import type { PatternData, ComputeParams, ScanParams } from './types';

const BASE_URL = '';

export async function fetchPattern(params: ComputeParams): Promise<PatternData> {
  const resp = await fetch(`${BASE_URL}/api/pattern/compute`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(params),
  });
  if (!resp.ok) {
    const body = await resp.text();
    throw new Error(`Compute failed (${resp.status}): ${body}`);
  }
  return resp.json();
}

export async function scanPattern(params: ScanParams): Promise<PatternData> {
  const resp = await fetch(`${BASE_URL}/api/pattern`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(params),
  });
  if (!resp.ok) {
    const body = await resp.text();
    throw new Error(`Scan failed (${resp.status}): ${body}`);
  }
  return resp.json();
}

export async function getStatus(): Promise<{ connected: boolean; device?: string }> {
  const resp = await fetch(`${BASE_URL}/api/status`);
  if (!resp.ok) throw new Error(`Status check failed (${resp.status})`);
  return resp.json();
}

export async function getBands(): Promise<Record<string, { start_hz: number; stop_hz: number }>> {
  const resp = await fetch(`${BASE_URL}/api/bands`);
  if (!resp.ok) throw new Error(`Bands fetch failed (${resp.status})`);
  return resp.json();
}

export type PatternCallback = (data: PatternData) => void;
export type StatusCallback = (connected: boolean) => void;

export function connectWebSocket(
  onPattern: PatternCallback,
  onStatus: StatusCallback
): { close: () => void } {
  let ws: WebSocket | null = null;
  let reconnectTimer: ReturnType<typeof setTimeout> | null = null;
  let closed = false;

  function connect() {
    if (closed) return;

    const protocol = window.location.protocol === 'https:' ? 'wss:' : 'ws:';
    const url = `${protocol}//${window.location.host}/ws/pattern`;
    ws = new WebSocket(url);

    ws.onopen = () => {
      onStatus(true);
    };

    ws.onmessage = (event) => {
      try {
        const data = JSON.parse(event.data) as PatternData;
        onPattern(data);
      } catch {
        // non-pattern message, ignore
      }
    };

    ws.onclose = () => {
      onStatus(false);
      if (!closed) {
        reconnectTimer = setTimeout(connect, 3000);
      }
    };

    ws.onerror = () => {
      ws?.close();
    };
  }

  connect();

  return {
    close() {
      closed = true;
      if (reconnectTimer) clearTimeout(reconnectTimer);
      ws?.close();
    },
  };
}