"""Parse ГОСТ-style captions: Рисунок / Таблица / Листинг (+ продолжения)."""

from __future__ import annotations

import re
from dataclasses import dataclass

from md2gost.word_fix import parse_caption_text

_FIGURE_RE = re.compile(
    r"^(?:Рисунок|Рис\.?)\s+(?P<number>[\d.]+)\s*(?:[—–\-]\s*(?P<title>.+))?$",
    re.IGNORECASE,
)
_TABLE_FULL_RE = re.compile(
    r"^(?:Продолжение\s+)?"
    r"(?P<kind>Таблица|Таблицы|Листинг|Листинга)\s+"
    r"(?P<number>[\d.]+)"
    r"(?:\s*[—–\-]\s*(?P<title>.+))?$",
    re.IGNORECASE,
)
_CONTINUATION_RE = re.compile(r"^Продолжение\s+(?:Таблицы|Листинга)\b", re.IGNORECASE)


@dataclass
class ParsedCaption:
    kind: str  # figure | table | listing
    number: str
    text: str | None = None
    is_continuation: bool = False


def caption_unique_id(kind: str, number: str) -> str:
    """Stable id from display number: 1.1 → fig1_1 / tbl1_1 / lst1_1."""
    safe = str(number).replace(".", "_")
    prefix = {"figure": "fig", "table": "tbl", "listing": "lst"}.get(kind, "obj")
    return f"{prefix}{safe}"


def parse_any_caption(text: str) -> ParsedCaption | None:
    """Parse figure / table / listing captions (including «Продолжение…»)."""
    raw = (text or "").replace("\r", "").replace("\x07", "").strip()
    if not raw:
        return None
    first = raw.split("\n", 1)[0].strip()

    m = _FIGURE_RE.match(first)
    if m:
        title = (m.group("title") or "").strip().rstrip(".") or None
        return ParsedCaption(kind="figure", number=m.group("number"), text=title)

    info = parse_caption_text(first)
    if info is not None:
        title = None
        m2 = _TABLE_FULL_RE.match(first)
        if m2 and m2.group("title"):
            title = m2.group("title").strip().rstrip(".") or None
        else:
            # Strip leading «Таблица N — » / «Продолжение…» for leftover title
            rest = _TABLE_FULL_RE.sub("", first).strip()
            if rest.startswith(("—", "–", "-")):
                rest = rest[1:].strip()
            title = rest.rstrip(".") or None if rest else None
        return ParsedCaption(
            kind=info.kind,
            number=info.number,
            text=title,
            is_continuation=info.is_continuation,
        )

    m3 = _TABLE_FULL_RE.match(first)
    if m3:
        kind_raw = m3.group("kind").lower()
        if kind_raw.startswith("табл"):
            kind = "table"
        elif kind_raw.startswith("лист"):
            kind = "listing"
        else:
            return None
        return ParsedCaption(
            kind=kind,
            number=m3.group("number"),
            text=(m3.group("title") or "").strip().rstrip(".") or None,
            is_continuation=bool(_CONTINUATION_RE.match(first)),
        )
    return None