import os
import re
import socket
from http.server import BaseHTTPRequestHandler, HTTPServer

MONITOR_HOST = os.getenv("MONITOR_HOST", "dark3proxy")
MONITOR_PORT = int(os.getenv("MONITOR_PORT", "6800"))
SOCKET_TIMEOUT = float(os.getenv("SOCKET_TIMEOUT", "2"))
EXPORTER_PORT = int(os.getenv("EXPORTER_PORT", "9100"))


def fetch_monitor_data() -> str:
    with socket.create_connection((MONITOR_HOST, MONITOR_PORT), timeout=SOCKET_TIMEOUT) as sock:
        sock.settimeout(SOCKET_TIMEOUT)
        chunks = []
        while True:
            data = sock.recv(4096)
            if not data:
                break
            chunks.append(data)
    return b"".join(chunks).decode("utf-8", errors="replace")


def metric_name(raw_parts: list[str]) -> str:
    name = "_".join(raw_parts).lower()
    name = re.sub(r"[^a-z0-9_]", "_", name)
    name = re.sub(r"_+", "_", name).strip("_")
    if not name or not name[0].isalpha():
        name = f"m_{name}" if name else "m_value"
    return f"proxy_{name}"


def parse_metrics(text: str) -> dict[str, float]:
    metrics: dict[str, float] = {}
    for line in text.splitlines():
        parts = line.strip().split()
        if len(parts) < 2:
            continue
        value_token = parts[-1].replace(",", ".")
        try:
            value = float(value_token)
        except ValueError:
            continue
        name = metric_name(parts[:-1])
        metrics[name] = value
    return metrics


def render_metrics() -> bytes:
    body_lines = []
    try:
        raw = fetch_monitor_data()
        metrics = parse_metrics(raw)
        body_lines.append("proxy_exporter_up 1")
        for name in sorted(metrics):
            body_lines.append(f"{name} {metrics[name]}")
    except Exception:
        body_lines.append("proxy_exporter_up 0")

    body = "\n".join(body_lines) + "\n"
    return body.encode("utf-8")


class Handler(BaseHTTPRequestHandler):
    def do_GET(self):
        if self.path not in ("/metrics", "/"):
            self.send_response(404)
            self.end_headers()
            return

        payload = render_metrics()
        self.send_response(200)
        self.send_header("Content-Type", "text/plain; version=0.0.4; charset=utf-8")
        self.send_header("Content-Length", str(len(payload)))
        self.end_headers()
        self.wfile.write(payload)

    def log_message(self, format, *args):
        return


if __name__ == "__main__":
    server = HTTPServer(("0.0.0.0", EXPORTER_PORT), Handler)
    server.serve_forever()