"""Dependency + template sentence restructure — thin re-export of engine stages.

Prefer ``app.engine`` for new code. Kept for scripts that import restructure APIs.
"""

from __future__ import annotations

from app.engine.classify import classify_sentence
from app.engine.models import RewritePlan as ReorderPlan
from app.engine.models import SentenceSlots
from app.engine.parse import extract_slots
from app.engine.plan import build_plan
from app.engine.rewrite import generate_from_plan, reorder_quality_ok
from app.engine.templates import (
    fill_template as _fill_template,
    rank_templates,
    try_because_front,
    try_discourse_front,
)


class RestructureResult:
    def __init__(
        self,
        text: str,
        template_id: str,
        confidence: float,
        plan: ReorderPlan | None = None,
    ) -> None:
        self.text = text
        self.template_id = template_id
        self.confidence = confidence
        self.plan = plan


def plan_reorder(slots: SentenceSlots) -> ReorderPlan | None:
    cands = rank_templates(slots)
    if not cands:
        return None
    return ReorderPlan(
        safe=True,
        slots=slots,
        template_id=cands[0].template_id,
        candidates=cands,
        confidence=cands[0].confidence,
    )


def fill_template(plan: ReorderPlan):
    """Back-compat: accept ReorderPlan like the old API."""
    if plan is None or not plan.slots:
        return None
    tid = plan.template_id or (plan.candidates[0].template_id if plan.candidates else "")
    if not tid:
        return None
    return _fill_template(tid, plan.slots)


def restructure_sentence(text: str, *, min_confidence: float = 0.55) -> RestructureResult | None:
    plan = build_plan(text, min_confidence=min_confidence)
    if not plan.safe:
        return None
    filled = generate_from_plan(plan)
    if not filled:
        return None
    return RestructureResult(
        text=filled,
        template_id=plan.template_id,
        confidence=plan.confidence,
        plan=plan,
    )


_reorder_quality_ok = reorder_quality_ok

__all__ = [
    "SentenceSlots",
    "ReorderPlan",
    "RestructureResult",
    "classify_sentence",
    "extract_slots",
    "plan_reorder",
    "fill_template",
    "restructure_sentence",
    "try_because_front",
    "try_discourse_front",
    "_reorder_quality_ok",
]