// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

package com.android.webview.chromium;

import android.Manifest;
import android.app.compat.CompatChanges;
import android.content.Context;
import android.content.pm.PackageManager;
import android.content.res.Resources;
import android.os.Build;
import android.os.Looper;
import android.os.Process;
import android.os.SystemClock;
import android.util.Log;
import android.webkit.CookieManager;
import android.webkit.GeolocationPermissions;
import android.webkit.WebSettings;
import android.webkit.WebStorage;
import android.webkit.WebViewDatabase;

import org.chromium.android_webview.AwBrowserContext;
import org.chromium.android_webview.AwBrowserProcess;
import org.chromium.android_webview.AwContents;
import org.chromium.android_webview.AwContentsStatics;
import org.chromium.android_webview.AwCookieManager;
import org.chromium.android_webview.AwDarkMode;
import org.chromium.android_webview.AwLocaleConfig;
import org.chromium.android_webview.AwNetworkChangeNotifierRegistrationPolicy;
import org.chromium.android_webview.AwProxyController;
import org.chromium.android_webview.AwServiceWorkerController;
import org.chromium.android_webview.AwThreadUtils;
import org.chromium.android_webview.AwTracingController;
import org.chromium.android_webview.HttpAuthDatabase;
import org.chromium.android_webview.ProductConfig;
import org.chromium.android_webview.R;
import org.chromium.android_webview.WebViewChromiumRunQueue;
import org.chromium.android_webview.common.AwResource;
import org.chromium.android_webview.common.AwSwitches;
import org.chromium.android_webview.gfx.AwDrawFnImpl;
import org.chromium.android_webview.variations.VariationsSeedLoader;
import org.chromium.base.BuildInfo;
import org.chromium.base.BundleUtils;
import org.chromium.base.CommandLine;
import org.chromium.base.ContextUtils;
import org.chromium.base.FieldTrialList;
import org.chromium.base.JNIUtils;
import org.chromium.base.PathService;
import org.chromium.base.ThreadUtils;
import org.chromium.base.TraceEvent;
import org.chromium.base.library_loader.LibraryLoader;
import org.chromium.base.metrics.RecordHistogram;
import org.chromium.base.metrics.ScopedSysTraceEvent;
import org.chromium.base.task.PostTask;
import org.chromium.build.BuildConfig;
import org.chromium.content_public.browser.UiThreadTaskTraits;
import org.chromium.net.NetworkChangeNotifier;
import org.chromium.ui.base.DeviceFormFactor;
import org.chromium.ui.base.ResourceBundle;

/**
 * Class controlling the Chromium initialization for WebView.
 * We hold on to most static objects used by WebView here.
 * This class is shared between the webkit glue layer and the support library glue layer.
 */
public class WebViewChromiumAwInit {
    private static final String TAG = "WebViewChromiumAwInit";

    private static final String HTTP_AUTH_DATABASE_FILE = "http_auth.db";

    // TODO(gsennton): store aw-objects instead of adapters here
    // Initialization guarded by mLock.
    private AwBrowserContext mBrowserContext;
    private AwTracingController mTracingController;
    private SharedStatics mSharedStatics;
    private GeolocationPermissionsAdapter mGeolocationPermissions;
    private CookieManagerAdapter mCookieManager;

    private WebIconDatabaseAdapter mWebIconDatabase;
    private WebStorageAdapter mWebStorage;
    private WebViewDatabaseAdapter mWebViewDatabase;
    private AwServiceWorkerController mServiceWorkerController;
    private AwTracingController mAwTracingController;
    private VariationsSeedLoader mSeedLoader;
    private Thread mSetUpResourcesThread;
    private AwProxyController mAwProxyController;

    // Guards accees to the other members, and is notifyAll() signalled on the UI thread
    // when the chromium process has been started.
    // This member is not private only because the downstream subclass needs to access it,
    // it shouldn't be accessed from anywhere else.
    /* package */ final Object mLock = new Object();

    // mInitState should only transition INIT_NOT_STARTED -> INIT_STARTED -> INIT_FINISHED
    private static final int INIT_NOT_STARTED = 0;
    private static final int INIT_STARTED = 1;
    private static final int INIT_FINISHED = 2;
    // Read/write protected by mLock
    private int mInitState;

    private final WebViewChromiumFactoryProvider mFactory;

    private boolean mIsPostedFromBackgroundThread;

    WebViewChromiumAwInit(WebViewChromiumFactoryProvider factory) {
        mFactory = factory;
        // Do not make calls into 'factory' in this ctor - this ctor is called from the
        // WebViewChromiumFactoryProvider ctor, so 'factory' is not properly initialized yet.
        TraceEvent.maybeEnableEarlyTracing(
                TraceEvent.ATRACE_TAG_WEBVIEW, /*readCommandLine=*/false);
    }

    public AwTracingController getAwTracingController() {
        synchronized (mLock) {
            if (mAwTracingController == null) {
                ensureChromiumStartedLocked(true);
            }
        }
        return mAwTracingController;
    }

    public AwProxyController getAwProxyController() {
        synchronized (mLock) {
            if (mAwProxyController == null) {
                ensureChromiumStartedLocked(true);
            }
        }
        return mAwProxyController;
    }

    // TODO: DIR_RESOURCE_PAKS_ANDROID needs to live somewhere sensible,
    // inlined here for simplicity setting up the HTMLViewer demo. Unfortunately
    // it can't go into base.PathService, as the native constant it refers to
    // lives in the ui/ layer. See ui/base/ui_base_paths.h
    private static final int DIR_RESOURCE_PAKS_ANDROID = 3003;

    protected void startChromiumLocked() {
        long startTime = SystemClock.uptimeMillis();
        try (ScopedSysTraceEvent event =
                        ScopedSysTraceEvent.scoped("WebViewChromiumAwInit.startChromiumLocked")) {
            assert Thread.holdsLock(mLock) && ThreadUtils.runningOnUiThread();

            // The post-condition of this method is everything is ready, so notify now to cover all
            // return paths. (Other threads will not wake-up until we release |mLock|, whatever).
            mLock.notifyAll();

            if (mInitState == INIT_FINISHED) {
                return;
            }

            final Context context = ContextUtils.getApplicationContext();

            JNIUtils.setClassLoader(WebViewChromiumAwInit.class.getClassLoader());

            ResourceBundle.setAvailablePakLocales(AwLocaleConfig.getWebViewSupportedPakLocales());

            BundleUtils.setIsBundle(ProductConfig.IS_BUNDLE);

            // We are rewriting Java resources in the background.
            // NOTE: Any reference to Java resources will cause a crash.

            try (ScopedSysTraceEvent e =
                            ScopedSysTraceEvent.scoped("WebViewChromiumAwInit.LibraryLoader")) {
                LibraryLoader.getInstance().ensureInitialized();
            }

            PathService.override(PathService.DIR_MODULE, "/system/lib/");
            PathService.override(DIR_RESOURCE_PAKS_ANDROID, "/system/framework/webview/paks");

            initPlatSupportLibrary();
            doNetworkInitializations(context);

            waitUntilSetUpResources();

            // NOTE: Finished writing Java resources. From this point on, it's safe to use them.

            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S && mIsPostedFromBackgroundThread) {
                // Try to work around the problem we're seeing with resources on Android 12. When
                // WebView is being initialized from a background thread, it's possible that the
                // asset path updated by WebViewFactory is no longer present by the time we get
                // here due to something on the UI thread having caused a resource update in the
                // app in the meantime, because WebViewFactory does not add the path persistently.
                // So, we can try to add them again using the "better" method in WebViewDelegate.

                // However, we only want to try this if the resources are actually missing, because
                // in the past we've seen this cause apps that were working to *start* crashing.
                // The first resource that gets accessed in startup happens during the
                // AwBrowserProcess.start() call when trying to determine if the device is a tablet,
                // and that's the most common place for us to crash. So, try calling that same
                // method and see if it throws - if so then we're unlikely to make the situation
                // any worse by trying to fix the path.
                try {
                    DeviceFormFactor.isTablet();
                } catch (Resources.NotFoundException e) {
                    mFactory.addWebViewAssetPath(context);
                }
            }

            AwBrowserProcess.configureChildProcessLauncher();

            // finishVariationsInitLocked() must precede native initialization so the seed is
            // available when AwFeatureListCreator::SetUpFieldTrials() runs.
            finishVariationsInitLocked();

            AwBrowserProcess.start();
            AwBrowserProcess.handleMinidumpsAndSetMetricsConsent(true /* updateMetricsConsent */);

            // This has to be done after variations are initialized, so components could be
            // registered or not depending on the variations flags.
            AwBrowserProcess.loadComponents();
            AwBrowserProcess.initializeMetricsLogUploader();

            mSharedStatics = new SharedStatics();
            if (BuildInfo.isDebugAndroid()) {
                mSharedStatics.setWebContentsDebuggingEnabledUnconditionally(true);
            }

            mInitState = INIT_FINISHED;

            RecordHistogram.recordSparseHistogram("Android.WebView.TargetSdkVersion",
                    context.getApplicationInfo().targetSdkVersion);

            try (ScopedSysTraceEvent e = ScopedSysTraceEvent.scoped(
                         "WebViewChromiumAwInit.initThreadUnsafeSingletons")) {
                // Initialize thread-unsafe singletons.
                AwBrowserContext awBrowserContext = getBrowserContextOnUiThread();
                mGeolocationPermissions = new GeolocationPermissionsAdapter(
                        mFactory, awBrowserContext.getGeolocationPermissions());
                mWebStorage =
                        new WebStorageAdapter(mFactory, mBrowserContext.getQuotaManagerBridge());
                mAwTracingController = getTracingController();
                mServiceWorkerController = awBrowserContext.getServiceWorkerController();
                mAwProxyController = new AwProxyController();
            }

            mFactory.getRunQueue().drainQueue();

            if (BuildInfo.isAtLeastT()
                            ? CompatChanges.isChangeEnabled(WebSettings.ENABLE_SIMPLIFIED_DARK_MODE)
                            : BuildInfo.targetsAtLeastT()) {
                AwDarkMode.enableSimplifiedDarkMode();
            }

            if (CommandLine.getInstance().hasSwitch(AwSwitches.WEBVIEW_VERBOSE_LOGGING)) {
                logCommandLineAndActiveTrials();
            }
        }
        RecordHistogram.recordTimesHistogram(
                "Android.WebView.Startup.CreationTime.StartChromiumLocked",
                SystemClock.uptimeMillis() - startTime);
    }

    /**
     * Set up resources on a background thread.
     * @param context The context.
     */
    public void setUpResourcesOnBackgroundThread(int packageId, Context context) {
        try (ScopedSysTraceEvent e = ScopedSysTraceEvent.scoped(
                     "WebViewChromiumAwInit.setUpResourcesOnBackgroundThread")) {
            assert mSetUpResourcesThread == null : "This method shouldn't be called twice.";

            // Make sure that ResourceProvider is initialized before starting the browser process.
            mSetUpResourcesThread = new Thread(new Runnable() {
                @Override
                public void run() {
                    // Run this in parallel as it takes some time.
                    setUpResources(packageId, context);
                }
            });
            mSetUpResourcesThread.start();
        }
    }

    private void waitUntilSetUpResources() {
        try (ScopedSysTraceEvent e = ScopedSysTraceEvent.scoped(
                     "WebViewChromiumAwInit.waitUntilSetUpResources")) {
            mSetUpResourcesThread.join();
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
    }

    private void setUpResources(int packageId, Context context) {
        try (ScopedSysTraceEvent e =
                        ScopedSysTraceEvent.scoped("WebViewChromiumAwInit.setUpResources")) {
            R.onResourcesLoaded(packageId);

            AwResource.setResources(context.getResources());
            AwResource.setConfigKeySystemUuidMapping(android.R.array.config_keySystemUuidMapping);
        }
    }

    boolean hasStarted() {
        return mInitState == INIT_FINISHED;
    }

    void startYourEngines(boolean fromThreadSafeFunction) {
        synchronized (mLock) {
            ensureChromiumStartedLocked(fromThreadSafeFunction);
        }
    }

    // This method is not private only because the downstream subclass needs to access it,
    // it shouldn't be accessed from anywhere else.
    /* package */ void ensureChromiumStartedLocked(boolean fromThreadSafeFunction) {
        assert Thread.holdsLock(mLock);

        if (mInitState == INIT_FINISHED) { // Early-out for the common case.
            return;
        }

        if (mInitState == INIT_NOT_STARTED) {
            // If we're the first thread to enter ensureChromiumStartedLocked, we need to determine
            // which thread will be the UI thread; declare init has started so that no other thread
            // will try to do this.
            mInitState = INIT_STARTED;
            setChromiumUiThreadLocked(fromThreadSafeFunction);
        }

        if (ThreadUtils.runningOnUiThread()) {
            // If we are currently running on the UI thread then we must do init now. If there was
            // already a task posted to the UI thread from another thread to do it, it will just
            // no-op when it runs.
            startChromiumLocked();
            return;
        }

        mIsPostedFromBackgroundThread = true;

        // If we're not running on the UI thread (because init was triggered by a thread-safe
        // function), post init to the UI thread, since init is *not* thread-safe.
        AwThreadUtils.postToUiThreadLooper(new Runnable() {
            @Override
            public void run() {
                synchronized (mLock) {
                    startChromiumLocked();
                }
            }
        });

        // Wait for the UI thread to finish init.
        while (mInitState != INIT_FINISHED) {
            try {
                mLock.wait();
            } catch (InterruptedException e) {
                // Keep trying; we can't abort init as WebView APIs do not declare that they throw
                // InterruptedException.
            }
        }
    }

    private void setChromiumUiThreadLocked(boolean fromThreadSafeFunction) {
        // If we're being started from a function that's allowed to be called on any thread,
        // then we can't just assume the current thread is the UI thread; instead we assume the
        // process's main looper will be the UI thread, because that's the case for almost all
        // Android apps.
        //
        // If we're being started from a function that must be called from the UI
        // thread, then by definition the current thread is the UI thread whether it's the main
        // looper or not.
        Looper looper = fromThreadSafeFunction ? Looper.getMainLooper() : Looper.myLooper();
        Log.v(TAG,
                "Binding Chromium to "
                        + (Looper.getMainLooper().equals(looper) ? "main" : "background")
                        + " looper " + looper);
        ThreadUtils.setUiThread(looper);
    }

    private void initPlatSupportLibrary() {
        try (ScopedSysTraceEvent e = ScopedSysTraceEvent.scoped(
                     "WebViewChromiumAwInit.initPlatSupportLibrary")) {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
                AwDrawFnImpl.setDrawFnFunctionTable(DrawFunctor.getDrawFnFunctionTable());
            }
            DrawGLFunctor.setChromiumAwDrawGLFunction(AwContents.getAwDrawGLFunction());
            AwContents.setAwDrawSWFunctionTable(GraphicsUtils.getDrawSWFunctionTable());
            AwContents.setAwDrawGLFunctionTable(GraphicsUtils.getDrawGLFunctionTable());
        }
    }

    private void doNetworkInitializations(Context applicationContext) {
        try (ScopedSysTraceEvent e = ScopedSysTraceEvent.scoped(
                     "WebViewChromiumAwInit.doNetworkInitializations")) {
            if (applicationContext.checkPermission(
                        Manifest.permission.ACCESS_NETWORK_STATE, Process.myPid(), Process.myUid())
                    == PackageManager.PERMISSION_GRANTED) {
                NetworkChangeNotifier.init();
                NetworkChangeNotifier.setAutoDetectConnectivityState(
                        new AwNetworkChangeNotifierRegistrationPolicy());
            }

            AwContentsStatics.setCheckClearTextPermitted(
                    applicationContext.getApplicationInfo().targetSdkVersion
                    >= Build.VERSION_CODES.O);
        }
    }

    public AwTracingController getTracingController() {
        if (mTracingController == null) {
            mTracingController = new AwTracingController();
        }
        return mTracingController;
    }

    // Only on UI thread.
    AwBrowserContext getBrowserContextOnUiThread() {
        assert mInitState == INIT_FINISHED;

        if (BuildConfig.ENABLE_ASSERTS && !ThreadUtils.runningOnUiThread()) {
            throw new RuntimeException(
                    "getBrowserContextOnUiThread called on " + Thread.currentThread());
        }

        if (mBrowserContext == null) {
            mBrowserContext = AwBrowserContext.getDefault();
        }
        return mBrowserContext;
    }

    /**
     * Returns the lock used for guarding chromium initialization.
     * We make this public to let higher-level classes use this lock to guard variables
     * dependent on this class, to avoid introducing new locks (which can cause deadlocks).
     */
    public Object getLock() {
        return mLock;
    }

    public SharedStatics getStatics() {
        synchronized (mLock) {
            if (mSharedStatics == null) {
                // TODO: Optimization potential: most these methods only need the native library
                // loaded and initialized, not the entire browser process started.
                // See also http://b/7009882
                ensureChromiumStartedLocked(true);
            }
        }
        return mSharedStatics;
    }

    public GeolocationPermissions getGeolocationPermissions() {
        synchronized (mLock) {
            if (mGeolocationPermissions == null) {
                ensureChromiumStartedLocked(true);
            }
        }
        return mGeolocationPermissions;
    }

    public CookieManager getCookieManager() {
        synchronized (mLock) {
            if (mCookieManager == null) {
                mCookieManager = new CookieManagerAdapter(new AwCookieManager());
            }
        }
        return mCookieManager;
    }

    public AwServiceWorkerController getServiceWorkerController() {
        synchronized (mLock) {
            if (mServiceWorkerController == null) {
                ensureChromiumStartedLocked(true);
            }
        }
        return mServiceWorkerController;
    }

    public android.webkit.WebIconDatabase getWebIconDatabase() {
        synchronized (mLock) {
            ensureChromiumStartedLocked(true);
            if (mWebIconDatabase == null) {
                mWebIconDatabase = new WebIconDatabaseAdapter();
            }
        }
        return mWebIconDatabase;
    }

    public WebStorage getWebStorage() {
        synchronized (mLock) {
            if (mWebStorage == null) {
                ensureChromiumStartedLocked(true);
            }
        }
        return mWebStorage;
    }

    public WebViewDatabase getWebViewDatabase(final Context context) {
        synchronized (mLock) {
            ensureChromiumStartedLocked(true);
            if (mWebViewDatabase == null) {
                mWebViewDatabase = new WebViewDatabaseAdapter(
                        mFactory, HttpAuthDatabase.newInstance(context, HTTP_AUTH_DATABASE_FILE));
            }
        }
        return mWebViewDatabase;
    }

    // See comments in VariationsSeedLoader.java on when it's safe to call this.
    public void startVariationsInit() {
        synchronized (mLock) {
            if (mSeedLoader == null) {
                mSeedLoader = new VariationsSeedLoader();
                mSeedLoader.startVariationsInit();
            }
        }
    }

    private void finishVariationsInitLocked() {
        try (ScopedSysTraceEvent e = ScopedSysTraceEvent.scoped(
                     "WebViewChromiumAwInit.finishVariationsInitLocked")) {
            assert Thread.holdsLock(mLock);
            if (mSeedLoader == null) {
                Log.e(TAG, "finishVariationsInitLocked() called before startVariationsInit()");
                startVariationsInit();
            }
            mSeedLoader.finishVariationsInit();
            mSeedLoader = null; // Allow this to be GC'd after its background thread finishes.
        }
    }

    // Log extra information, for debugging purposes. Do the work asynchronously to avoid blocking
    // startup.
    private void logCommandLineAndActiveTrials() {
        PostTask.postTask(UiThreadTaskTraits.BEST_EFFORT, () -> {
            // TODO(ntfschr): CommandLine can change at any time. For simplicity, only log it
            // once during startup.
            AwContentsStatics.logCommandLineForDebugging();
            // Field trials can be activated at any time. We'll continue logging them as they're
            // activated.
            FieldTrialList.logActiveTrials();
            // SafeMode was already determined earlier during the startup sequence, this just
            // fetches the cached boolean state. If SafeMode was enabled, we already logged detailed
            // information about the SafeMode config.
            Log.i(TAG, "SafeMode enabled: " + mFactory.isSafeModeEnabled());
        });
    }

    public WebViewChromiumRunQueue getRunQueue() {
        return mFactory.getRunQueue();
    }
}