from __future__ import annotations

import hashlib
import unicodedata
from dataclasses import dataclass

_BIDI = {"RLE", "LRE", "RLO", "LRO", "PDF", "RLI", "LRI", "FSI", "PDI"}


@dataclass(frozen=True)
class NormalizedText:
    display: str
    analysis: str
    analysis_sha256: bytes
    flags: tuple[str, ...]


def normalize_text(raw: str) -> NormalizedText:
    display = unicodedata.normalize("NFKC", raw.replace("\r\n", "\n").replace("\r", "\n"))
    if len(display) > 10_000:
        raise ValueError("text exceeds 10000 normalized code points")
    flags: set[str] = set()
    analysis: list[str] = []
    scripts: set[str] = set()
    for char in display:
        category = unicodedata.category(char)
        bidi = unicodedata.bidirectional(char)
        name = unicodedata.name(char, "")
        if bidi in _BIDI:
            flags.add("bidi_control")
            continue
        if category == "Cf":
            flags.add("default_ignorable")
            if char in {"\u200b", "\u200c", "\u200d", "\ufeff"}:
                flags.add("zero_width")
            continue
        if char.isspace():
            analysis.append(" " if char != "\n" else "\n")
        else:
            analysis.append(char)
        if "LATIN" in name:
            scripts.add("latin")
        elif "CYRILLIC" in name:
            scripts.add("cyrillic")
    if len(scripts) > 1:
        flags.add("mixed_script")
    analysis_form = "".join(analysis)
    return NormalizedText(
        display=display,
        analysis=analysis_form,
        analysis_sha256=hashlib.sha256(analysis_form.encode()).digest(),
        flags=tuple(sorted(flags)),
    )