"""Local journal shape after the model. Does not invent or rewrite content."""
from __future__ import annotations

import re

NEW_PHASE = re.compile(
    r"^(?:Heute|Gestern|Morgens|Mittags|Abends|Nachts|Danach|Später|Dann|Zuerst|"
    r"Schließlich|Irgendwann|Unterwegs|Zurück|"
    r"Um\s+\d|Nach\s+(?:ca\.|einer|einem|dem|der|kurzer|weiteren)|"
    r"Als\s+(?:wir|ich)\b)",
    re.I,
)


def _strip_roles(text: str) -> str:
    lines = [re.sub(r"^(?:user|assistant):\s*", "", line, flags=re.I) for line in (text or "").splitlines()]
    return "\n".join(lines).strip()


def _norm(text: str) -> str:
    return re.sub(r"[^\w\s]+", " ", re.sub(r"\s+", " ", _strip_roles(text).lower())).strip()


def _turns(user_bodies: list[str]) -> list[str]:
    return [re.sub(r"\s+", " ", item).strip() for item in user_bodies if (item or "").strip()]


def is_verbatim_join(body: str, user_bodies: list[str]) -> bool:
    """Diagnostic helper. Must not be used to overwrite accepted model text."""
    turns = _turns(user_bodies)
    if not turns or not (body or "").strip():
        return False
    got = _norm(body)
    return got == _norm(" ".join(turns)) or got == _norm("\n\n".join(turns))


def paragraphize(body: str) -> str:
    """Optional local preview helper. Must not rewrite an accepted model draft."""
    text = (body or "").strip()
    if "\n\n" in text:
        return text
    sentences = [item.strip() for item in re.split(r"(?<=[.!?])\s+", text) if item.strip()]
    if len(sentences) < 4:
        return text
    chunks: list[str] = []
    current: list[str] = []
    for sentence in sentences:
        split = bool(current) and (NEW_PHASE.match(sentence) or len(current) >= 3)
        if split:
            chunks.append(" ".join(current))
            current = [sentence]
        else:
            current.append(sentence)
    if current:
        chunks.append(" ".join(current))
    return "\n\n".join(chunks)


def shape_journal(
    title: str,
    body: str,
    user_bodies: list[str],
    person_labels: list[str] | None = None,
    *,
    source: str = "model",
) -> tuple[str, str]:
    """Safe technical trim only. Never replaces names, pronouns, or accepted wording."""
    del user_bodies, person_labels
    heading = (title or "").strip()
    text = _strip_roles(body or "").strip()
    if source == "fallback" and "\n\n" not in text:
        text = paragraphize(text)
    return heading, text