/**
 * DC-106: Reverse Proxy Visual Builder — pure-function unit tests.
 *
 * These tests cover the deterministic, DOM-free surface of the builder:
 *   - state → POST /generate payload mapping (buildPayload)
 *   - template application (applyTemplate hydrates state from a template config)
 *
 * DOM-bound behavior (event handlers, renderHeadersList, copy/validate
 * buttons) is exercised via the headless-browser smoke test
 * `caddy-builder.browser.smoke.test.js` which uses the running dev server.
 * That test is in the `__tests__/integration/` directory and is run on
 * demand; the unit test below has zero jsdom dependency so it runs on
 * every CI tick.
 *
 * The module under test uses an IIFE; we extract the pure helpers via a
 * re-loadable harness that exposes them on globalThis without requiring
 * DOM globals.
 */

// --- DOM stub: minimal window/document/injectModal/escapeHtml shims ---
// The caddy-builder.js IIFE needs window.injectModal, window.escapeHtml,
// window.fetch, document.body.insertAdjacentHTML, and document.getElementById
// at module-load time. We stub all of them with no-ops so the IIFE runs
// without exploding — but no actual DOM rendering happens. That's fine for
// testing the pure helpers, which only need `state`.

global.window = global.window || {};
global.window.injectModal = () => {};
global.window.escapeHtml = (text) => String(text ?? '')
  .replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;')
  .replace(/"/g, '&quot;').replace(/'/g, '&#39;');
// Also expose as bare globals — the module's IIFE references `injectModal`
// and `escapeHtml` as bare identifiers, so they need to be resolvable in
// the eval scope.
global.injectModal = global.window.injectModal;
global.escapeHtml = global.window.escapeHtml;

// Tiny DOM shim — only what caddy-builder.js touches at load time.
// Built in two passes to avoid the "Cannot access 'stubEl' before
// initialization" TDZ trap (parentNode self-reference).
function buildStubEl() {
  const el = {
    style: {},
    classList: { add() {}, remove() {} },
    dataset: {},
    addEventListener() {},
    removeEventListener() {},
    insertAdjacentHTML() {},
    setAttribute() {},
    getAttribute() { return null; },
    dispatchEvent() {},
    focus() {},
    blur() {},
    set innerHTML(_) {},
    get innerHTML() { return ''; },
    set textContent(_) {},
    get textContent() { return ''; },
    set value(_) {},
    get value() { return ''; },
    set checked(_) {},
    get checked() { return false; },
    set disabled(_) {},
    get disabled() { return false; },
    children: [],
    parentNode: null,
    firstChild: null,
  };
  el.parentNode = el;
  el.firstChild = el;
  el.appendChild = function(child) {
    el.children.push(child);
    child.parentNode = el;
    return child;
  };
  el.querySelector = () => el;
  el.querySelectorAll = () => [];
  return el;
}
const stubEl = buildStubEl();

const elementById = new Map();
function makeEl(id, tag) {
  const el = Object.create(stubEl);
  el.id = id;
  el.tagName = (tag || 'div').toUpperCase();
  el.children = [];
  el.parentNode = stubEl;
  el._children = [];
  el.appendChild = function(child) { el.children.push(child); child.parentNode = el; return child; };
  el.querySelector = function(sel) {
    // Very dumb: return first descendant whose tag matches the selector's tagname
    const m = sel.match(/^[a-z]+/);
    const tag = m ? m[0].toUpperCase() : null;
    function find(node) {
      if (tag && node.tagName === tag) return node;
      for (const c of (node.children || [])) {
        const r = find(c);
        if (r) return r;
      }
      return null;
    }
    return find(el) || stubEl;
  };
  el.querySelectorAll = function() { return []; };
  elementById.set(id, el);
  return el;
}

global.document = {
  body: stubEl,
  getElementById: (id) => elementById.get(id) || makeEl(id),
  createElement: (tag) => makeEl('dyn-' + Math.random().toString(36).slice(2), tag),
  createRange: () => ({ selectNodeContents() {}, setStart() {}, setEnd() {}, collapse() {} }),
};

global.Event = class Event {
  constructor(type) { this.type = type; }
};
global.navigator = { clipboard: { writeText: async () => {} } };
global.fetch = jest.fn();
global.setTimeout = setTimeout;
global.clearTimeout = clearTimeout;

// --- Load the module under test ---
function loadModule() {
  const fs = require('fs');
  const path = require('path');
  const code = fs.readFileSync(
    path.join(__dirname, '..', '..', '..', 'status', 'js', 'caddy-builder.js'),
    'utf8'
  );
  // eslint-disable-next-line no-eval
  (0, eval)(code);
  return global.window.__caddyBuilder;
}

// --- Tests ---------------------------------------------------------------

describe('DC-106: Caddy Visual Builder (pure)', () => {
  let builder;

  beforeEach(() => {
    fetch.mockReset();
    // loadTemplates() runs at module-load time and hits /caddycode/templates.
    // Mock it to resolve with the 5 template presets so applyTemplate works.
    fetch.mockResolvedValue({
      ok: true,
      status: 200,
      json: async () => ({
        success: true,
        templates: {
          'simple-proxy': { label: 'Simple reverse proxy', config: { domain: 'app.example.com', upstream: 'localhost:8080' } },
          'websocket-app': { label: 'WebSocket application', config: { domain: 'app.example.com', upstream: 'localhost:3000', websocket: true, compress: true } },
          'auth-gated': { label: 'Auth-gated (DashCaddy SSO)', config: { domain: 'app.example.com', upstream: 'localhost:8096', auth: true, authService: 'app' } },
          'cors-api': { label: 'API with CORS', config: { domain: 'api.example.com', upstream: 'localhost:3001', cors: true, compress: true } },
          'subdirectory': { label: 'Subdirectory proxy', config: { domain: 'example.com', upstream: 'localhost:8080', stripPrefix: '/app' } },
        },
      }),
    });
    elementById.clear();
    builder = loadModule();
  });

  // Filter helper: count only POST /generate or POST /validate calls.
  const postCalls = () => fetch.mock.calls.filter(([url, opts]) =>
    String(url).includes('/caddycode/') && opts && opts.method === 'POST'
  );

  describe('state defaults', () => {
    it('initializes with sensible defaults', () => {
      expect(builder.state.domain).toBe('blog.example.com');
      expect(builder.state.upstream).toBe('localhost:8080');
      expect(builder.state.upstreamProtocol).toBe('http');
      expect(builder.state.tls).toBe('auto');
      expect(builder.state.auth).toBe(false);
      expect(builder.state.compress).toBe(true);
      expect(builder.state.headers).toEqual([]);
    });

    it('exposes the generated state via getCaddyfile()', () => {
      expect(builder.getCaddyfile()).toBe('');
    });
  });

  describe('buildPayload', () => {
    it('maps state → POST /generate payload (happy path)', () => {
      builder.state.domain = 'app.example.com';
      builder.state.upstream = 'localhost:3000';
      builder.state.websocket = true;
      builder.state.cors = true;
      builder.state.headers = [{ key: 'X-Forwarded-For', value: '{remote_host}' }];
      const payload = builder.buildPayload();
      expect(payload).toEqual({
        domain: 'app.example.com',
        upstream: 'localhost:3000',
        upstreamProtocol: 'http',
        tls: 'auto',
        auth: false,
        authService: null,
        websocket: true,
        cors: true,
        compress: true,
        stripPrefix: null,
        redirectToHttps: true,
        headers: { 'X-Forwarded-For': '{remote_host}' },
      });
    });

    it('trims whitespace on domain / upstream / stripPrefix', () => {
      builder.state.domain = '  app.example.com  ';
      builder.state.upstream = '\tlocalhost:8080\n';
      builder.state.stripPrefix = '  /api  ';
      const p = builder.buildPayload();
      expect(p.domain).toBe('app.example.com');
      expect(p.upstream).toBe('localhost:8080');
      expect(p.stripPrefix).toBe('/api');
    });

    it('drops blank header keys (only headers with non-blank keys are sent)', () => {
      builder.state.headers = [
        { key: 'X-Real-IP', value: '{remote_host}' },
        { key: '', value: 'ignored' },
        { key: '   ', value: 'also ignored' },
      ];
      const p = builder.buildPayload();
      expect(p.headers).toEqual({ 'X-Real-IP': '{remote_host}' });
    });

    it('nullifies authService when auth is off (security: never leaks auth_id without auth=true)', () => {
      builder.state.auth = false;
      builder.state.authService = 'leftover';
      const p = builder.buildPayload();
      expect(p.authService).toBe(null);
    });

    it('passes authService when auth is on', () => {
      builder.state.auth = true;
      builder.state.authService = 'blog';
      const p = builder.buildPayload();
      expect(p.authService).toBe('blog');
    });

    it('nullifies stripPrefix when blank', () => {
      builder.state.stripPrefix = '';
      const p = builder.buildPayload();
      expect(p.stripPrefix).toBe(null);
    });

    it('sends all boolean fields with explicit values (no undefined)', () => {
      const p = builder.buildPayload();
      expect(typeof p.websocket).toBe('boolean');
      expect(typeof p.cors).toBe('boolean');
      expect(typeof p.compress).toBe('boolean');
      expect(typeof p.redirectToHttps).toBe('boolean');
      expect(typeof p.auth).toBe('boolean');
    });
  });

  describe('applyTemplate', () => {
    it('hydrates state from an auth-gated template', () => {
      builder.applyTemplate('auth-gated');
      expect(builder.state.auth).toBe(true);
      expect(builder.state.authService).toBe('app');
      expect(builder.state.upstream).toBe('localhost:8096');
    });

    it('hydrates state from a cors-api template', () => {
      builder.applyTemplate('cors-api');
      expect(builder.state.cors).toBe(true);
      expect(builder.state.compress).toBe(true);
      expect(builder.state.upstream).toBe('localhost:3001');
    });

    it('does nothing for unknown template id', () => {
      const before = JSON.stringify(builder.state);
      builder.applyTemplate('does-not-exist');
      const after = JSON.stringify(builder.state);
      expect(after).toBe(before);
    });
  });

  describe('fetch integration (mocked)', () => {
    it('generate() POSTs to /caddycode/generate with correct headers', async () => {
      fetch.mockResolvedValueOnce({
        ok: true,
        status: 200,
        json: async () => ({
          success: true,
          caddyfile: 'app.example.com {\n  reverse_proxy localhost:8080\n}',
        }),
      });
      builder.state.domain = 'app.example.com';
      builder.state.upstream = 'localhost:8080';
      await builder.generate();
      expect(fetch).toHaveBeenCalledWith('/api/v1/caddycode/generate', expect.objectContaining({
        method: 'POST',
        credentials: 'same-origin',
        headers: expect.objectContaining({ 'Content-Type': 'application/json' }),
      }));
    });

    it('generate() stores the returned caddyfile on success', async () => {
      fetch.mockResolvedValueOnce({
        ok: true,
        status: 200,
        json: async () => ({
          success: true,
          caddyfile: 'app.example.com {\n  reverse_proxy localhost:8080\n}',
        }),
      });
      builder.state.domain = 'app.example.com';
      builder.state.upstream = 'localhost:8080';
      await builder.generate();
      expect(builder.getCaddyfile()).toContain('reverse_proxy localhost:8080');
    });

    it('generate() captures 400 errors without throwing', async () => {
      fetch.mockResolvedValueOnce({
        ok: false,
        status: 400,
        json: async () => ({
          success: false,
          error: 'Invalid configuration',
          errors: ['upstream must be host:port'],
        }),
      });
      builder.state.domain = 'app.example.com';
      builder.state.upstream = 'bad';
      await expect(builder.generate()).resolves.toBeUndefined();
      expect(builder.getCaddyfile()).toBe('');
    });

    it('generate() handles network failures gracefully', async () => {
      fetch.mockRejectedValueOnce(new Error('ECONNREFUSED'));
      builder.state.domain = 'app.example.com';
      builder.state.upstream = 'localhost:8080';
      await expect(builder.generate()).resolves.toBeUndefined();
    });

    it('generate() short-circuits when domain missing', async () => {
      builder.state.domain = '';
      builder.state.upstream = 'localhost:8080';
      await builder.generate();
      // loadTemplates() (run at module load) makes a GET to /templates; we
      // only care that generate() didn't POST /generate. Filter to POST.
      expect(postCalls()).toHaveLength(0);
    });

    it('generate() short-circuits when upstream missing', async () => {
      builder.state.domain = 'app.example.com';
      builder.state.upstream = '';
      await builder.generate();
      expect(postCalls()).toHaveLength(0);
    });
  });

  describe('XSS protection (escapeHtml integration)', () => {
    it('escapes user-typed values when headers would be rendered', () => {
      // The caddy-builder.js module calls escapeHtml() in renderHeadersList
      // to attribute-escape header keys/values before innerHTML injection.
      // Verify the global escapeHtml contract the module depends on.
      const malicious = '<script>alert(1)</script>"&<>\'onerror=x';
      const escaped = global.escapeHtml(malicious);
      expect(escaped).not.toContain('<script>');
      expect(escaped).not.toContain('"');
      expect(escaped).toContain('&lt;script&gt;');
      expect(escaped).toContain('&quot;');
      expect(escaped).toContain('&amp;');
    });
  });
});