# -*- coding: utf-8 -*-
"""
设计师派单数据库（SQLite）

同一设计师在不同店铺对应不同 group_id，派单时从在线设计师中轮询。
企微群「上线」/「下线」通过 update_online(wechat_user_id, is_online) 更新。
"""
import sqlite3
import os
from typing import Optional

_DB_PATH = os.path.join(os.path.dirname(__file__), "designer_roster_db", "roster.db")
_DB_TYPE = os.getenv("DB_TYPE", "sqlite").lower()
_MYSQL_HOST = os.getenv("MYSQL_HOST", "127.0.0.1")
_MYSQL_PORT = int(os.getenv("MYSQL_PORT", "3306"))
_MYSQL_USER = os.getenv("MYSQL_USER", "root")
_MYSQL_PASSWORD = os.getenv("MYSQL_PASSWORD", "")
_MYSQL_DATABASE = os.getenv("MYSQL_DATABASE", "ai_cs")


class _CompatResult:
    def __init__(self, rows=None, rowcount: int = 0, lastrowid: int = 0):
        self._rows = rows or []
        self.rowcount = rowcount
        self.lastrowid = lastrowid

    def fetchall(self):
        return self._rows

    def fetchone(self):
        return self._rows[0] if self._rows else None


class _PyMySQLCompatConn:
    def __init__(self, conn):
        self._conn = conn

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc, tb):
        if exc_type:
            try:
                self._conn.rollback()
            except Exception:
                pass
        self._conn.close()

    def execute(self, query: str, args=None):
        cur = self._conn.cursor()
        cur.execute(query, args or ())
        rows = cur.fetchall() if cur.description else []
        res = _CompatResult(rows=rows, rowcount=cur.rowcount, lastrowid=getattr(cur, "lastrowid", 0))
        cur.close()
        return res

    def commit(self):
        self._conn.commit()

def _is_mysql() -> bool:
    return _DB_TYPE in ("mysql", "mariadb")

def _sql(query: str) -> str:
    return query.replace("?", "%s") if _is_mysql() else query


def _get_conn() -> sqlite3.Connection:
    if _is_mysql():
        import pymysql
        conn = pymysql.connect(
            host=_MYSQL_HOST,
            port=_MYSQL_PORT,
            user=_MYSQL_USER,
            password=_MYSQL_PASSWORD,
            database=_MYSQL_DATABASE,
            charset="utf8mb4",
            cursorclass=pymysql.cursors.DictCursor,
            autocommit=False,
        )
        return _PyMySQLCompatConn(conn)
    os.makedirs(os.path.dirname(_DB_PATH), exist_ok=True)
    conn = sqlite3.connect(_DB_PATH)
    conn.row_factory = sqlite3.Row
    return conn


def init_db():
    with _get_conn() as conn:
        if _is_mysql():
            conn.execute("""
                CREATE TABLE IF NOT EXISTS designers (
                    id INTEGER PRIMARY KEY AUTO_INCREMENT,
                    name VARCHAR(255) NOT NULL,
                    wechat_user_id VARCHAR(128) UNIQUE NOT NULL
                ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
            """)
            conn.execute("""
                CREATE TABLE IF NOT EXISTS designer_shops (
                    designer_id INTEGER NOT NULL,
                    shop_id VARCHAR(128) NOT NULL,
                    group_id VARCHAR(128) NOT NULL,
                    PRIMARY KEY (designer_id, shop_id),
                    FOREIGN KEY (designer_id) REFERENCES designers(id)
                ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
            """)
            conn.execute("""
                CREATE TABLE IF NOT EXISTS designer_online (
                    wechat_user_id VARCHAR(128) PRIMARY KEY,
                    is_online INTEGER NOT NULL DEFAULT 0,
                    updated_at DATETIME
                ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
            """)
            conn.execute("""
                CREATE TABLE IF NOT EXISTS round_robin (
                    shop_id VARCHAR(128) PRIMARY KEY,
                    last_index INTEGER NOT NULL DEFAULT 0
                ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
            """)
        else:
            conn.execute("""
                CREATE TABLE IF NOT EXISTS designers (
                    id INTEGER PRIMARY KEY AUTOINCREMENT,
                    name TEXT NOT NULL,
                    wechat_user_id TEXT UNIQUE NOT NULL
                )
            """)
            conn.execute("""
                CREATE TABLE IF NOT EXISTS designer_shops (
                    designer_id INTEGER NOT NULL,
                    shop_id TEXT NOT NULL,
                    group_id TEXT NOT NULL,
                    PRIMARY KEY (designer_id, shop_id),
                    FOREIGN KEY (designer_id) REFERENCES designers(id)
                )
            """)
            conn.execute("""
                CREATE TABLE IF NOT EXISTS designer_online (
                    wechat_user_id TEXT PRIMARY KEY,
                    is_online INTEGER NOT NULL DEFAULT 0,
                    updated_at TEXT
                )
            """)
            conn.execute("""
                CREATE TABLE IF NOT EXISTS round_robin (
                    shop_id TEXT PRIMARY KEY,
                    last_index INTEGER NOT NULL DEFAULT 0
                )
            """)
        conn.commit()


init_db()


# ========== 设计师管理 ==========

def add_designer(name: str, wechat_user_id: str) -> int:
    """添加设计师，返回 id"""
    with _get_conn() as conn:
        if _is_mysql():
            conn.execute(
                "INSERT IGNORE INTO designers (name, wechat_user_id) VALUES (%s, %s)",
                (name, wechat_user_id),
            )
        else:
            conn.execute(
                "INSERT OR IGNORE INTO designers (name, wechat_user_id) VALUES (?, ?)",
                (name, wechat_user_id),
            )
        conn.commit()
        row = conn.execute(_sql("SELECT id FROM designers WHERE wechat_user_id = ?"), (wechat_user_id,)).fetchone()
        return row["id"] if row else 0


def set_designer_shop(designer_id: int, shop_id: str, group_id: str):
    """设置设计师在某店铺的分组 ID（同一设计师不同店铺不同 group_id）"""
    with _get_conn() as conn:
        if _is_mysql():
            conn.execute(
                "REPLACE INTO designer_shops (designer_id, shop_id, group_id) VALUES (%s, %s, %s)",
                (designer_id, shop_id, group_id),
            )
        else:
            conn.execute(
                "INSERT OR REPLACE INTO designer_shops (designer_id, shop_id, group_id) VALUES (?, ?, ?)",
                (designer_id, shop_id, group_id),
            )
        conn.commit()


def update_online(wechat_user_id: str, is_online: bool):
    """更新设计师在线状态（企微群「上线」/「下线」解析后调用）"""
    from datetime import datetime
    ts = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
    with _get_conn() as conn:
        if _is_mysql():
            conn.execute(
                "REPLACE INTO designer_online (wechat_user_id, is_online, updated_at) VALUES (%s, %s, %s)",
                (wechat_user_id, 1 if is_online else 0, ts),
            )
        else:
            conn.execute(
                "INSERT OR REPLACE INTO designer_online (wechat_user_id, is_online, updated_at) VALUES (?, ?, ?)",
                (wechat_user_id, 1 if is_online else 0, ts),
            )
        conn.commit()


# ========== 派单 ==========

def get_transfer_group_for_shop(shop_id: str) -> Optional[str]:
    """
    为店铺轮询派单，返回分组 ID。
    从该店铺的在线设计师中轮询选一个，返回其在该店铺的 group_id。
    无人在线则返回 None。
    """
    with _get_conn() as conn:
        rows = conn.execute(_sql("""
            SELECT d.wechat_user_id, ds.group_id
            FROM designer_shops ds
            JOIN designers d ON d.id = ds.designer_id
            JOIN designer_online o ON o.wechat_user_id = d.wechat_user_id AND o.is_online = 1
            WHERE ds.shop_id = ?
        """), (shop_id,)).fetchall()

    if not rows:
        return None

    with _get_conn() as conn:
        rr = conn.execute(_sql("SELECT last_index FROM round_robin WHERE shop_id = ?"), (shop_id,)).fetchone()
        last = rr["last_index"] if rr else 0
        idx = last % len(rows)
        chosen = rows[idx]
        if _is_mysql():
            conn.execute(
                "REPLACE INTO round_robin (shop_id, last_index) VALUES (%s, %s)",
                (shop_id, idx + 1),
            )
        else:
            conn.execute(
                "INSERT OR REPLACE INTO round_robin (shop_id, last_index) VALUES (?, ?)",
                (shop_id, idx + 1),
            )
        conn.commit()

    return chosen["group_id"]


# ========== 查询 ==========

def get_all_wechat_user_ids() -> list:
    """获取所有设计师的 wechat_user_id（用于同步在线状态）"""
    with _get_conn() as conn:
        rows = conn.execute("SELECT wechat_user_id FROM designers").fetchall()
        return [r["wechat_user_id"] for r in rows]


def list_designers():
    """列出所有设计师及其店铺分组"""
    with _get_conn() as conn:
        designers = conn.execute("SELECT id, name, wechat_user_id FROM designers").fetchall()
        result = []
        for d in designers:
            shops = conn.execute(
                _sql("SELECT shop_id, group_id FROM designer_shops WHERE designer_id = ?"),
                (d["id"],),
            ).fetchall()
            online = conn.execute(
                _sql("SELECT is_online FROM designer_online WHERE wechat_user_id = ?"),
                (d["wechat_user_id"],),
            ).fetchone()
            result.append({
                "id": d["id"],
                "name": d["name"],
                "wechat_user_id": d["wechat_user_id"],
                "shops": {s["shop_id"]: s["group_id"] for s in shops},
                "is_online": bool(online and online["is_online"]),
            })
        return result