// The pages of routers and home routers (apps/routerPages.ts), the firewall
// log behind them, and TCP counting Java's characters, where
// routerWebJava.test.ts's stories do not go.

import { describe, expect, it } from 'vitest';
import {
  deviceConfiguration,
  firewallConfiguration,
  firewallLogPage,
  firewallRule,
  firewallRuleText,
  forwardingTablePage,
  interfaceKey,
  javaTextLength,
  NetworkRuntimeEngine,
  topologySnapshot,
  portSnapshot,
  ripTablePage,
  routerIndexPage,
  type RouteRow,
  type TopologySnapshotInput,
} from '../src/index.js';
import { link, pc, startedEngine, uuid } from './fixtures.js';

const row = (fields: Partial<RouteRow>): RouteRow => ({
  destinationNetwork: '10.0.0.0',
  subnetMask: '255.255.255.0',
  nextHop: '10.0.0.1',
  interfaceIPAddress: '10.0.0.1',
  origin: 'connected',
  isEditable: false,
  ...fields,
});

describe('the pages of a router', () => {
  it('colours the forwarding table: own networks and localhost green with 0 hops, the default gateway blue, others with "?"', () => {
    const page = forwardingTablePage(
      [
        row({}),
        row({ destinationNetwork: '127.0.0.0', subnetMask: '255.0.0.0', nextHop: '127.0.0.1', interfaceIPAddress: '127.0.0.1' }),
        row({ destinationNetwork: '0.0.0.0', subnetMask: '0.0.0.0', nextHop: '10.0.0.254' }),
        row({ destinationNetwork: '30.0.0.0', nextHop: '10.0.0.9' }),
      ],
      'de',
    );
    expect(page).toContain(
      "<tr style='background-color:#aaffaa'><td>10.0.0.0</td><td>255.255.255.0</td><td> 0 </td><td>unbegrenzt</td><td><a href=\"http://10.0.0.1/routes\">10.0.0.1</a></td><td> - </td></tr>" +
        "<tr style='background-color:#aaffaa'><td>127.0.0.0</td>",
    );
    expect(page).toContain("<tr style='background-color:#aaaaff'><td>0.0.0.0</td><td>0.0.0.0</td><td> ? </td>");
    expect(page).toContain('<tr><td>30.0.0.0</td><td>255.255.255.0</td><td> ? </td>');
    // A route over the loopback interface counts as local, whatever its next hop.
    expect(forwardingTablePage([row({ destinationNetwork: '50.0.0.0', nextHop: '10.0.0.7', interfaceIPAddress: '127.0.0.1' })], 'de')).toContain(
      "<tr style='background-color:#aaffaa'><td>50.0.0.0</td><td>255.255.255.0</td><td> 0 </td>",
    );
    expect(page).toContain('Routing-/Weiterleitungs-Tabelle');
  });

  it('shows a RIP route in red at 16 hops, its time left in whole seconds', () => {
    const page = ripTablePage(
      [row({ metric: 0, hopPublicIPAddress: '10.0.0.1' }), row({ destinationNetwork: '40.0.0.0', nextHop: '10.0.0.2', metric: 16, expiresAtMilliseconds: 10_999, hopPublicIPAddress: '10.0.0.2' })],
      1_000,
      'en',
    );
    expect(page).toContain("<tr style='background-color:#aaffaa'><td>10.0.0.0</td><td>255.255.255.0</td><td>0</td><td>unlimited</td>");
    expect(page).toContain("<tr style='background-color:#ffaaaa'><td>40.0.0.0</td><td>255.255.255.0</td><td>16</td><td>9</td><td>10.0.0.2</td><td><a href=\"http://10.0.0.2/routes\">10.0.0.2</a></td></tr>");
    expect(page).toContain('Routing Table');
    expect(page).toContain('This table is generated and updated by the Routing Information Protocol (RIP).');
  });

  it('writes the index pages in the project language', () => {
    expect(routerIndexPage('router', 'en')).toContain('<title>Router Administration</title>');
    expect(routerIndexPage('gateway', 'de')).toBe(
      '<html>\n  <head>\n    <title>Administration des Gateways</title>\n  </head>\n  <body>\n    <h1>Firewall-Administration</h1>\n' +
        '    <p> <a href="konfig">Konfiguration</a> </p>\n    <p> <a href="log">Log-Eintr&auml;ge anzeigen</a> </p>\n  </body>\n</html>\n',
    );
  });

  it('names a rule as Java does: empty fields as *, "directly connected" by the first network', () => {
    const first = { ipAddress: '10.0.0.1', subnetMask: '255.255.255.0' };
    expect(firewallRuleText(firewallRule({ protocol: 'all', action: 'accept' }), first)).toBe('*/* -> */*; *:*  => ACCEPT');
    expect(firewallRuleText(firewallRule({ sourceIPAddress: '999.999.999.999', destinationIPAddress: '20.0.0.0', destinationSubnetMask: '255.0.0.0', protocol: 'udp', port: 53 }), first)).toBe(
      '10.0.0.0/255.255.255.0 -> 20.0.0.0/255.0.0.0; UDP:53  => DROP',
    );
  });
});

const ROUTER = uuid(0x4001);
const LEFT = uuid(0x4002);
const RIGHT = uuid(0x4003);

/** 10.0.0.2 — router 10.0.0.1/20.0.0.1 with a firewall — 20.0.0.2. */
function network(changes: Partial<TopologySnapshotInput> = {}): TopologySnapshotInput {
  return {
    nodes: [{ id: ROUTER, kind: 'router', ports: [portSnapshot(uuid(0x4011), 'eth0'), portSnapshot(uuid(0x4012), 'eth1')] }, pc(LEFT, uuid(0x4021)), pc(RIGHT, uuid(0x4031))],
    links: [link(ROUTER, uuid(0x4011), LEFT, uuid(0x4021)), link(ROUTER, uuid(0x4012), RIGHT, uuid(0x4031))],
    deviceConfigurations: new Map([
      [ROUTER, deviceConfiguration('10.0.0.1', '255.255.255.0', '', '')],
      [LEFT, deviceConfiguration('10.0.0.2', '255.255.255.0', '10.0.0.1', '')],
      [RIGHT, deviceConfiguration('20.0.0.2', '255.255.255.0', '20.0.0.1', '')],
    ]),
    interfaceConfigurations: new Map([
      [interfaceKey(ROUTER, uuid(0x4011)), { ipAddress: '10.0.0.1', subnetMask: '255.255.255.0' }],
      [interfaceKey(ROUTER, uuid(0x4012)), { ipAddress: '20.0.0.1', subnetMask: '255.255.255.0' }],
    ]),
    firewallConfigurationsByNodeId: new Map([
      [ROUTER, firewallConfiguration({ isActive: true, defaultPolicy: 'accept', rules: [firewallRule({ protocol: 'udp', port: 7, action: 'drop' })] })],
    ]),
    ...changes,
  };
}

describe("a router's firewall log", () => {
  it('logs a UDP rule that matched, and keeps the log over a new start, as Java does', () => {
    const engine = startedEngine(network());
    const send = () => engine.sendUdp(engine.bindUdpSocket(LEFT, { remoteIPAddress: '20.0.0.2', remotePort: 7 })!, new TextEncoder().encode('x'));
    send();
    engine.handle({ type: 'advance', toMilliseconds: 2_000 });
    engine.handle({ type: 'stop' });
    engine.handle({ type: 'start', snapshot: engine.state.topologySnapshot, seed: 14, initialTimeMilliseconds: 0 });
    send();
    engine.handle({ type: 'advance', toMilliseconds: 2_000 });
    expect(engine.firewallLog(ROUTER)).toHaveLength(2);
    expect(firewallLogPage(engine.firewallLog(ROUTER), 'en')).toBe(
      '<html>\n\t<head>\n\t\t<title>Log-data set entry of the firewall</title>\n\t</head>\n\t<body>\n\t\t<h2>Log-data set entry of the firewall</h2>\n\n' +
        '<br /> \nFirewall rule matched: #1 (*/* -> */*; UDP:7  => DROP)  -> drop<br /> \nFirewall rule matched: #1 (*/* -> */*; UDP:7  => DROP)  -> drop' +
        '\n\n\t</body>\n</html>',
    );
  });

  it('has the router switch on its web server at the start; with swiftRouters none, as in Swift', () => {
    const engine = startedEngine(network());
    expect(engine.webServer(ROUTER)?.isActive).toBe(true);
    expect(engine.webServer(ROUTER)?.log.all.map((line) => line.kind)).toEqual(['acceptingStarted']);
    expect(engine.webServer(LEFT)).toBeUndefined();
    const swift = new NetworkRuntimeEngine(14, undefined, { swiftRouters: true });
    swift.handle({ type: 'start', snapshot: topologySnapshot(network()), seed: 14, initialTimeMilliseconds: 0 });
    expect(swift.webServer(ROUTER)).toBeUndefined();
    expect(swift.state.socketsById.size).toBe(0);
  });
});

describe("a RIP route's public address (hopPublicIp)", () => {
  it('is the telling router\'s, also when a shorter way replaces the route', () => {
    const engine = startedEngine(network({ ripEnabledByNodeId: new Map([[ROUTER, true]]), firewallConfigurationsByNodeId: new Map() }));
    type Learn = (nodeId: string, message: unknown) => void;
    const learn = (engine as unknown as { learnRipRoutes: Learn }).learnRipRoutes.bind(engine);
    const message = (ipAddress: string, publicIPAddress: string, hops: number) => ({
      ipAddress,
      publicIPAddress,
      infinity: 16,
      timeoutMilliseconds: 75_000,
      routes: [{ network: '60.0.0.0', mask: '255.0.0.0', hops }],
    });
    const route = () => engine.ripTable(ROUTER)!.find((each) => each.destinationNetwork === '60.0.0.0');
    learn(ROUTER, message('10.0.0.5', '10.0.0.5', 2));
    expect(route()).toMatchObject({ metric: 3, nextHop: '10.0.0.5', hopPublicIPAddress: '10.0.0.5' });
    learn(ROUTER, message('20.0.0.6', '30.0.0.6', 0));
    expect(route()).toMatchObject({ metric: 1, nextHop: '20.0.0.6', hopPublicIPAddress: '30.0.0.6' });
    learn(ROUTER, message('10.0.0.5', '10.0.0.5', 0));
    expect(route()).toMatchObject({ metric: 1, nextHop: '20.0.0.6', hopPublicIPAddress: '30.0.0.6' });
  });
});

describe('TCP as Java counts it', () => {
  it('counts characters, not bytes, and never cuts a character of two units in halves', () => {
    expect(javaTextLength(new TextEncoder().encode('Grüße'))).toBe(5);
    expect(javaTextLength(new Uint8Array([0xff, 0x00]))).toBe(2);

    const engine = startedEngine(network({ firewallConfigurationsByNodeId: new Map() }));
    const listener = engine.openTcpServerSocket(RIGHT, 80)!;
    const client = engine.openTcpClientSocket(LEFT, '20.0.0.2', 80)!;
    expect(engine.connectTcpWithResult(client)).toBe('connected');
    const accepted = engine.state.tcpAcceptedSocketIdsByListenerId.get(listener)![0]!;
    const text = `${'ä'.repeat(1_459)}😀${'b'.repeat(10)}`;
    expect(engine.sendTcp(client, new TextEncoder().encode(text))).toBe(true);
    expect(new TextDecoder().decode(engine.receiveTcp(accepted))).toBe(text);
    const lengths = engine.state.packetTraces
      .filter((trace) => trace.nodeId === LEFT && trace.detail?.startsWith('TCP data') === true)
      .map((trace) => Number(trace.afterHeaders.find((header) => header.name === 'payloadLength')?.value));
    // 1459 two-byte characters (the emoji does not fit whole), then the emoji and the rest.
    expect(lengths).toEqual([2 * 1_459, 4 + 10]);
  });
});