Subversion Repositories SmartDukaan

package com.smartdukaan.cron.scheduled;

import nu.pattern.OpenCV;

import org.apache.commons.io.FileUtils;

import org.apache.logging.log4j.LogManager;

import org.apache.logging.log4j.Logger;

import org.opencv.core.Mat;

import org.opencv.core.Size;

import org.opencv.imgcodecs.Imgcodecs;

import org.opencv.imgproc.Imgproc;

import org.json.JSONObject;

import org.openqa.selenium.*;

import org.openqa.selenium.chrome.ChromeDriver;

import org.openqa.selenium.chrome.ChromeOptions;

import org.openqa.selenium.interactions.Actions;

import org.openqa.selenium.support.ui.ExpectedConditions;

import org.openqa.selenium.support.ui.WebDriverWait;

import org.springframework.stereotype.Component;

import javax.imageio.ImageIO;

import java.awt.image.BufferedImage;

import java.io.File;

import java.time.LocalDate;

import java.time.format.DateTimeFormatter;

import java.time.Instant;

import java.time.ZoneId;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.concurrent.TimeUnit;

import java.util.stream.Collectors;

@Component

public class CheckOppoWarrantyTask {

    private static final Logger LOGGER = LogManager.getLogger(CheckOppoWarrantyTask.class);

    static {

        try {

            OpenCV.loadShared();

        } catch (Throwable t) {

            LogManager.getLogger(CheckOppoWarrantyTask.class).warn("OpenCV not available on this platform: {}", t.getMessage());

        }

    }

    public Map<String, LocalDate> checkWarranty(List<String> imeis) {

        Map<String, LocalDate> dateMap = new HashMap<>();

        LOGGER.info("Initiating webdriver...");

        Map<String, Object> prefsMap = new HashMap<>();

        prefsMap.put("profile.default_content_settings.popups", 0);

        prefsMap.put("download.prompt", false);

        prefsMap.put("download.directory_upgrade", true);

        System.setProperty("webdriver.chrome.driver", "/usr/bin/chromedriver");

        //I need this

        //System.setProperty("webdriver.chrome.driver", "/Users/amit/cft/chromedriver/chromedriver");

        ChromeOptions options = new ChromeOptions();

        //options.setBinary("/Users/amit/cft/chrome/Google Chrome for Testing.app/Contents/MacOS/Google Chrome For Testing");

        options.setExperimentalOption("prefs", prefsMap);

        //options.setExperimentalOption("detach", true);

        options.addArguments("--headless");

        options.addArguments("--user-agent=\"Mozilla/5.0 (Windows Phone 10.0; Android 4.2.1; Microsoft; Lumia 640 XL LTE) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.135 Mobile Safari/537.36 Edge/12.10166\"");

        options.addArguments("--no-sandbox");

        options.addArguments("start-maximized");

        options.addArguments("disable-infobars");

        options.addArguments("--disable-extensions");

        options.addArguments("--force-device-scale-factor=1");

        options.addArguments("--test-type");

        WebDriver driver = null;

        try {

            driver = new ChromeDriver(options);

            driver.manage().timeouts().setScriptTimeout(6, TimeUnit.SECONDS);

            driver.manage().window().setSize(new Dimension(1600, 900));

            driver.manage().window().maximize();

            // Deleting all the cookies

            driver.manage().deleteAllCookies();

            // Specifiying pageLoadTimeout and Implicit wait

            driver.manage().timeouts().pageLoadTimeout(15, TimeUnit.SECONDS);

            driver.manage().timeouts().implicitlyWait(9, TimeUnit.SECONDS);

            int mainCount = 0;

            List<String> remainingImeis = imeis;

            WebDriverWait wait10Sec = new WebDriverWait(driver, 8);

            WebDriverWait wait5Sec = new WebDriverWait(driver, 4);

            WebElement slideButton;

            Actions actionProvider = new Actions(driver);

            do {

                driver.get("https://support.oppo.com/in/warranty-check/");

                installResponseCapture(driver);

                try {

                    driver.findElement(By.cssSelector(".cp-cookie-tip a.close")).click();

                } catch (Exception e) {

                }

                for (int i = 0; i < remainingImeis.size(); i++) {

                    String imei = remainingImeis.get(i);

                    try {

                        LOGGER.info("Starting fresh with new IMEI " + imei);

                        if (driver.findElement(By.className("el-input__inner")).getAttribute("value").length() > 0) {

                            LOGGER.info("Darn.. leaving" + driver.findElement(By.className("el-input__inner")).getAttribute("value"));

                            driver.get("https://support.oppo.com/in/warranty-check/");

                            installResponseCapture(driver);

                            break;

                        }

                        driver.findElement(By.className("el-input__inner")).sendKeys(imei);

                        //driver.findElement(By.className("el-button--primary")).click();

                        driver.findElement(By.cssSelector("div.searchBtn")).click();

                        // Perform click-and-hold action on the element

                        int counter = 1;

                        boolean captchaNotBroken = true;

                        // release() is only reached on the moveByOffset > 0 path, so an attempt

                        // that fails detection or calibration leaves the button DOWN. Measured in

                        // production: 79% of presses were never released. Actions is one instance

                        // per driver, created outside the imei loop, so the stuck press leaks into

                        // the next attempt AND the next imei -- the following clickAndHold lands on

                        // an already-held button, so the widget never repositions the handle and the

                        // drag continues from wherever the pointer was abandoned.

                        boolean pressed = false;

                        do {

                            String fileName = "/tmp/oppo-simple-i-" + counter + " " + System.currentTimeMillis() + ".png";

                            try {

                                LOGGER.info("Starting Do");

                                wait10Sec.until(ExpectedConditions.visibilityOfElementLocated(By.xpath("//*[starts-with(@id, 'dx_captcha_basic_wrapper_')]")));

                                wait10Sec.until(ExpectedConditions.visibilityOfElementLocated(By.xpath("//*[starts-with(@id, 'dx_captcha_basic_slider_')]")));

                                By sliderBy = By.xpath("//*[starts-with(@id, 'dx_captcha_basic_slider_')]");

                                slideButton = driver.findElement(sliderBy);

                                LOGGER.info("Margin Left before- " + marginLeftOf(slideButton));

                                try {

                                    actionProvider.moveToElement(slideButton).clickAndHold()

                                            .moveByOffset(1, 0)

                                            .perform();

                                } catch (StaleElementReferenceException stale) {

                                    // The retry refresh (doubleClick at the end of the previous

                                    // attempt) swaps the widget's DOM, so the handle located at the

                                    // top of THIS attempt can already be detached by the time we act

                                    // on it. Re-find and try once, rather than abandoning the imei

                                    // and reloading the page: this killed 19% of oppo attempts

                                    // (54 of 284), against 0 on realme.

                                    LOGGER.info("Slider went stale before the drag - re-finding and retrying once");

                                    slideButton = driver.findElement(sliderBy);

                                    actionProvider.moveToElement(slideButton).clickAndHold()

                                            .moveByOffset(1, 0)

                                            .perform();

                                }

                                pressed = true;

                                LOGGER.info("Margin Left after - " + marginLeftOf(slideButton));

                                //Thread.sleep(5000);

                            } catch (Exception e) {

                                LOGGER.warn("Slider captcha widget (dx_captcha_basic_*) not found or not draggable"

                                        + " - reloading. Cause: " + e.getMessage());

                                driver.get("https://support.oppo.com/in/warranty-check/");

                                installResponseCapture(driver);

                                break;

                            }

                            double[] circles = getMatCircles2(driver, fileName);

                            if (circles != null) {

                                double firstCircleX = circles[0];

                                double secondCircleX = circles[1];

                                double distance = Math.abs(firstCircleX - secondCircleX);

                                LOGGER.info("Distance is " + distance);

                                // Closed loop: no assumed ratio, every move re-measures.

                                int moveByOffset = aim(driver, actionProvider, distance);

                                if (moveByOffset > 0) {

                                    actionProvider.release().perform();

                                    pressed = false;

                                    LOGGER.info("Move click performed (main {}px)", moveByOffset);

                                    try {

                                        try {

                                            wait5Sec.until(ExpectedConditions.visibilityOfElementLocated(By.className("dx_captcha_basic_bar-inform")));

                                            // realme logs the widget's own verdict here and oppo did not,

                                            // which is why realme's failures name POSITION_MISMATCH and

                                            // oppo's 85% say nothing at all. Same line, oppo's variables.

                                            LOGGER.warn("Failed = {} (captcha said: {})", counter, captchaSignal(driver));

                                        } catch (Exception notFailedException) {

                                            LOGGER.info("Success  at attempt " + counter);

                                            // Read the JSON the page itself received rather than the

                                            // rendered text. The DOM value is built from two text nodes -- the

                                            // date plus a "(UTC+x)" suffix derived from the browser timezone --

                                            // and the old locator tested only the first, so it matched nothing.

                                            // The API carries regDate as epoch millis, which has no format or

                                            // timezone ambiguity at all.

                                            String json = awaitResponse(driver, 8000);

                                            LocalDate activationDate = regDateFrom(json);

                                            if (json == null) {

                                                LOGGER.warn("No getDeviceInfo response for imei {} (captcha said: {})",

                                                        imei, captchaSignal(driver));

                                            } else {

                                                LOGGER.info("Activation lookup for {} -> {}", imei,

                                                        activationDate != null ? activationDate : "no activation date");

                                            }

                                            // Always record the imei, even with a null date: findElement used to

                                            // throw here, so the row was never written and came back every run.

                                            dateMap.put(imei, activationDate);

                                            clearCapture(driver);

                                            if (dateMap.size() == imeis.size()) {

                                                return dateMap;

                                            }

                                            WebElement checkAgainButton = driver.findElement(By.className("c-btn"));

                                            captchaNotBroken = false;

                                            checkAgainButton.click();

                                            break;

                                        }

                                    } catch (Throwable e) {

                                        LOGGER.warn("Failed = " + counter + " ----------" + e.getMessage());

                                    }

                                }

                            }

                            // Any path that got here without releasing (null circles, unusable

                            // calibration) must let go before the next attempt re-presses.

                            if (pressed) {

                                try {

                                    actionProvider.release().perform();

                                } catch (Exception releaseFailed) {

                                    LOGGER.warn("Could not release the slider: " + releaseFailed.getMessage());

                                }

                                pressed = false;

                            }

                            LOGGER.info("After circles conditions");

                            wait10Sec.until(ExpectedConditions.visibilityOfElementLocated(By.xpath("//*[starts-with(@id, 'dx_captcha_basic_wrapper_')]")));

                            wait10Sec.until(ExpectedConditions.visibilityOfElementLocated(By.xpath("//*[starts-with(@id, 'dx_captcha_basic_slider_')]")));

                            slideButton = driver.findElement(By.xpath("//*[starts-with(@id, 'dx_captcha_basic_slider_')]"));

                            actionProvider.moveToElement(slideButton).doubleClick().perform();

                            LOGGER.info("Ending Do" + counter++);

                        } while (captchaNotBroken && counter <= 20);

                        // The widget-not-found path breaks out mid-iteration; do not carry a held

                        // button into the next imei.

                        if (pressed) {

                            try {

                                actionProvider.release().perform();

                            } catch (Exception releaseFailed) {

                                LOGGER.warn("Could not release the slider: " + releaseFailed.getMessage());

                            }

                        }

                        LOGGER.warn("Counter reached upto 20");

                    } catch (Exception e) {

                        LOGGER.error("Oppo warranty check failed for imei " + imei, e);

                    }

                    driver.get("https://support.oppo.com/in/warranty-check/");

                    // Every navigation destroys the JS context, taking the capture hook

                    // with it. Miss one of these and the page is blind from the second

                    // imei onwards: __oppoResp and __oppoCaptcha both come back null,

                    // which reads as "the captcha failed" when it may well have passed.

                    installResponseCapture(driver);

                }

                mainCount++;

                remainingImeis = imeis.stream().filter(x -> !dateMap.containsKey(x)).collect(Collectors.toList());

                if (remainingImeis.isEmpty()) break;

            } while (mainCount < 5);

        } finally {

            if (driver != null) {

                try {

                    driver.quit(); //Ensures cleanup even on return or error

                } catch (Exception e) {

                    LOGGER.warn("Error closing driver: " + e.getMessage());

                }

            }

        }

        return dateMap;

    }

    /** Stash the getDeviceInfo response on window as the page receives it. */

    private void installResponseCapture(WebDriver driver) {

        try {

            ((JavascriptExecutor) driver).executeScript(

                "if (!window.__oppoCapInstalled) {"

              + "  window.__oppoCapInstalled = true; window.__oppoResp = null; window.__oppoCaptcha = null;"

              // __oppoCaptcha is last-captcha-call-wins, and the widget refetches a puzzle

              // (/api/a) straight after a rejected verify (/api/v1). We then wait up to 5s

              // for the error element before reading it, which is ample time for the

              // refetch to overwrite the verdict -- so "all failures show /api/a" cannot

              // distinguish "never verified" from "verified, rejected, then overwritten".

              // Keep the verify separately, and a count, so the two are distinguishable.

              + "  window.__oppoVerify = null; window.__oppoVerifyCount = 0;"

              // axios can sit on either transport, and realme's page uses fetch --

              // an XHR-only hook silently captures nothing, which is exactly what

              // 'no getDeviceInfo response captured' was reporting.

              + "  var O = XMLHttpRequest.prototype.open;"

              + "  XMLHttpRequest.prototype.open = function(m,u){"

              + "    this.addEventListener('load', function(){"

              + "      try { var s=String(u);"

              + "        if (s.indexOf('getDeviceInfo') !== -1) window.__oppoResp = this.responseText;"

              + "        else if (s.indexOf('/api/v1') !== -1) { window.__oppoVerifyCount++; window.__oppoVerify = (this.responseText||'').slice(0,160); window.__oppoCaptcha = s + ' -> ' + (this.responseText||'').slice(0,200); }"

              + "        else if (s.indexOf('captcha') !== -1) window.__oppoCaptcha = s + ' -> ' + (this.responseText||'').slice(0,200);"

              + "      } catch(e){}"

              + "    });"

              + "    return O.apply(this, arguments);"

              + "  };"

              + "  var F = window.fetch;"

              + "  if (F) { window.fetch = function(){"

              + "    var u = arguments[0]; u = (u && u.url) ? u.url : String(u);"

              + "    return F.apply(this, arguments).then(function(r){"

              + "      try { if (u.indexOf('getDeviceInfo') !== -1) { r.clone().text().then(function(t){ window.__oppoResp = t; }); } } catch(e){}"

              + "      return r;"

              + "    });"

              + "  }; }"

              // A window.fetch wrapper only catches clients that resolve fetch at call

              // time. Anything that captured globalThis.fetch when its bundle loaded --

              // Nuxt's $fetch/ofetch does exactly this, and it is what hid realme's

              // lookup from us -- sails straight past it. Response.prototype is resolved

              // per call, so it catches every client regardless.

              // Read the clone with the ORIGINAL reader; the patched one recurses forever.

              + "  ['json','text'].forEach(function(name){"

              + "    var orig = Response.prototype[name];"

              + "    if (!orig) return;"

              + "    Response.prototype[name] = function(){"

              + "      try { var u = this.url || '';"

              + "        if (u.indexOf('getDeviceInfo') !== -1 && !this.__oppoSeenBody) {"

              + "          var c = this.clone(); c.__oppoSeenBody = 1;"

              + "          orig.call(c).then(function(t){ window.__oppoResp = (typeof t === 'string') ? t : JSON.stringify(t); });"

              + "        } } catch(e){}"

              + "      return orig.apply(this, arguments);"

              + "    };"

              + "  });"

              + "}");

        } catch (Exception e) {

            LOGGER.warn("Could not install the response capture hook: " + e.getMessage());

        }

    }

    /** Last response from the captcha widget itself -- says WHY a drag was refused. */

    private String captchaSignal(WebDriver driver) {

        try {

            Object v = ((JavascriptExecutor) driver).executeScript(

                    "return 'verifies=' + (window.__oppoVerifyCount||0)"

                  + " + ' lastVerify=' + (window.__oppoVerify || 'NONE')"

                  + " + ' | ' + (window.__oppoCaptcha || 'none');");

            return v == null ? null : v.toString();

        } catch (Exception e) {

            return null;

        }

    }

    /** Poll for the response instead of reading once: the success signal can fire

     *  before the lookup request has completed, which loses the payload. */

    private String awaitResponse(WebDriver driver, long timeoutMs) {

        long deadline = System.currentTimeMillis() + timeoutMs;

        while (System.currentTimeMillis() < deadline) {

            String json = capturedResponse(driver);

            if (json != null && !json.trim().isEmpty()) return json;

            try {

                Thread.sleep(300);

            } catch (InterruptedException ie) {

                Thread.currentThread().interrupt();

                return null;

            }

        }

        return null;

    }

    private String capturedResponse(WebDriver driver) {

        try {

            Object v = ((JavascriptExecutor) driver).executeScript("return window.__oppoResp || null;");

            return v == null ? null : v.toString();

        } catch (Exception e) {

            return null;

        }

    }

    private void clearCapture(WebDriver driver) {

        try {

            ((JavascriptExecutor) driver).executeScript("window.__oppoResp = null;");

        } catch (Exception ignored) {

        }

    }

    /** data.regDate is epoch millis; absent or blank means the device is not activated yet. */

    private LocalDate regDateFrom(String json) {

        if (json == null) return null;

        try {

            JSONObject data = new JSONObject(json).optJSONObject("data");

            if (data == null) return null;

            String reg = data.optString("regDate", "");

            if (reg == null || reg.trim().isEmpty() || "null".equals(reg)) return null;

            return Instant.ofEpochMilli(Long.parseLong(reg.trim()))

                    .atZone(ZoneId.of("Asia/Kolkata")).toLocalDate();

        } catch (Exception e) {

            LOGGER.warn("Could not read regDate from the Oppo response: " + e.getMessage());

            return null;

        }

    }

    /**

     * Calibration nudge, in slider px, sized from the gap rather than fixed.

     *

     * A fixed 15px was far too small: it closed only ~25px, so the ratio came from a

     * measurement ~20% noise and the aim landed ~30px out. A fixed 60px then proved too

     * large in the other direction -- production data showed 85% of attempts with a gap

     * under 60px ended up UNUSABLE (the piece shot past the hole and the measured gap

     * grew), and 45% overall.

     *

     * Aim to close about half the gap: the piece travels roughly ASSUMED_RATIO px per

     * slider px, so nudge ~= gap / (2 * ratio), clamped. The real ratio is still derived

     * from the measurement; this only sizes the probe.

     */

    private static final double ALIGNED_PX = 2.0;

    /**

     * margin-left for logging only. Reading it off a detached element throws, and this is

     * a diagnostic -- it must never be the reason an attempt is abandoned.

     */

    private String marginLeftOf(WebElement el) {

        try {

            return el.getCssValue("margin-left");

        } catch (Exception e) {

            return "?";

        }

    }

    /** Seed probe, in slider px. Deliberately small: it only has to produce a first

     *  measurable movement, and it must be too small to cross the hole. */

    private static final int SEED_NUDGE = 12;

    private static final int MAX_AIM_STEPS = 5;

    private static final int MAX_STEP = 140;

    /**

     * Drag onto the hole without ever assuming a ratio.

     *

     * The old path derived px-per-px ONCE from a single probe and then trusted it for

     * the main move and the correction alike, so one noisy probe poisoned everything

     * downstream. Here every move is also a measurement: after each one the ratio is

     * re-derived from what that move actually achieved, so the estimate improves as the

     * piece approaches instead of being fixed at its least informed point.

     *

     * It also gets to see overshoot, which a single pass cannot. The gap is |c1 - c2|,

     * so it cannot tell "not there yet" from "gone past" -- but if a move makes the gap

     * GROW, we crossed the hole, and the sign of the next step flips.

     *

     * @return total slider px moved, or 0 if the circles could not be read at all.

     */

    private int aim(WebDriver driver, Actions actionProvider, double gap) throws Exception {

        double ratio = 0;               // slider px per gap px, derived from real moves

        int total = 0;

        int step = SEED_NUDGE;

        for (int i = 0; i < MAX_AIM_STEPS; i++) {

            actionProvider.moveByOffset(step, 0).perform();

            total += step;

            double[] c = getMatCircles2(driver, "/tmp/" + Thread.currentThread().getName() + "-aim" + i + ".png");

            if (c == null) {

                LOGGER.warn("Aim step {}: lost the circles after {}px", i, total);

                return total;

            }

            double now = Math.abs(c[0] - c[1]);

            double closed = gap - now;

            if (closed != 0) {

                // What this move actually bought us, in slider px per gap px.

                double observed = Math.abs(step) / Math.abs(closed);

                // Blend once an estimate exists, so a single bad frame cannot swing it.

                ratio = (ratio <= 0) ? observed : (ratio + observed) / 2;

            }

            LOGGER.info("Aim step {}: moved {}px, gap {} -> {}, ratio now {}",

                    i, step, gap, now, String.format("%.2f", ratio));

            if (now <= ALIGNED_PX) {

                LOGGER.info("Aim: aligned within {}px after {} step(s), {}px total", ALIGNED_PX, i + 1, total);

                return total;

            }

            if (ratio <= 0) {                       // nothing measurable yet, probe again

                gap = now;

                step = SEED_NUDGE;

                continue;

            }

            int next = (int) Math.round(now * ratio);

            if (next == 0) next = 1;

            if (next > MAX_STEP) next = MAX_STEP;

            // Gap grew => we are past the hole; go back instead of further away.

            step = (closed < 0) ? -next : next;

            gap = now;

        }

        LOGGER.info("Aim: {} steps used, {}px total", MAX_AIM_STEPS, total);

        return total;

    }

    private Mat getMatCircles(WebDriver driver, String fileName) throws Exception {

        File screenshot = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE);

        BufferedImage fullImg = ImageIO.read(screenshot);

        // Get the location of element on the page

        WebElement imageElement = driver.findElement(By.xpath("//*[starts-with(@id, 'dx_captcha_basic_bg_')]"));

        Point point = imageElement.getLocation();

        // Get width and height of the element

        int eleWidth = imageElement.getSize().getWidth();

        int eleHeight = imageElement.getSize().getHeight();

        // Crop the entire page screenshot to get only element screenshot

        BufferedImage eleScreenshot = fullImg.getSubimage(point.getX(), point.getY(),

                eleWidth, eleHeight);

        ImageIO.write(eleScreenshot, "png", screenshot);

        // Copy the element screenshot to disk

        File screenshotLocation = new File(fileName);

        FileUtils.copyFile(screenshot, screenshotLocation);

        Imgcodecs imageCodecs = new Imgcodecs();

        Mat grayMatrix = imageCodecs.imread(fileName, Imgcodecs.IMREAD_COLOR);

        Imgproc.cvtColor(grayMatrix, grayMatrix, Imgproc.COLOR_BGR2GRAY);

        Mat medianBlur = new Mat();

        Imgproc.medianBlur(grayMatrix, medianBlur, 5);

        Mat circles = new Mat();

        Imgproc.HoughCircles(medianBlur, circles, Imgproc.HOUGH_GRADIENT, 1, 15, 50, 20, 17, 25);

        return circles;

    }

    private double[] getMatCircles2(WebDriver driver, String fileName) throws Exception {

        File screenshot = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE);

        BufferedImage fullImg = ImageIO.read(screenshot);

        // Get the location of element on the page

        WebElement imageElement = driver.findElement(By.xpath("//*[starts-with(@id, 'dx_captcha_basic_bg_')]"));

        Point point = imageElement.getLocation();

        // Get width and height of the element

        int eleWidth = imageElement.getSize().getWidth();

        int eleHeight = imageElement.getSize().getHeight();

        // Crop the entire page screenshot to get only element screenshot

        BufferedImage eleScreenshot = fullImg.getSubimage(point.getX(), point.getY(),

                eleWidth, eleHeight);

        ImageIO.write(eleScreenshot, "png", screenshot);

        // Copy the element screenshot to disk

        File screenshotLocation = new File(fileName);

        FileUtils.copyFile(screenshot, screenshotLocation);

        Mat src = Imgcodecs.imread(fileName);

        if (src.empty()) {

            System.err.println("Cannot read image: " + fileName);

            new File(fileName).delete();

            return null;

        }

        Mat gray = new Mat();

        Imgproc.cvtColor(src, gray, Imgproc.COLOR_BGR2GRAY);

        Imgproc.GaussianBlur(gray, gray, new Size(9, 9), 2, 2);

        Mat circles = new Mat();

        Imgproc.HoughCircles(gray, circles, Imgproc.HOUGH_GRADIENT, 1.0,

                20, // min distance between centers

                100, 20, // param1 (Canny high threshold), param2 (accumulator threshold)

                10, 50); // minRadius, maxRadius (adjust as needed)

        if (circles.cols() < 2) {

            new File(fileName).delete();

            return null;

        }

        for (int i = 0; i < circles.cols(); i++) {

            double[] c1 = circles.get(0, i);

            for (int j = i + 1; j < circles.cols(); j++) {

                double[] c2 = circles.get(0, j);

                if (Math.abs(c1[2] - c2[2]) < 3) { // check similar radius

                    new File(fileName).delete();

                    return new double[] {

                            c1[0], c2[0] // x-coordinates

                    };

                }

            }

        }

        new File(fileName).delete();

        return null;

    }

}