## $Id: batching.py 8349 2012-05-04 22:49:57Z 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
##
"""Batch processing components for student objects.

Batch processors eat CSV files to add, update or remove large numbers
of certain kinds of objects at once.

Here we define the processors for students specific objects like
students, studycourses, payment tickets and accommodation tickets.
"""
import grok
import csv
from zope.interface import Interface
from zope.schema import getFields
from zope.component import queryUtility, getUtility
from zope.event import notify
from zope.catalog.interfaces import ICatalog
from hurry.workflow.interfaces import IWorkflowState, IWorkflowInfo
from waeup.kofa.interfaces import (
    IBatchProcessor, FatalCSVError, IObjectConverter, IUserAccount,
    IObjectHistory, VALIDATED, IGNORE_MARKER)
from waeup.kofa.interfaces import MessageFactory as _
from waeup.kofa.students.interfaces import (
    IStudent, IStudentStudyCourse,
    IStudentUpdateByRegNo, IStudentUpdateByMatricNo,
    IStudentStudyLevel, ICourseTicket,
    IStudentOnlinePayment, IStudentVerdictUpdate)
from waeup.kofa.students.workflow import  (
    IMPORTABLE_STATES, IMPORTABLE_TRANSITIONS)
from waeup.kofa.utils.batching import BatchProcessor

class StudentProcessor(BatchProcessor):
    """A batch processor for IStudent objects.
    """
    grok.implements(IBatchProcessor)
    grok.provides(IBatchProcessor)
    grok.context(Interface)
    util_name = 'studentprocessor'
    grok.name(util_name)

    name = u'Student Processor'
    iface = IStudent

    location_fields = []
    factory_name = 'waeup.Student'

    @property
    def available_fields(self):
        fields = getFields(self.iface)
        return sorted(list(set(
            ['student_id','reg_number','matric_number',
            'password', 'state', 'transition'] + fields.keys())))

    def checkHeaders(self, headerfields, mode='create'):
        if 'state' in headerfields and 'transition' in headerfields:
            raise FatalCSVError(
                "State and transition can't be  imported at the same time!")
        if not 'reg_number' in headerfields and not 'student_id' \
            in headerfields and not 'matric_number' in headerfields:
            raise FatalCSVError(
                "Need at least columns student_id or reg_number " +
                "or matric_number for import!")
        if mode == 'create':
            for field in self.required_fields:
                if not field in headerfields:
                    raise FatalCSVError(
                        "Need at least columns %s for import!" %
                        ', '.join(["'%s'" % x for x in self.required_fields]))
        # Check for fields to be ignored...
        not_ignored_fields = [x for x in headerfields
                              if not x.startswith('--')]
        if len(set(not_ignored_fields)) < len(not_ignored_fields):
            raise FatalCSVError(
                "Double headers: each column name may only appear once.")
        return True

    def parentsExist(self, row, site):
        return 'students' in site.keys()

    def getLocator(self, row):
        if row.get('student_id',None) not in (None, IGNORE_MARKER):
            return 'student_id'
        elif row.get('reg_number',None) not in (None, IGNORE_MARKER):
            return 'reg_number'
        elif row.get('matric_number',None) not in (None, IGNORE_MARKER):
            return 'matric_number'
        else:
            return None

    # The entry never exists in create mode.
    def entryExists(self, row, site):
        return self.getEntry(row, site) is not None

    def getParent(self, row, site):
        return site['students']

    def getEntry(self, row, site):
        if not 'students' in site.keys():
            return None
        if self.getLocator(row) == 'student_id':
            if row['student_id'] in site['students']:
                student = site['students'][row['student_id']]
                return student
        elif self.getLocator(row) == 'reg_number':
            reg_number = row['reg_number']
            cat = queryUtility(ICatalog, name='students_catalog')
            results = list(
                cat.searchResults(reg_number=(reg_number, reg_number)))
            if results:
                return results[0]
        elif self.getLocator(row) == 'matric_number':
            matric_number = row['matric_number']
            cat = queryUtility(ICatalog, name='students_catalog')
            results = list(
                cat.searchResults(matric_number=(matric_number, matric_number)))
            if results:
                return results[0]
        return None

    def addEntry(self, obj, row, site):
        parent = self.getParent(row, site)
        parent.addStudent(obj)
        # We have to log this if state is provided. If not,
        # logging is done by the event handler handle_student_added
        if row.has_key('state'):
            parent.logger.info('%s - Student record created' % obj.student_id)
        history = IObjectHistory(obj)
        history.addMessage(_('Student record created'))
        return

    def delEntry(self, row, site):
        student = self.getEntry(row, site)
        if student is not None:
            parent = self.getParent(row, site)
            parent.logger.info('%s - Student removed' % student.student_id)
            del parent[student.student_id]
        pass

    def checkUpdateRequirements(self, obj, row, site):
        """Checks requirements the object must fulfill when being updated.

        This method is not used in case of deleting or adding objects.

        Returns error messages as strings in case of requirement
        problems.
        """
        transition = row.get('transition', IGNORE_MARKER)
        if transition not in (IGNORE_MARKER, ''):
            allowed_transitions = IWorkflowInfo(obj).getManualTransitionIds()
            if transition not in allowed_transitions:
                return 'Transition not allowed.'
        return None

    def updateEntry(self, obj, row, site):
        """Update obj to the values given in row.
        """
        items_changed = ''

        # Remove student_id from row if empty
        if row.has_key('student_id') and row['student_id'] in (
            None, IGNORE_MARKER):
            row.pop('student_id')

        # Update password
        passwd = row.get('password', IGNORE_MARKER)
        if passwd not in ('', IGNORE_MARKER):
            if passwd.startswith('{SSHA}'):
                # already encrypted password
                obj.password = passwd
            else:
                # not yet encrypted password
                IUserAccount(obj).setPassword(passwd)
            row.pop('password')

        # Update registration state
        state = row.get('state', IGNORE_MARKER)
        if state not in (IGNORE_MARKER, ''):
            value = row['state']
            IWorkflowState(obj).setState(value)
            msg = _("State '${a}' set", mapping = {'a':value})
            history = IObjectHistory(obj)
            history.addMessage(msg)
            row.pop('state')
        transition = row.get('transition', IGNORE_MARKER)
        if transition not in (IGNORE_MARKER, ''):
            value = row['transition']
            IWorkflowInfo(obj).fireTransition(value)
            row.pop('transition')

        # apply other values...
        items_changed = super(StudentProcessor, self).updateEntry(
            obj, row, site)

        # Log actions...
        parent = self.getParent(row, site)
        if hasattr(obj,'student_id'):
            # Update mode: the student exists and we can get the student_id
            parent.logger.info(
                '%s - Student record updated: %s'
                % (obj.student_id, items_changed))
        else:
            # Create mode: the student does not yet exist
            parent.logger.info('Student data imported: %s' % items_changed)
        return items_changed

    def getMapping(self, path, headerfields, mode):
        """Get a mapping from CSV file headerfields to actually used fieldnames.
        """
        result = dict()
        reader = csv.reader(open(path, 'rb'))
        raw_header = reader.next()
        for num, field in enumerate(headerfields):
            if field not in ['student_id', 'reg_number', 'matric_number'
                             ] and mode == 'remove':
                continue
            if field == u'--IGNORE--':
                # Skip ignored columns in failed and finished data files.
                continue
            result[raw_header[num]] = field
        return result

    def checkConversion(self, row, mode='create'):
        """Validates all values in row.
        """
        iface = self.iface
        if mode in ['update', 'remove']:
            if self.getLocator(row) == 'reg_number':
                iface = IStudentUpdateByRegNo
            elif self.getLocator(row) == 'matric_number':
                iface = IStudentUpdateByMatricNo
        converter = IObjectConverter(iface)
        errs, inv_errs, conv_dict =  converter.fromStringDict(
            row, self.factory_name, mode=mode)
        if row.has_key('transition') and \
            not row['transition'] in IMPORTABLE_TRANSITIONS:
            if row['transition'] not in (IGNORE_MARKER, ''):
                errs.append(('transition','not allowed'))
        if row.has_key('state') and \
            not row['state'] in IMPORTABLE_STATES:
            if row['state'] not in (IGNORE_MARKER, ''):
                errs.append(('state','not allowed'))
            else:
                # state is an attribute of Student and must not
                # be changed if empty
                conv_dict['state'] = IGNORE_MARKER
        return errs, inv_errs, conv_dict


class StudentProcessorBase(BatchProcessor):
    """A base for student subitem processor.

    Helps reducing redundancy.
    """
    grok.baseclass()

    #: required fields beside 'student_id', 'reg_number' and 'matric_number'
    additional_fields = []

    #: header fields additional required
    additional_headers = []

    @property
    def available_fields(self):
        fields = ['student_id','reg_number','matric_number'
                  ] + self.additional_fields
        return sorted(list(set(fields + getFields(
                self.iface).keys())))

    def checkHeaders(self, headerfields, mode='ignore'):
        if not 'reg_number' in headerfields and not 'student_id' \
            in headerfields and not 'matric_number' in headerfields:
            raise FatalCSVError(
                "Need at least columns student_id " +
                "or reg_number or matric_number for import!")
        for name in self.additional_headers:
            if not name in headerfields:
                raise FatalCSVError(
                    "Need %s for import!" % name)

        # Check for fields to be ignored...
        not_ignored_fields = [x for x in headerfields
                              if not x.startswith('--')]
        if len(set(not_ignored_fields)) < len(not_ignored_fields):
            raise FatalCSVError(
                "Double headers: each column name may only appear once.")
        return True

    def _getStudent(self, row, site):
        NON_VALUES = ['', IGNORE_MARKER]
        if not 'students' in site.keys():
            return None
        if row.get('student_id', '') not in NON_VALUES:
            if row['student_id'] in site['students']:
                student = site['students'][row['student_id']]
                return student
        elif row.get('reg_number', '') not in NON_VALUES:
            reg_number = row['reg_number']
            cat = queryUtility(ICatalog, name='students_catalog')
            results = list(
                cat.searchResults(reg_number=(reg_number, reg_number)))
            if results:
                return results[0]
        elif row.get('matric_number', '') not in NON_VALUES:
            matric_number = row['matric_number']
            cat = queryUtility(ICatalog, name='students_catalog')
            results = list(
                cat.searchResults(matric_number=(matric_number, matric_number)))
            if results:
                return results[0]
        return None

    def parentsExist(self, row, site):
        return self.getParent(row, site) is not None

    def entryExists(self, row, site):
        return self.getEntry(row, site) is not None

    def checkConversion(self, row, mode='ignore'):
        """Validates all values in row.
        """
        converter = IObjectConverter(self.iface)
        errs, inv_errs, conv_dict =  converter.fromStringDict(
            row, self.factory_name, mode=mode)
        return errs, inv_errs, conv_dict


class StudentStudyCourseProcessor(StudentProcessorBase):
    """A batch processor for IStudentStudyCourse objects.
    """
    grok.implements(IBatchProcessor)
    grok.provides(IBatchProcessor)
    grok.context(Interface)
    util_name = 'studycourseupdater'
    grok.name(util_name)

    name = u'StudentStudyCourse Processor (update only)'
    iface = IStudentStudyCourse
    factory_name = 'waeup.StudentStudyCourse'

    location_fields = []
    additional_fields = []

    def getParent(self, row, site):
        return self._getStudent(row, site)

    def getEntry(self, row, site):
        student = self.getParent(row, site)
        if student is None:
            return None
        return student.get('studycourse')

    def updateEntry(self, obj, row, site):
        """Update obj to the values given in row.
        """
        items_changed = super(StudentStudyCourseProcessor, self).updateEntry(
            obj, row, site)
        parent = self.getParent(row, site)
        parent.__parent__.logger.info(
            '%s - Study course updated: %s'
            % (parent.student_id, items_changed))
        # Update the students_catalog
        notify(grok.ObjectModifiedEvent(obj.__parent__))
        return

    def checkConversion(self, row, mode='ignore'):
        """Validates all values in row.
        """
        errs, inv_errs, conv_dict = super(
            StudentStudyCourseProcessor, self).checkConversion(row, mode=mode)
        # We have to check if current_level is in range of certificate.
        if conv_dict.has_key('certificate'):
          cert = conv_dict['certificate']
          if conv_dict['current_level'] < cert.start_level or \
              conv_dict['current_level'] > cert.end_level+120:
              errs.append(('current_level','not in range'))
        return errs, inv_errs, conv_dict

class StudentStudyLevelProcessor(StudentProcessorBase):
    """A batch processor for IStudentStudyLevel objects.
    """
    grok.implements(IBatchProcessor)
    grok.provides(IBatchProcessor)
    grok.context(Interface)
    util_name = 'studylevelprocessor'
    grok.name(util_name)

    name = u'StudentStudyLevel Processor'
    iface = IStudentStudyLevel
    factory_name = 'waeup.StudentStudyLevel'

    location_fields = []
    additional_fields = ['level']
    additional_headers = ['level']

    def getParent(self, row, site):
        student = self._getStudent(row, site)
        if student is None:
            return None
        return student['studycourse']

    def getEntry(self, row, site):
        studycourse = self.getParent(row, site)
        if studycourse is None:
            return None
        return studycourse.get(row['level'])

    def addEntry(self, obj, row, site):
        parent = self.getParent(row, site)
        obj.level = int(row['level'])
        parent[row['level']] = obj
        return

    def checkConversion(self, row, mode='ignore'):
        """Validates all values in row.
        """
        errs, inv_errs, conv_dict = super(
            StudentStudyLevelProcessor, self).checkConversion(row, mode=mode)

        # We have to check if level is a valid integer.
        # This is not done by the converter.
        try:
            level = int(row['level'])
            if level not in range(0,700,10):
                errs.append(('level','no valid integer'))
        except ValueError:
            errs.append(('level','no integer'))
        return errs, inv_errs, conv_dict

class CourseTicketProcessor(StudentProcessorBase):
    """A batch processor for ICourseTicket objects.
    """
    grok.implements(IBatchProcessor)
    grok.provides(IBatchProcessor)
    grok.context(Interface)
    util_name = 'courseticketprocessor'
    grok.name(util_name)

    name = u'CourseTicket Processor'
    iface = ICourseTicket
    factory_name = 'waeup.CourseTicket'

    location_fields = []
    additional_fields = ['level', 'code']
    additional_headers = ['level', 'code']

    def getParent(self, row, site):
        student = self._getStudent(row, site)
        if student is None:
            return None
        return student['studycourse'].get(row['level'])

    def getEntry(self, row, site):
        level = self.getParent(row, site)
        if level is None:
            return None
        return level.get(row['code'])

    def addEntry(self, obj, row, site):
        parent = self.getParent(row, site)
        catalog = getUtility(ICatalog, name='courses_catalog')
        entries = list(catalog.searchResults(code=(row['code'],row['code'])))
        obj.fcode = entries[0].__parent__.__parent__.__parent__.code
        obj.dcode = entries[0].__parent__.__parent__.code
        obj.title = entries[0].title
        obj.credits = entries[0].credits
        obj.passmark = entries[0].passmark
        obj.semester = entries[0].semester
        parent[row['code']] = obj
        return

    def checkConversion(self, row, mode='ignore'):
        """Validates all values in row.
        """
        errs, inv_errs, conv_dict = super(
            CourseTicketProcessor, self).checkConversion(row, mode=mode)

        # We have to check if course really exists.
        # This is not done by the converter.
        catalog = getUtility(ICatalog, name='courses_catalog')
        entries = catalog.searchResults(code=(row['code'],row['code']))
        if len(entries) == 0:
            errs.append(('code','non-existent'))
            return errs, inv_errs, conv_dict
        return errs, inv_errs, conv_dict

class StudentOnlinePaymentProcessor(StudentProcessorBase):
    """A batch processor for IStudentOnlinePayment objects.
    """
    grok.implements(IBatchProcessor)
    grok.provides(IBatchProcessor)
    grok.context(Interface)
    util_name = 'paymentprocessor'
    grok.name(util_name)

    name = u'Payment Processor'
    iface = IStudentOnlinePayment
    factory_name = 'waeup.StudentOnlinePayment'

    location_fields = []
    additional_fields = ['p_id']
    additional_headers = ['p_id']

    def parentsExist(self, row, site):
        return self.getParent(row, site) is not None

    def getParent(self, row, site):
        student = self._getStudent(row, site)
        if student is None:
            return None
        return student['payments']

    def getEntry(self, row, site):
        payments = self.getParent(row, site)
        if payments is None:
            return None
        # We can use the hash symbol at the end of p_id in import files
        # to avoid annoying automatic number transformation
        # by Excel or Calc
        p_id = row['p_id'].strip('#')
        if p_id.startswith('p'):
            entry = payments.get(p_id)
        else:
            # For data migration from old SRP
            entry = payments.get('p' + p_id[6:])
        return entry

    def addEntry(self, obj, row, site):
        parent = self.getParent(row, site)
        p_id = row['p_id'].strip('#')
        if not p_id.startswith('p'):
            # For data migration from old SRP
            obj.p_id = 'p' + p_id[6:]
            parent[obj.p_id] = obj
        else:
            parent[p_id] = obj
        return

    def checkConversion(self, row, mode='ignore'):
        """Validates all values in row.
        """
        errs, inv_errs, conv_dict = super(
            StudentOnlinePaymentProcessor, self).checkConversion(row, mode=mode)

        # We have to check p_id.
        p_id = row['p_id'].strip('#')
        if p_id.startswith('p'):
            if not len(p_id) == 14:
                errs.append(('p_id','invalid length'))
                return errs, inv_errs, conv_dict
        else:
            if not len(p_id) == 19:
                errs.append(('p_id','invalid length'))
                return errs, inv_errs, conv_dict
        return errs, inv_errs, conv_dict

class StudentVerdictProcessor(StudentStudyCourseProcessor):
    """A batch processor for verdicts.

    Import verdicts and perform workflow transitions.
    """

    util_name = 'verdictupdater'
    grok.name(util_name)

    name = u'Verdict Processor (update only)'
    iface = IStudentVerdictUpdate
    factory_name = 'waeup.StudentStudyCourse'

    additional_fields = ['current_session', 'current_level']

    def checkUpdateRequirements(self, obj, row, site):
        """Checks requirements the studycourse and the student must fulfill
        before being updated.
        """
        # Check if current_levels correspond
        if obj.current_level != row['current_level']:
            return 'Current level does not correspond.'
        # Check if current_sessions correspond
        if obj.current_session != row['current_session']:
            return 'Current session does not correspond.'
        # Check if student is in state REGISTERED
        if obj.getStudent().state != VALIDATED:
            return 'Student in wrong state.'
        return None

    def updateEntry(self, obj, row, site):
        """Update obj to the values given in row.
        """
        # Don't set current_session, current_level
        vals_to_set = dict((key, val) for key, val in row.items()
                           if key not in ('current_session','current_level'))
        items_changed = super(StudentVerdictProcessor, self).updateEntry(
            obj, vals_to_set, site)
        parent = self.getParent(row, site)
        parent.__parent__.logger.info(
            '%s - Verdict updated: %s'
            % (parent.student_id, items_changed))
        # Fire transition
        IWorkflowInfo(obj.__parent__).fireTransition('return')
        # Update the students_catalog
        notify(grok.ObjectModifiedEvent(obj.__parent__))
        return