import fs from 'fs';
import path from 'path';
import {extract} from "tar";
import {Reader} from '@maxmind/geoip2-node';

const ENABLE_MAXMIND=false

let ipdb = null
function setDbFile(file) {
    const dbBuffer = fs.readFileSync(file);
    ipdb = Reader.openBuffer(dbBuffer);
}

/**
 * Downloads and extracts a .tar.gz file from a given URL.
 * @param {string} url - The URL to download the file from.
 * @param {string} outputDir - The directory to move the final .mmdb file to.
 * @param {string} tempDir - The directory to use for temporary files.
 * @param {string} username - The username for HTTP basic auth.
 * @param {string} password - The password for HTTP basic auth.
 */
async function downloadAndExtractMaxmindData(url, outputDir, tempDir, username, password) {
    console.log('Downloading MaxMind database...');
    const tempFilePath = path.join(tempDir, `temp_${Date.now()}_${Math.random().toString(36).slice(2, 10)}.tar.gz`);
    const tempExtractDir = path.join(tempDir, `temp_extract_${Date.now()}_${Math.random().toString(36).slice(2, 10)}`);

    try {
        // Ensure the output directory exists
        if (!fs.existsSync(outputDir)) {
            fs.mkdirSync(outputDir, {recursive: true});
        }

        // Create a temporary extract directory
        if (!fs.existsSync(tempExtractDir)) {
            fs.mkdirSync(tempExtractDir, {recursive: true});
        }

        // Download the file with HTTP basic authentication and save it as a temporary tar.gz file
        const response = await fetch(url, {
            headers: {
                Authorization: 'Basic ' + Buffer.from(`${username}:${password}`).toString('base64')
            }
        });
        if (!response.ok) {
            throw new Error(`Failed to download file: ${response.statusText}`);
        }

        const fileStream = fs.createWriteStream(tempFilePath);
        const reader = response.body.getReader();
        await new Promise((resolve, reject) => {
            function processChunk({done, value}) {
                if (done) {
                    fileStream.end();
                    resolve();
                    return;
                }
                fileStream.write(value, () => reader.read().then(processChunk).catch(reject));
            }

            reader.read().then(processChunk).catch(reject);
        });

        // Extract the tar.gz file into the temporary extract directory
        await extract({
            file: tempFilePath,
            cwd: tempExtractDir
        });

        // Find the .mmdb file in the temporary extract directory
        const mmdbFile = fs.readdirSync(tempExtractDir, {withFileTypes: true})
            .map(dirent => {
                const fullPath = path.join(tempExtractDir, dirent.name);
                if (dirent.isDirectory()) {
                    const subFiles = fs.readdirSync(fullPath).map(subFile => path.join(fullPath, subFile));
                    return subFiles.find(file => file.endsWith('.mmdb')) || null;
                }
                return dirent.name.endsWith('.mmdb') ? fullPath : null;
            })
            .filter(Boolean)[0];

        if (!mmdbFile) {
            throw new Error('No .mmdb file found in the extracted contents.');
        }

        // Move the .mmdb file to the output directory
        const dest = path.join(outputDir, path.basename(mmdbFile));
        fs.copyFileSync(
            mmdbFile,
            dest
        );
        console.log(`MaxMind database downloaded to ${dest}`);
        return dest
    } finally {
        // Clean up the temporary tar.gz file and temporary extract directory
        if (fs.existsSync(tempFilePath)) {
            fs.unlinkSync(tempFilePath);
        }
        if (fs.existsSync(tempExtractDir)) {
            fs.rmSync(tempExtractDir, {recursive: true, force: true});
        }
    }
}


/**
 * Checks for up-to-date MaxMind database files in the specified output directory. If none of the files
 * meet the update criteria, the function downloads and extracts updated MaxMind data from the provided source.
 *
 * @param {string} outputDir - Directory where MaxMind database files are stored.
 * @param {string} tempDir - Temporary directory used during the download and extraction process.
 * @param {string} url - URL to download the MaxMind data.
 * @param {string} username - Username for authentication to access the MaxMind download service.
 * @param {string} password - Password for authentication to access the MaxMind download service.
 * @return {Promise<void>} Resolves when the data check and optional update process is completed.
 */
async function checkAndUpdateMaxmindData(outputDir, tempDir, url, username, password) {
    if (username === '' || password === '') {
        console.log('No MaxMind credentials provided. Skipping MaxMind database update.');
        return
    }

    console.log('Checking for MaxMind database updates.');

    // Ensure the output directory exists
    if (!fs.existsSync(outputDir)) {
        fs.mkdirSync(outputDir, {recursive: true});
    }

    const mmdbFiles = fs.readdirSync(outputDir).filter(file => file.endsWith('.mmdb'));
    let shouldDownload = true;

    if (mmdbFiles.length) {
        for (const mmdbFile of mmdbFiles) {
            const filePath = path.join(outputDir, mmdbFile);
            const stats = fs.statSync(filePath);
            const modifiedDate = new Date(stats.mtime);
            const fourDaysAgo = new Date(Date.now() - 4 * 24 * 60 * 60 * 1000);

            if (modifiedDate > fourDaysAgo) {
                shouldDownload = false;
                console.log(`MaxMind database '${mmdbFile}' is recent.`);
                setDbFile(filePath)
                break;
            }
        }
    }

    if (shouldDownload) {
        setDbFile(await downloadAndExtractMaxmindData(url, outputDir, tempDir, username, password));
    }
}


const url = 'https://download.maxmind.com/geoip/databases/GeoIP2-Country/download?suffix=tar.gz';
const outputDirectory = './maxmind';
// const username = '1102431';
// const password = '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';
const username = process.env.MAXMIND_ACCOUNT_NUMBER;
const password = process.env.MAXMIND_LICENSE_KEY;

if( ENABLE_MAXMIND ) {

    await checkAndUpdateMaxmindData(outputDirectory, '/tmp', url, username, password);


    setInterval(async () => {
        try {
            await checkAndUpdateMaxmindData(outputDirectory, '/tmp', url, username, password);
        } catch (error) {
            console.error('Error during MaxMind database update:', error);
        }
    }, 24 * 60 * 60 * 1000 + 1000); // 1 day + 1 second

}


export function countryForIP(ipAddress) {
    if (!ipdb) return null
    try {
        const code = ipdb.country(ipAddress).country.isoCode;
        console.log(ipAddress, code)
        return code;
    }
    catch (e) {
        console.warn(`IP lookup failed for ${ipAddress}: ${e.message}`)
        return null
    }
}