/*
 * SPDX-FileCopyrightText: syuilo and misskey-project
 * SPDX-License-Identifier: AGPL-3.0-only
 */

import * as fs from 'node:fs';
import { fileURLToPath } from 'node:url';
import { dirname, resolve } from 'node:path';
import * as yaml from 'js-yaml';
import ts from 'typescript';

const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);
const parameterRegExp = /\{(\w+)\}/g;

interface LocaleRecord {
	[key: string]: string | LocaleRecord;
}

function createMemberType(item: string | LocaleRecord): ts.TypeNode {
	if (typeof item !== 'string') {
		return ts.factory.createTypeLiteralNode(createMembers(item));
	}
	const parameters = Array.from(
		item.matchAll(parameterRegExp),
		([, parameter]) => parameter,
	);
	return parameters.length
		? ts.factory.createTypeReferenceNode(
			ts.factory.createIdentifier('ParameterizedString'),
			[
				ts.factory.createUnionTypeNode(
					parameters.map((parameter) =>
						ts.factory.createLiteralTypeNode(ts.factory.createStringLiteral(parameter)),
					),
				),
			],
		)
		: ts.factory.createKeywordTypeNode(ts.SyntaxKind.StringKeyword);
}

function createMembers(record: LocaleRecord): ts.TypeElement[] {
	return Object.entries(record).map(([k, v]) => {
		const node = ts.factory.createPropertySignature(
			undefined,
			ts.factory.createStringLiteral(k),
			undefined,
			createMemberType(v),
		);
		if (typeof v === 'string') {
			ts.addSyntheticLeadingComment(
				node,
				ts.SyntaxKind.MultiLineCommentTrivia,
				`*
 * ${v.replace(/\n/g, '\n * ')}
 `,
				true,
			);
		}
		return node;
	});
}

export async function generateLocaleInterface(localesDir: string): Promise<void> {
	const locale = yaml.load(fs.readFileSync(`${localesDir}/ja-JP.yml`, 'utf-8').toString()) as LocaleRecord;
	const members = createMembers(locale);

	const elements: ts.Statement[] = [
		ts.factory.createImportDeclaration(
			undefined,
			ts.factory.createImportClause(
				false,
				undefined,
				ts.factory.createNamedImports([
					ts.factory.createImportSpecifier(
						true,
						undefined,
						ts.factory.createIdentifier('ILocale'),
					),
					ts.factory.createImportSpecifier(
						true,
						undefined,
						ts.factory.createIdentifier('ParameterizedString'),
					),
				]),
			),
			ts.factory.createStringLiteral('../types.js'),
			undefined,
		),
		ts.factory.createInterfaceDeclaration(
			[ts.factory.createToken(ts.SyntaxKind.ExportKeyword)],
			ts.factory.createIdentifier('Locale'),
			undefined,
			[
				ts.factory.createHeritageClause(ts.SyntaxKind.ExtendsKeyword, [
					ts.factory.createExpressionWithTypeArguments(
						ts.factory.createIdentifier('ILocale'),
						undefined,
					),
				]),
			],
			members,
		),
	];

	ts.addSyntheticLeadingComment(
		elements[0],
		ts.SyntaxKind.MultiLineCommentTrivia,
		' eslint-disable ',
		true,
	);
	ts.addSyntheticLeadingComment(
		elements[0],
		ts.SyntaxKind.SingleLineCommentTrivia,
		' This file is generated by scripts/generateLocaleInterface.ts',
		true,
	);
	ts.addSyntheticLeadingComment(
		elements[0],
		ts.SyntaxKind.SingleLineCommentTrivia,
		' Do not edit this file directly.',
		true,
	);

	const printed = ts
		.createPrinter({
			newLine: ts.NewLineKind.LineFeed,
		})
		.printList(
			ts.ListFormat.MultiLine,
			ts.factory.createNodeArray(elements),
			ts.createSourceFile(
				'locale.ts',
				'',
				ts.ScriptTarget.ESNext,
				true,
				ts.ScriptKind.TS,
			),
		);

	const autogenDir = `${__dirname}/../src/autogen`;
	fs.mkdirSync(autogenDir, { recursive: true });

	// 一瞬ファイルが存在しなくなって途切れる→不安定になるらしいので、リネームで対処
	fs.writeFileSync(`${autogenDir}/_locale.ts`, printed, 'utf-8');
	fs.renameSync(`${autogenDir}/_locale.ts`, `${autogenDir}/locale.ts`);
}

// スクリプトとして直接実行された場合
const isMain = import.meta.url === `file://${process.argv[1]}`;
if (isMain) {
	await generateLocaleInterface(resolve(__dirname, '../../../locales'));
}