#! /usr/bin/env python
# -*- coding: utf-8 -*-
#
# PyKota : Print Quotas for CUPS
#
# (c) 2003-2013 Jerome Alet <alet@librelogiciel.com>
# 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 3 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, see <http://www.gnu.org/licenses/>.
#
# $Id: pkinvoice 3561 2013-01-04 22:34:24Z jerome $
#
#

"""An invoice generator for PyKota"""

import sys
import os
import pwd
import time
import cStringIO

try :
    from reportlab.pdfgen import canvas
    from reportlab.lib import pagesizes
    from reportlab.lib.units import cm
except ImportError :
    hasRL = False
else :
    hasRL = True

try :
    import PIL.Image
except ImportError :
    hasPIL = False
else :
    hasPIL = True

import pykota.appinit
from pykota.utils import run
from pykota.commandline import PyKotaOptionParser, \
                               checkandset_pagesize, \
                               checkandset_positiveint, \
                               checkandset_percent
from pykota.pdfutils import getPageSize
from pykota.errors import PyKotaToolError, PyKotaCommandLineError
from pykota.tool import PyKotaTool
from pykota.progressbar import Percent

class PKInvoice(PyKotaTool) :
    """A class for invoice generator."""
    validfilterkeys = [ "username",
                        "printername",
                        "hostname",
                        "jobid",
                        "billingcode",
                        "start",
                        "end",
                      ]

    def printVar(self, label, value, size) :
        """Outputs a variable onto the PDF canvas.

           Returns the number of points to substract to current Y coordinate.
        """
        xcenter = (self.pagesize[0] / 2.0) - 1*cm
        self.canvas.saveState()
        self.canvas.setFont("Helvetica-Bold", size)
        self.canvas.setFillColorRGB(0, 0, 0)
        self.canvas.drawRightString(xcenter, self.ypos, "%s :" % label)
        self.canvas.setFont("Courier-Bold", size)
        self.canvas.setFillColorRGB(0, 0, 1)
        self.canvas.drawString(xcenter + 0.5*cm, self.ypos, value)
        self.canvas.restoreState()
        self.ypos -= (size + 4)

    def pagePDF(self, invoicenumber, name, values, unit, vat) :
        """Generates a new page in the PDF document."""
        amount = values["nbcredits"]
        if amount : # is there's something due ?
            ht = ((amount * 10000.0) / (100.0 + vat)) / 100.0
            vatamount = amount - ht
            self.canvas.doForm("background")
            self.ypos = self.yorigine - (cm + 20)
            self.printVar(_("Invoice"), "#%s" % invoicenumber, 22)
            self.printVar(_("Username"), name, 22)
            self.ypos -= 20
            datetime = time.strftime("%c", time.localtime()).decode(self.charset, "replace")
            self.printVar(_("Edited on"), datetime, 14)

            self.ypos -= 20
            self.printVar(_("Number of jobs printed"), str(values["nbjobs"]), 18)
            self.printVar(_("Number of pages printed"), str(values["nbpages"]), 18)
            self.ypos -= 20
            self.printVar(_("Amount due"), "%.3f %s" % (amount, unit), 18)
            if vat :
                self.ypos += 8
                self.printVar("%s (%.2f%%)" % (_("Included VAT"), vat), "%.3f %s" % (vatamount, unit), 14)
            self.canvas.showPage()
            return 1
        return 0

    def initPDF(self, logo) :
        """Initializes the PDF document."""
        self.pdfDocument = cStringIO.StringIO()
        self.canvas = c = canvas.Canvas(self.pdfDocument, \
                                        pagesize=self.pagesize, \
                                        pageCompression=1)

        c.setAuthor(self.effectiveUserName)
        c.setTitle(_("PyKota invoices"))
        c.setSubject(_("Invoices generated with PyKota"))

        self.canvas.beginForm("background")
        self.canvas.saveState()

        self.ypos = self.pagesize[1] - (2 * cm)

        xcenter = self.pagesize[0] / 2.0
        if logo :
            try :
                imglogo = PIL.Image.open(logo)
            except IOError :
                self.printInfo("Unable to open image %s" % logo, "warn")
            else :
                (width, height) = imglogo.size
                multi = float(width) / (8 * cm)
                width = float(width) / multi
                height = float(height) / multi
                self.ypos -= height
                c.drawImage(logo, xcenter - (width / 2.0), \
                                  self.ypos, \
                                  width, height)

        self.ypos -= (cm + 20)
        self.canvas.setFont("Helvetica-Bold", 14)
        self.canvas.setFillColorRGB(0, 0, 0)
        msg = _("Here's the invoice for your printouts")
        self.canvas.drawCentredString(xcenter, self.ypos, "%s :" % msg)

        self.yorigine = self.ypos
        self.canvas.restoreState()
        self.canvas.endForm()

    def endPDF(self, fname) :
        """Flushes the PDF generator."""
        self.canvas.save()
        if fname != "-" :
            outfile = open(fname, "w")
            outfile.write(self.pdfDocument.getvalue())
            outfile.close()
        else :
            sys.stdout.write(self.pdfDocument.getvalue())
            sys.stdout.flush()

    def genInvoices(self, peruser, logo, outfname, firstnumber, unit, vat) :
        """Generates the invoices file."""
        if len(peruser) :
            percent = Percent(self, size=len(peruser))
            if outfname != "-" :
                percent.display("%s...\n" % _("Generating invoices"))

            self.initPDF(logo)
            number = firstnumber
            for (name, values) in peruser.items() :
                number += self.pagePDF(number, name, values, unit, vat)
                if outfname != "-" :
                    percent.oneMore()

            if number > firstnumber :
                self.endPDF(outfname)

            if outfname != "-" :
                percent.done()

    def main(self, arguments, options) :
        """Generate invoices."""
        if not hasRL :
            raise PyKotaToolError, "The ReportLab module is missing. Download it from http://www.reportlab.org"
        if not hasPIL :
            raise PyKotaToolError, "The Python Imaging Library is missing. Download it from http://www.pythonware.com/downloads"

        self.adminOnly()

        self.pagesize = getPageSize(options.pagesize)

        extractonly = {}
        for filterexp in arguments :
            if filterexp.strip() :
                try :
                    (filterkey, filtervalue) = [part.strip() for part in filterexp.split("=")]
                    filterkey = filterkey.lower()
                    if filterkey not in self.validfilterkeys :
                        raise ValueError
                except ValueError :
                    raise PyKotaCommandLineError, _("Invalid filter value [%s], see help.") % filterexp
                else :
                    extractonly.update({ filterkey : filtervalue })

        percent = Percent(self)
        outfname = options.output.strip().encode(sys.getfilesystemencoding())
        if outfname != "-" :
            percent.display("%s..." % _("Extracting datas"))

        username = extractonly.get("username")
        if username :
            user = self.storage.getUser(username)
        else :
            user = None

        printername = extractonly.get("printername")
        if printername :
            printer = self.storage.getPrinter(printername)
        else :
            printer = None

        start = extractonly.get("start")
        end = extractonly.get("end")
        (start, end) = self.storage.cleanDates(start, end)

        jobs = self.storage.retrieveHistory(user=user,
                                            printer=printer,
                                            hostname=extractonly.get("hostname"),
                                            billingcode=extractonly.get("billingcode"),
                                            jobid=extractonly.get("jobid"),
                                            start=start,
                                            end=end,
                                            limit=0)

        peruser = {}
        nbjobs = 0
        nbpages = 0
        nbcredits = 0.0
        percent.setSize(len(jobs))
        if outfname != "-" :
            percent.display("\n")
        for job in jobs :
            if job.JobSize and (job.JobAction not in ("DENY", "CANCEL", "REFUND")) :
                nbpages += job.JobSize
                nbcredits += job.JobPrice
                counters = peruser.setdefault(job.UserName, { "nbjobs" : 0, "nbpages" : 0, "nbcredits" : 0.0 })
                counters["nbpages"] += job.JobSize
                counters["nbcredits"] += job.JobPrice
                counters["nbjobs"] += 1
                nbjobs += 1
                if outfname != "-" :
                    percent.oneMore()
        if outfname != "-" :
            percent.done()
        self.genInvoices(peruser,
                         options.logo.strip().encode(sys.getfilesystemencoding()),
                         outfname,
                         options.number,
                         options.unit or _("Credits"),
                         options.vat)
        if outfname != "-" :
            nbusers = len(peruser)
            self.display("%s\n" % (_("Invoiced %(nbusers)i users for %(nbjobs)i jobs, %(nbpages)i pages and %(nbcredits).3f credits") \
                     % locals()))

if __name__ == "__main__" :
    parser = PyKotaOptionParser(description=_("Invoice generator for PyKota."),
                                usage="pkinvoice [options] [filterexpr]")
    parser.add_option("-l", "--logo",
                            dest="logo",
                            default=u"/usr/share/pykota/logos/pykota.jpeg",
                            help=_("The image to use as a logo. The logo will be drawn at the center top of the page. The default logo is %default."))
    parser.add_option("-p", "--pagesize",
                            type="string",
                            action="callback",
                            callback=checkandset_pagesize,
                            dest="pagesize",
                            default=u"A4",
                            help=_("Set the size of the page. Most well known page sizes are recognized, like 'A4' or 'Letter' to name a few. The default page size is %default."))
    parser.add_option("-n", "--number",
                            dest="number",
                            type="int",
                            action="callback",
                            callback=checkandset_positiveint,
                            default=1,
                            help=_("Set the number of the first invoice. This number will automatically be incremented for each invoice. The default value is %default."))
    parser.add_option("-o", "--output",
                            dest="output",
                            type="string",
                            default=u"-",
                            help=_("The name of the file to which the PDF invoices will be written. If not set or set to '%default', the PDF document will be sent to the standard output."))

    # TODO : due to Python's optparse.py bug #1498146 fixed in rev 46861
    # TODO : we can't use 'default=_("Credits")' for this option
    parser.add_option("-u", "--unit",
                            dest="unit",
                            type="string",
                            help=_("The name of the unit to use on the invoices. The default value is 'Credits' or its locale translation."))

    parser.add_option("-V", "--vat",
                            dest="vat",
                            type="float",
                            action="callback",
                            callback=checkandset_percent,
                            default=0.0,
                            help=_("The value in percent of the applicable VAT to be exposed. The default is %default, meaning no VAT."))

    parser.add_filterexpression("username", _("User's name"))
    parser.add_filterexpression("printername", _("Printer's name"))
    parser.add_filterexpression("hostname", _("Host's name"))
    parser.add_filterexpression("jobid", _("Job's id"))
    parser.add_filterexpression("billingcode", _("Job's billing code"))
    parser.add_filterexpression("start", _("Job's date of printing"))
    parser.add_filterexpression("end", _("Job's date of printing"))

    parser.add_example('--unit EURO --output /tmp/invoices.pdf start=now-30',
                       _("This would generate a PDF document containing invoices for all users who have spent some credits last month. Amounts would be in EURO and not VAT information would be included."))

    run(parser, PKInvoice)