from StringIO import StringIO

from pdfminer.pdfparser import PDFParser
from pdfminer.pdfdocument import PDFDocument
from pdfminer.pdfpage import PDFPage
from pdfminer.pdfinterp import PDFResourceManager
from pdfminer.pdfinterp import PDFPageInterpreter as PI
from pdfminer.pdfdevice import PDFDevice
from pdfminer.converter import TextConverter

import utils

__all__ = ['PDF']

class PDFPageInterpreter(PI):
    def process_page(self, page):
        if 1 <= self.debug:
            print >>stderr, 'Processing page: %r' % page
        (x0,y0,x1,y1) = page.mediabox
        if page.rotate == 90:
            ctm = (0,-1,1,0, -y0,x1)
        elif page.rotate == 180:
            ctm = (-1,0,0,-1, x1,y1)
        elif page.rotate == 270:
            ctm = (0,1,-1,0, y1,-x0)
        else:
            ctm = (1,0,0,1, -x0,-y0)
        self.device.outfp.seek(0)
        self.device.outfp.buf = ''
        self.device.begin_page(page, ctm)
        self.render_contents(page.resources, page.contents, ctm=ctm)
        self.device.end_page(page)
        return self.device.outfp.getvalue()

class PDF(list):
    def __init__(self, file, password='', just_text=1):
        self.parser = PDFParser(file)
        self.doc = PDFDocument(self.parser)
        if self.doc.is_extractable:
            self.resmgr = PDFResourceManager()
            self.device = TextConverter(self.resmgr, outfp=StringIO())
            self.interpreter = PDFPageInterpreter(
               self.resmgr, self.device)
            for page in PDFPage.create_pages(self.doc):
                self.append(self.interpreter.process_page(page))
            self.metadata = self.doc.info
        if just_text:
            self._cleanup()

    def _cleanup(self):
        """
        Frees lots of non-textual information, such as the fonts
        and images and the objects that were needed to parse the
        PDF.
        """
        del self.device
        del self.doc
        del self.parser
        del self.resmgr
        del self.interpreter

    def text(self, clean=True):
        """
        Returns the text of the PDF as a single string.
        Options:

          :clean:
            Removes misc cruft, like lots of whitespace.
        """
        if clean:
            return ''.join(utils.trim_whitespace(page) for page in self)
        else:
            return ''.join(self)