from asyncio import gather, get_event_loop, run
from functools import partial, wraps
from os import makedirs, path
from typing import List

from PIL import Image
from bs4 import BeautifulSoup, Tag
from lxml.html import fromstring
from pypub import Chapter, Epub, create_chapter_from_string  # type: ignore
from pypub.const import SUPPORTED_TAGS  # type: ignore
from requests import get


UNSUPPORTED_TAGS = ["a", "h3"]
OUTPUT_DIR = "output"


class MyChapter(Chapter):
    def parse_etree(self):
        """generate new filtered element-tree"""
        etree = fromstring(self.content)
        # check if we can minimalize the scope
        body = etree.xpath(".//body")
        etree = body[0] if body else etree
        article = etree.xpath(".//article")
        etree = article[0] if article else etree
        # iterate elements in tree and delete/modify them
        for elem in [elem for elem in etree.iter()][1:]:
            if elem.tag in UNSUPPORTED_TAGS:
                parent = elem.getparent()
                parent.remove(elem)
            # if element tag is supported
            elif elem.tag in SUPPORTED_TAGS:
                # remove attributes not approved for specific tag
                for attr in elem.attrib:
                    if attr != "style" and attr not in SUPPORTED_TAGS[elem.tag]:
                        elem.attrib.pop(attr)
            # if element is not supported, append children to parent
            else:
                parent = elem.getparent()
                for child in elem.getchildren():
                    parent.append(child)
                parent.remove(elem)
                # NOTE: this is a bug with lxml, some children have
                # text in the parent included in the tail rather
                # than text attribute, so we also append tail to text
                if elem.tail and elem.tail.strip():
                    parent.text = (parent.text or "") + elem.tail.strip()
        # ensure all images with no src are removed
        for img in etree.xpath(".//img"):
            if "src" not in img.attrib:
                img.getparent().remove(img)
        # return new element-tree
        return etree

    def replace_images(self, image_dir: str, timeout: int = 10):
        super().replace_images(image_dir, timeout)
        for img in self.etree.xpath(".//img"):
            if img.attrib["src"].startswith("http"):
                img.getparent().remove(img)
            else:
                src = f"{path.dirname(image_dir)}/{img.attrib['src']}"
                image = Image.open(src)
                image.thumbnail((1000, 2000))
                image.save(src)


def async_wrap(func):
    @wraps(func)
    async def run(*args, loop=None, executor=None, **kwargs):
        if loop is None:
            loop = get_event_loop()

        pfunc = partial(func, *args, **kwargs)
        return await loop.run_in_executor(executor, pfunc)

    return run


makedirs(name=OUTPUT_DIR, exist_ok=True)
cover_req = get(
    url="https://i0.wp.com/thefantasyinn.com/wp-content/uploads/2018/08/twi.jpg",
    stream=True,
)
Image.open(cover_req.raw).save(f"{OUTPUT_DIR}/cover.png")


def process_volume(epub: Epub, urls: List[str]):
    for url in urls:
        page_req = get(url)
        page_html = BeautifulSoup(markup=page_req.text, features="lxml")
        page_content = page_html.select_one("div.entry-content")
        page_title = page_html.select_one("h1.entry-title")
        page_date = page_html.find(name="meta", property="article:modified_time")

        if not page_content or not page_title or type(page_date) is not Tag:
            raise Exception()

        galleries = page_content.select("div.tiled-gallery")

        for gallery in galleries:
            gallery.decompose()

        title = page_title.get_text().strip()
        chapter = create_chapter_from_string(
            html=page_content.prettify(),
            title=title,
            factory=MyChapter,
        )

        print(f"{epub.title} - {title}")
        epub.add_chapter(chapter)

    epub.create_epub(OUTPUT_DIR)


@async_wrap
def process_book(url: str, creator: str, publisher: str, language: str):
    toc_req = get(url)
    toc_html = BeautifulSoup(markup=toc_req.text, features="lxml")
    toc_content = toc_html.select("div.entry-content > p")
    toc_title = toc_html.select_one("#site-title > span > a")
    toc_date = toc_html.find(name="meta", property="article:modified_time")

    if not toc_title or type(toc_date) is not Tag:
        raise Exception()

    for i, toc_line in enumerate(toc_content):
        if i % 2 == 0:
            title = toc_title.get_text().strip()
            volume = toc_line.get_text().strip()
        elif volume:
            epub = Epub(
                title=f"{title} - {volume}",
                creator=creator,
                language=language,
                publisher=publisher,
                date=toc_date["content"],
                cover=f"{OUTPUT_DIR}/cover.png",
                epub_dir=f"{OUTPUT_DIR}/{title} - {volume}",
            )

            urls = []
            for link in toc_line.select("a"):
                urls.append(link.attrs["href"])

            process_volume(epub=epub, urls=urls)


async def create_books():
    await gather(
        process_book(
            url="https://aubergevagabonde.wordpress.com/sommaire/",
            creator="Pirateaba",
            publisher="ElliVia",
            language="fr",
        ),
        process_book(
            url="https://wanderinginn.com/table-of-contents/",
            creator="Pirateaba",
            publisher="Xefir",
            language="en",
        ),
        return_exceptions=True,
    )


run(create_books())