import redis
from Ansjer.config import SERVER_HOST


# 本地调试把注释打开
# SERVER_HOST = '127.0.0.1'


class RedisObject:

    def __init__(self, db=0, host=SERVER_HOST):
        self.POOL = redis.ConnectionPool(host=host, port=6379, db=db)
        self.CONN = redis.Redis(connection_pool=self.POOL)

    def set_data(self, key, val, expire=0):
        try:
            self.CONN.set(key, val)
            if expire > 0:
                self.CONN.expire(key, expire)
        except Exception as e:
            return False
        else:
            return True

    def set_expire(self, key, ttl):
        self.CONN.expire(key, ttl)

    def get_data(self, key):
        try:
            val = self.CONN.get(key)
        except Exception as e:
            print(repr(e))
            return False
        else:
            if val:
                return val.decode('utf-8')
            else:
                return False

    def del_data(self, key):
        try:
            val = self.CONN.delete(key)
        except Exception as e:
            print(repr(e))
            return False
        else:
            return True

    def get_size(self):
        return self.CONN.dbsize()

    # 向列表插入数据
    def rpush(self, name, val):
        self.CONN.rpush(name, val)

    # 向列表插入列表数据
    def rpush_list(self, name, list_val):
        self.CONN.rpush(name, *list_val)

    def lpop(self, name):
        val = self.CONN.lpop(name)
        if val:
            return val.decode('utf-8')
        else:
            return False

    # 获取列表长度
    def llen(self, name):
        return self.CONN.llen(name=name)

    # 获取列表所有数据
    def lrange(self, name, start, end):
        return self.CONN.lrange(name, start, end)

    # 删除列表指定数据
    def lrem(self, name, num, value):
        """
        num:列表方向，删除个数（0:所有）
        value:删除的值
        """
        return self.CONN.lrem(name, num, value)

    def get_ttl(self, key):
        ttl = self.CONN.ttl(key)
        if ttl:
            return ttl
        else:
            return 0

    def get_keys(self, key):
        keys = self.CONN.keys(key)
        if keys:
            return keys
        else:
            return False

    def set_ex_data(self, key, val, expire=0):
        try:
            self.CONN.setex(name=key, time=expire, value=val)
        except Exception as e:
            return False
        else:
            return True

    def set_hash_data(self, key, kwargs):
        self.CONN.hmset(key, kwargs)

    def get_hash_data(self, key, file):
        value = self.CONN.hmget(key, file)[0]
        if value:
            return value.decode('utf-8')
        else:
            return False

    def get_all_hash_data(self, key):
        return self.CONN.hgetall(key)

    def set_persist(self, key):
        return self.CONN.persist(key)

    def try_lock(self, lock_key, request_id, expire, time_unit_second):
        """
        获取分布式锁 原子性
        :param lock_key: 锁的key
        :param request_id: 请求id
        :param expire: 锁过期时间
        :param time_unit_second: 时间单位（秒）
        :return: True or False
        """
        try:
            # 使用set命令尝试获取锁，并设置nx=True
            result = self.CONN.set(lock_key, request_id, ex=time_unit_second * expire, nx=True)
            return result is not None
        except Exception as e:
            print("redis lock error.", e)
            return False

    def release_lock(self, lock_key, request_id):
        """
        释放锁
        :param lock_key: 锁的key
        :param request_id: 请求id
        :return: True or False
        """
        try:
            # 使用Lua脚本来释放锁，避免在执行脚本时发生异常导致锁无法释放
            lua_script = """
            if redis.call('get', KEYS[1]) == ARGV[1] then
                return redis.call('del', KEYS[1])
            else
                return 0
            end
            """
            result = self.CONN.eval(lua_script, 1, lock_key, request_id)
            return result == 1
        except Exception as e:
            print("redis unlock error.", e)
            return False