Introduce app building capabilities into Srcbook

.prettierignore

@@ -1,3 +1,4 @@
 pnpm*.yaml
 packages/api/drizzle/*
+packages/api/apps/templates/**/*
 **/*.src.md

packages/api/.eslintrc.cjs

@@ -10,4 +10,5 @@ module.exports = {
   globals: {
     Bun: false,
   },
+  ignorePatterns: ['apps/templates/**/*'],
 };

packages/api/apps/app.mts

@@ -0,0 +1,71 @@
+import { CodeLanguageType, randomid, type AppType } from '@srcbook/shared';
+import { db } from '../db/index.mjs';
+import { type App as DBAppType, apps as appsTable } from '../db/schema.mjs';
+import { createViteApp, deleteViteApp, pathToApp } from './disk.mjs';
+import { CreateAppSchemaType } from './schemas.mjs';
+import { asc, desc, eq } from 'drizzle-orm';
+import { npmInstall } from '../exec.mjs';
+
+function toSecondsSinceEpoch(date: Date): number {
+  return Math.floor(date.getTime() / 1000);
+}
+
+export function serializeApp(app: DBAppType): AppType {
+  return {
+    id: app.externalId,
+    name: app.name,
+    language: app.language as CodeLanguageType,
+    createdAt: toSecondsSinceEpoch(app.createdAt),
+    updatedAt: toSecondsSinceEpoch(app.updatedAt),
+  };
+}
+
+async function insert(
+  attrs: Pick<DBAppType, 'name' | 'language' | 'externalId'>,
+): Promise<DBAppType> {
+  const [app] = await db.insert(appsTable).values(attrs).returning();
+  return app!;
+}
+
+export async function createApp(data: CreateAppSchemaType): Promise<DBAppType> {
+  const app = await insert({
+    name: data.name,
+    language: data.language,
+    externalId: randomid(),
+  });
+
+  await createViteApp(app);
+
+  // TODO: handle this better.
+  // This should be done somewhere else and surface issues or retries.
+  // Not awaiting here because it's "happening in the background".
+  npmInstall({
+    cwd: pathToApp(app.externalId),
+    stdout(data) {
+      console.log(data.toString('utf8'));
+    },
+    stderr(data) {
+      console.error(data.toString('utf8'));
+    },
+    onExit(code) {
+      console.log(`npm install exit code: ${code}`);
+    },
+  });
+
+  return app;
+}
+
+export async function deleteApp(id: string) {
+  await db.delete(appsTable).where(eq(appsTable.externalId, id));
+  await deleteViteApp(id);
+}
+
+export function loadApps(sort: 'asc' | 'desc') {
+  const sorter = sort === 'asc' ? asc : desc;
+  return db.select().from(appsTable).orderBy(sorter(appsTable.updatedAt));
+}
+
+export async function loadApp(id: string) {
+  const [app] = await db.select().from(appsTable).where(eq(appsTable.externalId, id));
+  return app;
+}

packages/api/apps/disk.mts

@@ -0,0 +1,170 @@
+import fs from 'node:fs/promises';
+import Path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { type App as DBAppType } from '../db/schema.mjs';
+import { APPS_DIR } from '../constants.mjs';
+import { toValidPackageName } from './utils.mjs';
+import { Dirent } from 'node:fs';
+import { FileType } from '@srcbook/shared';
+
+export function pathToApp(id: string) {
+  return Path.join(APPS_DIR, id);
+}
+
+function pathToTemplate(template: string) {
+  return Path.resolve(fileURLToPath(import.meta.url), '..', 'templates', template);
+}
+
+export function deleteViteApp(id: string) {
+  return fs.rm(pathToApp(id), { recursive: true });
+}
+
+export async function createViteApp(app: DBAppType) {
+  const appPath = pathToApp(app.externalId);
+
+  // Use recursive because its parent directory may not exist.
+  await fs.mkdir(appPath, { recursive: true });
+
+  // Scaffold all the necessary project files.
+  await scaffold(app, appPath);
+
+  return app;
+}
+
+async function scaffold(app: DBAppType, destDir: string) {
+  const template = `react-${app.language}`;
+
+  function write(file: string, content?: string) {
+    const targetPath = Path.join(destDir, file);
+    return content === undefined
+      ? copy(Path.join(templateDir, file), targetPath)
+      : fs.writeFile(targetPath, content, 'utf-8');
+  }
+
+  const templateDir = pathToTemplate(template);
+  const files = await fs.readdir(templateDir);
+  for (const file of files.filter((f) => f !== 'package.json')) {
+    await write(file);
+  }
+
+  const [pkgContents, idxContents] = await Promise.all([
+    fs.readFile(Path.join(templateDir, 'package.json'), 'utf-8'),
+    fs.readFile(Path.join(templateDir, 'index.html'), 'utf-8'),
+  ]);
+
+  const pkg = JSON.parse(pkgContents);
+  pkg.name = toValidPackageName(app.name);
+  const updatedPkgContents = JSON.stringify(pkg, null, 2) + '\n';
+
+  const updatedIdxContents = idxContents.replace(
+    /<title>.*<\/title>/,
+    `<title>${app.name}</title>`,
+  );
+
+  await Promise.all([
+    write('package.json', updatedPkgContents),
+    write('index.html', updatedIdxContents),
+  ]);
+}
+
+export function fileUpdated(app: DBAppType, file: FileType) {
+  const path = Path.join(pathToApp(app.externalId), file.path);
+  return fs.writeFile(path, file.source, 'utf-8');
+}
+
+async function copy(src: string, dest: string) {
+  const stat = await fs.stat(src);
+  if (stat.isDirectory()) {
+    return copyDir(src, dest);
+  } else {
+    return fs.copyFile(src, dest);
+  }
+}
+
+async function copyDir(srcDir: string, destDir: string) {
+  await fs.mkdir(destDir, { recursive: true });
+  const files = await fs.readdir(srcDir);
+  for (const file of files) {
+    const srcFile = Path.resolve(srcDir, file);
+    const destFile = Path.resolve(destDir, file);
+    await copy(srcFile, destFile);
+  }
+}
+
+// TODO: This does not scale.
+export async function getProjectFiles(app: DBAppType) {
+  const projectDir = Path.join(APPS_DIR, app.externalId);
+
+  const { files, directories } = await getDiskEntries(projectDir, {
+    exclude: ['node_modules', 'dist'],
+  });
+
+  const nestedFiles = await Promise.all(
+    directories.flatMap(async (dir) => {
+      const entries = await fs.readdir(Path.join(projectDir, dir.name), {
+        withFileTypes: true,
+        recursive: true,
+      });
+      return entries.filter((entry) => entry.isFile());
+    }),
+  );
+
+  const entries = [...files, ...nestedFiles.flat()];
+
+  return Promise.all(
+    entries.map(async (entry) => {
+      const fullPath = Path.join(entry.parentPath, entry.name);
+      const relativePath = Path.relative(projectDir, fullPath);
+      const contents = await fs.readFile(fullPath);
+      const binary = isBinary(entry.name);
+      const source = !binary ? contents.toString('utf-8') : `TODO: handle this`;
+      return { path: relativePath, source, binary };
+    }),
+  );
+}
+
+async function getDiskEntries(projectDir: string, options: { exclude: string[] }) {
+  const result: { files: Dirent[]; directories: Dirent[] } = {
+    files: [],
+    directories: [],
+  };
+
+  for (const entry of await fs.readdir(projectDir, { withFileTypes: true })) {
+    if (options.exclude.includes(entry.name)) {
+      continue;
+    }
+
+    if (entry.isFile()) {
+      result.files.push(entry);
+    } else {
+      result.directories.push(entry);
+    }
+  }
+
+  return result;
+}
+
+// TODO: This does not scale.
+// What's the best way to know whether a file is a "binary"
+// file or not? Inspecting bytes for invalid utf8?
+const TEXT_FILE_EXTENSIONS = [
+  '.ts',
+  '.cts',
+  '.mts',
+  '.tsx',
+  '.js',
+  '.cjs',
+  '.mjs',
+  '.jsx',
+  '.md',
+  '.markdown',
+  '.json',
+  '.css',
+  '.html',
+];
+
+function isBinary(basename: string) {
+  const isDotfile = basename.startsWith('.'); // Assume these are text for now, e.g., .gitignore
+  const isTextFile = TEXT_FILE_EXTENSIONS.includes(Path.extname(basename));
+  return !(isDotfile || isTextFile);
+}

packages/api/apps/schemas.mts

@@ -0,0 +1,9 @@
+import z from 'zod';
+
+export const CreateAppSchema = z.object({
+  name: z.string(),
+  language: z.union([z.literal('typescript'), z.literal('javascript')]),
+  prompt: z.string().optional(),
+});
+
+export type CreateAppSchemaType = z.infer<typeof CreateAppSchema>;

packages/api/apps/templates/README.md

@@ -0,0 +1 @@
+These templates were copied from https://github.com/vitejs/vite/tree/main/packages/create-vite

packages/api/apps/templates/react-javascript/eslint.config.js

@@ -0,0 +1,38 @@
+import js from '@eslint/js'
+import globals from 'globals'
+import react from 'eslint-plugin-react'
+import reactHooks from 'eslint-plugin-react-hooks'
+import reactRefresh from 'eslint-plugin-react-refresh'
+
+export default [
+  { ignores: ['dist'] },
+  {
+    files: ['**/*.{js,jsx}'],
+    languageOptions: {
+      ecmaVersion: 2020,
+      globals: globals.browser,
+      parserOptions: {
+        ecmaVersion: 'latest',
+        ecmaFeatures: { jsx: true },
+        sourceType: 'module',
+      },
+    },
+    settings: { react: { version: '18.3' } },
+    plugins: {
+      react,
+      'react-hooks': reactHooks,
+      'react-refresh': reactRefresh,
+    },
+    rules: {
+      ...js.configs.recommended.rules,
+      ...react.configs.recommended.rules,
+      ...react.configs['jsx-runtime'].rules,
+      ...reactHooks.configs.recommended.rules,
+      'react/jsx-no-target-blank': 'off',
+      'react-refresh/only-export-components': [
+        'warn',
+        { allowConstantExport: true },
+      ],
+    },
+  },
+]

packages/api/apps/templates/react-javascript/index.html

@@ -0,0 +1,13 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <link rel="icon" type="image/svg+xml" href="/vite.svg" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Vite + React</title>
+  </head>
+  <body>
+    <div id="root"></div>
+    <script type="module" src="/src/main.jsx"></script>
+  </body>
+</html>

packages/api/apps/templates/react-javascript/package.json

@@ -0,0 +1,28 @@
+{
+  "name": "vite-react-starter",
+  "private": true,
+  "version": "0.0.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "lint": "eslint .",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "react": "^18.3.1",
+    "react-dom": "^18.3.1"
+  },
+  "devDependencies": {
+    "@eslint/js": "^9.10.0",
+    "@types/react": "^18.3.6",
+    "@types/react-dom": "^18.3.0",
+    "@vitejs/plugin-react": "^4.3.1",
+    "eslint": "^9.10.0",
+    "eslint-plugin-react": "^7.36.1",
+    "eslint-plugin-react-hooks": "^5.1.0-rc.0",
+    "eslint-plugin-react-refresh": "^0.4.12",
+    "globals": "^15.9.0",
+    "vite": "^5.4.6"
+  }
+}

packages/api/apps/templates/react-javascript/src/App.css

@@ -0,0 +1,42 @@
+#root {
+  max-width: 1280px;
+  margin: 0 auto;
+  padding: 2rem;
+  text-align: center;
+}
+
+.logo {
+  height: 6em;
+  padding: 1.5em;
+  will-change: filter;
+  transition: filter 300ms;
+}
+.logo:hover {
+  filter: drop-shadow(0 0 2em #646cffaa);
+}
+.logo.react:hover {
+  filter: drop-shadow(0 0 2em #61dafbaa);
+}
+
+@keyframes logo-spin {
+  from {
+    transform: rotate(0deg);
+  }
+  to {
+    transform: rotate(360deg);
+  }
+}
+
+@media (prefers-reduced-motion: no-preference) {
+  a:nth-of-type(2) .logo {
+    animation: logo-spin infinite 20s linear;
+  }
+}
+
+.card {
+  padding: 2em;
+}
+
+.read-the-docs {
+  color: #888;
+}