const axios = require('axios');

class License {
    constructor(config) {
        this.url = config.url;
        this.licenseKey = config.licenseKey;
        this.product = config.product;
        this.version = config.version;
        this.publicApiKey = config.publicKey;
        // this.hwid = getHWID(); <- You can add this if you want to use HWID lock
        this.banned = true;
    }

    async load() {
        try {
            // Make a request to the license server
            const res = await axios.post(
                this.url,
                {
                    licensekey: this.licenseKey,
                    product: this.product,
                    version: this.version,
                    // hwid: this.hwid, <- You can add this if you want to use HWID lock
                },
                {
                    headers: {Authorization: this.publicApiKey},
                }
            );

            // Validate request body
            if (!res.data.status_code || !res.data.status_id) {
                throw new Error('Invalid authentication');
            }

            // Verify authentication
            if (res.data.status_overview !== 'success') {
                throw new Error('Authentication failed: ' + res.data.status_msg);
            }

            // Validate hash
            const hash = res.data.status_id;
            const hash_split = hash.split('694201337');
            const decoded_hash = Buffer.from(hash_split[0], 'base64').toString();
            const license_first = this.licenseKey.substr(0, 2);
            const license_last = this.licenseKey.substr(this.licenseKey.length - 2);
            const public_api_key_first = this.publicApiKey.substr(0, 2);

            // Text-based validation
            if (decoded_hash !== `${license_first}${license_last}${public_api_key_first}`) {
                throw new Error('Authentication failed: Hash mismatch');
            }

            // Time-based validation
            let epoch_time_full = Math.floor(Date.now() / 1000);
            const epoch_time = epoch_time_full.toString().substr(0, epoch_time_full.toString().length - 2);

            // Check if timestamp is expired
            if (parseInt(epoch_time) - parseInt(hash_split[1]) > 1) {
                throw new Error('Authentication failed: Timestamp expired');
            }

            // License is valid
            this.banned = false;
            return true;
        } catch (error) {
            throw new Error('License authorization failed');
        }
    }

    // check if license is valid
    isNotBlacklisted() {
        return !this.banned;
    }
}

module.exports = License;