import os
import asyncio
from datetime import datetime, timedelta
from typing import Optional
from contextlib import asynccontextmanager

from fastapi import FastAPI, Request
from fastapi.responses import HTMLResponse
from fastapi.templating import Jinja2Templates

from monitors import ServiceMonitor, ServiceStatus


# Configuration
BACKEND_URL = os.getenv("BACKEND_URL", "http://backend:8000")
FRONTEND_URL = os.getenv("FRONTEND_URL", "http://frontend:80")
BOT_URL = os.getenv("BOT_URL", "http://bot:8080")
CHECK_INTERVAL = int(os.getenv("CHECK_INTERVAL", "30"))

# Initialize monitor
monitor = ServiceMonitor()

# Background task reference
background_task: Optional[asyncio.Task] = None


async def periodic_health_check():
    """Background task to check services periodically"""
    while True:
        await monitor.check_all_services(
            backend_url=BACKEND_URL,
            frontend_url=FRONTEND_URL,
            bot_url=BOT_URL
        )
        await asyncio.sleep(CHECK_INTERVAL)


@asynccontextmanager
async def lifespan(app: FastAPI):
    """Startup and shutdown events"""
    global background_task
    # Start background health checks
    background_task = asyncio.create_task(periodic_health_check())
    yield
    # Cancel background task on shutdown
    if background_task:
        background_task.cancel()
        try:
            await background_task
        except asyncio.CancelledError:
            pass


app = FastAPI(
    title="Status Monitor",
    description="Service health monitoring",
    lifespan=lifespan
)

templates = Jinja2Templates(directory="templates")


@app.get("/", response_class=HTMLResponse)
async def status_page(request: Request):
    """Main status page"""
    services = monitor.get_all_statuses()
    overall_status = monitor.get_overall_status()

    return templates.TemplateResponse(
        "index.html",
        {
            "request": request,
            "services": services,
            "overall_status": overall_status,
            "last_check": monitor.last_check,
            "check_interval": CHECK_INTERVAL
        }
    )


@app.get("/api/status")
async def api_status():
    """API endpoint for service statuses"""
    services = monitor.get_all_statuses()
    overall_status = monitor.get_overall_status()

    return {
        "overall_status": overall_status,
        "services": {name: status.to_dict() for name, status in services.items()},
        "last_check": monitor.last_check.isoformat() if monitor.last_check else None,
        "check_interval_seconds": CHECK_INTERVAL
    }


@app.get("/api/health")
async def health():
    """Health check for this service"""
    return {"status": "ok", "service": "status-monitor"}


@app.post("/api/refresh")
async def refresh_status():
    """Force refresh all service statuses"""
    await monitor.check_all_services(
        backend_url=BACKEND_URL,
        frontend_url=FRONTEND_URL,
        bot_url=BOT_URL
    )
    return {"status": "refreshed"}