// The firewall settings page of routers and home routers (konfig,
// apps/firewallSettings.ts) against Java FILIUS' own: tools/java-oracle's
// KonfigCases fed Java's page with the steps of firewall-settings.cases.txt
// (firewall-settings.<de|en>.java.json). Each step's page and the firewall
// after it must be Java's, in both languages, except where Java errs.

import { readFileSync } from 'node:fs';
import { dirname, join } from 'node:path';
import { fileURLToPath } from 'node:url';
import { describe, expect, it } from 'vitest';
import {
  applyFirewallSettings,
  firewallConfiguration,
  firewallRule,
  firewallSettingsPage,
  javaUrlDecode,
  type FirewallConfiguration,
  type FirewallRule,
  type PageLanguage,
} from '../src/index.js';

const here = dirname(fileURLToPath(import.meta.url));

type JavaRule = [string, string, string, string, number, string, string];

interface JavaFirewall {
  isActive: boolean;
  dropIcmp: boolean;
  filterSynSegmentsOnly: boolean;
  defaultPolicy: string;
  rules: JavaRule[];
}

interface JavaStep {
  post: string | null;
  page: string | null;
  firewall: JavaFirewall;
}

interface JavaCase {
  name: string;
  start: string;
  steps: JavaStep[];
}

function javaRule(rule: FirewallRule): JavaRule {
  return [rule.sourceIPAddress, rule.sourceSubnetMask, rule.destinationIPAddress, rule.destinationSubnetMask, rule.port, rule.protocol, rule.action];
}

function asJava(configuration: FirewallConfiguration): JavaFirewall {
  return {
    isActive: configuration.isActive,
    dropIcmp: configuration.dropIcmp,
    filterSynSegmentsOnly: configuration.filterSynSegmentsOnly,
    defaultPolicy: configuration.defaultPolicy,
    rules: configuration.rules.map(javaRule),
  };
}

/** KonfigCases' start states. */
const STARTS: Record<string, FirewallConfiguration> = {
  empty: firewallConfiguration(),
  three: firewallConfiguration({
    isActive: true,
    rules: [
      firewallRule({ port: 80, protocol: 'tcp', action: 'accept' }),
      firewallRule({ sourceIPAddress: '999.999.999.999', destinationIPAddress: '20.0.0.0', destinationSubnetMask: '255.0.0.0', protocol: 'udp', action: 'drop' }),
      firewallRule({ sourceIPAddress: '10.0.0.0', sourceSubnetMask: '255.0.0.0', protocol: 'all', action: 'drop' }),
    ],
  }),
  sourceRule: firewallConfiguration({ rules: [firewallRule({ sourceIPAddress: '10.0.0.0', sourceSubnetMask: '255.255.255.0', port: 80, protocol: 'tcp', action: 'drop' })] }),
  portZero: firewallConfiguration({ rules: [firewallRule({ port: 0, protocol: 'icmp', action: 'accept' })] }),
  destinationRule: firewallConfiguration({ rules: [firewallRule({ destinationIPAddress: '20.0.0.0', destinationSubnetMask: '255.0.0.0', protocol: 'udp', action: 'accept' })] }),
};

type Cases = Record<string, JavaCase>;

const step = (cases: Cases, name: string, index: number) => cases[name]!.steps[index]!;

/** A step as Java means it: another step's page and firewall, which Java answers for the same state. */
const asStep =
  (name: string, index: number) =>
  (cases: Cases, measured: JavaStep): JavaStep => ({ ...step(cases, name, index), post: measured.post });

/**
 * Where Java errs, each step as Java means it (the core's departures, see
 * firewallSettings.ts).
 */
const JAVA_BUGS: Record<string, Record<number, (cases: Cases, measured: JavaStep) => JavaStep>> = {
  // Java checks the source IP against the mask not read yet, and the mask
  // against the IP not read yet: it refuses every rule with an address,
  // whichever field comes first. The core takes the rule.
  addSource: { 0: asStep('sourceRule', 0) },
  addSourceMaskFirst: { 0: asStep('sourceRule', 0) },
  addDestination: { 0: asStep('destinationRule', 0) },
  addDestinationMaskFirst: { 0: asStep('destinationRule', 0) },
  // Java keeps the error of a failed add for every later page.
  errors: { 1: asStep('getThree', 0) },
  // Save and add at once: Java saves, but writes the add's errors as a bare
  // list and fills the form in. The core answers the saved firewall.
  errorAndSave: { 0: asStep('deactivate', 0) },
  // Java writes the form's text into the page as it came.
  markup: { 0: (_, measured) => ({ ...measured, page: measured.page!.replace('value="<b>""', 'value="&lt;b&gt;&quot;"') }) },
  // A "$" in the form's text: Java's replaceAll reads it as a group, throws,
  // and the page fails (500). The core answers as for any other bad address.
  dollar: { 0: (cases, measured) => ({ ...measured, page: step(cases, 'markup', 0).page!.replace('value="<b>""', 'value="$1"') }) },
  // An "&" typed into a field: Java decodes the data before it splits it,
  // reads an empty source and adds a rule. The core keeps the "&" in its
  // field and answers as for any other bad address.
  ampersand: { 0: (cases) => ({ ...step(cases, 'markup', 0), page: step(cases, 'markup', 0).page!.replace('value="<b>""', 'value="&amp;"') }) },
  // Moving rule 0 down: Java throws (its worker thread ends, no page comes).
  moveDownZero: { 0: asStep('getThree', 0) },
  // An escape that is not one: Java's decoder throws. The core reads the
  // data as it came, as Java's code means to.
  malformed: { 0: asStep('moveUp', 0), 1: asStep('getThree', 0) },
};

function javaCases(language: PageLanguage): Cases {
  const list = JSON.parse(readFileSync(join(here, `firewall-settings.${language}.java.json`), 'utf8')) as JavaCase[];
  return Object.fromEntries(list.map((each) => [each.name, each]));
}

describe('the firewall settings page as Java FILIUS answers it', () => {
  for (const language of ['de', 'en'] as const) {
    const cases = javaCases(language);

    it(`corrects Java only where it errs (${language})`, () => {
      for (const [name, steps] of Object.entries(JAVA_BUGS)) {
        for (const [index, correct] of Object.entries(steps)) {
          const measured = step(cases, name, Number(index));
          expect(correct(cases, measured), `${name} ${index}`).not.toEqual(measured);
        }
      }
    });

    for (const [name, javaCase] of Object.entries(cases)) {
      it(`${name} (${language})`, () => {
        let configuration = STARTS[javaCase.start]!;
        for (const [index, measured] of javaCase.steps.entries()) {
          const expected = JAVA_BUGS[name]?.[index]?.(cases, measured) ?? measured;
          const result = applyFirewallSettings(configuration, measured.post ?? undefined);
          configuration = result.configuration;
          expect(asJava(configuration), `step ${index}: the firewall`).toEqual(expected.firewall);
          expect(firewallSettingsPage(configuration, language, result.rejected), `step ${index}: the page`).toBe(expected.page);
        }
      });
    }
  }
});

describe("a form's data as Java's URLDecoder reads it", () => {
  it('turns + into spaces and runs of escapes into UTF-8 characters', () => {
    expect(javaUrlDecode('a+b%C3%BC%E2%82%AC%41')).toBe('a bü€A');
    expect(javaUrlDecode('%+f%-0x')).toBe('\u000f\u0000x');
  });

  it('fails where Java throws: an escape cut off, not hexadecimal, or negative', () => {
    expect(javaUrlDecode('%zz')).toBeUndefined();
    expect(javaUrlDecode('%4')).toBeUndefined();
    expect(javaUrlDecode('%41%')).toBeUndefined();
    expect(javaUrlDecode('%-1')).toBeUndefined();
  });
});