/*
 * Copyright (C) 2015 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package androidx.test.jank.internal;

import android.app.Instrumentation;
import android.os.Build;
import androidx.test.jank.GfxMonitor;
import androidx.test.jank.GfxFrameStatsMonitor;
import androidx.test.jank.IMonitor;
import androidx.test.jank.IMonitorFactory;
import androidx.test.jank.JankTestBase;
import androidx.test.jank.WindowAnimationFrameStatsMonitor;
import androidx.test.jank.WindowContentFrameStatsMonitor;
import android.util.Log;

import junit.framework.Assert;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.List;

/**
 * An {@link IMonitorFactory} for constructing monitors that detect Jank.
 * @hide
 */
public class JankMonitorFactory implements IMonitorFactory {

    private static String TAG = "JankTestHelper";

    static final int API_LEVEL_ACTUAL = Build.VERSION.SDK_INT
            + ("REL".equals(Build.VERSION.CODENAME) ? 0 : 1);

    private Instrumentation mInstrumentation;

    /**
     * Default constructor.
     */
    public JankMonitorFactory(Instrumentation instrumentation) {
        mInstrumentation = instrumentation;
    }

    /**
     * {@inheritDoc}
     */
    public List<IMonitor> getMonitors(Method testMethod, Object testInstance) {
        List<IMonitor> monitors = new ArrayList<>();

        GfxMonitor gfxMonitorArgs = testMethod.getAnnotation(GfxMonitor.class);
        if (gfxMonitorArgs != null) {
            // GfxMonitor only works on M+. NB: Hard coding value since SDK 22 isn't in prebuilts.
            if (API_LEVEL_ACTUAL <= 22) {
                Log.w(TAG, "Skipping GfxMonitor. Not supported by current platform.");
            } else {
                String process = gfxMonitorArgs.processName();
                if (process.startsWith("#")) {
                    process = resolveGfxMonitorProcessName(process.substring(1), testInstance);
                }
                monitors.add(new GfxMonitorImpl(getInstrumentation(), process));
            }
        }

        GfxFrameStatsMonitor gfxFrameStatsMonitorArgs = testMethod.getAnnotation(
                GfxFrameStatsMonitor.class);
        if (gfxFrameStatsMonitorArgs != null) {
            // GfxMonitor only works on M+. NB: Hard coding value since SDK 22 isn't in prebuilts.
            if (API_LEVEL_ACTUAL <= 22) {
                Log.w(TAG, "Skipping GfxMonitor. Not supported by current platform.");
            } else {
                String process = gfxFrameStatsMonitorArgs.processName();
                if (process.startsWith("#")) {
                    process = resolveGfxMonitorProcessName(process.substring(1), testInstance);
                }
                monitors.add(new GfxFrameStatsMonitorImpl(getInstrumentation(), process));
            }
        }

        WindowAnimationFrameStatsMonitor animationFrameMonitorArgs = testMethod.getAnnotation(
                WindowAnimationFrameStatsMonitor.class);
        if (animationFrameMonitorArgs != null) {
            monitors.add(new WindowAnimationFrameStatsMonitorImpl(getInstrumentation()));
        }

        WindowContentFrameStatsMonitor contentFrameMonitorArgs = testMethod.getAnnotation(
                WindowContentFrameStatsMonitor.class);
        if (contentFrameMonitorArgs != null) {
            monitors.add(new WindowContentFrameStatsMonitorImpl(getInstrumentation()));
        }

        return monitors;
    }

    /**
     * Call the method with the given {@code methodName} to obtain the name of the process that
     * GfxMonitor should watch.
     */
    protected String resolveGfxMonitorProcessName(String methodName, Object target) {
        String processName = null;
        try {
            Method method = target.getClass().getMethod(methodName, (Class[])null);
            processName = (String)method.invoke(target);
        } catch (NoSuchMethodException e) {
            String msg = String.format("Method \"%s\" not found", methodName);
            throw new AssertionError(msg, e);
        } catch (ClassCastException e) {
            String msg = String.format("Method \"%s\" should return a String", methodName);
            throw new AssertionError(msg, e);
        } catch (IllegalAccessException e) {
            // Shouldn't happen. If the method is private, getMethod(..) will throw
            // NoSuchMethodException first. Catching this just to keep the compiler happy.
            String msg = String.format("Method \"%s\" should be public", methodName);
            throw new AssertionError(msg, e);
        } catch (InvocationTargetException e) {
            String msg = String.format("Exception while invoking \"%s\" to obtain process name: %s",
                      methodName, e.getCause() != null ? e.getCause().toString() : e.toString());
            throw new AssertionError(msg, e.getCause() != null ? e.getCause() : e);
        }
        return processName;
    }

    /**
     * Returns the {@link Instrumentation} instance.
     */
    protected Instrumentation getInstrumentation() {
        return mInstrumentation;
    }
}