@developers-joyride/shortify/dist/services/shortener.service.js

High performance URL shortener library with multi-database support (MongoDB, SQLite, PostgreSQL, MySQL)

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.ShortenerService = void 0;
const url_1 = require("url");
const id_generator_1 = require("../utils/id-generator");
class ShortenerService {
    constructor(baseUrl, dbAdapter) {
        this.defaultUrlLength = 8;
        // Ensure the base URL ends with a slash
        this.baseUrl = baseUrl.endsWith("/") ? baseUrl : `${baseUrl}/`;
        this.dbAdapter = dbAdapter;
    }
    /**
     * Validate if a URL is properly formatted
     */
    isValidUrl(urlString) {
        try {
            const url = new url_1.URL(urlString);
            return url.protocol === "http:" || url.protocol === "https:";
        }
        catch (error) {
            return false;
        }
    }
    /**
     * Generate a short URL ID
     */
    generateUrlId(length = this.defaultUrlLength) {
        return (0, id_generator_1.generateId)(length);
    }
    /**
     * Check if a URL ID already exists in the database
     * For performance, we use this to avoid duplicate URL IDs
     */
    async findExistingUrlId(urlId) {
        return this.dbAdapter.findUrlByUrlId(urlId);
    }
    /**
     * Shorten a URL
     */
    async shorten(originalUrl, options = {}) {
        // Validate the original URL
        if (!this.isValidUrl(originalUrl)) {
            throw new Error("Invalid URL format");
        }
        // Apply options with defaults
        const urlLength = options.urlLength || this.defaultUrlLength;
        const baseUrl = options.baseUrl || this.baseUrl;
        // Generate URL ID (either custom or generated)
        let urlId = options.customUrlId || this.generateUrlId(urlLength);
        // Check if the URL ID already exists and generate a new one if needed
        let existingUrl = await this.findExistingUrlId(urlId);
        while (existingUrl) {
            urlId = this.generateUrlId(urlLength);
            existingUrl = await this.findExistingUrlId(urlId);
        }
        // Calculate expiration date if provided
        let expiresAt = undefined;
        if (options.expiresInDays) {
            expiresAt = new Date();
            expiresAt.setDate(expiresAt.getDate() + options.expiresInDays);
        }
        // Create the short URL
        const shortUrl = `${baseUrl}${urlId}`;
        // Save the URL to database
        await this.dbAdapter.createUrl({
            urlId,
            originalUrl,
            shortUrl,
            clicks: 0,
            expiresAt,
        });
        return {
            originalUrl,
            shortUrl,
            urlId,
            expiresAt,
        };
    }
    /**
     * Resolve a short URL to its original URL
     */
    async resolve(urlId) {
        const url = await this.dbAdapter.findUrlByUrlId(urlId);
        if (!url) {
            return null;
        }
        // Check if URL has expired
        if (url.expiresAt && url.expiresAt < new Date()) {
            // URL has expired, delete it
            await this.dbAdapter.deleteUrl(urlId);
            return null;
        }
        // Increment click count
        await this.dbAdapter.updateUrlClicks(urlId, url.clicks + 1);
        return url.originalUrl;
    }
    /**
     * Get URL stats
     */
    async getUrlStats(urlId) {
        const url = await this.dbAdapter.findUrlByUrlId(urlId);
        if (!url) {
            return null;
        }
        return {
            urlId: url.urlId,
            originalUrl: url.originalUrl,
            shortUrl: url.shortUrl,
            clicks: url.clicks,
            createdAt: url.createdAt,
            expiresAt: url.expiresAt,
        };
    }
    /**
     * Delete a shortened URL
     */
    async deleteUrl(urlId) {
        return this.dbAdapter.deleteUrl(urlId);
    }
}
exports.ShortenerService = ShortenerService;