Clase PDFHandler

# -*- encoding: utf-8 -*-
from django.template.loader import get_template
from django.template import Context
from django.conf import settings

import cStringIO as StringIO
import ho.pisa as pisa
import datetime
import os
import subprocess


WK_OPCIONES_MULTIPLES_ENTRADAS_A3 = {
    '--margin-bottom ': '0',
    '--margin-left ': '0',
    '--margin-right ': '0',
    '--margin-top ': '0',
    '--orientation ': 'Portrait',
    '--dpi ': '300',
    '--disable-smart-shrinking': '',
    '--page-size ': 'A3',
    '--footer-center ': u""""[page] / [topage]\"""",
    '-q': '',
}

WK_OPCIONES_MULTIPLES_ENTRADAS_186x80 = {
    '--page-width ': '186mm',
    '--page-height ': '80mm',
    '--dpi ': '300',
    '--margin-bottom ': '0',
    '--margin-left ': '0',
    '--margin-right ': '0',
    '--margin-top ': '0',
    '--disable-smart-shrinking': '',
    '-q': '',
}

WK_OPCIONES_ENTRADA_EVENTO_A4 = {
    '--margin-bottom ': '0',
    '--margin-left ': '0',
    '--margin-right ': '0',
    '--margin-top ': '0',
    '--dpi ': '300',
    '--disable-smart-shrinking': '',
    '--page-size ': 'A4',
    '-q': '',
}


class PDFHandler(object):
    """ Se encarga de crear ficheros PDF temporales en el sistema de ficheros
    local, para luego poder usar en cualquier lugar, por ejemplo como respuesta
    de una vista, como creación de un adjunto de un correo.

    Recordar que es mejor que se lancen excepciones desde aquí, y se manipulen
    en la capa superior (vistas generalmente).
    """
    contexto = {}
    wk_options = {'--margin-bottom ': '0',
                  '--margin-left ': '0',
                  '--margin-right ': '0',
                  '--margin-top ': '0',
                  '--dpi ': '96',
                  '--disable-smart-shrinking': '',
                  '-q': '',
                  }

    # Ins
    template_path = None
    template = None
    nombre_base = u''

    # Outs
    pdf_file_path = None
    rendered_filenames = ()  # Lista de absolute paths de ficheros renderizados

    def __init__(self, *args, **kwargs):
        for key, value in kwargs.iteritems():
            setattr(self, key, value)
        super(PDFHandler, self).__init__(*args, **kwargs)
        return

    # Renders privados
    def _render_via_wkhtml(self, **kwargs):
        self.nombre_base += u'%s' % (
            unicode(datetime.datetime.now()).replace(' ', '_'), )
        _filename_in = os.path.join(
            settings.TEMP_ROOT, '%s.html' % self.nombre_base)
        _filein = open(_filename_in, 'w')
        _filein.write(self.template)
        _filein.close()
        self.rendered_filenames += (_filename_in, )

        # PDF
        _cmd_tuple = ('wkhtmltopdf',)
        for item, value in self.wk_options.iteritems():
            _cmd_tuple += (item + value, )
        _filename_out = os.path.join(
            settings.TEMP_ROOT, '%s.pdf' % self.nombre_base)
        _cmd_tuple += (_filename_in, _filename_out, )

        if settings.DEBUG:
            print 'DEBUG;', ' '.join(_cmd_tuple)

        _out = subprocess.call(' '.join(_cmd_tuple), shell=True, close_fds=True)
        if _out != 0:
            raise RuntimeError(
                u"""Salida del wkhtmltopdf: %d - filenamein:
                %s - filenameout: %s - comando: %s""" % (
                    _out, _filename_in, _filename_out, _cmd_tuple, )
            )
        _fileout = open(_filename_out)  # Test
        _fileout.close()
        self.pdf_file_path = _filename_out
        self.rendered_filenames += (_filename_out, )
        return

    def _render_template(self, template, contexto_dict=None, contexto=None):
        _contexto = contexto or Context(contexto_dict)
        self.template = get_template(template)
        self.template = self.template.render(_contexto)
        self.template = self.template.encode("UTF-8")

    # Métodos públicos
    def clear(self):
        # Elimina los ficheros creados
        for item in self.rendered_filenames:
            try:
                os.unlink(item)
            except OSError:
                pass
        self.rendered_filenames = ()
        return

    def render_wkhtmlpdf(self, template, contexto_dict=None, contexto=None):
        self._render_template(template, contexto_dict, contexto)
        self._render_via_wkhtml()
        return

    def render_pisa(self, template, contexto_dict=None, contexto=None):
        from cgi import escape

        result = StringIO.StringIO()
        self._render_template(template, contexto_dict, contexto)
        _pdf = pisa.pisaDocument(
            StringIO.StringIO(self.template), result,
            link_callback=self._fetch_resources_pisa, encoding='UTF-8')
        self.result = result.getvalue()
        return

    def _fetch_resources_pisa(self, uri, rel):
        return settings.MEDIA_ROOT + uri.replace(settings.MEDIA_URL, "/")

    # Customs
    def render_entrada_evento(self, entrada, contexto={}, debug_local=False):
        self.contexto = Context(contexto)
        self.contexto['entrada'] = entrada
        self.contexto['sesion'] = entrada.recibo.inscripcion.tarifa.sesion
        self.contexto['MEDIA_ROOT'] = settings.MEDIA_ROOT
        self.contexto['MEDIA_URL'] = settings.MEDIA_URL

        self.contexto['absolute_static_paths'] = not debug_local

        self.template_path = 'eventos/pdf/entrada_a4.html'
        self.template = get_template(self.template_path)
        self.template = self.template.render(self.contexto)
        self.template = self.template.encode("UTF-8")

        if debug_local:
            return

        self.wk_options.update(WK_OPCIONES_ENTRADA_EVENTO_A4)
        self._render_via_wkhtml()
        return

    # Múltiples: Como norma no se debería usar en vistas
    def render_multiples_entradas_186x80(self, query, contexto={},
                                         debug_local=False, **kwargs):
        self.contexto = Context(contexto)
        self.contexto['object_list'] = query
        self.template_path = kwargs['template']

        if debug_local:
            self.contexto['absolute_static_paths'] = False
            self.contexto['MEDIA_URL'] = settings.MEDIA_URL
        else:
            self.contexto['absolute_static_paths'] = True
            self.contexto['MEDIA_ROOT'] = settings.MEDIA_ROOT

        self.template = get_template(self.template_path)
        self.template = self.template.render(self.contexto)
        self.template = self.template.encode("UTF-8")
        self.wk_options.update(WK_OPCIONES_MULTIPLES_ENTRADAS_186x80)
        self.nombre_base = kwargs['template'].replace('/', '_')
        self._render_via_wkhtml()
        return

    def render_multiples_entradas_evento_a3(self, bloques, contexto={},
                                            debug_local=False, **kwargs):
        """ Página con bloques de diez
        """
        self.contexto = Context(contexto)
        try:
            self.template_path = kwargs['template']
        except KeyError:
            self.template_path = 'eventos/pdf/entradas_multiples_a3.html'

        self.contexto['bloques_entradas'] = bloques

        if debug_local:
            self.contexto['absolute_static_paths'] = False
            self.contexto['MEDIA_URL'] = settings.MEDIA_URL
        else:
            self.contexto['absolute_static_paths'] = True
            self.contexto['MEDIA_ROOT'] = settings.MEDIA_ROOT

        self.template = get_template(self.template_path)
        self.template = self.template.render(self.contexto)
        self.template = self.template.encode("UTF-8")
        self.wk_options = WK_OPCIONES_MULTIPLES_ENTRADAS_A3

        _kwargs = {}
        try:
            self.nombre_base = kwargs['raiz_nombre']
        except KeyError:
            self.nombre_base = kwargs['template'].replace('/', '_')
        self._render_via_wkhtml(**_kwargs)
        return