## $Id: utils.py 7511 2012-01-25 14:25:17Z 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
##
"""General helper functions and utilities for the student section.
"""
import grok
from random import SystemRandom as r
from datetime import datetime
from reportlab.pdfgen import canvas
from reportlab.lib import colors
from reportlab.lib.units import cm
from reportlab.lib.enums import TA_RIGHT
from reportlab.lib.pagesizes import A4
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.platypus import (Frame, Paragraph, Image,
    Table, Spacer)
from reportlab.platypus.tables import TableStyle
from reportlab.platypus.flowables import PageBreak
from zope.component import getUtility
from zope.formlib.form import setUpEditWidgets
from waeup.sirp.interfaces import IExtFileStore
from waeup.sirp.students.interfaces import IStudentsUtils

SLIP_STYLE = [
    ('VALIGN',(0,0),(-1,-1),'TOP'),
    #('FONT', (0,0), (-1,-1), 'Helvetica', 11),
    ]

CONTENT_STYLE = [
    ('VALIGN',(0,0),(-1,-1),'TOP'),
    #('FONT', (0,0), (-1,-1), 'Helvetica', 8),
    #('TEXTCOLOR',(0,0),(-1,0),colors.white),
    ('BACKGROUND',(0,0),(-1,0),colors.black),
    ]

FONT_SIZE = 10
FONT_COLOR = 'black'

def formatted_label(color=FONT_COLOR, size=FONT_SIZE):
    tag1 ='<font color=%s size=%d>' % (color, size)
    return tag1 + '%s:</font>'

def formatted_text(text, color=FONT_COLOR, size=FONT_SIZE):
    """Turn `text`, `color` and `size` into an HTML snippet.

    The snippet is suitable for use with reportlab and generating PDFs.
    Wraps the `text` into a ``<font>`` tag with passed attributes.

    Also non-strings are converted. Raw strings are expected to be
    utf-8 encoded (usually the case for widgets etc.).

    The returned snippet is unicode type.
    """
    if not isinstance(text, unicode):
        if isinstance(text, basestring):
            text = text.decode('utf-8')
        else:
            text = unicode(text)
    tag1 = u'<font color="%s" size="%d">' % (color, size)
    return tag1 + u'%s</font>' % text

def generate_student_id(students,letter):
    if letter == '?':
        letter= r().choice('ABCDEFGHKLMNPQRSTUVWXY')
    sid = u"%c%d" % (letter,r().randint(99999,1000000))
    while sid in students.keys():
        sid = u"%c%d" % (letter,r().randint(99999,1000000))
    return sid

def set_returning_data(student):
    student['studycourse'].current_level += 100
    student['studycourse'].current_session += 1
    verdict = student['studycourse'].current_verdict
    student['studycourse'].current_verdict = '0'
    student['studycourse'].previous_verdict = verdict
    return

def set_up_widgets(view, ignore_request=False):
    view.adapters = {}
    view.widgets = setUpEditWidgets(
        view.form_fields, view.prefix, view.context, view.request,
        adapters=view.adapters, for_display=True,
        ignore_request=ignore_request
        )

def render_student_data(studentview):
    """Render student table for an existing frame.
    """
    width, height = A4
    set_up_widgets(studentview, ignore_request=True)
    data_left = []
    data_right = []
    style = getSampleStyleSheet()
    img = getUtility(IExtFileStore).getFileByContext(
        studentview.context, attr='passport.jpg')
    if img is None:
        from waeup.sirp.browser import DEFAULT_PASSPORT_IMAGE_PATH
        img = open(DEFAULT_PASSPORT_IMAGE_PATH, 'rb')
    doc_img = Image(img.name, width=4*cm, height=4*cm, kind='bound')
    data_left.append([doc_img])
    #data.append([Spacer(1, 12)])
    for widget in studentview.widgets:
        if widget.name == 'form.adm_code':
            continue
        f_label = formatted_label() % widget.label.strip()
        f_label = Paragraph(f_label, style["Normal"])
        f_text = formatted_text(widget())
        f_text = Paragraph(f_text, style["Normal"])
        data_right.append([f_label,f_text])
    table_left = Table(data_left,style=SLIP_STYLE)
    table_right = Table(data_right,style=SLIP_STYLE, colWidths=[4*cm, 10*cm])
    table = Table([[table_left, table_right],],style=SLIP_STYLE)
    return table

def render_table_data(tableheader,tabledata):
    """Render children table for an existing frame.
    """
    data = []
    #data.append([Spacer(1, 12)])
    line = []
    style = getSampleStyleSheet()
    for element in tableheader:
        field = formatted_text(element[0], color='white')
        field = Paragraph(field, style["Normal"])
        line.append(field)
    data.append(line)
    for ticket in tabledata:
        line = []
        for element in tableheader:
              field = formatted_text(getattr(ticket,element[1],u' '))
              field = Paragraph(field, style["Normal"])
              line.append(field)
        data.append(line)
    table = Table(data,colWidths=[
        element[2]*cm for element in tableheader], style=CONTENT_STYLE)
    return table


def insert_footer(pdf,width,style,text=None, number_of_pages=1):
      """Render the whole footer frame.
      """
      story = []
      frame_footer = Frame(1*cm,0,width-(2*cm),1*cm)
      timestamp = datetime.now().strftime("%d/%m/%Y %H:%M:%S")
      left_text = '<font size=10>%s</font>' % timestamp
      story.append(Paragraph(left_text, style["Normal"]))
      frame_footer.addFromList(story,pdf)
      story = []
      frame_footer = Frame(1*cm,0,width-(2*cm),1*cm)
      right_text = '<font size=10>%s Page %s of %s</font>' % (
          text, pdf.getPageNumber(), number_of_pages)
      story.append(Paragraph(right_text, style["Right"]))
      frame_footer.addFromList(story,pdf)

class StudentsUtils(grok.GlobalUtility):
    """A collection of methods subject to customization.
    """
    grok.implements(IStudentsUtils)

    def getPaymentDetails(self,category, student):
        d = {}
        d['p_item'] = u''
        d['amount'] = 0
        d['error'] = u''
        d['p_session'] = student['studycourse'].current_session
        session = str(d['p_session'])
        try:
            academic_session = grok.getSite()['configuration'][session]
        except KeyError:
            d['error'] = u'Session configuration object is not available.'
            return d
        d['surcharge_1'] = academic_session.surcharge_1
        d['surcharge_2'] = academic_session.surcharge_2
        d['surcharge_3'] = academic_session.surcharge_3
        if category == 'schoolfee':
            d['amount'] = academic_session.school_fee_base
            d['p_item'] = student['studycourse'].certificate.code
        elif category == 'clearance':
            d['p_item'] = student['studycourse'].certificate.code
            d['amount'] = academic_session.clearance_fee
        elif category == 'bed_allocation':
            d['p_item'] = self.getAccommodationDetails(student)['bt']
            d['amount'] = academic_session.booking_fee
        return d

    def getAccommodationDetails(self, student):
        d = {}
        d['error'] = u''
        site_configuration = grok.getSite()['configuration']
        d['booking_session'] = site_configuration.accommodation_session
        d['allowed_states'] = site_configuration.accommodation_states
        # Determine bed type
        studycourse = student['studycourse']
        certificate = getattr(studycourse,'certificate',None)
        entry_session = studycourse.entry_session
        current_level = studycourse.current_level
        if not (entry_session and current_level and certificate):
            return
        end_level = certificate.end_level
        if entry_session == grok.getSite()['configuration'].accommodation_session:
            bt = 'fr'
        elif current_level >= end_level:
            bt = 'fi'
        else:
            bt = 're'
        if student.sex == 'f':
            sex = 'female'
        else:
            sex = 'male'
        special_handling = 'regular'
        d['bt'] = u'%s_%s_%s' % (special_handling,sex,bt)
        return d

    # In the standard configuration we select the first bed found,
    # but can also randomize the selection if we like.
    def selectBed(self, available_beds):
        return available_beds[0]

    def renderPDF(self, view, filename='slip.pdf',
        student=None, studentview=None, tableheader=None, tabledata=None):
        # (0,0),(-1,-1) = whole table
        # (0,0),(0,-1) = first column
        # (-1,0),(-1,-1) = last column
        # (0,0),(-1,0) = first row
        # (0,-1),(-1,-1) = last row

        pdf = canvas.Canvas(filename,pagesize=A4)
        pdf.setTitle(view.label)
        pdf.setSubject(view.title)
        pdf.setAuthor('%s (%s)' % (view.request.principal.title,
            view.request.principal.id))
        pdf.setCreator('WAeUP SIRP')
        width, height = A4
        footer_text = view.label
        if student is not None:
            footer_text = "%s - %s - " % (student.student_id, footer_text)
        style = getSampleStyleSheet()
        style.add(ParagraphStyle(name='Right', alignment=TA_RIGHT))
        pdf.line(1*cm,height-(1.8*cm),width-(1*cm),height-(1.8*cm))

        story = []
        frame_header = Frame(1*cm,1*cm,width-(1.7*cm),height-(1.7*cm))
        header_title = getattr(grok.getSite(), 'name', u'Sample University')
        story.append(Paragraph(header_title, style["Heading1"]))
        frame_header.addFromList(story,pdf)

        # Insert student data table
        story = []
        frame_body = Frame(1*cm,1*cm,width-(2*cm),height-(3.5*cm))
        story.append(Paragraph(view.label, style["Heading2"]))
        if student is not None:
            #story.append(Spacer(1, 12))
            story.append(Paragraph('Student Base Data', style["Heading3"]))
            studenttable = render_student_data(studentview)
            story.append(studenttable)

        # Insert widgets
        story.append(Paragraph(view.title, style["Heading3"]))
        set_up_widgets(view)
        data = []
        for widget in view.widgets:
            f_label = formatted_label() % widget.label.strip()
            f_label = Paragraph(f_label, style["Normal"])
            f_text = formatted_text(widget())
            f_text = Paragraph(f_text, style["Normal"])
            data.append([f_label,f_text])
        table = Table(data,style=SLIP_STYLE, colWidths=[5*cm, 13.5*cm])
        story.append(table)

        # Import browser components locally
        # to avoid circular import
        from waeup.sirp.students.viewlets import FileManager
        from waeup.sirp.browser import DEFAULT_IMAGE_PATH
        data = []
        # Collect viewlets
        fm = FileManager(view.context, view.request, view)
        fm.update()
        if fm.viewlets:
            story.append(Paragraph('Scanned Documents', style["Heading3"]))
            # Insert list of scanned documents
            for viewlet in fm.viewlets:
                f_label = formatted_label() % viewlet.label
                f_label = Paragraph(f_label, style["Normal"])
                if viewlet.template.__grok_name__ == 'imagedisplay':
                    # In case we define FileDisplay viewlets with
                    # an imagedisplay template in the customization package
                    img = getUtility(IExtFileStore).getFileByContext(
                        view.context, attr=viewlet.download_name)
                    if img is None:
                        img = open(DEFAULT_IMAGE_PATH, 'rb')
                    doc_img = Image(img.name, width=2*cm, height=1*cm, kind='bound')
                    data.append([f_label,doc_img])
                else:
                    f_text = formatted_text(viewlet.title)
                    f_text = Paragraph(f_text, style["Normal"])
                    data.append([f_label,f_text])
            table = Table(data,style=SLIP_STYLE, colWidths=[5*cm, 13.5*cm])
            story.append(table)

        try:
            frame_body.addFromList(story,pdf)
        except IOError:
            view.flash('Error in image file.')
            return view.redirect(view.url(view.context))

        if tabledata and tableheader:
            insert_footer(pdf,width,style,footer_text,number_of_pages=2)
        else:
            insert_footer(pdf,width,style,footer_text)

        # Insert content table on second page
        if tabledata and tableheader:
            pdf.showPage()
            frame_body = Frame(1*cm,1*cm,width-(2*cm),height-(2*cm))
            story = []
            story.append(Paragraph(view.content_title, style["Heading3"]))
            #story.append(Spacer(1, 12))
            contenttable = render_table_data(tableheader,tabledata)
            story.append(contenttable)
            frame_body.addFromList(story,pdf)
            insert_footer(pdf,width,style,footer_text,number_of_pages=2)

        view.response.setHeader(
            'Content-Type', 'application/pdf')
        return pdf.getpdfdata()