import fs from "node:fs";
import path from "node:path";
import { execSync } from "node:child_process";

const ROOT = process.cwd();
const DOCS_DIR = path.resolve(ROOT, "docs");
const OUT_DIR = path.resolve(ROOT, ".vitepress/.generated");
const OUT_FILE = path.join(OUT_DIR, "i18n-status.json");

const LOCALES = ["en", "ru"];

function walk(dir) {
    const out = [];
    for (const name of fs.readdirSync(dir)) {
        const p = path.join(dir, name);
        const st = fs.statSync(p);
        if (st.isDirectory()) out.push(...walk(p));
        else if (p.endsWith(".md")) out.push(p);
    }
    return out;
}

function gitLastCommitISO(fileAbsPath) {
    const rel = path.relative(ROOT, fileAbsPath).replaceAll("\\", "/");
    try {
        const iso = execSync(`git log -1 --format=%cI -- "${rel}"`, {
            encoding: "utf8",
        }).trim();
        return iso || null;
    } catch {
        return null;
    }
}

function toRouteFromDocsRel(relToDocs) {
    let route = "/" + relToDocs.replace(/\.md$/, "");
    route = route.replace(/\/index$/, "/");
    return route;
}

const zhFiles = walk(DOCS_DIR).filter((p) => {
    const rel = path.relative(DOCS_DIR, p).replaceAll("\\", "/");
    return !LOCALES.some((l) => rel.startsWith(l + "/"));
});

const zhByRel = new Map(); // relToDocs -> abs
for (const abs of zhFiles) {
    const relToDocs = path.relative(DOCS_DIR, abs).replaceAll("\\", "/");
    zhByRel.set(relToDocs, abs);
}

const data = {};
for (const locale of LOCALES) {
    const localeDir = path.join(DOCS_DIR, locale);
    if (!fs.existsSync(localeDir)) continue;

    const tFiles = walk(localeDir);
    for (const tAbs of tFiles) {
        const relToDocs = path.relative(DOCS_DIR, tAbs).replaceAll("\\", "/"); // en/config/log.md
        const relNoLocale = relToDocs.replace(new RegExp(`^${locale}/`), ""); // config/log.md
        const zhAbs = zhByRel.get(relNoLocale);

        const tRoute = toRouteFromDocsRel(relToDocs); // /en/config/log
        const zhRoute = toRouteFromDocsRel(relNoLocale); // /config/log

        const tISO = gitLastCommitISO(tAbs);
        const zhISO = zhAbs ? gitLastCommitISO(zhAbs) : null;

        const stale =
            Boolean(zhISO && tISO) &&
            new Date(tISO).getTime() < new Date(zhISO).getTime();

        data[tRoute] = {
            locale,
            zhRoute,
            translated: true,
            stale,
            tLastUpdated: tISO,
            zhLastUpdated: zhISO,
        };
    }
}

for (const [zhRel, zhAbs] of zhByRel.entries()) {
    const zhRoute = toRouteFromDocsRel(zhRel);
    const zhISO = gitLastCommitISO(zhAbs);

    for (const locale of LOCALES) {
        const tRoute = "/" + locale + (zhRoute === "/" ? "/" : zhRoute);
        if (!data[tRoute]) {
            data[tRoute] = {
                locale,
                zhRoute,
                translated: false,
                stale: true,
                tLastUpdated: null,
                zhLastUpdated: zhISO,
            };
        }
    }
}

fs.mkdirSync(OUT_DIR, { recursive: true });
fs.writeFileSync(OUT_FILE, JSON.stringify(data, null, 2), "utf8");
console.log(`Generated i18n status -> ${OUT_FILE}`);