def merge_pdfs(link_infos, output):
pdf_writer = PdfFileWriter()
# Add parent PDF
pdf_reader = PdfFileReader("parent.pdf")
parent_height = pdf_reader.getPage(0).mediaBox[3]
parent_width = pdf_reader.getPage(0).mediaBox[2]
page_count = pdf_reader.getNumPages()
for page in range(pdf_reader.getNumPages()):
pdf_writer.addPage(pdf_reader.getPage(page))
# Add children PDFs
bad_children = []
for link_info in link_infos:
try:
pdf_reader = PdfFileReader(link_info["id"])
except:
bad_children.append(link_info["id"])
continue
link_info["pgTo"] = page_count
page_count += pdf_reader.getNumPages()
for page in range(pdf_reader.getNumPages()):
# Add each page to the writer object
pdf_writer.addPage(pdf_reader.getPage(page))
pdf_writer.removeLinks()
for link_info in link_infos:
if link_info["id"] in bad_children:
continue
try:
add_link(pdf_writer, link_info["pgNum"], link_info["pgTo"],
link_info["coords"], parent_height, parent_width, True)
except:
print("Failed to add a link for {}".format(link_info))
# Write out the merged PDF
with open(output, 'wb') as out:
pdf_writer.write(out)
def handler(event, context):
# Extract links and S3 URI's for PDF's from step function input
print("Extracting URIs")
html_pdf_uri = event['htmlPdfUri'] + '.pdf'
url_pdf_uris = [x + '.pdf' for x in event['urlPdfUris']]
links = event['links']
# Prep S3 buckets and client
s3_client = boto3.client('s3')
html_bucket = "html-pdfs"
url_bucket = "url-pdfs"
merged_bucket = "merged-pdfs"
# Download the PDF's from S3 into buffer then into file
# TODO remove write to file
print("Downloading HTML PDF")
html_pdf_obj = s3_client.get_object(Bucket=html_bucket, Key=html_pdf_uri)
html_pdf_bytes = html_pdf_obj['Body'].read()
with open("/tmp/html_pdf_file.pdf", 'w+b') as f_obj:
f_obj.write(html_pdf_bytes)
print("Downloading URL PDFs")
for i, url_pdf_uri in enumerate(url_pdf_uris):
url_pdf_obj = s3_client.get_object(Bucket=url_bucket, Key=url_pdf_uri)
url_pdf_bytes = url_pdf_obj['Body'].read()
url_pdf_filename = f"/tmp/url_pdf_file_{i}.pdf"
add_to_links(links, {
'url_pdf_filename': url_pdf_filename,
'url_pdf_uri': url_pdf_uri
})
with open(url_pdf_filename, 'w+b') as f_obj:
f_obj.write(url_pdf_bytes)
# Find root coordinates of where to place links
print("Finding link coordinates")
find_links("/tmp/html_pdf_file.pdf", links)
# Add the PDF's to the merger object
pdf_writer = PdfFileWriter()
# Starting with the html pdf
print("Merging in HTML PDF")
pdf_reader = PdfFileReader("/tmp/html_pdf_file.pdf")
height = pdf_reader.getPage(0).mediaBox[3]
width = pdf_reader.getPage(0).mediaBox[2]
page_count = pdf_reader.getNumPages()
for page in range(page_count):
pdf_writer.addPage(pdf_reader.getPage(page))
# Now add the url pdfs
print("Merging in URL PDFs")
for link in links:
pdf_reader = PdfFileReader(link['url_pdf_filename'])
link["pg_to"] = page_count
page_count += pdf_reader.getNumPages()
for page in range(pdf_reader.getNumPages()):
pdf_writer.addPage(pdf_reader.getPage(page))
pdf_writer.removeLinks()
# Add links to the PDF
print("Linking links")
for link in links:
try:
add_link(pdf_writer,
link["pg_num"],
link["pg_to"],
link["coords"],
height,
width,
True)
except:
print("Failed to add a link for {}".format(link))
# Save the PDF to file
print("Saving merged pdf to S3")
with open("/tmp/merged-pdf.pdf", 'wb') as out:
pdf_writer.write(out)
# Generate ulid for merged PDF filename
merged_name = ulid.new().str + '.pdf'
# Upload the PDF to S3
with open("/tmp/merged-pdf.pdf", "rb") as pdf:
s3_client.put_object(Bucket=merged_bucket, Key=merged_name, Body=pdf)
return {
'status': 201,
'message': "created"
}
