/*
 * Copyright (C) 2013-2015 Dominik Schürmann <dominik@dominikschuermann.de>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.sufficientlysecure.keychain.remote.ui;

import android.content.ActivityNotFoundException;
import android.content.Context;
import android.content.Intent;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.content.res.Resources;
import android.database.Cursor;
import android.database.CursorJoiner;
import android.database.MatrixCursor;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.support.v4.app.LoaderManager;
import android.support.v4.content.CursorLoader;
import android.support.v4.content.Loader;
import android.support.v4.widget.CursorAdapter;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ImageView;
import android.widget.TextView;

import org.sufficientlysecure.keychain.Constants;
import org.sufficientlysecure.keychain.R;
import org.sufficientlysecure.keychain.provider.KeychainContract;
import org.sufficientlysecure.keychain.provider.KeychainContract.ApiApps;
import org.sufficientlysecure.keychain.util.Log;

public class AppsListFragment extends ListFragment implements
        LoaderManager.LoaderCallbacks<Cursor>, OnItemClickListener {

    AppsAdapter mAdapter;

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

        getListView().setOnItemClickListener(this);

        // NOTE: No setEmptyText(), we always have the default entries

        // We have a menu item to show in action bar.
        setHasOptionsMenu(true);

        // Create an empty adapter we will use to display the loaded data.
        mAdapter = new AppsAdapter(getActivity(), null, 0);
        setListAdapter(mAdapter);

        // NOTE: Loader is started in onResume!
    }

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

        // Start out with a progress indicator.
        setListShown(false);

        // After coming back from Google Play -> reload
        getLoaderManager().restartLoader(0, null, this);
    }

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        String selectedPackageName = mAdapter.getItemPackageName(position);
        boolean installed = mAdapter.getItemIsInstalled(position);
        boolean registered = mAdapter.getItemIsRegistered(position);

        if (installed) {
            if (registered) {
                // Edit app settings
                Intent intent = new Intent(getActivity(), AppSettingsActivity.class);
                intent.setData(KeychainContract.ApiApps.buildByPackageNameUri(selectedPackageName));
                startActivity(intent);
            } else {
                Intent i;
                PackageManager manager = getActivity().getPackageManager();
                try {
                    i = manager.getLaunchIntentForPackage(selectedPackageName);
                    if (i == null) {
                        throw new PackageManager.NameNotFoundException();
                    }
                    // Start like the Android launcher would do
                    i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
                    i.addCategory(Intent.CATEGORY_LAUNCHER);
                    startActivity(i);
                } catch (PackageManager.NameNotFoundException e) {
                    Log.e(Constants.TAG, "startApp", e);
                }
            }
        } else {
            try {
                startActivity(new Intent(Intent.ACTION_VIEW,
                        Uri.parse("market://details?id=" + selectedPackageName)));
            } catch (ActivityNotFoundException anfe) {
                startActivity(new Intent(Intent.ACTION_VIEW,
                        Uri.parse("https://play.google.com/store/apps/details?id=" + selectedPackageName)));
            }
        }
    }

    private static final String TEMP_COLUMN_NAME = "NAME";
    private static final String TEMP_COLUMN_INSTALLED = "INSTALLED";
    private static final String TEMP_COLUMN_REGISTERED = "REGISTERED";
    private static final String TEMP_COLUMN_ICON_RES_ID = "ICON_RES_ID";

    static final String[] PROJECTION = new String[]{
            ApiApps._ID, // 0
            ApiApps.PACKAGE_NAME, // 1
            "null as " + TEMP_COLUMN_NAME, // installed apps can retrieve app name from Android OS
            "0 as " + TEMP_COLUMN_INSTALLED, // changed later in cursor joiner
            "1 as " + TEMP_COLUMN_REGISTERED, // if it is in db it is registered
            "0 as " + TEMP_COLUMN_ICON_RES_ID // not used
    };

    private static final int INDEX_ID = 0;
    private static final int INDEX_PACKAGE_NAME = 1;
    private static final int INDEX_NAME = 2;
    private static final int INDEX_INSTALLED = 3;
    private static final int INDEX_REGISTERED = 4;
    private static final int INDEX_ICON_RES_ID = 5;

    public Loader<Cursor> onCreateLoader(int id, Bundle args) {
        // This is called when a new Loader needs to be created. This
        // sample only has one Loader, so we don't care about the ID.
        // First, pick the base URI to use depending on whether we are
        // currently filtering.
        Uri baseUri = ApiApps.CONTENT_URI;

        // Now create and return a CursorLoader that will take care of
        // creating a Cursor for the data being displayed.
        return new AppsLoader(getActivity(), baseUri, PROJECTION, null, null,
                ApiApps.PACKAGE_NAME + " COLLATE LOCALIZED ASC");
    }

    public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
        // Swap the new cursor in. (The framework will take care of closing the
        // old cursor once we return.)
        mAdapter.swapCursor(data);

        // The list should now be shown.
        setListShown(true);
    }

    public void onLoaderReset(Loader<Cursor> loader) {
        // This is called when the last Cursor provided to onLoadFinished()
        // above is about to be closed. We need to make sure we are no
        // longer using it.
        mAdapter.swapCursor(null);
    }

    /**
     * Besides the queried cursor with all registered apps, this loader also returns non-installed
     * proposed apps using a MatrixCursor.
     */
    private static class AppsLoader extends CursorLoader {

        public AppsLoader(Context context) {
            super(context);
        }

        public AppsLoader(Context context, Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
            super(context, uri, projection, selection, selectionArgs, sortOrder);
        }

        @Override
        public Cursor loadInBackground() {
            // Load registered apps from content provider
            Cursor data = super.loadInBackground();

            MatrixCursor availableAppsCursor = new MatrixCursor(new String[]{
                    ApiApps._ID,
                    ApiApps.PACKAGE_NAME,
                    TEMP_COLUMN_NAME,
                    TEMP_COLUMN_INSTALLED,
                    TEMP_COLUMN_REGISTERED,
                    TEMP_COLUMN_ICON_RES_ID
            });
            // NOTE: SORT ascending by package name, this is REQUIRED for CursorJoiner!
            // Drawables taken from projects res/drawables-xxhdpi/ic_launcher.png
            availableAppsCursor.addRow(new Object[]{1, "com.fsck.k9", "K-9 Mail", 0, 0, R.drawable.apps_k9});
            availableAppsCursor.addRow(new Object[]{1, "com.zeapo.pwdstore", "Password Store", 0, 0, R.drawable.apps_password_store});
            availableAppsCursor.addRow(new Object[]{1, "eu.siacs.conversations", "Conversations (Instant Messaging)", 0, 0, R.drawable.apps_conversations});

            MatrixCursor mergedCursor = new MatrixCursor(new String[]{
                    ApiApps._ID,
                    ApiApps.PACKAGE_NAME,
                    TEMP_COLUMN_NAME,
                    TEMP_COLUMN_INSTALLED,
                    TEMP_COLUMN_REGISTERED,
                    TEMP_COLUMN_ICON_RES_ID
            });

            CursorJoiner joiner = new CursorJoiner(
                    availableAppsCursor,
                    new String[]{ApiApps.PACKAGE_NAME},
                    data,
                    new String[]{ApiApps.PACKAGE_NAME});
            for (CursorJoiner.Result joinerResult : joiner) {
                switch (joinerResult) {
                    case LEFT: {
                        // handle case where a row in availableAppsCursor is unique
                        String packageName = availableAppsCursor.getString(INDEX_PACKAGE_NAME);

                        mergedCursor.addRow(new Object[]{
                                1, // no need for unique _ID
                                packageName,
                                availableAppsCursor.getString(INDEX_NAME),
                                isInstalled(packageName),
                                0,
                                availableAppsCursor.getInt(INDEX_ICON_RES_ID)
                        });
                        break;
                    }
                    case RIGHT: {
                        // handle case where a row in data is unique
                        String packageName = data.getString(INDEX_PACKAGE_NAME);

                        mergedCursor.addRow(new Object[]{
                                1, // no need for unique _ID
                                packageName,
                                null,
                                isInstalled(packageName),
                                1, // registered!
                                R.mipmap.ic_launcher // icon is retrieved later
                        });
                        break;
                    }
                    case BOTH: {
                        // handle case where a row with the same key is in both cursors
                        String packageName = data.getString(INDEX_PACKAGE_NAME);

                        String name;
                        if (isInstalled(packageName) == 1) {
                            name = data.getString(INDEX_NAME);
                        } else {
                            // if not installed take name from available apps list
                            name = availableAppsCursor.getString(INDEX_NAME);
                        }

                        mergedCursor.addRow(new Object[]{
                                1, // no need for unique _ID
                                packageName,
                                name,
                                isInstalled(packageName),
                                1, // registered!
                                R.mipmap.ic_launcher // icon is retrieved later
                        });
                        break;
                    }
                }
            }

            return mergedCursor;
        }

        private int isInstalled(String packageName) {
            try {
                getContext().getPackageManager().getApplicationInfo(packageName, 0);
                return 1;
            } catch (final PackageManager.NameNotFoundException e) {
                return 0;
            }
        }
    }

    private class AppsAdapter extends CursorAdapter {

        private LayoutInflater mInflater;
        private PackageManager mPM;

        public AppsAdapter(Context context, Cursor c, int flags) {
            super(context, c, flags);

            mInflater = LayoutInflater.from(context);
            mPM = context.getApplicationContext().getPackageManager();
        }

        /**
         * Similar to CursorAdapter.getItemId().
         * Required to build Uris for api apps, which are not based on row ids
         */
        public String getItemPackageName(int position) {
            if (mDataValid && mCursor != null && mCursor.moveToPosition(position)) {
                return mCursor.getString(INDEX_PACKAGE_NAME);
            } else {
                return null;
            }
        }

        public boolean getItemIsInstalled(int position) {
            return mDataValid && mCursor != null
                    && mCursor.moveToPosition(position) && (mCursor.getInt(INDEX_INSTALLED) == 1);
        }

        public boolean getItemIsRegistered(int position) {
            return mDataValid && mCursor != null
                    && mCursor.moveToPosition(position) && (mCursor.getInt(INDEX_REGISTERED) == 1);
        }

        @Override
        public void bindView(View view, Context context, Cursor cursor) {
            TextView text = (TextView) view.findViewById(R.id.api_apps_adapter_item_name);
            ImageView icon = (ImageView) view.findViewById(R.id.api_apps_adapter_item_icon);
            ImageView installIcon = (ImageView) view.findViewById(R.id.api_apps_adapter_install_icon);

            String packageName = cursor.getString(INDEX_PACKAGE_NAME);
            Log.d(Constants.TAG, "packageName: " + packageName);
            int installed = cursor.getInt(INDEX_INSTALLED);
            String name = cursor.getString(INDEX_NAME);
            int iconResName = cursor.getInt(INDEX_ICON_RES_ID);

            // get application name and icon
            try {
                ApplicationInfo ai = mPM.getApplicationInfo(packageName, 0);

                text.setText(mPM.getApplicationLabel(ai));
                icon.setImageDrawable(mPM.getApplicationIcon(ai));
            } catch (final PackageManager.NameNotFoundException e) {
                // fallback
                if (name == null) {
                    text.setText(packageName);
                } else {
                    text.setText(name);
                    try {
                        icon.setImageDrawable(getResources().getDrawable(iconResName));
                    } catch (Resources.NotFoundException e1) {
                        // silently fail
                    }
                }
            }

            if (installed == 1) {
                installIcon.setVisibility(View.GONE);
            } else {
                installIcon.setVisibility(View.VISIBLE);
            }
        }

        @Override
        public View newView(Context context, Cursor cursor, ViewGroup parent) {
            return mInflater.inflate(R.layout.api_apps_adapter_list_item, null);
        }
    }

}