const globalClient = require('../../../client.js');
const svgCaptcha = require('svg-captcha');
const sharp = require('sharp');

class CaptchaGenerator {
    constructor() {
        this.options = {
            size: 6, // Length of captcha text
            noise: 8, // Number of noise lines
            color: true, // Colors enabled
            background: 'transparent',
            width: 300,
            height: 150,
            fontSize: 100,
            charPreset: 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789' // Characters to use
        };
    }

    /**
     * Generate a captcha with both text and image
     * @returns {Promise<{text: string, image: Buffer}>} Captcha text and PNG buffer
     */
    async generate() {
        try {
            // Generate SVG captcha
            const captcha = svgCaptcha.create(this.options);

            // Convert SVG to PNG using sharp
            const pngBuffer = await sharp(Buffer.from(captcha.data))
                .composite([{
                    input: Buffer.from(`<svg>
                        <rect width="100%" height="100%" fill="white"/>
                    </svg>`),
                    blend: 'dest-over'
                }])
                .png()
                .toBuffer();

            return {
                text: captcha.text, // The captcha solution
                imageBuffer: pngBuffer // PNG buffer that can be used to save or send the image
            };
        } catch (error) {
            throw new Error(`Failed to generate captcha: ${error.message}`);
        }
    }

    /**
     * Customize captcha generation options
     * @param {Object} newOptions - Options to override defaults
     */
    setOptions(newOptions) {
        this.options = {
            ...this.options,
            ...newOptions
        };
    }
}

module.exports = {
    name: 'captchaGenerator',
    priority: 0,
    initialize: async () => {
        const generator = new CaptchaGenerator();
        const namespace = globalClient.registerNamespace('captcha');

        namespace.generate = generator.generate.bind(generator);
        namespace.setOptions = generator.setOptions.bind(generator);

        return true;
    }
};