import { readFileSync, writeFileSync } from 'fs'
import path from 'path'
import { namedTypes } from 'ast-types'
import { glob } from 'glob'
import { parse, print, visit } from 'recast'

export function sortUnions(tsbuildDir: string) {
	for (const file of glob.sync(path.join(tsbuildDir, '**/*.d.ts'))) {
		try {
			const code = parse(readFileSync(file, 'utf8'), {
				parser: require('recast/parsers/typescript'),
			})

			visit(code, {
				visitTSUnionType(path) {
					this.traverse(path)
					const val = path.value as namedTypes.TSUnionType
					val.types = val.types.sort((a, b) => {
						const aText = print(a).code
						const bText = print(b).code
						return aText.localeCompare(bText)
					})
					return false
				},
				visitTSTypeLiteral(path) {
					this.traverse(path)
					const val = path.value as namedTypes.TSTypeLiteral
					val.members = val.members.sort((a, b) => {
						const aText = print(a).code
						const bText = print(b).code
						return aText.localeCompare(bText)
					})
					return false
				},
			})

			writeFileSync(file, print(code).code)
		} catch (e) {
			throw new Error(`Error sorting unions in ${file}`, { cause: e })
		}
	}
}