import socket
import threading
import time

import httpx
import uvicorn
from fastapi import FastAPI
from fastapi.staticfiles import StaticFiles
from jinja2 import Environment, PackageLoader

from velping.config import Config, ServiceConfig, load_cfg

http = httpx.Client(
	headers={"User-Agent": "velping"},
	follow_redirects=True,
)
app = FastAPI()
app.mount("/static", StaticFiles(packages=["velping"]), name="static")
uptime: dict[str, list[str]] = {}
templates = Environment(loader=PackageLoader("velping", "templates"))
cfg = load_cfg()


def handle_service_status(
	service_name: str,
	down: bool = False,
	error: str | None = None,
) -> None:
	"""Update service status and send notifications if configured."""
	last_status = uptime[service_name][-1]
	new_status = "O" if down else "I"

	if cfg.ntfy.enabled and last_status != new_status:
		message = f"Service {service_name} is {'offline' if down else 'online'}"
		http.post(
			url=f"https://{cfg.ntfy.server}/{cfg.ntfy.topic}",
			data=message,
		)

	uptime[service_name].pop(0)
	uptime[service_name].append(new_status)

	if down:
		print(f"[E] Error pinging {service_name}: {error}")
	else:
		print(f"[I] Pinging {service_name} succeeded!")


def tcp_ping(service: ServiceConfig) -> None:
	"""Continuously ping a service via TCP."""

	socket_type = socket.AF_INET if service.ipv == 4 else socket.AF_INET6

	while True:
		print(f"[I] Pinging {service.name}")

		try:
			with socket.socket(family=socket_type, type=socket.SOCK_STREAM) as sock:
				sock.settimeout(service.timeout)
				sock.connect((service.hostname, service.port))

			handle_service_status(service_name=service.name, down=False)

		except socket.timeout:
			handle_service_status(
				service_name=service.name,
				down=True,
				error=f"Connection to {service.name} timed out",
			)
		except Exception as err:
			handle_service_status(
				service_name=service.name,
				down=True,
				error=str(err),
			)

		time.sleep(cfg.pinging.rate)


def http_ping(service: ServiceConfig) -> None:
	"""Continuously ping a service via HTTP."""
	while True:
		print(f"[I] Pinging {service.name}")

		try:
			resp = http.get(url=service.url, timeout=service.timeout)
			resp.raise_for_status()
			handle_service_status(service_name=service.name, down=False)

		except Exception as e:
			handle_service_status(
				service_name=service.name,
				down=True,
				error=str(e),
			)

		time.sleep(cfg.pinging.rate)


@app.get("/")
async def root(cfg: Config) -> str:
	template = templates.get_template("index.xht")
	return template.render(
		cfg=cfg,
		services=cfg.services,
		uptime=uptime,
	)


for service in cfg.services:
	uptime[service.name] = ["?"] * cfg.web.pings

	ping_func = http_ping if service.type == "http" else tcp_ping
	threading.Thread(
		target=ping_func,
		args=(service,),
		daemon=True,
	).start()

uvicorn.run(app, host=cfg.web.addr, port=cfg.web.port)