/*
 * Copyright (C) 2013-2014 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.ui;

import android.annotation.TargetApi;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Color;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.Messenger;
import android.support.v4.app.LoaderManager;
import android.support.v4.content.CursorLoader;
import android.support.v4.content.Loader;
import android.support.v4.view.MenuItemCompat;
import android.support.v4.widget.CursorAdapter;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.SearchView;
import android.text.TextUtils;
import android.view.ActionMode;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.AbsListView.MultiChoiceModeListener;
import android.widget.AdapterView;
import android.widget.FrameLayout;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;

import com.beardedhen.androidbootstrap.BootstrapButton;
import com.devspark.appmsg.AppMsg;

import org.sufficientlysecure.keychain.Constants;
import org.sufficientlysecure.keychain.R;
import org.sufficientlysecure.keychain.helper.ExportHelper;
import org.sufficientlysecure.keychain.pgp.KeyRing;
import org.sufficientlysecure.keychain.provider.KeychainContract.KeyRingData;
import org.sufficientlysecure.keychain.provider.KeychainContract.KeyRings;
import org.sufficientlysecure.keychain.ui.dialog.DeleteKeyDialogFragment;
import org.sufficientlysecure.keychain.util.Highlighter;
import org.sufficientlysecure.keychain.util.Log;

import java.util.Date;
import java.util.HashMap;

import se.emilsjolander.stickylistheaders.StickyListHeadersAdapter;
import se.emilsjolander.stickylistheaders.StickyListHeadersListView;

/**
 * Public key list with sticky list headers. It does _not_ extend ListFragment because it uses
 * StickyListHeaders library which does not extend upon ListView.
 */
public class KeyListFragment extends LoaderFragment
        implements SearchView.OnQueryTextListener, AdapterView.OnItemClickListener,
        LoaderManager.LoaderCallbacks<Cursor> {

    private KeyListAdapter mAdapter;
    private StickyListHeadersListView mStickyList;

    private String mQuery;
    private SearchView mSearchView;
    // empty list layout
    private BootstrapButton mButtonEmptyCreate;
    private BootstrapButton mButtonEmptyImport;


    /**
     * Load custom layout with StickyListView from library
     */
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup superContainer, Bundle savedInstanceState) {
        View root = super.onCreateView(inflater, superContainer, savedInstanceState);
        View view = inflater.inflate(R.layout.key_list_fragment, getContainer());

        mStickyList = (StickyListHeadersListView) view.findViewById(R.id.key_list_list);
        mStickyList.setOnItemClickListener(this);

        // empty view
        mButtonEmptyCreate = (BootstrapButton) view.findViewById(R.id.key_list_empty_button_create);
        mButtonEmptyCreate.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent intent = new Intent(getActivity(), EditKeyActivity.class);
                intent.setAction(EditKeyActivity.ACTION_CREATE_KEY);
                intent.putExtra(EditKeyActivity.EXTRA_GENERATE_DEFAULT_KEYS, true);
                intent.putExtra(EditKeyActivity.EXTRA_USER_IDS, ""); // show user id view
                startActivityForResult(intent, 0);
            }
        });
        mButtonEmptyImport = (BootstrapButton) view.findViewById(R.id.key_list_empty_button_import);
        mButtonEmptyImport.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent intent = new Intent(getActivity(), ImportKeysActivity.class);
                intent.setAction(ImportKeysActivity.ACTION_IMPORT_KEY_FROM_FILE);
                startActivityForResult(intent, 0);
            }
        });

        return root;
    }

    /**
     * Define Adapter and Loader on create of Activity
     */
    @TargetApi(Build.VERSION_CODES.HONEYCOMB)
    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        mStickyList.setOnItemClickListener(this);
        mStickyList.setAreHeadersSticky(true);
        mStickyList.setDrawingListUnderStickyHeader(false);
        mStickyList.setFastScrollEnabled(true);

        /*
         * Multi-selection is only available for Android >= 3.0
         */
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
            mStickyList.setFastScrollAlwaysVisible(true);

            mStickyList.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE_MODAL);
            mStickyList.getWrappedList().setMultiChoiceModeListener(new MultiChoiceModeListener() {

                @Override
                public boolean onCreateActionMode(ActionMode mode, Menu menu) {
                    android.view.MenuInflater inflater = getActivity().getMenuInflater();
                    inflater.inflate(R.menu.key_list_multi, menu);
                    return true;
                }

                @Override
                public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
                    return false;
                }

                @Override
                public boolean onActionItemClicked(ActionMode mode, MenuItem item) {

                    // get IDs for checked positions as long array
                    long[] ids;

                    switch (item.getItemId()) {
                        case R.id.menu_key_list_multi_encrypt: {
                            ids = mAdapter.getCurrentSelectedMasterKeyIds();
                            encrypt(mode, ids);
                            break;
                        }
                        case R.id.menu_key_list_multi_delete: {
                            ids = mAdapter.getCurrentSelectedMasterKeyIds();
                            showDeleteKeyDialog(mode, ids, mAdapter.isAnySecretSelected());
                            break;
                        }
                        case R.id.menu_key_list_multi_export: {
                            ids = mAdapter.getCurrentSelectedMasterKeyIds();
                            ExportHelper mExportHelper = new ExportHelper((ActionBarActivity) getActivity());
                            mExportHelper.showExportKeysDialog(
                                    ids, Constants.Path.APP_DIR_FILE, mAdapter.isAnySecretSelected());
                            break;
                        }
                        case R.id.menu_key_list_multi_select_all: {
                            // select all
                            for (int i = 0; i < mStickyList.getCount(); i++) {
                                mStickyList.setItemChecked(i, true);
                            }
                            break;
                        }
                    }
                    return true;
                }

                @Override
                public void onDestroyActionMode(ActionMode mode) {
                    mAdapter.clearSelection();
                }

                @Override
                public void onItemCheckedStateChanged(ActionMode mode, int position, long id,
                                                      boolean checked) {
                    if (checked) {
                        mAdapter.setNewSelection(position, checked);
                    } else {
                        mAdapter.removeSelection(position);
                    }
                    int count = mStickyList.getCheckedItemCount();
                    String keysSelected = getResources().getQuantityString(
                            R.plurals.key_list_selected_keys, count, count);
                    mode.setTitle(keysSelected);
                }

            });
        }

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

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

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

        // Prepare the loader. Either re-connect with an existing one,
        // or start a new one.
        getLoaderManager().initLoader(0, null, this);
    }

    // These are the rows that we will retrieve.
    static final String[] PROJECTION = new String[]{
            KeyRings._ID,
            KeyRings.MASTER_KEY_ID,
            KeyRings.USER_ID,
            KeyRings.IS_REVOKED,
            KeyRings.EXPIRY,
            KeyRings.VERIFIED,
            KeyRings.HAS_ANY_SECRET
    };

    static final int INDEX_MASTER_KEY_ID = 1;
    static final int INDEX_USER_ID = 2;
    static final int INDEX_IS_REVOKED = 3;
    static final int INDEX_EXPIRY = 4;
    static final int INDEX_VERIFIED = 5;
    static final int INDEX_HAS_ANY_SECRET = 6;

    static final String ORDER =
            KeyRings.HAS_ANY_SECRET + " DESC, UPPER(" + KeyRings.USER_ID + ") ASC";


    @Override
    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.
        Uri baseUri = KeyRings.buildUnifiedKeyRingsUri();
        String where = null;
        String whereArgs[] = null;
        if (mQuery != null) {
            String[] words = mQuery.trim().split("\\s+");
            whereArgs = new String[words.length];
            for (int i = 0; i < words.length; ++i) {
                if (where == null) {
                    where = "";
                } else {
                    where += " AND ";
                }
                where += KeyRings.USER_ID + " LIKE ?";
                whereArgs[i] = "%" + words[i] + "%";
            }
        }

        // Now create and return a CursorLoader that will take care of
        // creating a Cursor for the data being displayed.
        return new CursorLoader(getActivity(), baseUri, PROJECTION, where, whereArgs, ORDER);
    }

    @Override
    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.setSearchQuery(mQuery);
        mAdapter.swapCursor(data);

        mStickyList.setAdapter(mAdapter);

        // this view is made visible if no data is available
        mStickyList.setEmptyView(getActivity().findViewById(R.id.key_list_empty));

        // The list should now be shown.
        if (isResumed()) {
            setContentShown(true);
        } else {
            setContentShownNoAnimation(true);
        }
    }

    @Override
    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);
    }

    /**
     * On click on item, start key view activity
     */
    @Override
    public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) {
        Intent viewIntent = new Intent(getActivity(), ViewKeyActivity.class);
        viewIntent.setData(
                KeyRings.buildGenericKeyRingUri(mAdapter.getMasterKeyId(position)));
        startActivity(viewIntent);
    }

    @TargetApi(Build.VERSION_CODES.HONEYCOMB)
    protected void encrypt(ActionMode mode, long[] masterKeyIds) {
        Intent intent = new Intent(getActivity(), EncryptActivity.class);
        intent.setAction(EncryptActivity.ACTION_ENCRYPT);
        intent.putExtra(EncryptActivity.EXTRA_ENCRYPTION_KEY_IDS, masterKeyIds);
        // used instead of startActivity set actionbar based on callingPackage
        startActivityForResult(intent, 0);

        mode.finish();
    }

    /**
     * Show dialog to delete key
     *
     * @param masterKeyIds
     * @param hasSecret must contain whether the list of masterKeyIds contains a secret key or not
     */
    @TargetApi(Build.VERSION_CODES.HONEYCOMB)
    public void showDeleteKeyDialog(final ActionMode mode, long[] masterKeyIds, boolean hasSecret) {
        // Can only work on singular secret keys
        if(hasSecret && masterKeyIds.length > 1) {
            AppMsg.makeText(getActivity(), R.string.secret_cannot_multiple,
                    AppMsg.STYLE_ALERT).show();
            return;
        }

        // Message is received after key is deleted
        Handler returnHandler = new Handler() {
            @Override
            public void handleMessage(Message message) {
                if (message.what == DeleteKeyDialogFragment.MESSAGE_OKAY) {
                    mode.finish();
                }
            }
        };

        // Create a new Messenger for the communication back
        Messenger messenger = new Messenger(returnHandler);

        DeleteKeyDialogFragment deleteKeyDialog = DeleteKeyDialogFragment.newInstance(messenger,
                masterKeyIds);

        deleteKeyDialog.show(getActivity().getSupportFragmentManager(), "deleteKeyDialog");
    }


    @Override
    public void onCreateOptionsMenu(final Menu menu, final MenuInflater inflater) {
        // Get the searchview
        MenuItem searchItem = menu.findItem(R.id.menu_key_list_search);
        mSearchView = (SearchView) MenuItemCompat.getActionView(searchItem);

        // Execute this when searching
        mSearchView.setOnQueryTextListener(this);

        View searchPlate = mSearchView.findViewById(android.support.v7.appcompat.R.id.search_plate);
        searchPlate.setBackgroundResource(R.drawable.keychaintheme_searchview_holo_light);

        // Erase search result without focus
        MenuItemCompat.setOnActionExpandListener(searchItem, new MenuItemCompat.OnActionExpandListener() {
            @Override
            public boolean onMenuItemActionExpand(MenuItem item) {
                return true;
            }

            @Override
            public boolean onMenuItemActionCollapse(MenuItem item) {
                mQuery = null;
                mSearchView.setQuery("", true);
                getLoaderManager().restartLoader(0, null, KeyListFragment.this);
                return true;
            }
        });

        super.onCreateOptionsMenu(menu, inflater);
    }

    @Override
    public boolean onQueryTextSubmit(String s) {
        return true;
    }

    @Override
    public boolean onQueryTextChange(String s) {
        // Called when the action bar search text has changed.  Update
        // the search filter, and restart the loader to do a new query
        // with this filter.
        mQuery = !TextUtils.isEmpty(s) ? s : null;
        getLoaderManager().restartLoader(0, null, this);
        return true;
    }

    /**
     * Implements StickyListHeadersAdapter from library
     */
    private class KeyListAdapter extends CursorAdapter implements StickyListHeadersAdapter {
        private String mQuery;
        private LayoutInflater mInflater;

        private HashMap<Integer, Boolean> mSelection = new HashMap<Integer, Boolean>();

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

            mInflater = LayoutInflater.from(context);
        }

        public void setSearchQuery(String query) {
            mQuery = query;
        }

        @Override
        public Cursor swapCursor(Cursor newCursor) {
            return super.swapCursor(newCursor);
        }

        private class ItemViewHolder {
            TextView mMainUserId;
            TextView mMainUserIdRest;
            View mStatusDivider;
            FrameLayout mStatusLayout;
            ImageButton mButton;
            TextView mRevoked;
            ImageView mVerified;
        }

        @Override
        public View newView(Context context, Cursor cursor, ViewGroup parent) {
            View view = mInflater.inflate(R.layout.key_list_item, parent, false);
            ItemViewHolder holder = new ItemViewHolder();
            holder.mMainUserId = (TextView) view.findViewById(R.id.mainUserId);
            holder.mMainUserIdRest = (TextView) view.findViewById(R.id.mainUserIdRest);
            holder.mStatusDivider = (View) view.findViewById(R.id.status_divider);
            holder.mStatusLayout = (FrameLayout) view.findViewById(R.id.status_layout);
            holder.mButton = (ImageButton) view.findViewById(R.id.edit);
            holder.mRevoked = (TextView) view.findViewById(R.id.revoked);
            holder.mVerified = (ImageView) view.findViewById(R.id.verified);
            view.setTag(holder);
            return view;
        }

        /**
         * Bind cursor data to the item list view
         * <p/>
         * NOTE: CursorAdapter already implements the ViewHolder pattern in its getView() method.
         * Thus no ViewHolder is required here.
         */
        @Override
        public void bindView(View view, Context context, Cursor cursor) {
            Highlighter highlighter = new Highlighter(context, mQuery);
            ItemViewHolder h = (ItemViewHolder) view.getTag();

            { // set name and stuff, common to both key types
                String userId = cursor.getString(INDEX_USER_ID);
                String[] userIdSplit = KeyRing.splitUserId(userId);
                if (userIdSplit[0] != null) {
                    h.mMainUserId.setText(highlighter.highlight(userIdSplit[0]));
                } else {
                    h.mMainUserId.setText(R.string.user_id_no_name);
                }
                if (userIdSplit[1] != null) {
                    h.mMainUserIdRest.setText(highlighter.highlight(userIdSplit[1]));
                    h.mMainUserIdRest.setVisibility(View.VISIBLE);
                } else {
                    h.mMainUserIdRest.setVisibility(View.GONE);
                }
            }

            { // set edit button and revoked info, specific by key type

                if (cursor.getInt(KeyListFragment.INDEX_HAS_ANY_SECRET) != 0) {
                    // this is a secret key - show the edit mButton
                    h.mStatusDivider.setVisibility(View.VISIBLE);
                    h.mStatusLayout.setVisibility(View.VISIBLE);
                    h.mRevoked.setVisibility(View.GONE);
                    h.mVerified.setVisibility(View.GONE);
                    h.mButton.setVisibility(View.VISIBLE);

                    final long id = cursor.getLong(INDEX_MASTER_KEY_ID);
                    h.mButton.setOnClickListener(new OnClickListener() {
                        public void onClick(View view) {
                            Intent editIntent = new Intent(getActivity(), EditKeyActivity.class);
                            editIntent.setData(KeyRingData.buildSecretKeyRingUri(Long.toString(id)));
                            editIntent.setAction(EditKeyActivity.ACTION_EDIT_KEY);
                            startActivityForResult(editIntent, 0);
                        }
                    });
                } else {
                    // this is a public key - hide the edit mButton, show if it's revoked
                    h.mStatusDivider.setVisibility(View.GONE);
                    h.mButton.setVisibility(View.GONE);

                    boolean isRevoked = cursor.getInt(INDEX_IS_REVOKED) > 0;
                    boolean isExpired = !cursor.isNull(INDEX_EXPIRY)
                            && new Date(cursor.getLong(INDEX_EXPIRY)*1000).before(new Date());
                    if(isRevoked || isExpired) {
                        h.mStatusLayout.setVisibility(View.VISIBLE);
                        h.mRevoked.setVisibility(View.VISIBLE);
                        h.mVerified.setVisibility(View.GONE);
                        h.mRevoked.setText(isRevoked ? R.string.revoked : R.string.expired);
                    } else {
                        boolean isVerified = cursor.getInt(INDEX_VERIFIED) > 0;
                        h.mStatusLayout.setVisibility(isVerified ? View.VISIBLE : View.GONE);
                        h.mRevoked.setVisibility(View.GONE);
                        h.mVerified.setVisibility(isVerified ? View.VISIBLE : View.GONE);
                    }
                }
            }

        }

        public boolean isSecretAvailable(int id) {
            if (!mCursor.moveToPosition(id)) {
                throw new IllegalStateException("couldn't move cursor to position " + id);
            }

            return mCursor.getInt(INDEX_HAS_ANY_SECRET) != 0;
        }
        public long getMasterKeyId(int id) {
            if (!mCursor.moveToPosition(id)) {
                throw new IllegalStateException("couldn't move cursor to position " + id);
            }

            return mCursor.getLong(INDEX_MASTER_KEY_ID);
        }

        /**
         * Creates a new header view and binds the section headers to it. It uses the ViewHolder
         * pattern. Most functionality is similar to getView() from Android's CursorAdapter.
         * <p/>
         * NOTE: The variables mDataValid and mCursor are available due to the super class
         * CursorAdapter.
         */
        @Override
        public View getHeaderView(int position, View convertView, ViewGroup parent) {
            HeaderViewHolder holder;
            if (convertView == null) {
                holder = new HeaderViewHolder();
                convertView = mInflater.inflate(R.layout.key_list_header, parent, false);
                holder.mText = (TextView) convertView.findViewById(R.id.stickylist_header_text);
                holder.mCount = (TextView) convertView.findViewById(R.id.contacts_num);
                convertView.setTag(holder);
            } else {
                holder = (HeaderViewHolder) convertView.getTag();
            }

            if (!mDataValid) {
                // no data available at this point
                Log.d(Constants.TAG, "getHeaderView: No data available at this point!");
                return convertView;
            }

            if (!mCursor.moveToPosition(position)) {
                throw new IllegalStateException("couldn't move cursor to position " + position);
            }

            if (mCursor.getInt(KeyListFragment.INDEX_HAS_ANY_SECRET) != 0) {
                { // set contact count
                    int num = mCursor.getCount();
                    String contactsTotal = getResources().getQuantityString(R.plurals.n_keys, num, num);
                    holder.mCount.setText(contactsTotal);
                    holder.mCount.setVisibility(View.VISIBLE);
                }

                holder.mText.setText(convertView.getResources().getString(R.string.my_keys));
                return convertView;
            }

            // set header text as first char in user id
            String userId = mCursor.getString(KeyListFragment.INDEX_USER_ID);
            String headerText = convertView.getResources().getString(R.string.user_id_no_name);
            if (userId != null && userId.length() > 0) {
                headerText = "" + userId.charAt(0);
            }
            holder.mText.setText(headerText);
            holder.mCount.setVisibility(View.GONE);
            return convertView;
        }

        /**
         * Header IDs should be static, position=1 should always return the same Id that is.
         */
        @Override
        public long getHeaderId(int position) {
            if (!mDataValid) {
                // no data available at this point
                Log.d(Constants.TAG, "getHeaderView: No data available at this point!");
                return -1;
            }

            if (!mCursor.moveToPosition(position)) {
                throw new IllegalStateException("couldn't move cursor to position " + position);
            }

            // early breakout: all secret keys are assigned id 0
            if (mCursor.getInt(KeyListFragment.INDEX_HAS_ANY_SECRET) != 0) {
                return 1L;
            }
            // otherwise, return the first character of the name as ID
            String userId = mCursor.getString(KeyListFragment.INDEX_USER_ID);
            if (userId != null && userId.length() > 0) {
                return Character.toUpperCase(userId.charAt(0));
            } else {
                return Long.MAX_VALUE;
            }
        }

        private class HeaderViewHolder {
            TextView mText;
            TextView mCount;
        }

        /**
         * -------------------------- MULTI-SELECTION METHODS --------------
         */
        public void setNewSelection(int position, boolean value) {
            mSelection.put(position, value);
            notifyDataSetChanged();
        }

        public boolean isAnySecretSelected() {
            for (int pos : mSelection.keySet()) {
                if(mAdapter.isSecretAvailable(pos))
                    return true;
            }
            return false;
        }

        public long[] getCurrentSelectedMasterKeyIds() {
            long[] ids = new long[mSelection.size()];
            int i = 0;
            // get master key ids
            for (int pos : mSelection.keySet()) {
                ids[i++] = mAdapter.getMasterKeyId(pos);
            }
            return ids;
        }

        public void removeSelection(int position) {
            mSelection.remove(position);
            notifyDataSetChanged();
        }

        public void clearSelection() {
            mSelection.clear();
            notifyDataSetChanged();
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // let the adapter handle setting up the row views
            View v = super.getView(position, convertView, parent);

            /**
             * Change color for multi-selection
             */
            if (mSelection.get(position) != null) {
                // selected position color
                v.setBackgroundColor(parent.getResources().getColor(R.color.emphasis));
            } else {
                // default color
                v.setBackgroundColor(Color.TRANSPARENT);
            }

            return v;
        }

    }

}