# app/services/sms_service.py

import json
from typing import List
from redis.asyncio import Redis
from app.schemas.sms import ShortMessageDetail


async def save_short_message(
    redis_client: Redis,
    phone: str,
    message: str,
    received_at: str,
    max_ttl: int
) -> ShortMessageDetail:
    """
    将短信保存到 Redis（异步版）
    key: sms:{phone}
    value: JSON 数组（最多保留最近 20 条）
    """
    key = f"sms:{phone}"

    # 1️⃣ 读取已有短信
    existing_data = await redis_client.get(key)
    if existing_data:
        messages = json.loads(existing_data)
    else:
        messages = []

    # 2️⃣ 添加新短信
    new_msg = ShortMessageDetail(
        phone=phone,
        message=message,
        received_at=received_at
    )
    messages.append(new_msg.dict())

    # 3️⃣ 保留最近 20 条
    messages = messages[-20:]

    # 4️⃣ 写回 Redis（重置 TTL）
    await redis_client.setex(
        key,
        max_ttl,
        json.dumps(messages)
    )

    return new_msg


async def query_short_message(
    redis_client: Redis,
    phone: str,
    keyword: str = None,
    sent_at: str = None
) -> List[ShortMessageDetail]:
    """
    从 Redis 查询短信（异步版）
    支持关键字 / 时间过滤
    """
    key = f"sms:{phone}"

    existing_data = await redis_client.get(key)
    if not existing_data:
        return []

    messages = [
        ShortMessageDetail(**m)
        for m in json.loads(existing_data)
    ]

    # 关键字过滤
    if keyword:
        messages = [
            m for m in messages
            if keyword in m.message
        ]

    # 时间过滤（字符串比较，ISO8601 安全）
    if sent_at:
        messages = [
            m for m in messages
            if m.received_at >= sent_at
        ]

    return messages