/*
 * Copyright (C) 2021 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 com.android.car.pm;

import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * A utility class to parse the window dump.
 */
class WindowDumpParser {
    private static final String WINDOW_TYPE_APPLICATION_STARTING = "APPLICATION_STARTING";

    /**
     * Parses the provided window dump and returns the list of windows only for a particular app.
     *
     * @param dump the window dump in string format as returned from `dumpsys window
     *         windows`.
     * @param appPackageName the package name of the app, which the windows are being
     *         requested for.
     * @return a list of parsed {@link Window} objects.
     */
    public static List<Window> getParsedAppWindows(String dump, String appPackageName) {
        Pattern dumpSplitter = Pattern.compile("(Window #)|\\n\\n");
        // \\n\\n to separate out the Global dump from the windows list.

        Pattern windowDetailsPattern = Pattern.compile("\\d*.*\\n"
                        + ".*mDisplayId=(\\S*).*\\n"
                        + ".*package=(\\S*).*\\n"
                        + ".*ty=(\\S*)"
                        + "((.*ActivityRecord\\{(.*?)\\}.*\\n)|(.*\\n))*"
                // (.*\\n) is required for skipping the lines before the line containing
                // ActivityRecord{}.
        );
        List<Window> windows = new ArrayList<>();

        String[] windowDumps = dumpSplitter.split(dump);
        for (int i = 1; i < windowDumps.length - 1; i++) {
            Matcher m = windowDetailsPattern.matcher(windowDumps[i]);
            if (m.find()) {
                // Only consider windows for the given appPackageName which are not the splash
                // screen windows.
                // TODO(b/192355798): Revisit this logic as window type can be changed.
                if (Objects.equals(m.group(2), appPackageName)
                        && !Objects.equals(m.group(3), WINDOW_TYPE_APPLICATION_STARTING)) {
                    windows.add(new Window(
                            /* packageName = */ m.group(2),
                            /* displayId = */ Integer.parseInt(m.group(1)),
                            /* activityRecord = */ m.group(6)
                    ));
                }
            }
        }
        return windows;
    }

    /**
     * A holder class that represents an app's window.
     */
    static class Window {
        private final String mPackageName;
        private final int mDisplayId;
        private final String mActivityRecord;

        Window(String packageName, int displayId, String activityRecord) {
            mPackageName = packageName;
            mDisplayId = displayId;
            mActivityRecord = activityRecord;
        }

        public String getPackageName() {
            return mPackageName;
        }

        public int getDisplayId() {
            return mDisplayId;
        }

        public String getActivityRecord() {
            return mActivityRecord;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (!(o instanceof Window)) return false;
            Window window = (Window) o;
            return mDisplayId == window.mDisplayId
                    && mPackageName.equals(window.mPackageName)
                    && Objects.equals(mActivityRecord, window.mActivityRecord);
        }

        @Override
        public int hashCode() {
            return Objects.hash(mPackageName, mDisplayId, mActivityRecord);
        }

        @Override
        public String toString() {
            return "Window{"
                    + "mPackageName=" + mPackageName
                    + ", mDisplayId=" + mDisplayId
                    + ", mActivityRecord={" + mActivityRecord + "}"
                    + "}";
        }
    }
}