"""
聊天记录数据库（SQLite）
每条消息独立存储，按客户ID分开，支持查询和展示。
"""

import sqlite3
import os
from datetime import datetime
from typing import List, Dict, Optional

_DB_PATH = os.path.join(os.path.dirname(__file__), "chat_log_db", "chats.db")


def _get_conn() -> sqlite3.Connection:
    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():
    """建表（首次运行时自动调用）"""
    with _get_conn() as conn:
        conn.execute("""
            CREATE TABLE IF NOT EXISTS chat_logs (
                id          INTEGER PRIMARY KEY AUTOINCREMENT,
                customer_id TEXT    NOT NULL,
                customer_name TEXT  DEFAULT '',
                acc_id      TEXT    DEFAULT '',
                platform    TEXT    DEFAULT '',
                direction   TEXT    NOT NULL CHECK(direction IN ('in','out')),
                message     TEXT    NOT NULL,
                msg_type    INTEGER DEFAULT 0,
                timestamp   TEXT    NOT NULL
            )
        """)
        conn.execute("CREATE INDEX IF NOT EXISTS idx_customer ON chat_logs(customer_id)")
        conn.execute("CREATE INDEX IF NOT EXISTS idx_ts ON chat_logs(timestamp)")
        # 兼容旧表：若缺少 acc_id 列则补上（必须在创建该列索引之前）
        try:
            conn.execute("ALTER TABLE chat_logs ADD COLUMN acc_id TEXT DEFAULT ''")
        except Exception:
            pass
        conn.execute("CREATE INDEX IF NOT EXISTS idx_acc ON chat_logs(acc_id)")
        conn.commit()


init_db()


# ========== 写入 ==========

def log_message(
    customer_id: str,
    message: str,
    direction: str,              # "in" = 客户发来，"out" = 客服回复
    customer_name: str = "",
    acc_id: str = "",            # 店铺账号ID
    platform: str = "",
    msg_type: int = 0,
):
    """记录一条聊天消息"""
    ts = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
    with _get_conn() as conn:
        conn.execute(
            "INSERT INTO chat_logs "
            "(customer_id, customer_name, acc_id, platform, direction, message, msg_type, timestamp) "
            "VALUES (?,?,?,?,?,?,?,?)",
            (customer_id, customer_name, acc_id, platform, direction, message, msg_type, ts),
        )
        conn.commit()


# ========== 查询 ==========

def get_customers(limit: int = 100) -> List[Dict]:
    """返回所有有记录的客户列表（按最新消息时间排序）"""
    with _get_conn() as conn:
        rows = conn.execute("""
            SELECT
                customer_id,
                MAX(customer_name) AS customer_name,
                MAX(platform)      AS platform,
                COUNT(*)           AS total_msgs,
                SUM(direction='in')  AS recv,
                SUM(direction='out') AS sent,
                MAX(timestamp)     AS last_time
            FROM chat_logs
            GROUP BY customer_id
            ORDER BY last_time DESC
            LIMIT ?
        """, (limit,)).fetchall()
    return [dict(r) for r in rows]


def get_conversation(customer_id: str, limit: int = 200) -> List[Dict]:
    """返回某客户的全部对话记录（按时间升序）"""
    with _get_conn() as conn:
        rows = conn.execute("""
            SELECT id, direction, message, msg_type, timestamp, acc_id
            FROM chat_logs
            WHERE customer_id = ?
            ORDER BY timestamp ASC, id ASC
            LIMIT ?
        """, (customer_id, limit)).fetchall()
    return [dict(r) for r in rows]


def get_recent_conversation(customer_id: str, acc_id: str = "", limit: int = 10) -> List[Dict]:
    """返回某客户近期对话（同店铺），用于企微推送保持连贯"""
    with _get_conn() as conn:
        if acc_id:
            rows = conn.execute("""
                SELECT id, direction, message, timestamp, acc_id
                FROM chat_logs
                WHERE customer_id = ? AND acc_id = ?
                ORDER BY id DESC
                LIMIT ?
            """, (customer_id, acc_id, limit)).fetchall()
        else:
            rows = conn.execute("""
                SELECT id, direction, message, timestamp, acc_id
                FROM chat_logs
                WHERE customer_id = ?
                ORDER BY id DESC
                LIMIT ?
            """, (customer_id, limit)).fetchall()
        out = [dict(r) for r in reversed(rows)]
    return out


def get_conversation_today(customer_id: str) -> List[Dict]:
    """返回某客户今天的对话"""
    today = datetime.now().strftime("%Y-%m-%d")
    with _get_conn() as conn:
        rows = conn.execute("""
            SELECT id, direction, message, msg_type, timestamp
            FROM chat_logs
            WHERE customer_id = ? AND timestamp LIKE ?
            ORDER BY timestamp ASC, id ASC
        """, (customer_id, f"{today}%")).fetchall()
    return [dict(r) for r in rows]


def get_daily_stats(date: str = "") -> List[Dict]:
    """
    返回指定日期各店铺的统计数据。
    date 格式 'YYYY-MM-DD'，默认今天。
    每条记录对应一个 acc_id（店铺）。
    """
    if not date:
        date = datetime.now().strftime("%Y-%m-%d")
    with _get_conn() as conn:
        rows = conn.execute("""
            SELECT
                acc_id,
                platform,
                COUNT(DISTINCT customer_id)          AS unique_customers,
                COUNT(*)                              AS total_msgs,
                SUM(direction='in')                   AS recv,
                SUM(direction='out')                  AS sent,
                MIN(timestamp)                        AS first_msg,
                MAX(timestamp)                        AS last_msg
            FROM chat_logs
            WHERE timestamp LIKE ?
            GROUP BY acc_id
            ORDER BY unique_customers DESC
        """, (f"{date}%",)).fetchall()
    return [dict(r) for r in rows]


def get_daily_conversations(date: str = "") -> List[Dict]:
    """
    返回指定日期每个客户的对话摘要（每人最多取前5条消息用于 AI 摘要）。
    """
    if not date:
        date = datetime.now().strftime("%Y-%m-%d")
    with _get_conn() as conn:
        rows = conn.execute("""
            SELECT
                acc_id,
                customer_id,
                MAX(customer_name)  AS customer_name,
                COUNT(*)            AS msg_count,
                GROUP_CONCAT(
                    CASE WHEN direction='in'  THEN '买:' || SUBSTR(message,1,40)
                         ELSE '客:' || SUBSTR(message,1,40) END,
                    ' | '
                ) AS snippet
            FROM chat_logs
            WHERE timestamp LIKE ?
            GROUP BY acc_id, customer_id
            ORDER BY acc_id, MAX(timestamp) DESC
        """, (f"{date}%",)).fetchall()
    return [dict(r) for r in rows]


def search_messages(keyword: str, customer_id: Optional[str] = None, limit: int = 50) -> List[Dict]:
    """全文搜索消息"""
    if customer_id:
        with _get_conn() as conn:
            rows = conn.execute("""
                SELECT customer_id, customer_name, direction, message, timestamp
                FROM chat_logs
                WHERE customer_id = ? AND message LIKE ?
                ORDER BY timestamp DESC LIMIT ?
            """, (customer_id, f"%{keyword}%", limit)).fetchall()
    else:
        with _get_conn() as conn:
            rows = conn.execute("""
                SELECT customer_id, customer_name, direction, message, timestamp
                FROM chat_logs
                WHERE message LIKE ?
                ORDER BY timestamp DESC LIMIT ?
            """, (f"%{keyword}%", limit)).fetchall()
    return [dict(r) for r in rows]