// Issue #208 (server side): symmetric transport keepalive for the reverse-WS
// SERVER. Each attached client is pinged; a client that goes fully silent for
// maxMissed consecutive intervals is terminated (and drops out of the
// connection set) so a half-open client can't wedge forever. A healthy or
// actively-messaging client must never be reaped — the same false-positive
// guard as the client adapter.
//
// Mock `@snowluma/websocket` (native addon isn't built in a plain checkout),
// mirroring network-bootstrap-meta.test.ts. Timers are faked and driven.

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

const { FakeWebSocket, FakeWebSocketServer, servers } = vi.hoisted(() => {
    // eslint-disable-next-line @typescript-eslint/no-require-imports
    const { EventEmitter } = require('node:events') as typeof import('node:events');
    const servers: FakeWebSocketServer[] = [];

    class FakeWebSocket extends EventEmitter {
        public readyState = 1; // OPEN
        public pings = 0;
        public terminated = false;
        send(_payload: string, cb?: (err?: Error | null) => void): void {
            cb?.(null);
        }
        ping(): void {
            this.pings += 1;
        }
        terminate(): void {
            if (this.readyState === 3) {
                return;
            }

            this.terminated = true;
            this.readyState = 3;
            this.emit('close');
        }
        close(): void {
            if (this.readyState < 2) {
                this.readyState = 2;
            }
        }
        simulatePong(): void {
            this.emit('pong', Buffer.alloc(0));
        }
        simulateMessage(): void {
            this.emit('message', Buffer.from('{}'), false);
        }
    }

    class FakeWebSocketServer extends EventEmitter {
        public closed = false;
        constructor(_opts: unknown) {
            super();
            servers.push(this);
        }
        close(): void {
            this.closed = true;
        }
        simulateConnection(socket: FakeWebSocket, request: unknown): void {
            this.emit('connection', socket, request);
        }
    }

    return { FakeWebSocket, FakeWebSocketServer, servers };
});

vi.mock('@snowluma/websocket', () => ({
    WebSocket: FakeWebSocket,
    WebSocketServer: FakeWebSocketServer,
}));

import { WsServerAdapter } from '../src/network/ws-server-adapter';
import type { NetworkAdapterContext } from '../src/network/adapter';
import type { WsServerNetwork } from '../src/types';

const INTERVAL = 30_000;
const MAX_MISSED = 2;

function ctx(): NetworkAdapterContext {
    return {
        uin: '10001',
        api: { processStreamRequest: async () => {} } as never,
        buildLifecycleEvent: () => ({}),
        buildHeartbeatEvent: () => ({}),
    };
}

function cfg(over: Partial<WsServerNetwork> = {}): WsServerNetwork {
    return {
        enabled: true,
        host: '0.0.0.0',
        port: 8080,
        path: '/',
        role: 'Universal',
        ...over,
    } as WsServerNetwork;
}

const REQUEST = { url: '/', headers: {} } as unknown;

function connect(): { adapter: WsServerAdapter; socket: InstanceType<typeof FakeWebSocket> } {
    const adapter = new WsServerAdapter('ws', cfg(), ctx());
    adapter.open();
    const server = servers[servers.length - 1];
    server.emit('listening'); // adapter marks itself listening → status 'ok'
    const socket = new FakeWebSocket();
    server.simulateConnection(socket, REQUEST);
    return { adapter, socket };
}

describe('WsServerAdapter — transport heartbeat (issue #208)', () => {
    beforeEach(() => {
        servers.length = 0;
    });

    it('reaps a silent client only after maxMissed intervals, then drops it', () => {
        vi.useFakeTimers();

        try {
            const { adapter, socket } = connect();
            expect(adapter.describeStatus().detail).toBe('1 个客户端');

            vi.advanceTimersByTime(INTERVAL * MAX_MISSED); // tolerated
            expect(socket.terminated).toBe(false);

            vi.advanceTimersByTime(INTERVAL); // threshold crossed
            expect(socket.terminated).toBe(true);
            expect(adapter.describeStatus().detail).toBe('0 个客户端');
        } finally {
            vi.useRealTimers();
        }
    });

    it('never reaps a client that keeps ponging', () => {
        vi.useFakeTimers();

        try {
            const { adapter, socket } = connect();

            for (let i = 0; i < 10; i++) {
                vi.advanceTimersByTime(INTERVAL);
                socket.simulatePong();
            }

            expect(socket.terminated).toBe(false);
            expect(adapter.describeStatus().detail).toBe('1 个客户端');
            expect(socket.pings).toBeGreaterThan(0);
        } finally {
            vi.useRealTimers();
        }
    });

    it('treats inbound messages as liveness', () => {
        vi.useFakeTimers();

        try {
            const { adapter, socket } = connect();

            for (let i = 0; i < 10; i++) {
                vi.advanceTimersByTime(INTERVAL);
                socket.simulateMessage();
            }

            expect(socket.terminated).toBe(false);
            expect(adapter.describeStatus().detail).toBe('1 个客户端');
        } finally {
            vi.useRealTimers();
        }
    });

    it('stops all client heartbeats on adapter close — no lingering pings', () => {
        vi.useFakeTimers();

        try {
            const { adapter, socket } = connect();
            adapter.close();
            const pingsAtClose = socket.pings;
            vi.advanceTimersByTime(INTERVAL * 5);
            expect(socket.pings).toBe(pingsAtClose);
            expect(socket.terminated).toBe(false); // closed cleanly, not reaped
        } finally {
            vi.useRealTimers();
        }
    });
});