import { NextApiRequest, NextApiResponse } from 'next';
import fs from 'fs';
import path from 'path';
import common from "../../../src/helpers/common";

function flattenTranslations(data) {
    const result = {};

    function recurse(cur, prop) {
        if (Object(cur) !== cur) {
            result[prop] = cur;
        } else if (Array.isArray(cur)) {
            for (let i = 0, l = cur.length; i < l; i++)
                recurse(cur[i], prop ? prop + "." + i : "" + i);
            if (l == 0)
                result[prop] = [];
        } else {
            let isEmpty = true;
            for (let p in cur) {
                isEmpty = false;
                recurse(cur[p], prop ? prop + "." + p : p);
            }
            if (isEmpty)
                result[prop] = {};
        }
    }
    recurse(data, "");
    return result;
}

function unflattenTranslations(data) {
    const result = {};

    for (let i in data) {
        const keys = i.split('.');
        keys.reduce((r, e, j) => {
            return r[e] || (r[e] = isNaN(Number(keys[j + 1])) ? (keys.length - 1 === j ? data[i] : {}) : []);
        }, result);
    }
    return result;
}

export default async function handler(req: NextApiRequest, res: NextApiResponse) {
    const { locale } = req.query;
    const filePath = path.join(process.cwd(), `content/i18n/${locale.join(".")}.json`);
    const modifiedFilePath = path.join(process.cwd(), `content/i18n/${locale}.modified.json`);

    switch (req.method) {
        case 'GET':
            let flat = common.parseBool(req.query.flat);
            try {
                const fileContents = fs.readFileSync(filePath, 'utf8');
                let translations = JSON.parse(fileContents);
                if (fs.existsSync(modifiedFilePath)) {
                    const modifiedTranslations = JSON.parse(fs.readFileSync(modifiedFilePath, 'utf8'));
                    translations = { ...translations, ...modifiedTranslations };
                }
                if (flat) {
                    translations = flattenTranslations(translations);
                }
                res.status(200).json(translations);
            } catch (error) {
                console.error('Error reading translation file:', error);
                res.status(500).json({ error: 'Failed to read translation file' });
            }
            break;

        case 'POST':
            try {
                const newTranslations = req.body;
                const reconstructedTranslations = unflattenTranslations(newTranslations);
                fs.writeFileSync(filePath, JSON.stringify(reconstructedTranslations, null, 2), 'utf8');
                res.status(200).json({ status: 'Updated' });
            } catch (error) {
                console.error('Error writing translation file:', error);
                res.status(500).json({ error: 'Failed to update translation file' });
            }
            break;

        default:
            res.setHeader('Allow', ['GET', 'POST']);
            res.status(405).end(`Method ${req.method} Not Allowed`);
    }
}