import * as en from './en';

type I18nParams = readonly unknown[] | Record<string, unknown>;

/**
 * 读取语言文本，并替换位置占位符（{0}）或命名占位符（{name}）。
 */
export function t(path: string, ...params: unknown[]): string {
    const value = path.split('.').reduce<unknown>((current, key) => {
        if (!current || typeof current !== 'object') return undefined;
        return (current as Record<string, unknown>)[key];
    }, en);

    if (typeof value !== 'string') return path;
    if (params.length === 0) return value;

    const replacements = getReplacements(params);

    return value.replace(/\{([^{}]+)\}/g, (placeholder, key) => {
        const replacement = Array.isArray(replacements)
            ? replacements[Number(key)]
            : replacements[key];
        return replacement === undefined ? placeholder : String(replacement);
    });
}

function getReplacements(params: unknown[]): I18nParams {
    const [firstParam] = params;
    if (params.length === 1 && Array.isArray(firstParam)) return firstParam;
    if (params.length === 1 && firstParam && typeof firstParam === 'object') {
        return firstParam as Record<string, unknown>;
    }
    return params;
}