/*
* 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 com.android.packageinstaller.permission.ui.wear;

import android.Manifest;
import android.app.Activity;
import android.app.Fragment;
import android.content.Intent;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PermissionInfo;
import android.os.Bundle;
import android.os.UserHandle;
import android.preference.Preference;
import android.preference.PreferenceFragment;
import android.preference.PreferenceScreen;
import android.preference.SwitchPreference;
import android.support.wearable.view.WearableDialogHelper;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;

import com.android.packageinstaller.R;
import com.android.packageinstaller.permission.model.AppPermissionGroup;
import com.android.packageinstaller.permission.model.AppPermissions;
import com.android.packageinstaller.permission.model.Permission;
import com.android.packageinstaller.permission.utils.LocationUtils;
import com.android.packageinstaller.permission.utils.SafetyNetLogger;
import com.android.packageinstaller.permission.utils.Utils;
import com.android.settingslib.RestrictedLockUtils;
import com.android.settingslib.RestrictedLockUtils.EnforcedAdmin;

import java.util.ArrayList;
import java.util.List;

public final class AppPermissionsFragmentWear extends PreferenceFragment {
    private static final String LOG_TAG = "AppPermFragWear";

    private static final String KEY_NO_PERMISSIONS = "no_permissions";

    public static AppPermissionsFragmentWear newInstance(String packageName) {
        return setPackageName(new AppPermissionsFragmentWear(), packageName);
    }

    private static <T extends Fragment> T setPackageName(T fragment, String packageName) {
        Bundle arguments = new Bundle();
        arguments.putString(Intent.EXTRA_PACKAGE_NAME, packageName);
        fragment.setArguments(arguments);
        return fragment;
    }

    private PackageManager mPackageManager;
    private List<AppPermissionGroup> mToggledGroups;
    private AppPermissions mAppPermissions;

    private boolean mHasConfirmedRevoke;

    /**
     * Provides click behavior for disabled preferences.
     * We can't use {@link PreferenceFragment#onPreferenceTreeClick}, as the base
     * {@link SwitchPreference} doesn't delegate to that method if the preference is disabled.
     */
    private static class PermissionSwitchPreference extends SwitchPreference {

        private final Activity mActivity;

        public PermissionSwitchPreference(Activity activity) {
            super(activity);
            this.mActivity = activity;
        }

        @Override
        public void performClick(PreferenceScreen preferenceScreen) {
            super.performClick(preferenceScreen);
            if (!isEnabled()) {
                // If setting the permission is disabled, it must have been locked
                // by the device or profile owner. So get that info and pass it to
                // the support details dialog.
                EnforcedAdmin deviceOrProfileOwner = RestrictedLockUtils.getProfileOrDeviceOwner(
                    mActivity, UserHandle.myUserId());
                RestrictedLockUtils.sendShowAdminSupportDetailsIntent(
                    mActivity, deviceOrProfileOwner);
            }
        }
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        String packageName = getArguments().getString(Intent.EXTRA_PACKAGE_NAME);
        Activity activity = getActivity();
        mPackageManager = activity.getPackageManager();

        PackageInfo packageInfo;

        try {
            packageInfo = mPackageManager.getPackageInfo(packageName, PackageManager.GET_PERMISSIONS);
        } catch (PackageManager.NameNotFoundException e) {
            Log.i(LOG_TAG, "No package:" + activity.getCallingPackage(), e);
            packageInfo = null;
        }

        if (packageInfo == null) {
            Toast.makeText(activity, R.string.app_not_found_dlg_title, Toast.LENGTH_LONG).show();
            activity.finish();
            return;
        }

        mAppPermissions = new AppPermissions(
                activity, packageInfo, null, true, () -> getActivity().finish());

        addPreferencesFromResource(R.xml.watch_permissions);
        initializePermissionGroupList();
    }

    @Override
    public void onResume() {
        super.onResume();
        mAppPermissions.refresh();

        // Also refresh the UI
        for (final AppPermissionGroup group : mAppPermissions.getPermissionGroups()) {
            if (Utils.areGroupPermissionsIndividuallyControlled(getContext(), group.getName())) {
                for (PermissionInfo perm : getPermissionInfosFromGroup(group)) {
                    setPreferenceCheckedIfPresent(perm.name,
                            group.areRuntimePermissionsGranted(new String[]{ perm.name }));
                }
            } else {
                setPreferenceCheckedIfPresent(group.getName(), group.areRuntimePermissionsGranted());
            }
        }
    }

    @Override
    public void onPause() {
        super.onPause();
        logAndClearToggledGroups();
    }

    private void initializePermissionGroupList() {
        final String packageName = mAppPermissions.getPackageInfo().packageName;
        List<AppPermissionGroup> groups = mAppPermissions.getPermissionGroups();
        List<SwitchPreference> nonSystemPreferences = new ArrayList<>();

        if (!groups.isEmpty()) {
            getPreferenceScreen().removePreference(findPreference(KEY_NO_PERMISSIONS));
        }

        for (final AppPermissionGroup group : groups) {
            if (!Utils.shouldShowPermission(group, packageName)) {
                continue;
            }

            boolean isPlatform = group.getDeclaringPackage().equals(Utils.OS_PKG);

            if (Utils.areGroupPermissionsIndividuallyControlled(getContext(), group.getName())) {
                // If permission is controlled individually, we show all requested permission
                // inside this group.
                for (PermissionInfo perm : getPermissionInfosFromGroup(group)) {
                    final SwitchPreference pref = createSwitchPreferenceForPermission(group, perm);
                    showOrAddToNonSystemPreferences(pref, nonSystemPreferences, isPlatform);
                }
            } else {
                final SwitchPreference pref = createSwitchPreferenceForGroup(group);
                showOrAddToNonSystemPreferences(pref, nonSystemPreferences, isPlatform);
            }
        }

        // Now add the non-system settings to the end of the list
        for (SwitchPreference nonSystemPreference : nonSystemPreferences) {
            getPreferenceScreen().addPreference(nonSystemPreference);
        }
    }

    private void showOrAddToNonSystemPreferences(SwitchPreference pref,
            List<SwitchPreference> nonSystemPreferences, // Mutate
            boolean isPlatform) {
        // The UI shows System settings first, then non-system settings
        if (isPlatform) {
            getPreferenceScreen().addPreference(pref);
        } else {
            nonSystemPreferences.add(pref);
        }
    }

    private SwitchPreference createSwitchPreferenceForPermission(AppPermissionGroup group,
            PermissionInfo perm) {
        final SwitchPreference pref = new PermissionSwitchPreference(getActivity());
        pref.setKey(perm.name);
        pref.setTitle(perm.loadLabel(mPackageManager));
        pref.setChecked(group.areRuntimePermissionsGranted(new String[]{ perm.name }));
        pref.setOnPreferenceChangeListener((p, newVal) -> {
            if((Boolean) newVal) {
                group.grantRuntimePermissions(false, new String[]{ perm.name });
            } else {
                group.revokeRuntimePermissions(true, new String[]{ perm.name });
            }
            return true;
        });
        return pref;
    }

    private SwitchPreference createSwitchPreferenceForGroup(AppPermissionGroup group) {
        final SwitchPreference pref = new PermissionSwitchPreference(getActivity());

        pref.setKey(group.getName());
        pref.setTitle(group.getLabel());
        pref.setChecked(group.areRuntimePermissionsGranted());

        if (group.isPolicyFixed()) {
            pref.setEnabled(false);
        } else {
            pref.setOnPreferenceChangeListener((p, newVal) -> {
                if (LocationUtils.isLocationGroupAndProvider(
                        group.getName(), group.getApp().packageName)) {
                    LocationUtils.showLocationDialog(
                            getContext(), mAppPermissions.getAppLabel());
                    return false;
                }

                if ((Boolean) newVal) {
                    setPermission(group, pref, true);
                } else {
                    final boolean grantedByDefault = group.hasGrantedByDefaultPermission();
                    if (grantedByDefault
                            || (!group.hasRuntimePermission() && !mHasConfirmedRevoke)) {
                        new WearableDialogHelper.DialogBuilder(getContext())
                                .setNegativeIcon(R.drawable.confirm_button)
                                .setPositiveIcon(R.drawable.cancel_button)
                                .setNegativeButton(R.string.grant_dialog_button_deny_anyway,
                                        (dialog, which) -> {
                                            setPermission(group, pref, false);
                                            if (!group.hasGrantedByDefaultPermission()) {
                                                mHasConfirmedRevoke = true;
                                            }
                                        })
                                .setPositiveButton(R.string.cancel, (dialog, which) -> {})
                                .setMessage(grantedByDefault ?
                                        R.string.system_warning : R.string.old_sdk_deny_warning)
                                .show();
                        return false;
                    } else {
                        setPermission(group, pref, false);
                    }
                }

                return true;
            });
        }
        return pref;
    }

    private void setPermission(AppPermissionGroup group, SwitchPreference pref, boolean grant) {
        if (grant) {
            group.grantRuntimePermissions(false);
        } else {
            group.revokeRuntimePermissions(false);
        }
        addToggledGroup(group);
        pref.setChecked(grant);
    }

    private void addToggledGroup(AppPermissionGroup group) {
        if (mToggledGroups == null) {
            mToggledGroups = new ArrayList<>();
        }
        // Double toggle is back to initial state.
        if (mToggledGroups.contains(group)) {
            mToggledGroups.remove(group);
        } else {
            mToggledGroups.add(group);
        }
    }

    private void logAndClearToggledGroups() {
        if (mToggledGroups != null) {
            String packageName = mAppPermissions.getPackageInfo().packageName;
            SafetyNetLogger.logPermissionsToggled(packageName, mToggledGroups);
            mToggledGroups = null;
        }
    }

    private List<PermissionInfo> getPermissionInfosFromGroup(AppPermissionGroup group) {
        ArrayList<PermissionInfo> permInfos = new ArrayList<>(group.getPermissions().size());
        for(Permission perm : group.getPermissions()) {
            try {
                permInfos.add(mPackageManager.getPermissionInfo(perm.getName(), 0));
            } catch (PackageManager.NameNotFoundException e) {
                Log.w(LOG_TAG, "No permission:" + perm.getName());
            }
        }
        return permInfos;
    }

    private void setPreferenceCheckedIfPresent(String preferenceKey, boolean checked) {
        Preference pref = findPreference(preferenceKey);
        if (pref instanceof SwitchPreference) {
            ((SwitchPreference) pref).setChecked(checked);
        }
    }
}