184 lines
6.7 KiB
Python
184 lines
6.7 KiB
Python
import os
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import markdown
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from .bookmark import Bookmark
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import html5lib
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from PyPDF2 import PdfFileWriter, PdfFileReader
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import tempfile
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import logging
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_logger = logging.getLogger(__name__)
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""" Main Stitcher class """
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class Stitcher:
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def __init__(self, inputBuffer):
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self.files = []
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self.currentPage = 1
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self.title = None
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self.bookmarks = []
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self.currentLevel = None
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self.oldBookmarks = []
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self.dir = os.path.dirname(os.path.abspath(inputBuffer.name))
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# TODO: This is a hack
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os.chdir(self.dir)
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text = inputBuffer.read()
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md = markdown.Markdown(extensions=['attr_list', 'meta'])
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html = md.convert(text)
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self.attributes = md.Meta
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document = html5lib.parseFragment(html, namespaceHTMLElements=False)
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for e in document.iter():
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self.iter(e)
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def _get_pdf_number_of_pages(self, filename):
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assert os.path.isfile(filename) and os.access(filename, os.R_OK), \
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"File {} doesn't exist or isn't readable".format(filename)
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pdf_reader = PdfFileReader(open(filename, "rb"))
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return pdf_reader.numPages
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def _getAttribute(self, key):
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return self.attributes.get(key, [None])[0]
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def iter(self, element):
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tag = element.tag
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b = None
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if(tag=='h1'):
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if (self.title == None):
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self.title = element.text
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b = Bookmark(self.currentPage, element.text, 1)
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self.currentLevel = 1
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elif(tag=='h2'):
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b = Bookmark(self.currentPage, element.text, 2)
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self.currentLevel = 2
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elif(tag =='h3'):
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b = Bookmark(self.currentPage, element.text, 3)
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self.currentLevel = 3
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elif(tag =='a'):
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file = element.attrib.get('href')
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b = Bookmark(self.currentPage, element.text, self.currentLevel+1)
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self.files.append((file, self.currentPage))
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# _logger.info("File: %s starts at %s", file, self.currentLevel)
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self.currentPage += self._get_pdf_number_of_pages(file)
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if b:
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self.bookmarks.append(b)
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def _existingBookmarkConfig(self):
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return self._getAttribute('existing_bookmarks')
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def _removeExistingBookmarks(self):
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return (self._existingBookmarkConfig() == 'remove')
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def _flattenBookmarks(self):
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return (self._existingBookmarkConfig() == 'flatten')
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"""
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Adds the existing bookmarks into the
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self.bookmarks list
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"""
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def _add_existing_bookmarks(self):
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self.bookmarks.sort()
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bookmarks = self.bookmarks.copy()
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if (self._removeExistingBookmarks() != True):
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for b in self.oldBookmarks:
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outer_level = self._get_level_from_page_number(b.page+1)
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if (self._flattenBookmarks()):
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increment = 2
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else:
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increment = b.level
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level = outer_level + increment - 1
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bookmarks.append(Bookmark(b.page+1, b.title, level))
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bookmarks.sort()
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self.bookmarks = bookmarks
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"""
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Gets the last bookmkark level at a given page number
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on the combined PDF
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"""
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def _get_level_from_page_number(self, page):
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previousBookmarkLevel = self.bookmarks[0].level
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for b in self.bookmarks:
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# _logger.info("testing: %s (P%s) [L%s]", b.title, b.page, b.level)
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if (b.page > page):
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# _logger.info("Returning L%s", previousBookmarkLevel)
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return previousBookmarkLevel
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previousBookmarkLevel = b.level
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return previousBookmarkLevel
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"""
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Recursive method to read the old bookmarks (which are nested)
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and push them to self.oldBookmarks
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"""
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def _iterate_old_bookmarks(self, pdf, startPage, bookmarks, level = 1):
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if (isinstance(bookmarks, list)):
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for inner_bookmark in bookmarks:
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self._iterate_old_bookmarks(pdf, startPage, inner_bookmark, level+1)
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else:
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localPageNumber = pdf.getDestinationPageNumber(bookmarks)
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globalPageNumber = startPage + localPageNumber - 1
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b = Bookmark(globalPageNumber, bookmarks.title, level)
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self.oldBookmarks.append(b)
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"""
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Insert the bookmarks into the PDF file
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Ref: https://stackoverflow.com/a/18867646
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# TODO: Interleave this into the merge method somehow
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"""
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def _update_metadata(self, old_filename, outputFilename):
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stack = []
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pdfInput = PdfFileReader(open(old_filename, 'rb'))
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pdfOutput = PdfFileWriter()
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pdfOutput.cloneDocumentFromReader(pdfInput)
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for b in self.bookmarks:
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existingRef = None
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# Trim the stack till the top is useful (stack.level < b.level)
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while len(stack) > 0 and stack[len(stack)-1][0].level >= b.level:
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stack.pop()
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# If stack has something, use it
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if (len(stack) > 0):
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existingRef = stack[len(stack) - 1]
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stack.append((b, pdfOutput.addBookmark(b.title, b.page - 1, existingRef[1])))
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# Else, push to top
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else:
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stack.append((b, pdfOutput.addBookmark(b.title, b.page - 1)))
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pdfOutput.write(open(outputFilename, 'wb'))
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"""
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Merge the PDF files together in order
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and iterate through the old bookmarks
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as we're reading them
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"""
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def _merge(self, output):
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writer = PdfFileWriter()
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for (inputFile,startPage) in self.files:
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assert os.path.isfile(inputFile), ERROR_PATH.format(inputFile)
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reader = PdfFileReader(open(inputFile, 'rb'))
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# Recursively iterate through the old bookmarks
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self._iterate_old_bookmarks(reader, startPage, reader.getOutlines())
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for page in range(1, reader.getNumPages()+1):
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writer.addPage(reader.getPage(page - 1))
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writer.write(output)
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output.close()
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"""
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Main entrypoint to generate the final PDF
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"""
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def generate(self, outputFilename, cleanup = False):
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tempPdf = tempfile.NamedTemporaryFile(suffix=".pdf", delete=False)
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self._merge(tempPdf)
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# Only read the additional bookmarks if we're not removing them
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if (not self._removeExistingBookmarks())
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self._add_existing_bookmarks()
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self._update_metadata(tempPdf.name, outputFilename)
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if (cleanup):
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_logger.info("Deleting temporary files")
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os.remove(tempMetadataFile.name)
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os.remove(tempPdf.name)
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else:
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# Why print? Because this is not logging, this is output
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print("Temporary files saved as ", tempPdf.name, tempMetadataFile.name)
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