import org.openqa.selenium.Capabilities;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.firefox.FirefoxOptions;
import org.openqa.selenium.firefox.FirefoxProfile;
import org.openqa.selenium.remote.DesiredCapabilities;
import org.openqa.selenium.remote.RemoteWebDriver;
import org.slf4j.Logger;

import java.net.URL;
import java.util.concurrent.LinkedTransferQueue;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;

import static com.codeborne.selenide.WebDriverRunner.CHROME;
import static com.codeborne.selenide.WebDriverRunner.FIREFOX;

/**
 * Pool of {@link RemoteWebDriver} objects for reusing existing RemoteWebDriver sessions in web tests
 * The number of available nodes is taken from the file of available quotas (grid-router).
 * If the browser version is not specified, is used the default version for the specified browser
 * from the quota configuration file is taken.
 * The {@link Quota} object and internal objects were generated by pojo
 *
 * Created by Shaburov Oleg on 24.09.2017.
 * shaburov.o.a@gmail.com
 */
public class SelenoidWebDriverPool {

    private Logger log;

    private LinkedTransferQueue<RemoteWebDriver> pool = new LinkedTransferQueue<>();
    private long timeout = 2;
    private TimeUnit unit = TimeUnit.SECONDS;

    private AtomicInteger availableNodes = new AtomicInteger(1);
    private AtomicBoolean isCanCreate = new AtomicBoolean(true);
    private AtomicBoolean hasWD = new AtomicBoolean(false);

    private URL address;
    private Capabilities capabilities;

    /**
     * The class constructor for the remote to run a Web test by means of grid-router
     */
    public SelenoidWebDriverPool(Logger logger, URL remoteAddress, Capabilities desiredCapabilities) {
        log = logger;
        address = remoteAddress;
        capabilities = desiredCapabilities;
        calculateAvailableNodes();
    }

    /**
     * The constructor for a local test run
     */
    public SelenoidWebDriverPool(Logger logger, String browser) {
        log = logger;
        try {
            log.info("Preparing a web driver for local startup: " + browser);
            switch (browser) {
                case CHROME:
                    availableNodes.decrementAndGet();
                    add(new ChromeDriver());
                    break;
                case FIREFOX:
                    FirefoxProfile firefoxProfile = new FirefoxProfile();
                    firefoxProfile.setAcceptUntrustedCertificates(true);
                    firefoxProfile.setAssumeUntrustedCertificateIssuer(true);
                    DesiredCapabilities dc = new FirefoxOptions()
                            .setProfile(firefoxProfile).addTo(DesiredCapabilities.firefox());
                    availableNodes.decrementAndGet();
                    add(new FirefoxDriver(dc));
                    break;
                default:
                    throw new TestFrameworkException("An unsupported web browser is received: " +
                            BaseConfig.getBrowser());
            }
        } catch (Exception e) {
            throw new TestFrameworkException("Error initializing the web browser: " +
                    BaseConfig.getBrowser(), e);
        }
    }

    /**
     * The method gets a list of available nodes from the quota file and
     * calculates the available nodes based on the browser and its version
     */
    private void calculateAvailableNodes() {
        availableNodes.set(0);
        int nodes = 0;
        Quota quota = new Quota("src/main/resources/gridrouter/quota/guest.xml");
        String browserVersion = "";
        for (Browser browser : quota.getBrowser()) {
            if (browser.getName().toLowerCase().equals(capabilities.getBrowserName().toLowerCase())) {
                for (Version version : browser.getVersion()) {
                    if (capabilities.getVersion() == null || capabilities.getVersion().isEmpty()) {
                        browserVersion = browser.getDefaultVersion();
                    }
                    if (version.getNumber().startsWith(browserVersion)) {
                        for (Region region : version.getRegion()) {
                            for (Host host : region.getHost()) {
                                int nodeCount = Integer.valueOf(host.getCount());
                                if (nodeCount > 0) {
                                    nodes += nodeCount;
                                }
                            }
                        }
                    }
                }
            }
        }
        availableNodes.set(nodes);
        if (availableNodes.compareAndSet(0, 0)) {
            throw new TestFrameworkException("The grid-router does not contain nodes for the " +
                    capabilities.getBrowserName() + "browser version " + browserVersion);
        }
        log.info("For {} version {} is available {} nodes",
                capabilities.getBrowserName(), browserVersion, availableNodes);
    }

    /**
     * Method for obtaining a free web driver from the pool.
     */
    public RemoteWebDriver get(String methodName) {
        if (hasWD.compareAndSet(false, true)) {
            return create(methodName);
        }
        try {
            log.info("[{}] In the queue {} threads.", methodName, pool.getWaitingConsumerCount());
            log.info("[{}] Obtaining a web driver from the pool.", methodName);
            RemoteWebDriver driver = (RemoteWebDriver) pool.poll(timeout, unit);
            if (driver == null) {
                return create(methodName);
            }
            log.info("[{}] A web driver from the pool was received. SessionId={}",
                    methodName, driver.getSessionId());
            return driver;
        } catch (InterruptedException e) {
            log.info("[{}] Interrupted expectation of web driver from the pool.", methodName);
            Thread.currentThread().interrupt();
        }
        return null;
    }

    /**
     * Method for creating a new web driver.
     */
    private RemoteWebDriver create(String methodName) {
        if (isCanCreate.compareAndSet(true, false)) {
            if (pool.isEmpty() && availableNodes.get() > 0) {
                try {
                    log.info("[{}] Creating a New Web Driver", methodName);
                    RemoteWebDriver driver = new RemoteWebDriver(address, capabilities);
                    availableNodes.decrementAndGet();
                    isCanCreate.set(true);
                    log.info("[{}] The web driver was successfully created. SessionId={}",
                            methodName, driver.getSessionId());
                    return driver;
                } finally {
                    isCanCreate.set(true);
                }
            } else {
                log.info("[{}] Created the maximum number of web-drivers.", methodName);
                isCanCreate.set(false);
            }
        }
        return get(methodName);
    }

    /**
     * Adds {@link RemoteWebDriver} object to the pool
     */
    private void add(RemoteWebDriver webDriver) {
        pool.add(webDriver);
        log.info("The web driver was successfully added to the pool. SessionId={}",
                webDriver.getSessionId());
    }

    /**
     * Returns a previously occupied {@link RemoteWebDriver} object to the pool
     */
    public void release(RemoteWebDriver webDriver, String method) {
        pool.add(webDriver);
        log.info("[{}] The web driver was successfully returned to the pool. " +
                "SessionId={}", method, webDriver.getSessionId());
    }

    /**
     * The method of completing all RemoteWebDriver sessions in the pool.
     */
    public void shutdown() {
        pool.forEach(wd -> {
            String sid = wd.getSessionId().toString();
            try {
                wd.quit();
                log.info("The browser is closed. SessionId={}", sid);
            } catch (Exception e) {
                log.error("Error when trying to close your web browser. SessionId={}", sid, e);
            }
        });
    }

    public void setTimeout(long timeout, TimeUnit unit) {
        this.timeout = timeout;
        this.unit = unit;
    }

}