from copy import copy
from dataclasses import dataclass
from typing import Generator

from docx.shared import Parented
from docx.text.paragraph import Paragraph as DocxParagraph
from docx.enum.text import WD_PARAGRAPH_ALIGNMENT

from md2gost.layout_tracker import LayoutState
from md2gost.renderable import Renderable
from md2gost.rendered_info import RenderedInfo
from .paragraph_sizer import ParagraphSizer
from ..util import create_element


# Map category → Word style name
CAPTION_STYLES = {
    "Рисунок": "Caption Figure",
    "Таблица": "Название таблицы",
    "Листинг": "Caption Listing",
}


@dataclass
class CaptionInfo:
    unique_name: str | None
    text: str | None
    with_listing: bool = False
    landscape: bool = False


class Caption(Renderable):
    def __init__(self, parent: Parented, category: str, caption_info: CaptionInfo | None,
                 number: str | None = None, before: bool = True):
        self._parent = parent
        self._before = before
        self._category = category
        self._docx_paragraph = DocxParagraph(create_element("w:p"), parent)

        style_name = CAPTION_STYLES.get(category, "Caption")
        try:
            self._docx_paragraph.style = style_name
        except KeyError:
            try:
                self._docx_paragraph.style = "Caption Table" if category == "Таблица" else "Caption"
            except KeyError:
                self._docx_paragraph.style = "Caption"

        # Format: «Рисунок 1.1 — Название» (or « - » if --emdash-to-hyphen)
        from ..profiles import dash_separator
        self._docx_paragraph.add_run(f"{category} ")
        self._numbering_run = self._docx_paragraph.add_run(str(number) if number else "?")
        if caption_info and caption_info.text:
            text = caption_info.text.strip().rstrip(".")
            if text:
                self._docx_paragraph.add_run(f"{dash_separator()}{text}")

    def center(self):
        self._docx_paragraph.alignment = WD_PARAGRAPH_ALIGNMENT.CENTER

    def render(self, previous_rendered: RenderedInfo, layout_state: LayoutState) -> Generator[
        "RenderedInfo | Renderable", None, None]:
        height_data = ParagraphSizer(
            self._docx_paragraph,
            previous_rendered.docx_element
            if previous_rendered and isinstance(previous_rendered.docx_element, DocxParagraph) else None,
            layout_state.max_width
        ).calculate_height()

        # Table/listing captions use keep_with_next. pageBreakBefore + keepWithNext
        # on a paragraph that Word already wraps to a new page produces a blank
        # page that the layout tracker / debug overlay never sees.
        leftover = 0
        need_new_page = (
            self._before
            and layout_state.current_page_height > 0
            and ((height_data.lines + 2 - 1) * height_data.line_spacing + 1) * height_data.line_height
            > layout_state.remaining_page_height
        )
        if need_new_page:
            leftover = layout_state.remaining_page_height
            height_data = ParagraphSizer(
                self._docx_paragraph,
                None,
                layout_state.max_width
            ).calculate_height()

        self._docx_paragraph.paragraph_format.page_break_before = False
        yield RenderedInfo(self._docx_paragraph, height_data.full + leftover)