import sqlite3
import time
import threading
import functools
from utils import util

def synchronized(func):
    @functools.wraps(func)
    def wrapper(self, *args, **kwargs):
        with self.lock:
            return func(self, *args, **kwargs)
    return wrapper

__content_tb = None
def new_instance():
    global __content_tb
    if __content_tb is None:
        __content_tb = Content_Db()
        __content_tb.init_db()
    return __content_tb

class Content_Db:

    def __init__(self) -> None:
        self.lock = threading.Lock()

    # 初始化数据库
    def init_db(self):
        conn = sqlite3.connect('fay.db')
        c = conn.cursor()
        c.execute('''CREATE TABLE IF NOT EXISTS T_Msg
            (id INTEGER PRIMARY KEY AUTOINCREMENT,
            type        CHAR(10),
            way         CHAR(10),
            content     TEXT    NOT NULL,
            createtime  INT,
            username    TEXT DEFAULT 'User',
            uid         INT);''')
        # 对话采纳记录表
        c.execute('''CREATE TABLE IF NOT EXISTS T_Adopted
            (id INTEGER PRIMARY KEY AUTOINCREMENT,
            msg_id      INTEGER UNIQUE,
            adopted_time INT,
            FOREIGN KEY(msg_id) REFERENCES T_Msg(id));''')
        conn.commit()
        conn.close()

    # 添加对话
    @synchronized
    def add_content(self, type, way, content, username='User', uid=0):
        conn = sqlite3.connect("fay.db")
        cur = conn.cursor()
        try:
            cur.execute("INSERT INTO T_Msg (type, way, content, createtime, username, uid) VALUES (?, ?, ?, ?, ?, ?)",
                        (type, way, content, int(time.time()), username, uid))
            conn.commit()
            last_id = cur.lastrowid
        except Exception as e:
            util.log(1, "请检查参数是否有误: {}".format(e))
            conn.close()
            return 0
        conn.close()
        return last_id

    # 根据ID查询对话记录
    @synchronized
    def get_content_by_id(self, msg_id):
        conn = sqlite3.connect("fay.db")
        cur = conn.cursor()
        cur.execute("SELECT * FROM T_Msg WHERE id = ?", (msg_id,))
        record = cur.fetchone()
        conn.close()
        return record

    # 添加对话采纳记录
    @synchronized
    def adopted_message(self, msg_id):
        conn = sqlite3.connect('fay.db')
        cur = conn.cursor()
        # 检查消息ID是否存在
        cur.execute("SELECT 1 FROM T_Msg WHERE id = ?", (msg_id,))
        if cur.fetchone() is None:
            util.log(1, "消息ID不存在")
            conn.close()
            return False
        try:
            cur.execute("INSERT INTO T_Adopted (msg_id, adopted_time) VALUES (?, ?)", (msg_id, int(time.time())))
            conn.commit()
        except sqlite3.IntegrityError:
            util.log(1, "该消息已被采纳")
            conn.close()
            return False
        conn.close()
        return True

    # 获取对话内容
    @synchronized
    def get_list(self, way, order, limit, uid=0):
        conn = sqlite3.connect("fay.db")
        cur = conn.cursor()
        where_uid = ""
        if int(uid) != 0:
            where_uid = f" AND T_Msg.uid = {uid} "
        base_query = f"""
            SELECT T_Msg.type, T_Msg.way, T_Msg.content, T_Msg.createtime,
                   datetime(T_Msg.createtime, 'unixepoch', 'localtime') AS timetext,
                   T_Msg.username,T_Msg.id,
                   CASE WHEN T_Adopted.msg_id IS NOT NULL THEN 1 ELSE 0 END AS is_adopted
            FROM T_Msg
            LEFT JOIN T_Adopted ON T_Msg.id = T_Adopted.msg_id
            WHERE 1 {where_uid}
        """
        if way == 'all':
            query = base_query + f" ORDER BY T_Msg.id {order} LIMIT ?"
            cur.execute(query, (limit,))
        elif way == 'notappended':
            query = base_query + f" AND T_Msg.way != 'appended' ORDER BY T_Msg.id {order} LIMIT ?"
            cur.execute(query, (limit,))
        else:
            query = base_query + f" AND T_Msg.way = ? ORDER BY T_Msg.id {order} LIMIT ?"
            cur.execute(query, (way, limit))
        list = cur.fetchall()
        conn.close()
        return list
    

    @synchronized
    def get_previous_user_message(self, msg_id):
        conn = sqlite3.connect("fay.db")
        cur = conn.cursor()
        cur.execute("""
            SELECT id, type, way, content, createtime, datetime(createtime, 'unixepoch', 'localtime') AS timetext, username
            FROM T_Msg
            WHERE id < ? AND type != 'fay'
            ORDER BY id DESC
            LIMIT 1
        """, (msg_id,))
        record = cur.fetchone()
        conn.close()
        return record