import socket
import threading
import time

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

from velping.config import HTTPServiceConfig, TCPServiceConfig, 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: TCPServiceConfig) -> 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: HTTPServiceConfig) -> 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("/api/v1/status")
async def api_v1_up() -> dict:
	rsp = {"healthy": True, "services": {}}
	for name, record in uptime.items():
		if record[-1] == "I":
			rsp["services"][name] = {"healthy": True}
		else:
			rsp["services"][name] = {"healthy": False}
			rsp["healthy"] = False

	return rsp


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


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)