#!/usr/bin/env python
# Copyright 2014 The PDFium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Expands a hand-written PDF testcase (template) into a valid PDF file.

There are several places in a PDF file where byte-offsets are required. This
script replaces {{name}}-style variables in the input with calculated results

  {{header}} - expands to the header comment required for PDF files.
  {{xref}} - expands to a generated xref table, noting the offset.
  {{trailer}} - expands to a standard trailer with "1 0 R" as the /Root.
  {{startxref} - expands to a startxref directive followed by correct offset.
  {{object x y}} - expands to |x y obj| declaration, noting the offset.
  {{streamlen}} - expands to |/Length n|.
  {{xfapreamble x y}} - expands to an object |x y obj| containing a XML preamble
                        to be used in XFA docs.
  {{xfaconfig x y}} - expands to an object |x y obj| containing a config XML
                      block to be used in XFA docs.
  {{xfalocale x y}} - expands to an object |x y obj| containing a locale XML
                      block to be used in XFA docs.
  {{xfapostamble x y}} - expands to an object |x y obj| containing a XML
                         posteamble to be used in XFA docs.
"""

import cStringIO
import optparse
import os
import re
import sys

class StreamLenState:
  START = 1
  FIND_STREAM = 2
  FIND_ENDSTREAM = 3

class TemplateProcessor:
  HEADER_TOKEN = '{{header}}'
  HEADER_REPLACEMENT = '%PDF-1.7\n%\xa0\xf2\xa4\xf4'

  XREF_TOKEN = '{{xref}}'
  XREF_REPLACEMENT = 'xref\n%d %d\n'

  XREF_REPLACEMENT_N = '%010d %05d n \n'
  XREF_REPLACEMENT_F = '0000000000 65535 f \n'
  # XREF rows must be exactly 20 bytes - space required.
  assert(len(XREF_REPLACEMENT_F) == 20)

  TRAILER_TOKEN = '{{trailer}}'
  TRAILER_REPLACEMENT = 'trailer<< /Root 1 0 R /Size %d >>'

  STARTXREF_TOKEN = '{{startxref}}'
  STARTXREF_REPLACEMENT = 'startxref\n%d'

  OBJECT_PATTERN = r'\{\{object\s+(\d+)\s+(\d+)\}\}'
  OBJECT_REPLACEMENT = r'\1 \2 obj'

  STREAMLEN_TOKEN = '{{streamlen}}'
  STREAMLEN_REPLACEMENT = '/Length %d'

  XFAPREAMBLE_PATTERN = r'\{\{xfapreamble\s+(\d+)\s+(\d+)\}\}'
  XFAPREAMBLE_REPLACEMENT = '%d %d obj\n<<\n  /Length %d\n>>\nstream\n%s\nendstream\nendobj\n'
  XFAPREAMBLE_STREAM = '<xdp:xdp xmlns:xdp="http://ns.adobe.com/xdp/" timeStamp="2018-02-23T21:37:11Z" uuid="21482798-7bf0-40a4-bc5d-3cefdccf32b5">'

  XFAPOSTAMBLE_PATTERN = r'\{\{xfapostamble\s+(\d+)\s+(\d+)\}\}'
  XFAPOSTAMBLE_REPLACEMENT = '%d %d obj\n<<\n  /Length %d\n>>\nstream\n%s\nendstream\nendobj\n'
  XFAPOSTAMBLE_STREAM = '</xdp:xdp>'

  XFACONFIG_PATTERN = r'\{\{xfaconfig\s+(\d+)\s+(\d+)\}\}'
  XFACONFIG_REPLACEMENT = '%d %d obj\n<<\n  /Length %d\n>>\nstream\n%s\nendstream\nendobj\n'
  XFACONFIG_STREAM = '''<config xmlns="http://www.xfa.org/schema/xci/3.0/">
  <agent name="designer">
    <destination>pdf</destination>
    <pdf>
      <fontInfo/>
    </pdf>
  </agent>
  <present>
    <pdf>
      <version>1.7</version>
      <adobeExtensionLevel>8</adobeExtensionLevel>
      <renderPolicy>client</renderPolicy>
      <scriptModel>XFA</scriptModel>
      <interactive>1</interactive>
    </pdf>
    <xdp>
      <packets>*</packets>
    </xdp>
    <destination>pdf</destination>
    <script>
      <runScripts>server</runScripts>
    </script>
  </present>
  <acrobat>
    <acrobat7>
      <dynamicRender>required</dynamicRender>
    </acrobat7>
    <validate>preSubmit</validate>
  </acrobat>
</config>'''

  XFALOCALE_PATTERN = r'\{\{xfalocale\s+(\d+)\s+(\d+)\}\}'
  XFALOCALE_REPLACEMENT = '%d %d obj\n<<\n  /Length %d\n>>\nstream\n%s\nendstream\nendobj\n'
  XFALOCALE_STREAM = '''<localeSet xmlns="http://www.xfa.org/schema/xfa-locale-set/2.7/">
  <locale name="en_US" desc="English (United States)">
    <calendarSymbols name="gregorian">
      <monthNames>
        <month>January</month>
        <month>February</month>
        <month>March</month>
        <month>April</month>
        <month>May</month>
        <month>June</month>
        <month>July</month>
        <month>August</month>
        <month>September</month>
        <month>October</month>
        <month>November</month>
        <month>December</month>
      </monthNames>
      <monthNames abbr="1">
        <month>Jan</month>
        <month>Feb</month>
        <month>Mar</month>
        <month>Apr</month>
        <month>May</month>
        <month>Jun</month>
        <month>Jul</month>
        <month>Aug</month>
        <month>Sep</month>
        <month>Oct</month>
        <month>Nov</month>
        <month>Dec</month>
      </monthNames>
      <dayNames>
        <day>Sunday</day>
        <day>Monday</day>
        <day>Tuesday</day>
        <day>Wednesday</day>
        <day>Thursday</day>
        <day>Friday</day>
        <day>Saturday</day>
      </dayNames>
      <dayNames abbr="1">
        <day>Sun</day>
        <day>Mon</day>
        <day>Tue</day>
        <day>Wed</day>
        <day>Thu</day>
        <day>Fri</day>
        <day>Sat</day>
      </dayNames>
      <meridiemNames>
        <meridiem>AM</meridiem>
        <meridiem>PM</meridiem>
      </meridiemNames>
      <eraNames>
        <era>BC</era>
        <era>AD</era>
      </eraNames>
    </calendarSymbols>
    <datePatterns>
      <datePattern name="full">EEEE, MMMM D, YYYY</datePattern>
      <datePattern name="long">MMMM D, YYYY</datePattern>
      <datePattern name="med">MMM D, YYYY</datePattern>
      <datePattern name="short">M/D/YY</datePattern>
    </datePatterns>
    <timePatterns>
      <timePattern name="full">h:MM:SS A Z</timePattern>
      <timePattern name="long">h:MM:SS A Z</timePattern>
      <timePattern name="med">h:MM:SS A</timePattern>
      <timePattern name="short">h:MM A</timePattern>
    </timePatterns>
    <dateTimeSymbols>GyMdkHmsSEDFwWahKzZ</dateTimeSymbols>
    <numberPatterns>
      <numberPattern name="numeric">z,zz9.zzz</numberPattern>
      <numberPattern name="currency">$z,zz9.99|($z,zz9.99)</numberPattern>
      <numberPattern name="percent">z,zz9%</numberPattern>
    </numberPatterns>
    <numberSymbols>
      <numberSymbol name="decimal">.</numberSymbol>
      <numberSymbol name="grouping">,</numberSymbol>
      <numberSymbol name="percent">%</numberSymbol>
      <numberSymbol name="minus">-</numberSymbol>
      <numberSymbol name="zero">0</numberSymbol>
    </numberSymbols>
    <currencySymbols>
      <currencySymbol name="symbol">$</currencySymbol>
      <currencySymbol name="isoname">USD</currencySymbol>
      <currencySymbol name="decimal">.</currencySymbol>
    </currencySymbols>
    <typefaces>
      <typeface name="Myriad Pro"/>
      <typeface name="Minion Pro"/>
      <typeface name="Courier Std"/>
      <typeface name="Adobe Pi Std"/>
      <typeface name="Adobe Hebrew"/>
      <typeface name="Adobe Arabic"/>
      <typeface name="Adobe Thai"/>
      <typeface name="Kozuka Gothic Pro-VI M"/>
      <typeface name="Kozuka Mincho Pro-VI R"/>
      <typeface name="Adobe Ming Std L"/>
      <typeface name="Adobe Song Std L"/>
      <typeface name="Adobe Myungjo Std M"/>
    </typefaces>
  </locale>
</localeSet>'''

  def __init__(self):
    self.streamlen_state = StreamLenState.START
    self.streamlens = []
    self.offset = 0
    self.xref_offset = 0
    self.max_object_number = 0
    self.objects = {}

  def insert_xref_entry(self, object_number, generation_number):
    self.objects[object_number] = (self.offset, generation_number)
    self.max_object_number = max(self.max_object_number, object_number)

  def generate_xref_table(self):
    result = self.XREF_REPLACEMENT % (0, self.max_object_number + 1)
    for i in range(0, self.max_object_number + 1):
      if i in self.objects:
        result += self.XREF_REPLACEMENT_N % self.objects[i]
      else:
        result += self.XREF_REPLACEMENT_F
    return result

  def preprocess_line(self, line):
    if self.STREAMLEN_TOKEN in line:
      assert(self.streamlen_state == StreamLenState.START)
      self.streamlen_state = StreamLenState.FIND_STREAM
      self.streamlens.append(0)
      return

    if (self.streamlen_state == StreamLenState.FIND_STREAM and
        line.rstrip() == 'stream'):
      self.streamlen_state = StreamLenState.FIND_ENDSTREAM
      return

    if self.streamlen_state == StreamLenState.FIND_ENDSTREAM:
      if line.rstrip() == 'endstream':
        self.streamlen_state = StreamLenState.START
      else:
        self.streamlens[-1] += len(line)

  def process_line(self, line):
    if self.HEADER_TOKEN in line:
      line = line.replace(self.HEADER_TOKEN, self.HEADER_REPLACEMENT)
    if self.STREAMLEN_TOKEN in line:
      sub = self.STREAMLEN_REPLACEMENT % self.streamlens.pop(0)
      line = re.sub(self.STREAMLEN_TOKEN, sub, line)
    if self.XREF_TOKEN in line:
      self.xref_offset = self.offset
      line = self.generate_xref_table()
    if self.TRAILER_TOKEN in line:
      replacement = self.TRAILER_REPLACEMENT % (self.max_object_number + 1)
      line = line.replace(self.TRAILER_TOKEN, replacement)
    if self.STARTXREF_TOKEN in line:
      replacement = self.STARTXREF_REPLACEMENT % self.xref_offset
      line = line.replace(self.STARTXREF_TOKEN, replacement)
    match = re.match(self.OBJECT_PATTERN, line)
    if match:
      self.insert_xref_entry(int(match.group(1)), int(match.group(2)))
      line = re.sub(self.OBJECT_PATTERN, self.OBJECT_REPLACEMENT, line)
    line = self.replace_xfa_tag(line,
                                self.XFAPREAMBLE_PATTERN,
                                self.XFAPREAMBLE_REPLACEMENT,
                                self.XFAPREAMBLE_STREAM)
    line = self.replace_xfa_tag(line,
                                self.XFACONFIG_PATTERN,
                                self.XFACONFIG_REPLACEMENT,
                                self.XFACONFIG_STREAM)
    line = self.replace_xfa_tag(line,
                                self.XFALOCALE_PATTERN,
                                self.XFALOCALE_REPLACEMENT,
                                self.XFALOCALE_STREAM)
    line = self.replace_xfa_tag(line,
                                self.XFAPOSTAMBLE_PATTERN,
                                self.XFAPOSTAMBLE_REPLACEMENT,
                                self.XFAPOSTAMBLE_STREAM)

    self.offset += len(line)
    return line

  def replace_xfa_tag(self, line, pattern, replacement, stream):
    match = re.match(pattern, line)
    if match:
      x = int(match.group(1))
      y = int(match.group(2))
      self.insert_xref_entry(x, y)
      line = replacement % (x, y, len(stream), stream)
    return line


def expand_file(input_path, output_path):
  processor = TemplateProcessor()
  try:
    with open(input_path, 'rb') as infile:
      with open(output_path, 'wb') as outfile:
        preprocessed = cStringIO.StringIO()
        for line in infile:
          preprocessed.write(line)
          processor.preprocess_line(line)
        preprocessed.seek(0)
        for line in preprocessed:
          outfile.write(processor.process_line(line))
  except IOError:
    print >> sys.stderr, 'failed to process %s' % input_path


def main():
  parser = optparse.OptionParser()
  parser.add_option('--output-dir', default='')
  options, args = parser.parse_args()
  for testcase_path in args:
    testcase_filename = os.path.basename(testcase_path)
    testcase_root, _ = os.path.splitext(testcase_filename)
    output_dir = os.path.dirname(testcase_path)
    if options.output_dir:
      output_dir = options.output_dir
    output_path = os.path.join(output_dir, testcase_root + '.pdf')
    expand_file(testcase_path, output_path)
  return 0


if __name__ == '__main__':
  sys.exit(main())