
    return levels


class StudyLevelSource(BasicContextualSourceFactory):
    """The StudyLevelSource is based on and extends the
    course_levels vocabulary defined in the university package.
    Repeating study levels are denoted by increments of 10, the
    first spillover level by the certificate's end level plus 100
    and the second spillover level by the end level plus 110.
    """
    def getValues(self, context):
        return study_levels(context)

    def getToken(self, context, value):
        return str(value)

    def getTitle(self, context, value):
        if context.certificate is not None:
            start_level = int(context.certificate.start_level)
            end_level = int(context.certificate.end_level)
        else:
            # default level range
            start_level = 100
            end_level = 1000
        if start_level == 999 or end_level == 999:
            if value != 999:
                return _('Error: wrong level id ${value}',
                    mapping={'value': value})
            return course_levels.by_value[999].title
        if value < start_level or value > end_level + 120:
            return _('Error: level id ${value} out of range',
                mapping={'value': value})
        # Special treatment for pre-studies level
        if value == 10:
            return course_levels.by_value[value].title
        level,repeat = divmod(value, 100)
        level = level * 100
        repeat = repeat//10
        title = course_levels.by_value[level].title
        if level > end_level and repeat == 1:
            title = course_levels.by_value[level - 100].title
            return _('${title} 2nd spillover', mapping={'title': title})
        if level > end_level and repeat == 2:
            title = course_levels.by_value[level - 100].title
            return _('${title} 3rd spillover', mapping={'title': title})
        if level > end_level:
            title = course_levels.by_value[level - 100].title
            return  _('${title} 1st spillover', mapping={'title': title})
        if repeat == 1:
            return _('${title} on 1st probation', mapping={'title': title})
        if repeat == 2:
            return _('${title} on 2nd probation', mapping={'title': title})
        return title

class GenderSource(BasicSourceFactory):
    """A gender source delivers basically a mapping
       ``{'m': 'Male', 'f': 'Female'}``

       Using a source, we make sure that the tokens (which are
       stored/expected for instance from CSV files) are something one
       can expect and not cryptic IntIDs.
    """
    def getValues(self):
        return ['m', 'f']

    def getToken(self, value):
        return value[0].lower()

    def getTitle(self, value):
        if value == 'm':
            return _('male')
        if value == 'f':
            return _('female')

class RegNumNotInSource(ValidationError):
    """Registration number exists already
    """
    # The docstring of ValidationErrors is used as error description
    # by zope.formlib.
    pass

class MatNumNotInSource(ValidationError):
    """Matriculation number exists already
    """
    # The docstring of ValidationErrors is used as error description
    # by zope.formlib.
    pass

class RegNumberSource(object):
    """A source that accepts any entry for a certain field if not used
    already.

    Using this kind of source means a way of setting an invariant.

    We accept a value iff:
    - the value cannot be found in catalog or
    - the value can be found as part of some item but the bound item
      is the context object itself.
    """
    implements(ISource)
    cat_name = 'students_catalog'
    field_name = 'reg_number'
    validation_error = RegNumNotInSource
    comp_field = 'student_id'
    def __init__(self, context):
        self.context = context
        return

    def __contains__(self, value):
        """We accept all values not already given to other students.
        """
        cat = queryUtility(ICatalog, self.cat_name)
        if cat is None:
            return True
        kw = {self.field_name: (value, value)}
        results = cat.searchResults(**kw)
        for entry in results:
            if not hasattr(self.context, self.comp_field):
                # we have no context with comp_field (most probably
                # while adding a new object, where the container is
                # the context) which means that the value was given
                # already to another object (as _something_ was found in
                # the catalog with that value). Fail on first round.
                raise self.validation_error(value)
            if getattr(entry, self.comp_field) != getattr(
                self.context, self.comp_field):
                # An entry already given to another student is not in our
                # range of acceptable values.
                raise self.validation_error(value)
                #return False
        return True

def contextual_reg_num_source(context):
    source = RegNumberSource(context)
    return source
directlyProvides(contextual_reg_num_source, IContextSourceBinder)

class MatNumberSource(RegNumberSource):
    field_name = 'matric_number'
    validation_error = MatNumNotInSource

def contextual_mat_num_source(context):
    source = MatNumberSource(context)
    return source
directlyProvides(contextual_mat_num_source, IContextSourceBinder)