import { readFile, writeFile, readdir } from 'node:fs/promises';

import { existsSync } from 'node:fs';

import { join } from 'node:path';

import {

buildRouteMetaMap,

routeToOgPath,

DIST,

SITE,

DEFAULT_IMAGE,

DEFAULT_DESC,

} from './lib/route-meta.mjs';

function escapeAttr(s) {

return String(s)

.replace(/&/g, '&')

.replace(/"/g, '"')

.replace(/</g, '&lt;')

.replace(/>/g, '&gt;');

}

function absoluteUrl(maybePath) {

if (!maybePath) return SITE + DEFAULT_IMAGE;

if (/^https?:\/\//.test(maybePath)) return maybePath;

return SITE + (maybePath.startsWith('/') ? maybePath : '/' + maybePath);

}

function resolveImage(route, meta) {

if (meta.image) return absoluteUrl(meta.image);

const generated = routeToOgPath(route);

const distPath = join(DIST, generated);

if (existsSync(distPath)) return absoluteUrl('/' + generated);

return absoluteUrl(DEFAULT_IMAGE);

}

function rewriteHead(html, route, meta) {

const title = meta.title || 'fezcodex';

const description = meta.description || DEFAULT_DESC;

const image = resolveImage(route, meta);

const url = SITE + route;

const type = meta.type || 'website';

const eTitle = escapeAttr(title);

const eDesc = escapeAttr(description);

const eImg = escapeAttr(image);

const eUrl = escapeAttr(url);

const eType = escapeAttr(type);

const subs = [

[/<title>[^<]*<\/title>/i, `<title>${eTitle}</title>`],

[

/<meta\s+name="description"\s+content="[^"]*"\s*\/?>/i,

`<meta name="description" content="${eDesc}" />`,

],

[

/<meta\s+property="og:type"\s+content="[^"]*"\s*\/?>/i,

`<meta property="og:type" content="${eType}" />`,

],

[

/<meta\s+property="og:url"\s+content="[^"]*"\s*\/?>/i,

`<meta property="og:url" content="${eUrl}" />`,

],

[

/<meta\s+property="og:title"\s+content="[^"]*"\s*\/?>/i,

`<meta property="og:title" content="${eTitle}" />`,

],

[

/<meta\s+property="og:description"\s+content="[^"]*"\s*\/?>/i,

`<meta property="og:description" content="${eDesc}" />`,

],

[

/<meta\s+property="og:image"\s+content="[^"]*"\s*\/?>/i,

`<meta property="og:image" content="${eImg}" />`,

],

[

/<meta\s+name="twitter:url"\s+content="[^"]*"\s*\/?>/i,

`<meta name="twitter:url" content="${eUrl}" />`,

],

[

/<meta\s+name="twitter:title"\s+content="[^"]*"\s*\/?>/i,

`<meta name="twitter:title" content="${eTitle}" />`,

],

[

/<meta\s+name="twitter:description"\s+content="[^"]*"\s*\/?>/i,

`<meta name="twitter:description" content="${eDesc}" />`,

],

[

/<meta\s+name="twitter:image"\s+content="[^"]*"\s*\/?>/i,

`<meta name="twitter:image" content="${eImg}" />`,

],

];

let out = html;

let hits = 0;

for (const [re, rep] of subs) {

const next = out.replace(re, rep);

if (next !== out) hits++;

out = next;

}

return { html: out, hits };

}

function fileToRoute(file) {

const rel = file.slice(DIST.length).replace(/\\/g, '/');

if (rel === '/index.html') return '/';

if (rel.endsWith('/index.html')) return rel.slice(0, -'/index.html'.length);

return null;

}

async function walkHtml(dir, out = []) {

for (const entry of await readdir(dir, { withFileTypes: true })) {

const full = join(dir, entry.name);

if (entry.isDirectory()) await walkHtml(full, out);

else if (entry.isFile() && entry.name === 'index.html') out.push(full);

}

return out;

}

async function main() {

const t0 = Date.now();

if (!existsSync(DIST)) {

console.error(`inject-meta: ${DIST} does not exist; run vite build first`);

process.exit(1);

}

const routeMap = buildRouteMetaMap();

console.log(`inject-meta: ${routeMap.size} routes have per-page metadata`);

const files = await walkHtml(DIST);

let touched = 0;

let skipped = 0;

let missing = 0;

for (const file of files) {

const route = fileToRoute(file);

if (route == null) {

skipped++;

continue;

}

const meta = routeMap.get(route);

if (!meta) {

missing++;

continue;

}

const html = await readFile(file, 'utf8');

const { html: next, hits } = rewriteHead(html, route, meta);

if (hits === 0) {

skipped++;

continue;

}

await writeFile(file, next, 'utf8');

touched++;

}

console.log(

`inject-meta: rewrote ${touched} file(s), ${missing} without per-page meta, ${skipped} skipped (${Date.now() - t0}ms)`

);

}

await main();