import fs from "fs/promises"
import url from "url"

import { type Theme } from "../Theme.js"

/**
 * Write theme variables to get autocomplete while developing. Only works from node.
 *
 * ```ts
 * // src/bin/generateThemeVars.ts
 *
 * import { theme } from "../theme.js" // import theme instance
 * import { writeTheme } from "metamorphisis/node/writeTheme.js"
 *
 * // write relative to file
 * writeTheme(theme, import.meta.url, "../assets/variables.scss")
 * ```
 * In package.json:
 *
 * ```json
 * "scripts": {
 * 	"gen:theme": "pnpm ts-node src/bin/generateThemeVars.ts"
 * }
 * ```
 *
 * @env node
 */
export async function writeTheme(theme: Theme, metaUrl: string, filepath: string): Promise<void> {
	const location = url.fileURLToPath(new URL(filepath, metaUrl))
	const css = Object.entries(theme.css).map(([key, val]) => `${key}: ${val};`).join("\n")

	const content = `/* Auto generated by metamorphisis Theme.write. For autocomplete purposes only. */\n${css}\n`
	await fs.writeFile(location, content)
}