## $Id: batching.py 9037 2012-07-21 15:25:18Z henrik $
##
## 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 time import time
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,
    FORBIDDEN_POSTGRAD_TRANS, FORBIDDEN_POSTGRAD_STATES)
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
    iface_byregnumber = IStudentUpdateByRegNo
    iface_bymatricnumber = IStudentUpdateByMatricNo

    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)
        # Reset _curr_stud_id if student_id has been imported
        if self.getLocator(row) == 'student_id':
            parent._curr_stud_id -= 1
        # 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.'
            if transition in FORBIDDEN_POSTGRAD_TRANS and \
                obj.is_postgrad:
                return 'Transition not allowed (pg student).'
        state = row.get('state', IGNORE_MARKER)
        if state not in (IGNORE_MARKER, ''):
            if state in FORBIDDEN_POSTGRAD_STATES and \
                obj.is_postgrad:
                return 'State not allowed (pg student).'
        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
        # XXX: Tale DELETION_MARKER into consideration
        if row.has_key('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)
                items_changed += ('%s=%s, ' % ('password', passwd))
            row.pop('password')

        # Update registration state
        if row.has_key('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)
                items_changed += ('%s=%s, ' % ('state', state))
            row.pop('state')

        if row.has_key('transition'):
            transition = row.get('transition', IGNORE_MARKER)
            if transition not in (IGNORE_MARKER, ''):
                value = row['transition']
                IWorkflowInfo(obj).fireTransition(value)
                items_changed += ('%s=%s, ' % ('transition', transition))
            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.
            # Create mode: the record contains 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 = self.iface_byregnumber
            elif self.getLocator(row) == 'matric_number':
                iface = self.iface_bymatricnumber
        converter = IObjectConverter(iface)
        errs, inv_errs, conv_dict =  converter.fromStringDict(
            row, self.factory_name, mode=mode)
        if row.has_key('transition'):
            if row['transition'] not in IMPORTABLE_TRANSITIONS:
                if row['transition'] not in (IGNORE_MARKER, ''):
                    errs.append(('transition','not allowed'))
        if row.has_key('state'):
            if row['state'] not 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
        try:
            # Correct stud_id counter. As the IConverter for students
            # creates student objects that are not used afterwards, we
            # have to fix the site-wide student_id counter.
            site = grok.getSite()
            students = site['students']
            students._curr_stud_id -= 1
        except (KeyError, TypeError, AttributeError):
                pass
        return errs, inv_errs, conv_dict


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

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

    # additional available  fields
    # beside 'student_id', 'reg_number' and 'matric_number'
    additional_fields = []

    #: header fields additionally 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

    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',
                             'p_id', 'code', 'level'
                             ] 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


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') and \
            conv_dict.has_key('current_level'):
            cert = conv_dict['certificate']
            level = conv_dict['current_level']
            if level < cert.start_level or level > cert.end_level+120:
                errs.append(('current_level','not in range'))
        return errs, inv_errs, conv_dict

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

        Returns error messages as strings in case of requirement
        problems.
        """
        current_level = row.get('current_level', None)
        if current_level == 999 and \
            obj.__parent__.state in FORBIDDEN_POSTGRAD_STATES:
            return 'Not a pg student.'
        return None

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 updateEntry(self, obj, row, site):
        """Update obj to the values given in row.
        """
        items_changed = super(StudentStudyLevelProcessor, self).updateEntry(
            obj, row, site)
        student = self.getParent(row, site).__parent__
        student.__parent__.logger.info(
            '%s - Study level updated: %s'
            % (student.student_id, items_changed))
        return

    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 updateEntry(self, obj, row, site):
        """Update obj to the values given in row.
        """
        items_changed = super(CourseTicketProcessor, self).updateEntry(
            obj, row, site)
        parent = self.getParent(row, site)
        student = self.getParent(row, site).__parent__.__parent__
        student.__parent__.logger.info(
            '%s - Course ticket in %s updated: %s'
            % (student.student_id,  parent.level, items_changed))
        return

    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 delEntry(self, row, site):
        ticket = self.getEntry(row, site)
        parent = self.getParent(row, site)
        if ticket is not None:
            student = self._getStudent(row, site)
            student.__parent__.logger.info('%s - Course ticket in %s removed: %s'
                % (student.student_id, parent.level, ticket.code))
            del parent[ticket.code]
        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'Student Payment Processor'
    iface = IStudentOnlinePayment
    factory_name = 'waeup.StudentOnlinePayment'

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

    def checkHeaders(self, headerfields, mode='ignore'):
        super(StudentOnlinePaymentProcessor, self).checkHeaders(headerfields)
        if mode in ('update', 'remove') and not 'p_id' in headerfields:
            raise FatalCSVError(
                "Need p_id for import in update and remove modes!")
        return True

    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
        p_id = row.get('p_id', None)
        if p_id 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 = p_id.strip('#')
        if not p_id.startswith('p'):
            # For data migration from old SRP only
            p_id = 'p' + p_id[7:] + '0'
        entry = payments.get(p_id)
        return entry

    def updateEntry(self, obj, row, site):
        """Update obj to the values given in row.
        """
        items_changed = super(StudentOnlinePaymentProcessor, self).updateEntry(
            obj, row, site)
        student = self.getParent(row, site).__parent__
        student.__parent__.logger.info(
            '%s - Payment ticket updated: %s'
            % (student.student_id, items_changed))
        return

    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[7:] + '0'
            parent[obj.p_id] = obj
        else:
            parent[p_id] = obj
        return

    def delEntry(self, row, site):
        payment = self.getEntry(row, site)
        parent = self.getParent(row, site)
        if payment is not None:
            student = self._getStudent(row, site)
            student.__parent__.logger.info('%s - Payment ticket removed: %s'
                % (student.student_id, payment.p_id))
            del parent[payment.p_id]
        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.get('p_id', None)
        if not p_id:
            timestamp = ("%d" % int(time()*10000))[1:]
            p_id = "p%s" % timestamp
            conv_dict['p_id'] = p_id
            return errs, inv_errs, conv_dict
        else:
            p_id = 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.student.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