from fastapi import APIRouter, Depends
import psutil
from pydantic import BaseModel
from sqlalchemy.orm import Session as DBSession

from app.core.discord.scheduler import send_useless_tip, send_weather_laundry_notification
from app.core.memory_kb.tagging import backfill_tags
from app.core.weather.weather_cache import get_latest as get_latest_weather
from app.core.memory_kb.word_memory import get_word_pool_with_counts
from app.db.database import get_db

router = APIRouter(prefix="/api/system", tags=["system"])


class MemoryStats(BaseModel):
    cpu_percent: float
    memory_percent: float
    memory_used_mb: float
    memory_total_mb: float
    gpu_memory_used_mb: float | None = None
    gpu_memory_total_mb: float | None = None
    gpu_memory_percent: float | None = None


@router.get("/memory", response_model=MemoryStats)
async def get_memory_stats():
    """CPU と GPU のメモリ使用状況を返す"""
    # CPU/メモリ情報
    cpu_percent = psutil.cpu_percent(interval=0.1)
    memory = psutil.virtual_memory()

    stats = {
        "cpu_percent": cpu_percent,
        "memory_percent": memory.percent,
        "memory_used_mb": memory.used / (1024 * 1024),
        "memory_total_mb": memory.total / (1024 * 1024),
    }

    # GPU 情報（オプション）
    try:
        import pynvml
        pynvml.nvmlInit()
        device_count = pynvml.nvmlDeviceGetCount()
        if device_count > 0:
            handle = pynvml.nvmlDeviceGetHandleByIndex(0)
            mem_info = pynvml.nvmlDeviceGetMemoryInfo(handle)
            stats["gpu_memory_used_mb"] = mem_info.used / (1024 * 1024)
            stats["gpu_memory_total_mb"] = mem_info.total / (1024 * 1024)
            stats["gpu_memory_percent"] = (mem_info.used / mem_info.total) * 100
        pynvml.nvmlShutdown()
    except Exception:
        pass

    return MemoryStats(**stats)


@router.post("/weather-notify/test")
async def test_weather_notify():
    """天気予報→Discord通知を手動で即時実行する（動作確認用）"""
    await send_weather_laundry_notification()
    return {"status": "sent"}


@router.post("/useless-tip/test")
async def test_useless_tip():
    """どうでもいいtips→Discord通知を手動で即時実行する（動作確認用）"""
    await send_useless_tip()
    return {"status": "sent"}


@router.get("/weather/latest")
async def get_latest_weather_data():
    """直近で取得した明日の天気データを返す（未取得ならnull）"""
    return get_latest_weather()


@router.get("/word-pool")
async def get_word_pool():
    """どうでもいいtips生成に使われているワードプールを出現回数順で返す"""
    return get_word_pool_with_counts()


@router.post("/tags/backfill")
async def run_tags_backfill(limit: int | None = None, db: DBSession = Depends(get_db)):
    """過去のユーザーメッセージのうち、タグが未生成のものにまとめてタグを付ける"""
    count = await backfill_tags(db, limit=limit)
    return {"tagged_count": count}