"""Lightweight document consistency without reparsing the full document."""

from __future__ import annotations

from app.engine.models import SentenceRecord

_FRONTING_TEMPLATES = frozenset(
    {
        "time_subj_manner_verb_place",
        "time_subj_verb_place",
        "time_subj_verb_object",
        "time_subj_verb_object_place",
        "time_front",
        "place_front",
        "adv_subj_verb_object",
    }
)


def suppress_template_streaks(records: list[SentenceRecord]) -> list[SentenceRecord]:
    """Revert consecutive identical fronting templates to reduce repetition."""
    adjusted: list[SentenceRecord] = []
    previous = ""
    for record in records:
        if (
            record.status == "rewritten"
            and record.template_id in _FRONTING_TEMPLATES
            and record.template_id == previous
        ):
            adjusted.append(
                SentenceRecord(
                    index=record.index,
                    original=record.original,
                    rewritten=record.original,
                    confidence=record.confidence,
                    status="reverted",
                    template_id="",
                    sentence_type=record.sentence_type,
                    reasons=record.reasons + ["template_streak"],
                    block_index=record.block_index,
                )
            )
            previous = ""
            continue
        adjusted.append(record)
        previous = record.template_id if record.status == "rewritten" else ""
    return adjusted


def apply_consistency(
    text: str,
    records: list[SentenceRecord],
) -> tuple[str, list[SentenceRecord]]:
    # Entity spellings are already preserved token-for-token by generation and safety.
    return text, suppress_template_streaks(records)