1/**
2 * SvelteKit live-mode adapter.
3 *
4 * SvelteKit must not be patched through src/app.html. That file is a document
5 * template, not framework-owned component chrome. The adapter keeps SvelteKit
6 * work limited to mounting a dev-only shadow host from +layout.svelte; the
7 * actual live UI remains the shared plain-DOM browser chrome.
8 */
9 
10import fs from 'node:fs';
11import path from 'node:path';
12 
13export const SVELTE_LIVE_ROOT_COMPONENT = 'src/lib/impeccable/ImpeccableLiveRoot.svelte';
14export const SVELTE_LAYOUT_MARKER_OPEN = '<!-- impeccable-live-svelte-start -->';
15export const SVELTE_LAYOUT_MARKER_CLOSE = '<!-- impeccable-live-svelte-end -->';
16export const SVELTE_ROOT_IMPORT = "import ImpeccableLiveRoot from '$lib/impeccable/ImpeccableLiveRoot.svelte';";
17 
18export function detectSvelteKitProject(cwd = process.cwd(), config = null) {
19  const appHtml = findSvelteKitAppHtml(cwd, config);
20  if (!appHtml) return null;
21  const hasTemplateMarkers = fileIncludes(path.join(cwd, appHtml), '%sveltekit.body%')
22    && fileIncludes(path.join(cwd, appHtml), '%sveltekit.head%');
23  if (!hasTemplateMarkers) return null;
24 
25  const hasSvelteConfig = fs.existsSync(path.join(cwd, 'svelte.config.js'))
26    || fs.existsSync(path.join(cwd, 'svelte.config.mjs'))
27    || fs.existsSync(path.join(cwd, 'svelte.config.cjs'))
28    || fs.existsSync(path.join(cwd, 'svelte.config.ts'));
29  const hasKitPackage = packageHasSvelteKit(cwd);
30  if (!hasSvelteConfig && !hasKitPackage) return null;
31 
32  return {
33    appHtml,
34    layoutFile: findSvelteKitLayout(cwd),
35    rootComponent: SVELTE_LIVE_ROOT_COMPONENT,
36  };
37}
38 
39export function applySvelteKitLiveAdapter({ cwd = process.cwd(), port, config = null } = {}) {
40  if (!Number.isFinite(Number(port))) {
41    throw new Error('SvelteKit live adapter requires a numeric port');
42  }
43  const detected = detectSvelteKitProject(cwd, config);
44  if (!detected) return null;
45 
46  ensureSvelteLiveRootComponent(cwd, Number(port));
47 
48  const layoutRel = detected.layoutFile;
49  const layoutAbs = path.join(cwd, layoutRel);
50  fs.mkdirSync(path.dirname(layoutAbs), { recursive: true });
51  const layoutExisted = fs.existsSync(layoutAbs);
52  const before = layoutExisted ? fs.readFileSync(layoutAbs, 'utf-8') : defaultSvelteLayout();
53  const after = patchSvelteLayout(before);
54  fs.writeFileSync(layoutAbs, after, 'utf-8');
55 
56  return {
57    file: layoutRel,
58    adapter: 'sveltekit',
59    inserted: after !== before || !layoutExisted,
60    appHtmlUntouched: true,
61    rootComponent: SVELTE_LIVE_ROOT_COMPONENT,
62  };
63}
64 
65export function removeSvelteKitLiveAdapter({ cwd = process.cwd(), config = null } = {}) {
66  const detected = detectSvelteKitProject(cwd, config);
67  if (!detected) return null;
68 
69  const layoutAbs = path.join(cwd, detected.layoutFile);
70  let removed = false;
71  if (fs.existsSync(layoutAbs)) {
72    const before = fs.readFileSync(layoutAbs, 'utf-8');
73    const after = unpatchSvelteLayout(before);
74    if (after !== before) {
75      fs.writeFileSync(layoutAbs, after, 'utf-8');
76      removed = true;
77    }
78  }
79 
80  const rootAbs = path.join(cwd, SVELTE_LIVE_ROOT_COMPONENT);
81  if (fs.existsSync(rootAbs)) {
82    fs.rmSync(rootAbs, { force: true });
83    removed = true;
84  }
85 
86  pruneEmptyDir(path.dirname(rootAbs), path.join(cwd, 'src'));
87 
88  return {
89    file: detected.layoutFile,
90    adapter: 'sveltekit',
91    removed,
92    appHtmlUntouched: true,
93    rootComponent: SVELTE_LIVE_ROOT_COMPONENT,
94  };
95}
96 
97export function patchSvelteLayout(content) {
98  let out = String(content || '');
99  if (!out.includes(SVELTE_ROOT_IMPORT)) {
100    const scriptMatch = out.match(/<script(?:\s[^>]*)?>/i);
101    if (scriptMatch) {
102      const insertAt = scriptMatch.index + scriptMatch[0].length;
103      out = out.slice(0, insertAt) + '\n  ' + SVELTE_ROOT_IMPORT + out.slice(insertAt);
104    } else {
105      out = `<script>\n  ${SVELTE_ROOT_IMPORT}\n</script>\n\n` + out;
106    }
107  }
108 
109  if (!out.includes(SVELTE_LAYOUT_MARKER_OPEN)) {
110    const block = `${SVELTE_LAYOUT_MARKER_OPEN}\n<ImpeccableLiveRoot />\n${SVELTE_LAYOUT_MARKER_CLOSE}\n`;
111    const renderMatch = out.match(/\{@render\s+children(?:\?\.)?\(\)\s*\}/);
112    const slotMatch = out.match(/<slot\s*\/?>/);
113    const match = renderMatch || slotMatch;
114    if (match) {
115      out = out.slice(0, match.index) + block + out.slice(match.index);
116    } else {
117      out = out.replace(/\s*$/, '\n\n' + block);
118    }
119  }
120 
121  return out;
122}
123 
124export function unpatchSvelteLayout(content) {
125  let out = String(content || '');
126  const blockRe = new RegExp(
127    '([ \\t]*)' + escapeRegExp(SVELTE_LAYOUT_MARKER_OPEN)
128    + '\\n<ImpeccableLiveRoot\\s*/>\\n'
129    + escapeRegExp(SVELTE_LAYOUT_MARKER_CLOSE)
130    + '\\n?',
131    'g',
132  );
133  out = out.replace(blockRe, '$1');
134  out = out.replace(new RegExp('^\\s*' + escapeRegExp(SVELTE_ROOT_IMPORT) + '\\s*\\n?', 'gm'), '');
135  out = out.replace(/<script>\s*<\/script>\s*\n?/g, '');
136  return out.replace(/\n{3,}/g, '\n\n');
137}
138 
139export function ensureSvelteLiveRootComponent(cwd, port) {
140  const file = path.join(cwd, SVELTE_LIVE_ROOT_COMPONENT);
141  fs.mkdirSync(path.dirname(file), { recursive: true });
142  fs.writeFileSync(file, buildSvelteLiveRootComponent(port), 'utf-8');
143  return file;
144}
145 
146export function buildSvelteLiveRootComponent(port) {
147  return `<script>
148  import { onMount } from 'svelte';
149 
150  const LIVE_URL = 'http://localhost:${Number(port)}/live.js';
151  const HOST_ID = 'impeccable-live-root';
152 
153  onMount(() => {
154    let host = document.querySelector('impeccable-live-root#' + HOST_ID) || document.getElementById(HOST_ID);
155    if (!host) {
156      host = document.createElement('impeccable-live-root');
157      host.id = HOST_ID;
158      document.body.appendChild(host);
159    }
160 
161    host.dataset.impeccableLiveAdapter = 'sveltekit';
162    host.style.setProperty('all', 'initial', 'important');
163    host.style.setProperty('display', 'block', 'important');
164    host.style.setProperty('position', 'fixed', 'important');
165    host.style.setProperty('top', '0', 'important');
166    host.style.setProperty('left', '0', 'important');
167    host.style.setProperty('width', '0', 'important');
168    host.style.setProperty('height', '0', 'important');
169    host.style.setProperty('overflow', 'visible', 'important');
170    host.style.setProperty('z-index', '2147483000', 'important');
171    host.style.setProperty('pointer-events', 'none', 'important');
172 
173    const root = host.shadowRoot || host.attachShadow({ mode: 'open' });
174    if (!root.querySelector('style[data-impeccable-live-reset]')) {
175      const reset = document.createElement('style');
176      reset.dataset.impeccableLiveReset = 'true';
177      reset.textContent = ':host, :host *, * { box-sizing: border-box; }';
178      root.appendChild(reset);
179    }
180 
181    window.__IMPECCABLE_LIVE_ADAPTER__ = 'sveltekit';
182    window.__IMPECCABLE_LIVE_UI_ROOT__ = root;
183    window.__IMPECCABLE_LIVE_CHROME_MOUNT__ = {
184      adapter: 'sveltekit',
185      version: 1,
186      host,
187      root,
188    };
189 
190    const script = document.createElement('script');
191    script.src = LIVE_URL;
192    script.async = true;
193    script.dataset.impeccableLiveScript = 'true';
194    document.head.appendChild(script);
195 
196    return () => {
197      script.remove();
198      if (window.__IMPECCABLE_LIVE_UI_ROOT__ === root) delete window.__IMPECCABLE_LIVE_UI_ROOT__;
199      if (window.__IMPECCABLE_LIVE_CHROME_MOUNT__?.root === root) delete window.__IMPECCABLE_LIVE_CHROME_MOUNT__;
200      if (window.__IMPECCABLE_LIVE_ADAPTER__ === 'sveltekit') delete window.__IMPECCABLE_LIVE_ADAPTER__;
201    };
202  });
203</script>
204`;
205}
206 
207function findSvelteKitAppHtml(cwd, config) {
208  const files = Array.isArray(config?.files) ? config.files : ['src/app.html'];
209  for (const rel of files) {
210    if (rel.includes('*')) continue;
211    const normalized = rel.split(path.sep).join('/');
212    if (!normalized.endsWith('app.html')) continue;
213    const abs = path.join(cwd, normalized);
214    if (fs.existsSync(abs)) return normalized;
215  }
216  const fallback = 'src/app.html';
217  return fs.existsSync(path.join(cwd, fallback)) ? fallback : null;
218}
219 
220function findSvelteKitLayout(cwd) {
221  const candidates = [
222    'src/routes/+layout.svelte',
223    'src/routes/(app)/+layout.svelte',
224  ];
225  for (const rel of candidates) {
226    if (fs.existsSync(path.join(cwd, rel))) return rel;
227  }
228  return 'src/routes/+layout.svelte';
229}
230 
231function defaultSvelteLayout() {
232  return `<script>\n  let { children } = $props();\n</script>\n\n{@render children?.()}\n`;
233}
234 
235function packageHasSvelteKit(cwd) {
236  const file = path.join(cwd, 'package.json');
237  if (!fs.existsSync(file)) return false;
238  try {
239    const pkg = JSON.parse(fs.readFileSync(file, 'utf-8'));
240    const deps = {
241      ...(pkg.dependencies || {}),
242      ...(pkg.devDependencies || {}),
243      ...(pkg.peerDependencies || {}),
244    };
245    return Boolean(deps['@sveltejs/kit'] || deps['@sveltejs/vite-plugin-svelte'] || deps.svelte);
246  } catch {
247    return false;
248  }
249}
250 
251function fileIncludes(file, text) {
252  try {
253    return fs.readFileSync(file, 'utf-8').includes(text);
254  } catch {
255    return false;
256  }
257}
258 
259function pruneEmptyDir(dir, stopDir) {
260  let current = dir;
261  while (current.startsWith(stopDir) && current !== stopDir) {
262    try {
263      if (fs.readdirSync(current).length > 0) return;
264      fs.rmdirSync(current);
265      current = path.dirname(current);
266    } catch {
267      return;
268    }
269  }
270}
271 
272function escapeRegExp(value) {
273  return String(value).replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
274}
275