#!/usr/bin/python3.7
#
# dumppdf.py - dump pdf contents in XML format.
#
#  usage: dumppdf.py [options] [files ...]
#  options:
#    -i objid : object id
#
import sys, os.path, re
from io import StringIO
from pdfminer.psparser import PSKeyword, PSLiteral, LIT
from pdfminer.pdfparser import PDFParser
from pdfminer.pdfdocument import PDFDocument, PDFNoOutlines
from pdfminer.pdftypes import PDFObjectNotFound, PDFValueError
from pdfminer.pdftypes import PDFStream, PDFObjRef, resolve1, stream_value
from pdfminer.pdfpage import PDFPage
from pdfminer.utils import isnumber, q


ESCAPE = set(map(ord, '&<>"'))
def encode(data):
    buf = StringIO()
    for b in data:
        if b < 32 or 127 <= b or b in ESCAPE:
            buf.write(f'&#{b};')
        else:
            buf.write(chr(b))
    return buf.getvalue()


# dumpxml
def dumpxml(out, obj, mode=None):
    if obj is None:
        out.write('<null />')
        return

    if isinstance(obj, dict):
        out.write('<dict size="%d">\n' % len(obj))
        for (k,v) in obj.items():
            out.write('<key>%s</key>\n' % k)
            out.write('<value>')
            dumpxml(out, v)
            out.write('</value>\n')
        out.write('</dict>')
        return

    if isinstance(obj, list):
        out.write('<list size="%d">\n' % len(obj))
        for v in obj:
            dumpxml(out, v)
            out.write('\n')
        out.write('</list>')
        return

    if isinstance(obj, bytes):
        out.write('<string size="%d">%s</string>' % (len(obj), encode(obj)))
        return

    if isinstance(obj, PDFStream):
        if mode == 'raw':
            out.buffer.write(obj.get_rawdata())
        elif mode == 'binary':
            out.buffer.write(obj.get_data())
        else:
            out.write('<stream>\n<props>\n')
            dumpxml(out, obj.attrs)
            out.write('\n</props>\n')
            if mode == 'text':
                data = obj.get_data()
                out.write('<data size="%d">%s</data>\n' % (len(data), encode(data)))
            out.write('</stream>')
        return

    if isinstance(obj, PDFObjRef):
        out.write('<ref id="%d" />' % obj.objid)
        return

    if isinstance(obj, PSKeyword):
        out.write('<keyword>%s</keyword>' % obj.name)
        return

    if isinstance(obj, PSLiteral):
        out.write('<literal>%s</literal>' % obj.name)
        return

    if isnumber(obj):
        out.write('<number>%s</number>' % obj)
        return

    raise TypeError(obj)

# dumptrailers
def dumptrailers(out, doc):
    for xref in doc.xrefs:
        out.write('<trailer>\n')
        dumpxml(out, xref.trailer)
        out.write('\n</trailer>\n\n')
    return

# dumpallobjs
def dumpallobjs(out, doc, mode=None):
    visited = set()
    out.write('<pdf>')
    for xref in doc.xrefs:
        for objid in xref.get_objids():
            if objid in visited: continue
            visited.add(objid)
            try:
                obj = doc.getobj(objid)
                if obj is None: continue
                out.write('<object id="%d">\n' % objid)
                dumpxml(out, obj, mode=mode)
                out.write('\n</object>\n\n')
            except PDFObjectNotFound as e:
                print >>sys.stderr, 'not found: %r' % e
    dumptrailers(out, doc)
    out.write('</pdf>')
    return

# dumpoutline
def dumpoutline(outfp, fname, objids, pagenos, password=b'',
                dumpall=False, mode=None, extractdir=None):
    with open(fname, 'rb') as fp:
        parser = PDFParser(fp)
        doc = PDFDocument(parser, password)
        pages = dict( (page.pageid, pageno) for (pageno,page)
                      in enumerate(PDFPage.create_pages(doc)) )
        def resolve_dest(dest):
            if isinstance(dest, str):
                dest = resolve1(doc.get_dest(dest))
            elif isinstance(dest, PSLiteral):
                dest = resolve1(doc.get_dest(dest.name))
            if isinstance(dest, dict):
                dest = dest['D']
            return dest
        try:
            outlines = doc.get_outlines()
            outfp.write('<outlines>\n')
            for (level,title,dest,a,se) in outlines:
                pageno = None
                if dest:
                    dest = resolve_dest(dest)
                    pageno = pages[dest[0].objid]
                elif a:
                    action = a.resolve()
                    if isinstance(action, dict):
                        subtype = action.get('S')
                        if subtype and repr(subtype) == '/GoTo' and action.get('D'):
                            dest = resolve_dest(action['D'])
                            pageno = pages[dest[0].objid]
                outfp.write('<outline level="%r" title="%s">\n' % (level, q(s)))
                if dest is not None:
                    outfp.write('<dest>')
                    dumpxml(outfp, dest)
                    outfp.write('</dest>\n')
                if pageno is not None:
                    outfp.write('<pageno>%r</pageno>\n' % pageno)
                outfp.write('</outline>\n')
            outfp.write('</outlines>\n')
        except PDFNoOutlines:
            pass
        parser.close()
    return

# extractembedded
LITERAL_FILESPEC = LIT('Filespec')
LITERAL_EMBEDDEDFILE = LIT('EmbeddedFile')
def extractembedded(outfp, fname, objids, pagenos, password=b'',
                    dumpall=False, mode=None, extractdir=None):
    def extract1(obj):
        filename = os.path.basename(obj['UF'] or obj['F'])
        fileref = obj['EF']['F']
        fileobj = doc.getobj(fileref.objid)
        if not isinstance(fileobj, PDFStream):
            raise PDFValueError(
                'unable to process PDF: reference for %r is not a PDFStream' %
                (filename))
        if fileobj.get('Type') is not LITERAL_EMBEDDEDFILE:
            raise PDFValueError(
                'unable to process PDF: reference for %r is not an EmbeddedFile' %
                (filename))
        path = os.path.join(extractdir, filename)
        if os.path.exists(path):
            raise IOError('file exists: %r' % path)
        print >>sys.stderr, 'extracting: %r' % path
        with open(path, 'wb') as out:
            out.write(fileobj.get_data())
        return

    with open(fname, 'rb') as fp:
        parser = PDFParser(fp)
        doc = PDFDocument(parser, password)
        for xref in doc.xrefs:
            for objid in xref.get_objids():
                obj = doc.getobj(objid)
                if isinstance(obj, dict) and obj.get('Type') is LITERAL_FILESPEC:
                    extract1(obj)
    return

# dumppdf
def dumppdf(outfp, fname, objids, pagenos, password=b'',
            dumpall=False, mode=None, extractdir=None):
    with open(fname, 'rb') as fp:
        parser = PDFParser(fp)
        doc = PDFDocument(parser, password)
        if objids:
            for objid in objids:
                obj = doc.getobj(objid)
                dumpxml(outfp, obj, mode=mode)
        if pagenos:
            for (pageno,page) in enumerate(PDFPage.create_pages(doc)):
                if pageno in pagenos:
                    if mode is not None:
                        for obj in page.contents:
                            obj = stream_value(obj)
                            dumpxml(outfp, obj, mode=mode)
                    else:
                        dumpxml(outfp, page.attrs)
        if dumpall:
            dumpallobjs(outfp, doc, mode=mode)
        if (not objids) and (not pagenos) and (not dumpall):
            dumptrailers(outfp, doc)
        if mode not in ('raw','binary'):
            outfp.write('\n')
    return


# main
def main(argv):
    import getopt
    def usage():
        print ('usage: %s [-P password] [-a] [-p pageid] [-i objid] [-o output] '
               '[-r|-b|-t] [-T] [-O output_dir] [-d] input.pdf ...' % argv[0])
        return 100
    try:
        (opts, args) = getopt.getopt(argv[1:], 'dP:ap:i:o:rbtTO:')
    except getopt.GetoptError:
        return usage()
    if not args: return usage()
    debug = 0
    objids = []
    pagenos = set()
    mode = None
    password = b''
    dumpall = False
    proc = dumppdf
    outfp = sys.stdout
    extractdir = None
    for (k, v) in opts:
        if k == '-d': debug += 1
        elif k == '-P': password = v.encode('ascii')
        elif k == '-a': dumpall = True
        elif k == '-p': pagenos.update( int(x)-1 for x in v.split(',') )
        elif k == '-i': objids.extend( int(x) for x in v.split(',') )
        elif k == '-o': outfp = open(v, 'wb')
        elif k == '-r': mode = 'raw'
        elif k == '-b': mode = 'binary'
        elif k == '-t': mode = 'text'
        elif k == '-T': proc = dumpoutline
        elif k == '-O':
            extractdir = v
            proc = extractembedded
    #
    PDFDocument.debug = debug
    PDFParser.debug = debug
    #
    for fname in args:
        proc(outfp, fname, objids, pagenos, password=password,
             dumpall=dumpall, mode=mode, extractdir=extractdir)
    return

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