talon/talon/html_quotations.py

"""
The module's functions operate on message bodies trying to extract original
messages (without quoted messages) from html
"""

import regex as re


CHECKPOINT_PREFIX = '#!%!'
CHECKPOINT_SUFFIX = '!%!#'
CHECKPOINT_PATTERN = re.compile(CHECKPOINT_PREFIX + '\d+' + CHECKPOINT_SUFFIX)

# HTML quote indicators (tag ids)
QUOTE_IDS = ['OLK_SRC_BODY_SECTION']


def add_checkpoint(html_note, counter):
    """Recursively adds checkpoints to html tree.
    """
    if html_note.text:
        html_note.text = (html_note.text + CHECKPOINT_PREFIX +
                          str(counter) + CHECKPOINT_SUFFIX)
    else:
        html_note.text = (CHECKPOINT_PREFIX + str(counter) +
                          CHECKPOINT_SUFFIX)
    counter += 1

    for child in html_note.iterchildren():
        counter = add_checkpoint(child, counter)

    if html_note.tail:
        html_note.tail = (html_note.tail + CHECKPOINT_PREFIX +
                          str(counter) + CHECKPOINT_SUFFIX)
    else:
        html_note.tail = (CHECKPOINT_PREFIX + str(counter) +
                          CHECKPOINT_SUFFIX)
    counter += 1

    return counter


def delete_quotation_tags(html_note, counter, quotation_checkpoints):
    """Deletes tags with quotation checkpoints from html tree.
    """
    tag_in_quotation = True

    if quotation_checkpoints[counter]:
        html_note.text = ''
    else:
        tag_in_quotation = False
    counter += 1

    quotation_children = []  # Children tags which are in quotation.
    for child in html_note.iterchildren():
        counter, child_tag_in_quotation = delete_quotation_tags(
            child, counter,
            quotation_checkpoints
        )
        if child_tag_in_quotation:
            quotation_children.append(child)

    if quotation_checkpoints[counter]:
        html_note.tail = ''
    else:
        tag_in_quotation = False
    counter += 1

    if tag_in_quotation:
        return counter, tag_in_quotation
    else:
        # Remove quotation children.
        for child in quotation_children:
            html_note.remove(child)
        return counter, tag_in_quotation


def cut_gmail_quote(html_message):
    ''' Cuts the outermost block element with class gmail_quote. '''
    gmail_quote = html_message.cssselect('.gmail_quote')
    if gmail_quote:
        gmail_quote[0].getparent().remove(gmail_quote[0])
        return True


def cut_microsoft_quote(html_message):
    ''' Cuts splitter block and all following blocks. '''
    splitter = html_message.xpath(
        #outlook 2007, 2010
        "//div[@style='border:none;border-top:solid #B5C4DF 1.0pt;"
        "padding:3.0pt 0cm 0cm 0cm']|"
        #windows mail
        "//div[@style='padding-top: 5px; "
        "border-top-color: rgb(229, 229, 229); "
        "border-top-width: 1px; border-top-style: solid;']"
    )

    if splitter:
        splitter = splitter[0]
        #outlook 2010
        if splitter == splitter.getparent().getchildren()[0]:
            splitter = splitter.getparent()
    else:
        #outlook 2003
        splitter = html_message.xpath(
            "//div"
            "/div[@class='MsoNormal' and @align='center' "
            "and @style='text-align:center']"
            "/font"
            "/span"
            "/hr[@size='3' and @width='100%' and @align='center' "
            "and @tabindex='-1']"
        )
        if len(splitter):
            splitter = splitter[0]
            splitter = splitter.getparent().getparent()
            splitter = splitter.getparent().getparent()

    if len(splitter):
        parent = splitter.getparent()
        after_splitter = splitter.getnext()
        while after_splitter is not None:
            parent.remove(after_splitter)
            after_splitter = splitter.getnext()
        parent.remove(splitter)
        return True

    return False


def cut_by_id(html_message):
    found = False
    for quote_id in QUOTE_IDS:
        quote = html_message.cssselect('#{}'.format(quote_id))
        if quote:
            found = True
            quote[0].getparent().remove(quote[0])
    return found


def cut_blockquote(html_message):
    ''' Cuts blockquote with wrapping elements. '''
    quote = html_message.find('.//blockquote')
    if quote is not None:
        quote.getparent().remove(quote)
        return True


def cut_from_block(html_message):
    """Cuts div tag which wraps block starting with "From:"."""
    # handle the case when From: block is enclosed in some tag
    block = html_message.xpath(
        ("//*[starts-with(mg:text_content(), 'From:')]|"
         "//*[starts-with(mg:text_content(), 'Date:')]"))

    if block:
        block = block[-1]
        while block.getparent() is not None:
            if block.tag == 'div':
                block.getparent().remove(block)
                return True
            else:
                block = block.getparent()
    else:
        # handle the case when From: block goes right after e.g. <hr>
        # and not enclosed in some tag
        block = html_message.xpath(
            ("//*[starts-with(mg:tail(), 'From:')]|"
             "//*[starts-with(mg:tail(), 'Date:')]"))
        if block:
            block = block[0]
            while(block.getnext() is not None):
                block.getparent().remove(block.getnext())
            block.getparent().remove(block)
            return True