from __future__ import annotations

import re
import uuid
from dataclasses import dataclass, field
from datetime import datetime, timezone
from typing import Any


def _now() -> str:
    return datetime.now(timezone.utc).isoformat()


@dataclass
class Session:
    id: str
    slots: dict[str, str] = field(default_factory=dict)
    messages: list[dict[str, Any]] = field(default_factory=list)
    phase: str = "collecting"  # collecting | scheme_ready | handoff
    last_scheme: dict[str, Any] | None = None
    created_at: str = field(default_factory=_now)
    updated_at: str = field(default_factory=_now)


class SessionStore:
    def __init__(self) -> None:
        self._sessions: dict[str, Session] = {}

    def create(self) -> Session:
        session = Session(id=str(uuid.uuid4()))
        self._sessions[session.id] = session
        return session

    def get(self, session_id: str) -> Session | None:
        return self._sessions.get(session_id)

    def touch(self, session: Session) -> None:
        session.updated_at = _now()


store = SessionStore()


def looks_like_handoff(text: str, phrases: list[str]) -> bool:
    t = text.strip().lower()
    return any(p.lower() in t for p in phrases)


def naive_fill_slots(message: str, slots_meta: list[dict[str, Any]], current: dict[str, str]) -> dict[str, str]:
    """每轮通常只推进一个槽：先做明确关键词，再把整句写入当前优先空槽。"""
    updated = dict(current)
    text = message.strip()
    if not text:
        return updated

    touched = False

    def set_slot(slot_id: str, value: str) -> None:
        nonlocal touched
        if not updated.get(slot_id):
            updated[slot_id] = value
            touched = True

    if re.search(r"TagPlus|USB|PDF", text, re.I):
        set_slot("tech_category", "TagPlus USB多次记录")
    elif re.search(r"BlueTag|蓝牙|不开箱", text, re.I):
        set_slot("tech_category", "BlueTag蓝牙手机读数")
    elif re.search(r"GAEA|网关|实时", text, re.I):
        set_slot("tech_category", "GAEA网关实时仓储")
    elif "不确定" in text:
        set_slot("tech_category", "不确定")

    if "产线" in text:
        set_slot("scenario", "产线")
    elif "户外" in text:
        set_slot("scenario", "户外监测")
    elif "实验室" in text:
        set_slot("scenario", "实验室小仓")
    elif any(k in text for k in ("冷库", "仓储", "仓库")):
        set_slot("scenario", "冷库仓储")
    elif any(k in text for k in ("冷链", "药品", "疫苗", "生鲜", "冷冻", "保温箱", "运输")):
        set_slot("scenario", text if len(text) <= 40 else "冷链运输")
    if "Fresh Tag" in text or "fresh tag" in text.lower():
        set_slot("scenario", "冷链运输")


    # 本轮若已通过关键词写入至少一个槽，就不再把整句灌进其它空槽
    # 但允许多个关键词槽在同一轮同时写入（如「冷库+实时」）
    if touched:
        return updated


    pending = sorted(
        [s for s in slots_meta if s.get("required") and not updated.get(s["id"])],
        key=lambda s: s.get("priority", 100),
    )
    if pending:
        updated[pending[0]["id"]] = text
        return updated

    optional = sorted(
        [s for s in slots_meta if not s.get("required") and not updated.get(s["id"])],
        key=lambda s: s.get("priority", 100),
    )
    if optional:
        updated[optional[0]["id"]] = text
    return updated


def next_slot_prompt(slots_meta: list[dict[str, Any]], filled: dict[str, str]) -> dict[str, str] | None:
    pending = sorted(
        [s for s in slots_meta if s.get("required") and not (filled.get(s["id"]) or "").strip()],
        key=lambda s: s.get("priority", 100),
    )
    if not pending:
        # optional slots: ask once if empty
        optional = sorted(
            [s for s in slots_meta if not s.get("required") and not (filled.get(s["id"]) or "").strip()],
            key=lambda s: s.get("priority", 100),
        )
        if optional:
            s = optional[0]
            return {"id": s["id"], "label": s["label"], "prompt": s["prompt"]}
        return None
    s = pending[0]
    return {"id": s["id"], "label": s["label"], "prompt": s["prompt"]}