import asyncio
import json
import logging
import os
from contextlib import asynccontextmanager
from pathlib import Path

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from fastapi.staticfiles import StaticFiles

from models.schemas import HealthCheck
from routers import drives, enclosures, leds, overview
from services.cache import cache_set, close_cache, init_cache, redis_available
from services.enclosure import discover_enclosures, list_slots
from services.smart import SMART_CACHE_TTL, _run_smartctl, sg_ses_available, smartctl_available
from services.zfs import get_zfs_pool_map

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s [%(levelname)s] %(name)s: %(message)s",
)
logger = logging.getLogger(__name__)

SMART_POLL_INTERVAL = int(os.environ.get("SMART_POLL_INTERVAL", "90"))

_tool_status: dict[str, bool] = {}
_poll_task: asyncio.Task | None = None


async def smart_poll_loop():
    """Pre-warm Redis with SMART data for all drives."""
    await asyncio.sleep(2)  # let app finish starting
    while True:
        try:
            # Discover all enclosure devices
            enclosures_raw = discover_enclosures()
            devices: set[str] = set()
            for enc in enclosures_raw:
                for slot in list_slots(enc["id"]):
                    if slot["device"]:
                        devices.add(slot["device"])

            # Discover host block devices via lsblk
            try:
                proc = await asyncio.create_subprocess_exec(
                    "lsblk", "-d", "-o", "NAME,TYPE", "-J",
                    stdout=asyncio.subprocess.PIPE,
                    stderr=asyncio.subprocess.PIPE,
                )
                stdout, _ = await proc.communicate()
                if stdout:
                    for dev in json.loads(stdout).get("blockdevices", []):
                        if dev.get("type") == "disk":
                            name = dev.get("name", "")
                            if name and name not in devices:
                                devices.add(name)
            except Exception as e:
                logger.warning("lsblk discovery failed in poller: %s", e)

            # Poll each drive and cache result
            for device in sorted(devices):
                try:
                    result = await _run_smartctl(device)
                    await cache_set(f"jbod:smart:{device}", result, SMART_CACHE_TTL)
                except Exception as e:
                    logger.warning("Poll failed for %s: %s", device, e)

            # Pre-warm ZFS map (bypasses cache by calling directly)
            await get_zfs_pool_map()

            logger.info("SMART poll complete: %d devices", len(devices))
        except Exception as e:
            logger.error("SMART poll loop error: %s", e)
        await asyncio.sleep(SMART_POLL_INTERVAL)


@asynccontextmanager
async def lifespan(app: FastAPI):
    global _poll_task
    # Startup
    _tool_status["smartctl"] = smartctl_available()
    _tool_status["sg_ses"] = sg_ses_available()

    if not _tool_status["smartctl"]:
        logger.warning("smartctl not found — install smartmontools for SMART data")
    if not _tool_status["sg_ses"]:
        logger.warning("sg_ses not found — install sg3-utils for enclosure SES data")
    if os.geteuid() != 0:
        logger.warning("Not running as root — smartctl may fail on some devices")

    await init_cache()
    _tool_status["redis"] = redis_available()

    if redis_available():
        _poll_task = asyncio.create_task(smart_poll_loop())

    yield

    # Shutdown
    if _poll_task is not None:
        _poll_task.cancel()
        try:
            await _poll_task
        except asyncio.CancelledError:
            pass
    await close_cache()


app = FastAPI(
    title="JBOD Monitor",
    description="Drive health monitoring for JBOD enclosures",
    version="0.1.0",
    lifespan=lifespan,
)

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_methods=["*"],
    allow_headers=["*"],
)

app.include_router(enclosures.router)
app.include_router(drives.router)
app.include_router(leds.router)
app.include_router(overview.router)


@app.get("/api/health", response_model=HealthCheck, tags=["health"])
async def health():
    _tool_status["redis"] = redis_available()
    return HealthCheck(status="ok", tools=_tool_status)


# Serve built frontend static files — mounted last so /api routes take priority.
STATIC_DIR = Path(__file__).parent / "static"

if STATIC_DIR.exists():
    app.mount("/", StaticFiles(directory=STATIC_DIR, html=True), name="static")