import { describe, expect, it, vi } from 'vitest';

import { PanelBridge, type PanelRequest, type PanelResponse, type PortLike } from '../../src/background/bridge.js';
import type { TransportStatus, VeloxTransport } from '../../src/background/transport/index.js';

function fakePort(): PortLike & { received: PanelResponse[]; emit(msg: PanelRequest): void; close(): void } {
  const msgListeners = new Set<(msg: PanelRequest) => void>();
  const discListeners = new Set<() => void>();
  const received: PanelResponse[] = [];
  return {
    name: 'velox-panel',
    received,
    postMessage: (m) => received.push(m),
    onMessage: { addListener: (cb) => msgListeners.add(cb) },
    onDisconnect: { addListener: (cb) => discListeners.add(cb) },
    emit: (msg) => msgListeners.forEach((cb) => cb(msg)),
    close: () => discListeners.forEach((cb) => cb()),
  };
}

function fakeTransport(status: TransportStatus): VeloxTransport & { fireStatus(s: TransportStatus): void; calls: unknown[] } {
  const stateListeners = new Set<(s: TransportStatus) => void>();
  const eventListeners = new Map<string, Set<(p: unknown) => void>>();
  const calls: unknown[] = [];
  return {
    kind: 'ws',
    state: status.state,
    status,
    calls,
    connect: async () => undefined,
    disconnect: () => undefined,
    call: (async (method: string, params: unknown) => {
      calls.push({ method, params });
      if (method === 'boom') throw Object.assign(new Error('nope'), { code: -32010 });
      return { echoed: params };
    }) as VeloxTransport['call'],
    on: ((event: string, cb: (p: unknown) => void) => {
      let s = eventListeners.get(event);
      if (!s) eventListeners.set(event, (s = new Set()));
      s.add(cb);
    }) as VeloxTransport['on'],
    off: (event: string, cb: (p: unknown) => void) => {
      eventListeners.get(event)?.delete(cb);
    },
    onStateChange: (cb: (s: TransportStatus) => void) => {
      stateListeners.add(cb);
      return () => stateListeners.delete(cb);
    },
    fireStatus: (s: TransportStatus) => stateListeners.forEach((cb) => cb(s)),
  } as unknown as VeloxTransport & { fireStatus(s: TransportStatus): void; calls: unknown[] };
}

const CONNECTED: TransportStatus = {
  state: 'connected',
  needsPairing: false,
  fatal: null,
  retryAfterSec: null,
  sessionId: 's1',
  daemonVersion: '1.0.0',
  capabilities: [],
};

describe('PanelBridge', () => {
  it('sends the current status on connect', () => {
    const t = fakeTransport(CONNECTED);
    const bridge = new PanelBridge({ getTransport: () => t, setOverride: async () => undefined });
    const port = fakePort();
    bridge.attach({ addListener: (cb) => cb(port) });

    expect(port.received[0]).toEqual({ type: 'status', status: { ...CONNECTED, kind: 'ws' } });
  });

  it('forwards a call and relays the result', async () => {
    const t = fakeTransport(CONNECTED);
    const bridge = new PanelBridge({ getTransport: () => t, setOverride: async () => undefined });
    const port = fakePort();
    bridge.attach({ addListener: (cb) => cb(port) });

    port.emit({ type: 'call', id: 7, method: 'download.list', params: {} });
    await vi.waitFor(() => expect(port.received.some((m) => m.type === 'result')).toBe(true));

    const result = port.received.find((m) => m.type === 'result');
    expect(result).toEqual({ type: 'result', id: 7, ok: true, result: { echoed: {} } });
  });

  it('relays a call error with its code', async () => {
    const t = fakeTransport(CONNECTED);
    const bridge = new PanelBridge({ getTransport: () => t, setOverride: async () => undefined });
    const port = fakePort();
    bridge.attach({ addListener: (cb) => cb(port) });

    port.emit({ type: 'call', id: 1, method: 'boom' as never, params: {} });
    await vi.waitFor(() => expect(port.received.some((m) => m.type === 'result')).toBe(true));

    const result = port.received.find((m) => m.type === 'result');
    expect(result).toEqual({ type: 'result', id: 1, ok: false, error: { code: -32010, message: 'nope' } });
  });

  it('relays a call error when there is no transport yet', async () => {
    const bridge = new PanelBridge({ getTransport: () => undefined, setOverride: async () => undefined });
    const port = fakePort();
    bridge.attach({ addListener: (cb) => cb(port) });

    port.emit({ type: 'call', id: 2, method: 'download.list', params: {} });
    await vi.waitFor(() => expect(port.received.some((m) => m.type === 'result')).toBe(true));

    const result = port.received.find((m) => m.type === 'result');
    expect(result).toEqual({ type: 'result', id: 2, ok: false, error: { message: 'transport not ready' } });
  });

  it('a disconnected port stops receiving after disconnect', () => {
    const t = fakeTransport(CONNECTED);
    const bridge = new PanelBridge({ getTransport: () => t, setOverride: async () => undefined });
    const port = fakePort();
    bridge.attach({ addListener: (cb) => cb(port) });

    port.close();
    expect(() => port.emit({ type: 'getStatus' })).not.toThrow();
  });

  it('relays event.speed.global to the port after subscribing', () => {
    const stateListeners = new Set<(s: TransportStatus) => void>();
    const eventCbs = new Map<string, (p: unknown) => void>();
    const t: VeloxTransport = {
      kind: 'ws',
      state: 'connected',
      status: CONNECTED,
      connect: async () => undefined,
      disconnect: () => undefined,
      call: (async () => ({})) as VeloxTransport['call'],
      on: ((event: string, cb: (p: unknown) => void) => {
        eventCbs.set(event, cb);
      }) as VeloxTransport['on'],
      off: () => undefined,
      onStateChange: (cb) => {
        stateListeners.add(cb);
        return () => stateListeners.delete(cb);
      },
    };
    const bridge = new PanelBridge({ getTransport: () => t, setOverride: async () => undefined });
    const port = fakePort();
    bridge.attach({ addListener: (cb) => cb(port) });

    port.emit({ type: 'subscribe', events: ['event.speed.global'] });
    eventCbs.get('event.speed.global')?.({ bytesPerSec: 4096 });

    expect(port.received).toContainEqual({ type: 'event', event: 'event.speed.global', payload: { bytesPerSec: 4096 } });
  });

  it('pairs with a code and reports the resulting status', async () => {
    const pairWithCode = vi.fn(async () => undefined);
    const t = { ...fakeTransport(CONNECTED), pairWithCode };
    const bridge = new PanelBridge({ getTransport: () => t, setOverride: async () => undefined });
    const port = fakePort();
    bridge.attach({ addListener: (cb) => cb(port) });

    port.emit({ type: 'pair', code: '4821' });
    await vi.waitFor(() => expect(pairWithCode).toHaveBeenCalledWith('4821'));
  });

  it('reports a pairError when the transport has no pairWithCode (e.g. native transport)', async () => {
    const t = fakeTransport(CONNECTED); // no pairWithCode
    const bridge = new PanelBridge({ getTransport: () => t, setOverride: async () => undefined });
    const port = fakePort();
    bridge.attach({ addListener: (cb) => cb(port) });

    port.emit({ type: 'pair', code: '4821' });
    await vi.waitFor(() => expect(port.received.some((m) => m.type === 'pairError')).toBe(true));
  });

  it('unpairs via the transport and reports status', async () => {
    const unpair = vi.fn(async () => undefined);
    const t = { ...fakeTransport(CONNECTED), unpair };
    const bridge = new PanelBridge({ getTransport: () => t, setOverride: async () => undefined });
    const port = fakePort();
    bridge.attach({ addListener: (cb) => cb(port) });

    port.emit({ type: 'unpair' });
    await vi.waitFor(() => expect(unpair).toHaveBeenCalled());
  });

  it('delegates setOverride to the deps and reports the new status', async () => {
    const setOverride = vi.fn(async () => undefined);
    const t = fakeTransport(CONNECTED);
    const bridge = new PanelBridge({ getTransport: () => t, setOverride });
    const port = fakePort();
    bridge.attach({ addListener: (cb) => cb(port) });

    port.emit({ type: 'setOverride', override: 'uds' });
    await vi.waitFor(() => expect(setOverride).toHaveBeenCalledWith('uds'));
  });

  it('getStatus answers with the disconnected sentinel when there is no transport', () => {
    const bridge = new PanelBridge({ getTransport: () => undefined, setOverride: async () => undefined });
    const port = fakePort();
    bridge.attach({ addListener: (cb) => cb(port) });
    port.received.length = 0;

    port.emit({ type: 'getStatus' });
    expect(port.received[0]).toEqual({
      type: 'status',
      status: { state: 'disconnected', needsPairing: false, fatal: null, retryAfterSec: null, sessionId: null, daemonVersion: null, capabilities: [], kind: null },
    });
  });
});