# paperdoorknob: Print glowfic
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation, version 3.


from abc import ABC, abstractmethod
from dataclasses import dataclass
import itertools

from typing import Iterable

from bs4 import BeautifulSoup
from bs4.element import Tag

from images import ImageStore
from texify import Texifier


@dataclass(frozen=True)
class Chunk:
    icon: str | None
    character: str | None
    screen_name: str | None
    author: str | None
    content: Tag

# We avoid the name "post" because the Glowfic community uses the term
# inconsistently:
#  * The Glowfic software sometimes uses "post" to refer to a whole thread
#    (in the URL), sometimes uses "post" to refer to chunks (in the CSS),
#    but mostly uses "post" to refer to just the first chunk in a thread
#    (in the HTML and UI).  The non-first chunks are "replies".
#  * Readers and this software don't need to distinguish first-chunks and
#    non-first-chunks.
#  * Humans in the community tend to use "posts" to mean chunks.


def chunkDOMs(html: BeautifulSoup) -> Iterable[Tag]:
    def text() -> Tag:
        body = html.body
        assert body
        text = body.find_next("div", class_="post-post")
        assert isinstance(text, Tag)
        return text

    def the_replies() -> Iterable[Tag]:
        rs = html.find_all("div", class_="post-reply")
        assert all(isinstance(r, Tag) for r in rs)
        return rs

    return itertools.chain([text()], the_replies())


def makeChunk(chunk_dom: Tag, image_store: ImageStore) -> Chunk:

    def getIcon() -> str | None:
        icon_div = chunk_dom.find_next('div', class_='post-icon')
        if icon_div is None:
            return None
        icon_img = icon_div.find_next('img')
        if icon_img is None:
            return None
        assert isinstance(icon_img, Tag)
        return image_store.get_image(icon_img.attrs['src'])

    def getTextByClass(css_class: str) -> str | None:
        div = chunk_dom.find_next('div', class_=css_class)
        if div is None:
            return None
        return div.text.strip()

    content = chunk_dom.find_next('div', class_='post-content')
    assert isinstance(content, Tag)

    return Chunk(getIcon(),
                 getTextByClass('post-character'),
                 getTextByClass('post-screenname'),
                 getTextByClass('post-author'),
                 content)


def renderIcon(icon_path: str | None, image_size: float) -> bytes:
    return b'\\includegraphics[width=%fmm,height=%fmm,keepaspectratio]{%s}' % (
        image_size, image_size, icon_path.encode('UTF-8')) if icon_path else b''


class Layout(ABC):

    @abstractmethod
    def renderChunk(self, chunk: Chunk) -> bytes:
        raise NotImplementedError()


class ContentOnlyLayout(Layout):

    def __init__(self, texifier: Texifier) -> None:
        self._texifier = texifier

    def renderChunk(self, chunk: Chunk) -> bytes:
        return self._texifier.texify(chunk.content)


class BelowIconLayout(Layout):

    def __init__(self, texifier: Texifier, image_size: float) -> None:
        self._texifier = texifier
        self._image_size = image_size

    def renderChunk(self, chunk: Chunk) -> bytes:
        icon_width = b'0.25\\textwidth'  # TODO: Make this configurable
        return b'''\\begin{wrapfigure}{l}{%s}
%s
%s
%s
%s
\\end{wrapfigure}
%s
''' % (
            icon_width,
            renderIcon(chunk.icon, self._image_size),
            chunk.character.encode('UTF-8') if chunk.character else b'',
            chunk.screen_name.encode('UTF-8') if chunk.screen_name else b'',
            chunk.author.encode('UTF-8') if chunk.author else b'',
            self._texifier.texify(chunk.content))