/*
 * Copyright (C) 2011 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.settingslib.net;

import android.app.AppGlobals;
import android.content.Context;
import android.content.pm.ApplicationInfo;
import android.content.pm.IPackageManager;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.content.pm.UserInfo;
import android.content.res.Resources;
import android.graphics.drawable.Drawable;
import android.net.ConnectivityManager;
import android.net.TrafficStats;
import android.os.UserManager;
import android.os.UserHandle;
import android.os.RemoteException;
import android.text.TextUtils;
import android.util.Log;
import android.util.SparseArray;

import com.android.settingslib.R;
import com.android.settingslib.Utils;

/**
 * Return details about a specific UID, handling special cases like
 * {@link TrafficStats#UID_TETHERING} and {@link UserInfo}.
 */
public class UidDetailProvider {
    private static final String TAG = "DataUsage";
    private final Context mContext;
    private final SparseArray<UidDetail> mUidDetailCache;

    public static final int OTHER_USER_RANGE_START = -2000;

    public static int buildKeyForUser(int userHandle) {
        return OTHER_USER_RANGE_START - userHandle;
    }

    public static boolean isKeyForUser(int key) {
        return key <= OTHER_USER_RANGE_START;
    }

    public static int getUserIdForKey(int key) {
        return OTHER_USER_RANGE_START - key;
    }

    public UidDetailProvider(Context context) {
        mContext = context.getApplicationContext();
        mUidDetailCache = new SparseArray<UidDetail>();
    }

    public void clearCache() {
        synchronized (mUidDetailCache) {
            mUidDetailCache.clear();
        }
    }

    /**
     * Resolve best descriptive label for the given UID.
     */
    public UidDetail getUidDetail(int uid, boolean blocking) {
        UidDetail detail;

        synchronized (mUidDetailCache) {
            detail = mUidDetailCache.get(uid);
        }

        if (detail != null) {
            return detail;
        } else if (!blocking) {
            return null;
        }

        detail = buildUidDetail(uid);

        synchronized (mUidDetailCache) {
            mUidDetailCache.put(uid, detail);
        }

        return detail;
    }

    /**
     * Build {@link UidDetail} object, blocking until all {@link Drawable}
     * lookup is finished.
     */
    private UidDetail buildUidDetail(int uid) {
        final Resources res = mContext.getResources();
        final PackageManager pm = mContext.getPackageManager();

        final UidDetail detail = new UidDetail();
        detail.label = pm.getNameForUid(uid);
        detail.icon = pm.getDefaultActivityIcon();

        // handle special case labels
        switch (uid) {
            case android.os.Process.SYSTEM_UID:
                detail.label = res.getString(R.string.process_kernel_label);
                detail.icon = pm.getDefaultActivityIcon();
                return detail;
            case TrafficStats.UID_REMOVED:
                detail.label = res.getString(UserManager.supportsMultipleUsers()
                        ? R.string.data_usage_uninstalled_apps_users
                        : R.string.data_usage_uninstalled_apps);
                detail.icon = pm.getDefaultActivityIcon();
                return detail;
            case TrafficStats.UID_TETHERING:
                final ConnectivityManager cm = (ConnectivityManager) mContext.getSystemService(
                        Context.CONNECTIVITY_SERVICE);
                detail.label = res.getString(Utils.getTetheringLabel(cm));
                detail.icon = pm.getDefaultActivityIcon();
                return detail;
        }

        final UserManager um = (UserManager) mContext.getSystemService(Context.USER_SERVICE);

        // Handle keys that are actually user handles
        if (isKeyForUser(uid)) {
            final int userHandle = getUserIdForKey(uid);
            final UserInfo info = um.getUserInfo(userHandle);
            if (info != null) {
                detail.label = Utils.getUserLabel(mContext, info);
                detail.icon = Utils.getUserIcon(mContext, um, info);
                return detail;
            }
        }

        // otherwise fall back to using packagemanager labels
        final String[] packageNames = pm.getPackagesForUid(uid);
        final int length = packageNames != null ? packageNames.length : 0;
        try {
            final int userId = UserHandle.getUserId(uid);
            UserHandle userHandle = new UserHandle(userId);
            IPackageManager ipm = AppGlobals.getPackageManager();
            if (length == 1) {
                final ApplicationInfo info = ipm.getApplicationInfo(packageNames[0],
                        0 /* no flags */, userId);
                if (info != null) {
                    detail.label = info.loadLabel(pm).toString();
                    detail.icon = um.getBadgedIconForUser(info.loadIcon(pm),
                            new UserHandle(userId));
                }
            } else if (length > 1) {
                detail.detailLabels = new CharSequence[length];
                detail.detailContentDescriptions = new CharSequence[length];
                for (int i = 0; i < length; i++) {
                    final String packageName = packageNames[i];
                    final PackageInfo packageInfo = pm.getPackageInfo(packageName, 0);
                    final ApplicationInfo appInfo = ipm.getApplicationInfo(packageName,
                            0 /* no flags */, userId);

                    if (appInfo != null) {
                        detail.detailLabels[i] = appInfo.loadLabel(pm).toString();
                        detail.detailContentDescriptions[i] = um.getBadgedLabelForUser(
                                detail.detailLabels[i], userHandle);
                        if (packageInfo.sharedUserLabel != 0) {
                            detail.label = pm.getText(packageName, packageInfo.sharedUserLabel,
                                    packageInfo.applicationInfo).toString();
                            detail.icon = um.getBadgedIconForUser(appInfo.loadIcon(pm), userHandle);
                        }
                    }
                }
            }
            detail.contentDescription = um.getBadgedLabelForUser(detail.label, userHandle);
        } catch (NameNotFoundException e) {
            Log.w(TAG, "Error while building UI detail for uid "+uid, e);
        } catch (RemoteException e) {
            Log.w(TAG, "Error while building UI detail for uid "+uid, e);
        }

        if (TextUtils.isEmpty(detail.label)) {
            detail.label = Integer.toString(uid);
        }

        return detail;
    }
}