svgtemplate.py

#!/usr/bin/env python3

import os
from itertools import zip_longest
import xml.etree.ElementTree as ET
import subprocess
from collections import namedtuple


class SVGTemplate:
    """Template SVG customizing some fields."""

    def __init__(self, tpl, outdir):
        self.tpl = ET.parse(tpl)
        self.outdir = outdir

    def patch(self, record, modifier):
        """Patch SVG using modifier function."""
        self.record = record
        for f, v in zip(record._fields, record):
                tag = self.tpl.find('.//*[@id="{}"]'.format(f))
                modifier(tag, v)

    def write(self, outfname=None):
        """
        Write patched SVG either to outfname if set, or to file name
        generated by fnamegen class property.
        Return outfname.
        """
        fname = outfname if outfname else self.fnamegen(self.record)
        with open(os.path.join(self.outdir, fname), 'wb') as outf:
            self.tpl.write(outf, encoding='utf-8', xml_declaration=True)
        return fname

    def template(self, record, modifier, outfname=None):
        """
        Template SVG using modifier function.
        Write it either to outfname if set, or to file name
        generated by fnamegen class property.
        Return outfname.
        """
        self.patch(record, modifier)
        return self.write(outfname)

    @staticmethod
    def textmodifier(tag, v):
            tag.text = v

    @staticmethod
    def xlinkmodifier(tag, v):
            tag.set('{http://www.w3.org/1999/xlink}href', v)

    def templatetext(self, record, outfname=None):
        """Template SVG text"""
        return self.template(record, self.textmodifier, outfname)

    def templatexlink(self, record, outfname=None):
        """Template SVG xlink"""
        return self.template(record, self.xlinkmodifier, outfname)


def reordercards(cards, rows=4, sheetrows=9, sheetcols=3, dummycard=""):
    """
    Reorder items in a way their ordering
    spans across ROWS rows of paper sheets.
    Fill empty positions with dummy cards.

    [0:8]   [36:44] [72:80]  <- first sheet
    [9:17]  [45:53] [81:89]  <- second sheet
    [18:26] [54:62] [90:98]
    [27:35] [63:71] [99:107]
    """
    module = rows * sheetrows * sheetcols
    cardsets = zip_longest(*[iter(cards)] * module, fillvalue=dummycard)
    for s in cardsets:
        for row in range(rows):
            rowoffset = row * sheetrows
            for sheetcol in range(sheetcols):
                coloffset = sheetcol * sheetrows * rows
                for sheetrow in range(sheetrows):
                    yield s[rowoffset + coloffset + sheetrow]


def gensheets(cards, layout, dummycard="", rows=4, ncards=27):
    """Put ncards cards on a sheet. Fill the rest of sheet with dummy cards.
    Align cards into column, considering rows of subsequent sheets.

    Arguments:
    cards -- an array of SVG file names of cards
    layout -- SVGTemplate() instance of the form layout
    dummycard -- name of card to fill empty spaces with
    rows -- number of sheet rows (used just for annotation)
    ncards -- number of cards per sheet
    """
    Sheet = namedtuple('Sheet', ['pos{}'.format(x) for x in range(ncards)])
    Annotation = namedtuple('Annotation', 'annotation')
    sheets = []
    cardsets = zip_longest(*[iter(cards)] * ncards, fillvalue=dummycard)
    for i, cardset in enumerate(cardsets):
        fname = "sheet{:02d}.svg".format(i+1)
        annotation = "Row: {} Col: {:02}".format(i % rows + 1, i // rows + 1)
        sheet = Sheet(*[c + "#layer1" for c in cardset])
        layout.patch(sheet, SVGTemplate.xlinkmodifier)
        layout.patch(Annotation(annotation), SVGTemplate.textmodifier)
        layout.write(fname)
        sheets.append(fname)
    return sheets


def pdfsheets(sheets):
    """Convert SVG sheets to PDF using Inkscape batch mode.

    Arguments:
    sheets -- list of SVG file names
    """
    isscript = []
    for fname in sheets:
        isscript.append(f'file-open:{fname}')
        isscript.append('export-type:pdf')
        isscript.append(f'export-filename:{fname[:-3]}pdf')
        isscript.append('export-do')
        isscript.append('file-close')
    isscript.append("quit\n")
    isscript = "\n".join(isscript).encode("utf-8")
    subprocess.check_output(['inkscape', '--shell'], input=isscript)


def pdfunite(sheets, output):
    """Unite PDF files into one.

    Arguments:
    sheets -- list of SVG file names (.pdf files are expected instead)
    output -- name of output file
    """
    cmd = ['pdfunite']
    cmd.extend(s.replace('.svg', '.pdf') for s in sheets)
    cmd.append(output)
    subprocess.check_output(cmd)