misskey/packages/frontend-shared/js/i18n.ts

252 lines
6.5 KiB
TypeScript

/*
* SPDX-FileCopyrightText: syuilo and misskey-project
* SPDX-License-Identifier: AGPL-3.0-only
*/
import type { ILocale, ParameterizedString } from '../../../locales/index.js';
// eslint-disable-next-line @typescript-eslint/no-explicit-any
type TODO = any;
type FlattenKeys<T extends ILocale, TPrediction> = keyof {
[K in keyof T as T[K] extends ILocale
? FlattenKeys<T[K], TPrediction> extends infer C extends string
? `${K & string}.${C}`
: never
: T[K] extends TPrediction
? K
: never]: T[K];
};
type ParametersOf<T extends ILocale, TKey extends FlattenKeys<T, ParameterizedString>> = TKey extends `${infer K}.${infer C}`
// @ts-expect-error -- C は明らかに FlattenKeys<T[K], ParameterizedString> になるが、型システムはここでは TKey がドット区切りであることのコンテキストを持たないので、型システムに合法にて示すことはできない。
? ParametersOf<T[K], C>
: TKey extends keyof T
? T[TKey] extends ParameterizedString<infer P>
? P
: never
: never;
type Tsx<T extends ILocale> = {
readonly [K in keyof T as T[K] extends string ? never : K]: T[K] extends ParameterizedString<infer P>
? (arg: { readonly [_ in P]: string | number }) => string
// @ts-expect-error -- 証明省略
: Tsx<T[K]>;
};
export class I18n<T extends ILocale> {
private tsxCache?: Tsx<T>;
private devMode: boolean;
constructor(public locale: T, devMode = false) {
this.devMode = devMode;
//#region BIND
this.t = this.t.bind(this);
//#endregion
}
public get ts(): T {
if (this.devMode) {
class Handler<TTarget extends ILocale> implements ProxyHandler<TTarget> {
get(target: TTarget, p: string | symbol): unknown {
const value = target[p as keyof TTarget];
if (typeof value === 'object') {
return new Proxy(value, new Handler<TTarget[keyof TTarget] & ILocale>());
}
if (typeof value === 'string') {
const parameters = Array.from(value.matchAll(/\{(\w+)\}/g), ([, parameter]) => parameter);
if (parameters.length) {
console.error(`Missing locale parameters: ${parameters.join(', ')} at ${String(p)}`);
}
return value;
}
console.error(`Unexpected locale key: ${String(p)}`);
return p;
}
}
return new Proxy(this.locale, new Handler());
}
return this.locale;
}
public get tsx(): Tsx<T> {
if (this.devMode) {
if (this.tsxCache) {
return this.tsxCache;
}
class Handler<TTarget extends ILocale> implements ProxyHandler<TTarget> {
get(target: TTarget, p: string | symbol): unknown {
const value = target[p as keyof TTarget];
if (typeof value === 'object') {
return new Proxy(value, new Handler<TTarget[keyof TTarget] & ILocale>());
}
if (typeof value === 'string') {
const quasis: string[] = [];
const expressions: string[] = [];
let cursor = 0;
while (~cursor) {
const start = value.indexOf('{', cursor);
if (!~start) {
quasis.push(value.slice(cursor));
break;
}
quasis.push(value.slice(cursor, start));
const end = value.indexOf('}', start);
expressions.push(value.slice(start + 1, end));
cursor = end + 1;
}
if (!expressions.length) {
console.error(`Unexpected locale key: ${String(p)}`);
return () => value;
}
return (arg: TODO) => {
let str = quasis[0];
for (let i = 0; i < expressions.length; i++) {
if (!Object.hasOwn(arg, expressions[i])) {
console.error(`Missing locale parameters: ${expressions[i]} at ${String(p)}`);
}
str += arg[expressions[i]] + quasis[i + 1];
}
return str;
};
}
console.error(`Unexpected locale key: ${String(p)}`);
return p;
}
}
return this.tsxCache = new Proxy(this.locale, new Handler()) as unknown as Tsx<T>;
}
if (this.tsxCache) {
return this.tsxCache;
}
function build(target: ILocale): Tsx<T> {
const result = {} as Tsx<T>;
for (const k in target) {
if (!Object.hasOwn(target, k)) {
continue;
}
const value = target[k as keyof typeof target];
if (typeof value === 'object') {
(result as TODO)[k] = build(value as ILocale);
} else if (typeof value === 'string') {
const quasis: string[] = [];
const expressions: string[] = [];
let cursor = 0;
while (~cursor) {
const start = value.indexOf('{', cursor);
if (!~start) {
quasis.push(value.slice(cursor));
break;
}
quasis.push(value.slice(cursor, start));
const end = value.indexOf('}', start);
expressions.push(value.slice(start + 1, end));
cursor = end + 1;
}
if (!expressions.length) {
continue;
}
(result as TODO)[k] = (arg: TODO) => {
let str = quasis[0];
for (let i = 0; i < expressions.length; i++) {
str += arg[expressions[i]] + quasis[i + 1];
}
return str;
};
}
}
return result;
}
return this.tsxCache = build(this.locale);
}
/**
* @deprecated なるべくこのメソッド使うよりも ts 直接参照の方が vue のキャッシュ効いてパフォーマンスが良いかも
*/
public t<TKey extends FlattenKeys<T, string>>(key: TKey): string;
/**
* @deprecated なるべくこのメソッド使うよりも tsx 直接参照の方が vue のキャッシュ効いてパフォーマンスが良いかも
*/
public t<TKey extends FlattenKeys<T, ParameterizedString>>(key: TKey, args: { readonly [_ in ParametersOf<T, TKey>]: string | number }): string;
public t(key: string, args?: { readonly [_: string]: string | number }) {
let str: string | ParameterizedString | ILocale = this.locale;
for (const k of key.split('.')) {
str = (str as TODO)[k];
if (this.devMode) {
if (typeof str === 'undefined') {
console.error(`Unexpected locale key: ${key}`);
return key;
}
}
}
if (args) {
if (this.devMode) {
const missing = Array.from((str as string).matchAll(/\{(\w+)\}/g), ([, parameter]) => parameter).filter(parameter => !Object.hasOwn(args, parameter));
if (missing.length) {
console.error(`Missing locale parameters: ${missing.join(', ')} at ${key}`);
}
}
for (const [k, v] of Object.entries(args)) {
const search = `{${k}}`;
if (this.devMode) {
if (!(str as string).includes(search)) {
console.error(`Unexpected locale parameter: ${k} at ${key}`);
}
}
str = (str as string).replace(search, v.toString());
}
}
return str;
}
}