/**
 * Languages Loader
 */

import fs from "fs";
import yaml from "js-yaml";
import path from "path";
import { fileURLToPath } from "url";

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

const languages: string[] = [];
const languages_custom: string[] = [];

const merge = (...args) =>
    args.reduce(
        (a, c) => ({
            ...a,
            ...c,
            ...Object.entries(a)
                .filter(([k]) => c && typeof c[k] === "object")
                .reduce((a, [k, v]) => ((a[k] = merge(v, c[k])), a), {}),
        }),
        {}
    );

fs.readdirSync(__dirname).forEach((file) => {
    if (file.includes(".yml")) {
        file = file.slice(0, file.indexOf("."));
        languages.push(file);
    }
});

fs.readdirSync(__dirname + "/../custom/locales").forEach((file) => {
    if (file.includes(".yml")) {
        file = file.slice(0, file.indexOf("."));
        languages_custom.push(file);
    }
});

const primaries = {
    en: "US",
    ja: "JP",
    zh: "CN",
};

// 何故か文字列にバックスペース文字が混入することがあり、YAMLが壊れるので取り除く
const clean = (text) =>
    text.replace(new RegExp(String.fromCodePoint(0x08), "g"), "");

// HACK: Type checking the locale
type LocaleMap = { [property: string]: LocaleMap } & string;
const locales: Record<string, LocaleMap> = languages.reduce(
    (a, c) => (
        (a[c] =
            yaml.load(clean(fs.readFileSync(`${__dirname}/${c}.yml`, "utf-8"))) ||
            {}),
        a
    ),
    {}
);
const locales_custom: Record<string, LocaleMap> = languages_custom.reduce(
    (a, c) => (
        (a[c] =
            yaml.load(
                clean(
                    fs.readFileSync(`${__dirname}/../custom/locales/${c}.yml`, "utf-8")
                )
            ) || {}),
        a
    ),
    {}
);
Object.assign(locales, locales_custom);

export default Object.entries(locales).reduce(
    (a, [k, v]) => (
        (a[k] = (() => {
            const [lang] = k.split("-");
            switch (k) {
                case "ja-JP":
                    return v;
                case "ja-KS":
                case "en-US":
                    return merge(locales["ja-JP"], v);
                default:
                    return merge(
                        locales["ja-JP"],
                        locales["en-US"],
                        locales[`${lang}-${primaries[lang]}`] || {},
                        v
                    );
            }
        })()),
        a
    ),
    {}
) as Record<string, LocaleMap>;