import { bundleAsync } from 'lightningcss'
import { ensureDir } from '$std/fs/mod.ts'
import { parse, resolve } from '$std/path/mod.ts'

console.log('building styles starts')
await ensureDir('_fresh/static')

try {
	//prevent Deno from exiting before bundle
	setTimeout(() => {}, 2_000)

	const cssImports = new Map()

	const { code, map } = await bundleAsync({
		filename: './src/stylesheets/main.css',
		minify: true,
		sourceMap: true,
		resolver: {
			read(path) {
				return Deno.readTextFile(path)
			},
			async resolve(specifier, from) {
				//resolve local files normally
				if (!specifier.startsWith('https://')) {
					return resolve(parse(from).dir, specifier)
				}
				//use cache for remote
				if (cssImports.has(specifier)) return cssImports.get(specifier)

				//update cache for new remote
				const response = await fetch(specifier)
				const file = await response.arrayBuffer()
                const hash = new Uint8Array(await crypto.subtle.digest('SHA-256', file))
                const filename = [...hash].map(value => value.toString(16).padStart(2, '0')).join('')

				const filepath = `_fresh/${filename}`
				await Deno.writeFile(filepath, new Uint8Array(file))
				cssImports.set(specifier, filepath)
				return filepath
			},
		},
	})

	await Deno.writeTextFile(
		'./static/styles.css',
		new TextDecoder().decode(code),
	)
	await Deno.writeTextFile(
		'./static/styles.map.css',
		new TextDecoder().decode(map!),
	)
} catch (error) {
	console.error(error)
}

console.log('building styles finish')