const { Logger } = require("./logger");
const { connect } = require("puppeteer-real-browser");
const os = require("os");

class BrowserService {
    constructor() {
        this.logger = new Logger("Browser");
        this.browser = null;
        this.browserContexts = new Set();
        this.cleanupTimer = null;
        this.isShuttingDown = false;
        this.reconnectAttempts = 0;
        this.maxReconnectAttempts = 5;
        this.cleanupInterval = 30000;
        this.contextTimeout = 300000;
        this.contextCreationTimes = new Map();
        this.stats = {
            totalContexts: 0,
            activeContexts: 0,
            memoryUsage: 0,
            cpuUsage: 0,
            lastCleanup: Date.now(),
        };
        const cpuCores = os.cpus().length;
        this.contextLimit = Math.max(cpuCores * 4, 16);
        this.logger.info(`Browser service initialized with context limit: ${this.contextLimit}`);
        this.setupGracefulShutdown();
        this.startPeriodicCleanup();
    }
    async initialize(options = {}) {
        if (this.isShuttingDown) return;
        try {
            await this.closeBrowser();
            this.logger.info("Launching browser...");
            const defaultWidth = 1024;
            const defaultHeight = 768;
            const width = options.width || defaultWidth;
            const height = options.height || defaultHeight;
            const { browser } = await connect({
                headless: false,
                turnstile: true,
                connectOption: {
                    defaultViewport: { width, height },
                    timeout: 120000,
                    protocolTimeout: 300000,
                    args: [
  `--window-size=${width},${height}`,
  '--no-sandbox',
  '--disable-setuid-sandbox',
  '--disable-dev-shm-usage',
  '--disable-gpu',
  '--disable-software-rasterizer',
  '--disable-background-networking',
  '--disable-default-apps',
  '--disable-extensions',
  '--disable-sync',
  '--disable-translate',
  '--disable-web-security',
  '--disable-features=VizDisplayCompositor',
  '--single-process',
  '--no-zygote',
  '--no-first-run'
],
                },
                disableXvfb: false,
            });
            if (!browser) throw new Error("Failed to connect to browser");
            this.browser = browser;
            this.reconnectAttempts = 0;
            this.setupBrowserEventHandlers();
            this.wrapBrowserMethods();
            this.logger.success("Browser launched successfully");
        } catch (error) {
            this.logger.error("Browser initialization failed:", error);
            if (this.reconnectAttempts < this.maxReconnectAttempts && !this.isShuttingDown) {
                this.reconnectAttempts++;
                this.logger.warn(`Retrying browser initialization (${this.reconnectAttempts}/${this.maxReconnectAttempts})`);
                await new Promise((resolve) => setTimeout(resolve, 5000 * this.reconnectAttempts));
                return this.initialize(options);
            }
            throw error;
        }
    }

    setupBrowserEventHandlers() {
        if (!this.browser) return;
        this.browser.on("disconnected", async () => {
            if (this.isShuttingDown) return;
            this.logger.warn("Browser disconnected, attempting to reconnect...");
            await this.handleBrowserDisconnection();
        });
        this.browser.on("targetcreated", () => this.updateStats());
        this.browser.on("targetdestroyed", () => this.updateStats());
    }

    wrapBrowserMethods() {
        if (!this.browser) return;
        const originalCreateContext = this.browser.createBrowserContext.bind(this.browser);
        this.browser.createBrowserContext = async (...args) => {
            if (this.browserContexts.size >= this.contextLimit) {
                await this.forceCleanupOldContexts();
                if (this.browserContexts.size >= this.contextLimit) {
                    throw new Error(`Browser context limit reached (${this.contextLimit})`);
                }
            }
            const context = await originalCreateContext(...args);
            if (context) {
                this.browserContexts.add(context);
                this.contextCreationTimes.set(context, Date.now());
                this.stats.totalContexts++;
                const originalClose = context.close.bind(context);
                context.close = async () => {
                    try {
                        await originalClose();
                    } catch (error) {
                        this.logger.warn("Error closing context:", error.message);
                    } finally {
                        this.browserContexts.delete(context);
                        this.contextCreationTimes.delete(context);
                        this.updateStats();
                    }
                };

                setTimeout(async () => {
                    if (this.browserContexts.has(context)) {
                        this.logger.debug("Force closing expired context");
                        try {
                            await context.close();
                        } catch { }
                    }
                }, this.contextTimeout);
            }
            this.updateStats();
            return context;
        };
    }

    async handleBrowserDisconnection() {
        try {
            const cleanupPromises = Array.from(this.browserContexts).map((context) => context.close().catch(() => { }));
            await Promise.allSettled(cleanupPromises);
            this.browserContexts.clear();
            this.contextCreationTimes.clear();
            if (this.reconnectAttempts < this.maxReconnectAttempts) {
                await new Promise((resolve) => setTimeout(resolve, 5000));
                await this.initialize();
            } else {
                this.logger.error("Max reconnection attempts reached");
            }
        } catch (error) {
            this.logger.error("Error handling browser disconnection:", error);
        }
    }

    startPeriodicCleanup() {
        this.cleanupTimer = setInterval(async () => {
            if (this.isShuttingDown) return;
            try {
                await this.performCleanup();
                this.updateStats();
            } catch (error) {
                this.logger.error("Periodic cleanup error:", error);
            }
        }, this.cleanupInterval);
    }

    async performCleanup() {
        const now = Date.now();
        const contextsToCleanup = [];
        for (const [context, creationTime] of this.contextCreationTimes.entries()) {
            if (now - creationTime > this.contextTimeout) {
                contextsToCleanup.push(context);
            }
        }
        if (contextsToCleanup.length > 0) {
            this.logger.debug(`Cleaning up ${contextsToCleanup.length} expired contexts`);
            const cleanupPromises = contextsToCleanup.map((context) => context.close().catch(() => { }));
            await Promise.allSettled(cleanupPromises);
        }
        if (this.browserContexts.size > this.contextLimit * 0.8) await this.forceCleanupOldContexts();
        this.stats.lastCleanup = now;
    }

    async forceCleanupOldContexts() {
        const contextsArray = Array.from(this.browserContexts);
        const sortedContexts = contextsArray.sort((a, b) => {
            const timeA = this.contextCreationTimes.get(a) || 0;
            const timeB = this.contextCreationTimes.get(b) || 0;
            return timeA - timeB;
        });
        const toCleanup = sortedContexts.slice(0, Math.floor(sortedContexts.length * 0.3));
        if (toCleanup.length > 0) {
            this.logger.warn(`Force cleaning up ${toCleanup.length} contexts due to limit`);
            const cleanupPromises = toCleanup.map((context) => context.close().catch(() => { }));
            await Promise.allSettled(cleanupPromises);
        }
    }

    updateStats() {
        this.stats.activeContexts = this.browserContexts.size;
        this.stats.memoryUsage = process.memoryUsage().heapUsed;
        const usage = process.cpuUsage();
        this.stats.cpuUsage = (usage.user + usage.system) / 1000000;
    }

    async createContext(options = {}) {
        if (!this.browser) await this.initialize();
        if (!this.browser) throw new Error("Browser not available");
        return await this.browser.createBrowserContext({
            ...options,
            ignoreHTTPSErrors: true,
        });
    }

    async withBrowserContext(callback) {
        let context = null;
        try {
            context = await this.createContext();
            return await callback(context);
        } finally {
            if (context) {
                try {
                    await context.close();
                } catch (error) {
                    this.logger.warn(`Failed to close context: ${error.message}`);
                }
            }
        }
    }

    getBrowserStats() {
        return { ...this.stats };
    }

    isReady() {
        return this.browser !== null && !this.isShuttingDown;
    }

    async closeBrowser() {
        if (this.browser) {
            try {
                const cleanupPromises = Array.from(this.browserContexts).map((context) => context.close().catch(() => { }));
                await Promise.allSettled(cleanupPromises);
                this.browserContexts.clear();
                this.contextCreationTimes.clear();
                await this.browser.close();
                this.logger.info("Browser closed successfully");
            } catch (error) {
                this.logger.error("Error closing browser:", error);
            } finally {
                this.browser = null;
            }
        }
    }

    setupGracefulShutdown() {
        const gracefulShutdown = async (signal) => {
            this.logger.warn(`Received ${signal}, shutting down browser service...`);
            this.isShuttingDown = true;
            if (this.cleanupTimer) clearInterval(this.cleanupTimer);
            await this.closeBrowser();
            this.logger.success("Browser service shutdown complete");
        };
        process.on("SIGTERM", () => gracefulShutdown("SIGTERM"));
        process.on("SIGINT", () => gracefulShutdown("SIGINT"));
    }

    async shutdown() {
        this.isShuttingDown = true;
        if (this.cleanupTimer) clearInterval(this.cleanupTimer);
        await this.closeBrowser();
    }
}

module.exports = { BrowserService };