"""数字分身管理服务层 — 同步连接数字分身应用的 SQLite 数据库"""
import os
from typing import Optional, Tuple

from sqlalchemy import create_engine, text
from sqlalchemy.orm import sessionmaker, Session

from app.core.config import settings


_engine = None
_SessionLocal: Optional[sessionmaker] = None


def _get_engine_and_session():
    global _engine, _SessionLocal
    if _engine is None:
        db_path = settings.AVATAR_DB_PATH
        if not db_path:
            # 默认路径：从 backend/app/core/ 向上三级
            base = os.path.dirname(os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__)))))
            db_path = os.path.join(base, "digital-avatar-app", "backend", "avatar.db")
        if not os.path.isabs(db_path):
            db_path = os.path.abspath(db_path)
        if not os.path.exists(db_path):
            # 数据库不存在时返回 None，由调用方处理
            return None, None
        _engine = create_engine(
            f"sqlite:///{db_path}",
            connect_args={"check_same_thread": False},
        )
        _SessionLocal = sessionmaker(bind=_engine, autoflush=False, expire_on_commit=False)
    return _engine, _SessionLocal()


def get_session() -> Optional[Session]:
    _, session = _get_engine_and_session()
    return session


def is_available() -> bool:
    """检查数字分身数据库是否可用"""
    engine, _ = _get_engine_and_session()
    return engine is not None


class AvatarService:

    @staticmethod
    def list_avatars(
        db: Session,
        page: int = 1,
        page_size: int = 20,
        keyword: Optional[str] = None,
        status: Optional[str] = None,
    ) -> Tuple[int, list]:
        """分页查询所有数字分身（含归属用户信息）"""
        where_clauses = []
        params = {}

        if keyword:
            where_clauses.append(
                "(a.name LIKE :kw OR a.display_name LIKE :kw)"
            )
            params["kw"] = f"%{keyword}%"

        if status:
            where_clauses.append("a.status = :status")
            params["status"] = status

        where_sql = ""
        if where_clauses:
            where_sql = "WHERE " + " AND ".join(where_clauses)

        # 计数
        count_sql = f"SELECT COUNT(*) FROM avatars a {where_sql}"
        total = db.execute(text(count_sql), params).scalar() or 0

        # 分页查询
        offset = (page - 1) * page_size
        params["limit"] = page_size
        params["offset"] = offset

        query = text(f"""
            SELECT
                a.id, a.name, a.display_name, a.description,
                a.photo_url, a.emoji, a.status, a.token_balance,
                a.config, a.created_at, a.updated_at,
                u.nickname AS owner_nickname,
                u.phone AS owner_phone
            FROM avatars a
            LEFT JOIN users u ON a.owner_id = u.huihui_user_id
            {where_sql}
            ORDER BY a.created_at DESC
            LIMIT :limit OFFSET :offset
        """)
        rows = db.execute(query, params).fetchall()

        items = []
        for row in rows:
            config = {}
            if row.config:
                if isinstance(row.config, str):
                    import json
                    try:
                        config = json.loads(row.config)
                    except (json.JSONDecodeError, ValueError):
                        config = {}
                elif isinstance(row.config, dict):
                    config = row.config
            items.append({
                "id": row.id,
                "name": row.name,
                "display_name": row.display_name,
                "description": row.description or "",
                "photo_url": row.photo_url or "",
                "emoji": row.emoji or "🤖",
                "status": row.status or "active",
                "token_balance": row.token_balance or 0,
                "config": config,
                "owner_nickname": row.owner_nickname or "",
                "owner_phone": row.owner_phone or "",
                "created_at": str(row.created_at) if row.created_at else "",
                "updated_at": str(row.updated_at) if row.updated_at else "",
            })

        return total, items

    @staticmethod
    def get_avatar(db: Session, avatar_id: str) -> Optional[dict]:
        """获取单个数字分身详情"""
        query = text("""
            SELECT
                a.id, a.name, a.display_name, a.description,
                a.photo_url, a.emoji, a.status, a.token_balance,
                a.config, a.created_at, a.updated_at,
                u.nickname AS owner_nickname,
                u.phone AS owner_phone
            FROM avatars a
            LEFT JOIN users u ON a.owner_id = u.huihui_user_id
            WHERE a.id = :avatar_id
        """)
        row = db.execute(query, {"avatar_id": avatar_id}).fetchone()
        if not row:
            return None

        config = {}
        if row.config:
            if isinstance(row.config, str):
                import json
                try:
                    config = json.loads(row.config)
                except (json.JSONDecodeError, ValueError):
                    config = {}
            elif isinstance(row.config, dict):
                config = row.config

        return {
            "id": row.id,
            "name": row.name,
            "display_name": row.display_name,
            "description": row.description or "",
            "photo_url": row.photo_url or "",
            "emoji": row.emoji or "🤖",
            "status": row.status or "active",
            "token_balance": row.token_balance or 0,
            "config": config,
            "owner_nickname": row.owner_nickname or "",
            "owner_phone": row.owner_phone or "",
            "created_at": str(row.created_at) if row.created_at else "",
            "updated_at": str(row.updated_at) if row.updated_at else "",
        }

    @staticmethod
    def update_status(db: Session, avatar_id: str, status: str) -> Optional[dict]:
        """更新数字分身状态（开关机）"""
        query = text("""
            UPDATE avatars SET status = :status, updated_at = datetime('now')
            WHERE id = :avatar_id
        """)
        result = db.execute(query, {"status": status, "avatar_id": avatar_id})
        db.commit()
        if result.rowcount == 0:
            return None
        return AvatarService.get_avatar(db, avatar_id)


avatar_service = AvatarService()