import xml.etree.ElementTree as ET
import zipfile
from pathlib import Path

from .utils import BaseParser


class Parser(BaseParser):
    """Extract text from open document files."""

    def extract(self, filename, **kwargs):
        # Inspiration from
        # https://github.com/odoo/odoo/blob/master/addons/document/odt2txt.py
        with Path(filename).open("rb") as stream:
            zip_stream = zipfile.ZipFile(stream)
            self.content = ET.fromstring(zip_stream.read("content.xml"))
        return self.to_string()

    def to_string(self):
        """Converts the document to a string."""
        buff = ""
        for child in self.content.iter():
            if child.tag in {self.qn("text:p"), self.qn("text:h")}:
                buff += self.text_to_string(child) + "\n"
        # remove last newline char
        if buff:
            buff = buff[:-1]
        return buff

    def text_to_string(self, element):
        buff = ""
        if element.text is not None:
            buff += element.text
        for child in element:
            if child.tag == self.qn("text:tab"):
                buff += "\t"
                if child.tail is not None:
                    buff += child.tail
            elif child.tag == self.qn("text:s"):
                buff += " "
                if child.get(self.qn("text:c")) is not None:
                    buff += " " * (int(child.get(self.qn("text:c"))) - 1)
                if child.tail is not None:
                    buff += child.tail
            else:
                buff += self.text_to_string(child)
        if element.tail is not None:
            buff += element.tail
        return buff

    def qn(self, namespace):
        """Connect tag prefix to longer namespace"""
        nsmap = {
            "text": "urn:oasis:names:tc:opendocument:xmlns:text:1.0",
        }
        spl = namespace.split(":")
        return f"{{{nsmap[spl[0]]}}}{spl[1]}"