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import fs from 'node:fs';
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import path from 'node:path';
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import { fileURLToPath } from 'node:url';
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import mime from 'mime-types';
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import { serverDirectory } from './server-directory.js';
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import { getRequestURL, isFileURL, isPathUnderParent } from './util.js';
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const originalFetch = globalThis.fetch;
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const ALLOWED_EXTENSIONS = [
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    '.wasm',
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];
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// Patched fetch function that handles file URLs
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globalThis.fetch = async (/** @type {string | URL | Request} */ request, /** @type {RequestInit | undefined} */ options) => {
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    if (!isFileURL(request)) {
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        return originalFetch(request, options);
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    }
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    const url = getRequestURL(request);
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    const filePath = path.resolve(fileURLToPath(url));
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    const isUnderServerDirectory = isPathUnderParent(serverDirectory, filePath);
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    if (!isUnderServerDirectory) {
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        throw new Error('Requested file path is outside of the server directory.');
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    }
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    const parsedPath = path.parse(filePath);
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    if (!ALLOWED_EXTENSIONS.includes(parsedPath.ext)) {
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        throw new Error('Unsupported file extension.');
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    }
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    const fileName = parsedPath.base;
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    const buffer = await fs.promises.readFile(filePath);
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    const response = new Response(buffer, {
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        status: 200,
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        statusText: 'OK',
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        headers: {
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            'Content-Type': mime.lookup(fileName) || 'application/octet-stream',
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            'Content-Length': buffer.length.toString(),
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        },
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    });
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    return response;
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};