text: import { existsSync, readFileSync, writeFileSync } from 'fs';
  import { posix } from 'path';
  import { execSync } from 'child_process';
  import esbuild from 'esbuild';
  import toml from '@iarna/toml';
  import { fileURLToPath } from 'url';
  
  /** @type {import('.')} */
  export default function () {
  	return {
  		name: '@sveltejs/adapter-cloudflare-workers',
  
  		async adapt(builder) {
  			const { site } = validate_config(builder);
  
  			const bucket = site.bucket;
  			const entrypoint = site['entry-point'] || 'workers-site';
  
  			const files = fileURLToPath(new URL('./files', import.meta.url));
  			const tmp = builder.getBuildDirectory('cloudflare-workers-tmp');
  
  			builder.rimraf(bucket);
  			builder.rimraf(entrypoint);
  
  			builder.log.info('Prerendering static pages...');
  			const { paths } = await builder.prerender({
  				dest: bucket
  			});
  
  			builder.log.info('Installing worker dependencies...');
  			builder.copy(`${files}/_package.json`, `${tmp}/package.json`);
  
  			// TODO would be cool if we could make this step unnecessary somehow
  			const stdout = execSync('npm install', { cwd: tmp });
  			builder.log.info(stdout.toString());
  
  			builder.log.minor('Generating worker...');
  			const relativePath = posix.relative(tmp, builder.getServerDirectory());
  
  			builder.copy(`${files}/entry.js`, `${tmp}/entry.js`, {
  				replace: {
  					APP: `${relativePath}/app.js`,
  					MANIFEST: './manifest.js'
  				}
  			});
  
  			writeFileSync(
  				`${tmp}/manifest.js`,
  				`export const manifest = ${builder.generateManifest({
  					relativePath
  				})};\n\nexport const prerendered = new Set(${JSON.stringify(paths)});\n`
  			);
  
  			await esbuild.build({
  				entryPoints: [`${tmp}/entry.js`],
  				outfile: `${entrypoint}/index.js`,
  				bundle: true,
  				target: 'es2020',
  				platform: 'browser'
  			});
  
  			writeFileSync(`${entrypoint}/package.json`, JSON.stringify({ main: 'index.js' }));
  
  			builder.log.minor('Copying assets...');
  			builder.writeClient(bucket);
  			builder.writeStatic(bucket);
  		}
  	};
  }
  
  /** @param {import('@sveltejs/kit').Builder} builder */
  function validate_config(builder) {
  	if (existsSync('wrangler.toml')) {
  		let wrangler_config;
  
  		try {
  			wrangler_config = toml.parse(readFileSync('wrangler.toml', 'utf-8'));
  		} catch (err) {
  			err.message = `Error parsing wrangler.toml: ${err.message}`;
  			throw err;
  		}
  
  		if (!wrangler_config.site || !wrangler_config.site.bucket) {
  			throw new Error(
  				'You must specify site.bucket in wrangler.toml. Consult https://developers.cloudflare.com/workers/platform/sites/configuration'
  			);
  		}
  
  		return wrangler_config;
  	}
  
  	builder.log.error(
  		'Consult https://developers.cloudflare.com/workers/platform/sites/configuration on how to setup your site'
  	);
  
  	builder.log(
  		`
  		Sample wrangler.toml:
  
  		name = "<your-site-name>"
  		type = "javascript"
  		account_id = "<your-account-id>"
  		workers_dev = true
  		route = ""
  		zone_id = ""
  
  		[site]
  		bucket = "./.cloudflare/assets"
  		entry-point = "./.cloudflare/worker"`
  			.replace(/^\t+/gm, '')
  			.trim()
  	);
  
  	throw new Error('Missing a wrangler.toml file');
  }
  