/*
 * Copyright (C) 2013 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.dialer.list;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ComparisonChain;
import com.google.common.collect.Lists;

import android.content.ContentProviderOperation;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.content.OperationApplicationException;
import android.content.res.Resources;
import android.database.Cursor;
import android.net.Uri;
import android.os.RemoteException;
import android.provider.ContactsContract;
import android.provider.ContactsContract.CommonDataKinds.Phone;
import android.provider.ContactsContract.Contacts;
import android.provider.ContactsContract.PinnedPositions;
import android.text.TextUtils;
import android.util.Log;
import android.util.LongSparseArray;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.FrameLayout;

import com.android.contacts.common.ContactPhotoManager;
import com.android.contacts.common.ContactTileLoaderFactory;
import com.android.contacts.common.list.ContactEntry;
import com.android.contacts.common.list.ContactTileAdapter.DisplayType;
import com.android.contacts.common.list.ContactTileView;
import com.android.dialer.R;

import java.util.ArrayList;
import java.util.Comparator;
import java.util.LinkedList;
import java.util.List;
import java.util.PriorityQueue;

/**
 * Also allows for a configurable number of columns as well as a maximum row of tiled contacts.
 */
public class PhoneFavoritesTileAdapter extends BaseAdapter implements
        OnDragDropListener {
    private static final String TAG = PhoneFavoritesTileAdapter.class.getSimpleName();
    private static final boolean DEBUG = false;

    public static final int NO_ROW_LIMIT = -1;

    public static final int ROW_LIMIT_DEFAULT = NO_ROW_LIMIT;

    private ContactTileView.Listener mListener;
    private OnDataSetChangedForAnimationListener mDataSetChangedListener;

    private Context mContext;
    private Resources mResources;

    /** Contact data stored in cache. This is used to populate the associated view. */
    protected ArrayList<ContactEntry> mContactEntries = null;
    /** Back up of the temporarily removed Contact during dragging. */
    private ContactEntry mDraggedEntry = null;
    /** Position of the temporarily removed contact in the cache. */
    private int mDraggedEntryIndex = -1;
    /** New position of the temporarily removed contact in the cache. */
    private int mDropEntryIndex = -1;
    /** New position of the temporarily entered contact in the cache. */
    private int mDragEnteredEntryIndex = -1;

    private boolean mAwaitingRemove = false;
    private boolean mDelayCursorUpdates = false;

    private ContactPhotoManager mPhotoManager;
    protected int mNumFrequents;
    protected int mNumStarred;

    protected int mIdIndex;
    protected int mLookupIndex;
    protected int mPhotoUriIndex;
    protected int mNameIndex;
    protected int mPresenceIndex;
    protected int mStatusIndex;

    private int mPhoneNumberIndex;
    private int mPhoneNumberTypeIndex;
    private int mPhoneNumberLabelIndex;
    private int mIsDefaultNumberIndex;
    private int mStarredIndex;
    protected int mPinnedIndex;
    protected int mContactIdIndex;

    /** Indicates whether a drag is in process. */
    private boolean mInDragging = false;

    // Pinned positions start from 1, so there are a total of 20 maximum pinned contacts
    public static final int PIN_LIMIT = 21;

    /**
     * The soft limit on how many contact tiles to show.
     * NOTE This soft limit would not restrict the number of starred contacts to show, rather
     * 1. If the count of starred contacts is less than this limit, show 20 tiles total.
     * 2. If the count of starred contacts is more than or equal to this limit,
     * show all starred tiles and no frequents.
     */
    private static final int TILES_SOFT_LIMIT = 20;

    final Comparator<ContactEntry> mContactEntryComparator = new Comparator<ContactEntry>() {
        @Override
        public int compare(ContactEntry lhs, ContactEntry rhs) {
            return ComparisonChain.start()
                    .compare(lhs.pinned, rhs.pinned)
                    .compare(lhs.name, rhs.name)
                    .result();
        }
    };

    public interface OnDataSetChangedForAnimationListener {
        public void onDataSetChangedForAnimation(long... idsInPlace);
        public void cacheOffsetsForDatasetChange();
    };

    public PhoneFavoritesTileAdapter(Context context, ContactTileView.Listener listener,
            OnDataSetChangedForAnimationListener dataSetChangedListener) {
        mDataSetChangedListener = dataSetChangedListener;
        mListener = listener;
        mContext = context;
        mResources = context.getResources();
        mNumFrequents = 0;
        mContactEntries = new ArrayList<ContactEntry>();


        bindColumnIndices();
    }

    public void setPhotoLoader(ContactPhotoManager photoLoader) {
        mPhotoManager = photoLoader;
    }

    /**
     * Indicates whether a drag is in process.
     *
     * @param inDragging Boolean variable indicating whether there is a drag in process.
     */
    public void setInDragging(boolean inDragging) {
        mDelayCursorUpdates = inDragging;
        mInDragging = inDragging;
    }

    /** Gets whether the drag is in process. */
    public boolean getInDragging() {
        return mInDragging;
    }

    /**
     * Sets the column indices for expected {@link Cursor}
     * based on {@link DisplayType}.
     */
    protected void bindColumnIndices() {
        mIdIndex = ContactTileLoaderFactory.CONTACT_ID;
        mLookupIndex = ContactTileLoaderFactory.LOOKUP_KEY;
        mPhotoUriIndex = ContactTileLoaderFactory.PHOTO_URI;
        mNameIndex = ContactTileLoaderFactory.DISPLAY_NAME;
        mStarredIndex = ContactTileLoaderFactory.STARRED;
        mPresenceIndex = ContactTileLoaderFactory.CONTACT_PRESENCE;
        mStatusIndex = ContactTileLoaderFactory.CONTACT_STATUS;

        mPhoneNumberIndex = ContactTileLoaderFactory.PHONE_NUMBER;
        mPhoneNumberTypeIndex = ContactTileLoaderFactory.PHONE_NUMBER_TYPE;
        mPhoneNumberLabelIndex = ContactTileLoaderFactory.PHONE_NUMBER_LABEL;
        mIsDefaultNumberIndex = ContactTileLoaderFactory.IS_DEFAULT_NUMBER;
        mPinnedIndex = ContactTileLoaderFactory.PINNED;
        mContactIdIndex = ContactTileLoaderFactory.CONTACT_ID_FOR_DATA;
    }

    /**
     * Gets the number of frequents from the passed in cursor.
     *
     * This methods is needed so the GroupMemberTileAdapter can override this.
     *
     * @param cursor The cursor to get number of frequents from.
     */
    protected void saveNumFrequentsFromCursor(Cursor cursor) {
        mNumFrequents = cursor.getCount() - mNumStarred;
    }

    /**
     * Creates {@link ContactTileView}s for each item in {@link Cursor}.
     *
     * Else use {@link ContactTileLoaderFactory}
     */
    public void setContactCursor(Cursor cursor) {
        if (!mDelayCursorUpdates && cursor != null && !cursor.isClosed()) {
            mNumStarred = getNumStarredContacts(cursor);
            if (mAwaitingRemove) {
                mDataSetChangedListener.cacheOffsetsForDatasetChange();
            }

            saveNumFrequentsFromCursor(cursor);
            saveCursorToCache(cursor);
            // cause a refresh of any views that rely on this data
            notifyDataSetChanged();
            // about to start redraw
            mDataSetChangedListener.onDataSetChangedForAnimation();
        }
    }

    /**
     * Saves the cursor data to the cache, to speed up UI changes.
     *
     * @param cursor Returned cursor with data to populate the view.
     */
    private void saveCursorToCache(Cursor cursor) {
        mContactEntries.clear();

        cursor.moveToPosition(-1);

        final LongSparseArray<Object> duplicates = new LongSparseArray<Object>(cursor.getCount());

        // Track the length of {@link #mContactEntries} and compare to {@link #TILES_SOFT_LIMIT}.
        int counter = 0;

        while (cursor.moveToNext()) {

            final int starred = cursor.getInt(mStarredIndex);
            final long id;

            // We display a maximum of TILES_SOFT_LIMIT contacts, or the total number of starred
            // whichever is greater.
            if (starred < 1 && counter >= TILES_SOFT_LIMIT) {
                break;
            } else {
                id = cursor.getLong(mContactIdIndex);
            }

            final ContactEntry existing = (ContactEntry) duplicates.get(id);
            if (existing != null) {
                // Check if the existing number is a default number. If not, clear the phone number
                // and label fields so that the disambiguation dialog will show up.
                if (!existing.isDefaultNumber) {
                    existing.phoneLabel = null;
                    existing.phoneNumber = null;
                }
                continue;
            }

            final String photoUri = cursor.getString(mPhotoUriIndex);
            final String lookupKey = cursor.getString(mLookupIndex);
            final int pinned = cursor.getInt(mPinnedIndex);
            final String name = cursor.getString(mNameIndex);
            final boolean isStarred = cursor.getInt(mStarredIndex) > 0;
            final boolean isDefaultNumber = cursor.getInt(mIsDefaultNumberIndex) > 0;

            final ContactEntry contact = new ContactEntry();

            contact.id = id;
            contact.name = (!TextUtils.isEmpty(name)) ? name :
                    mResources.getString(R.string.missing_name);
            contact.photoUri = (photoUri != null ? Uri.parse(photoUri) : null);
            contact.lookupKey = lookupKey;
            contact.lookupUri = ContentUris.withAppendedId(
                    Uri.withAppendedPath(Contacts.CONTENT_LOOKUP_URI, lookupKey), id);
            contact.isFavorite = isStarred;
            contact.isDefaultNumber = isDefaultNumber;

            // Set phone number and label
            final int phoneNumberType = cursor.getInt(mPhoneNumberTypeIndex);
            final String phoneNumberCustomLabel = cursor.getString(mPhoneNumberLabelIndex);
            contact.phoneLabel = (String) Phone.getTypeLabel(mResources, phoneNumberType,
                    phoneNumberCustomLabel);
            contact.phoneNumber = cursor.getString(mPhoneNumberIndex);

            contact.pinned = pinned;
            mContactEntries.add(contact);

            duplicates.put(id, contact);

            counter++;
        }

        mAwaitingRemove = false;

        arrangeContactsByPinnedPosition(mContactEntries);

        notifyDataSetChanged();
    }

    /**
     * Iterates over the {@link Cursor}
     * Returns position of the first NON Starred Contact
     * Returns -1 if {@link DisplayType#STARRED_ONLY}
     * Returns 0 if {@link DisplayType#FREQUENT_ONLY}
     */
    protected int getNumStarredContacts(Cursor cursor) {
        cursor.moveToPosition(-1);
        while (cursor.moveToNext()) {
            if (cursor.getInt(mStarredIndex) == 0) {
                return cursor.getPosition();
            }
        }

        // There are not NON Starred contacts in cursor
        // Set divider positon to end
        return cursor.getCount();
    }

    /**
     * Returns the number of frequents that will be displayed in the list.
     */
    public int getNumFrequents() {
        return mNumFrequents;
    }

    @Override
    public int getCount() {
        if (mContactEntries == null) {
            return 0;
        }

        return mContactEntries.size();
    }

    /**
     * Returns an ArrayList of the {@link ContactEntry}s that are to appear
     * on the row for the given position.
     */
    @Override
    public ContactEntry getItem(int position) {
        return mContactEntries.get(position);
    }

    /**
     * For the top row of tiled contacts, the item id is the position of the row of
     * contacts.
     * For frequent contacts, the item id is the maximum number of rows of tiled contacts +
     * the actual contact id. Since contact ids are always greater than 0, this guarantees that
     * all items within this adapter will always have unique ids.
     */
    @Override
    public long getItemId(int position) {
        return getItem(position).id;
    }

    @Override
    public boolean hasStableIds() {
        return true;
    }

    @Override
    public boolean areAllItemsEnabled() {
        return true;
    }

    @Override
    public boolean isEnabled(int position) {
        return getCount() > 0;
    }

    @Override
    public void notifyDataSetChanged() {
        if (DEBUG) {
            Log.v(TAG, "notifyDataSetChanged");
        }
        super.notifyDataSetChanged();
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if (DEBUG) {
            Log.v(TAG, "get view for " + String.valueOf(position));
        }

        int itemViewType = getItemViewType(position);

        PhoneFavoriteTileView tileView = null;

        if (convertView instanceof PhoneFavoriteTileView) {
            tileView  = (PhoneFavoriteTileView) convertView;
        }

        if (tileView == null) {
            tileView = (PhoneFavoriteTileView) View.inflate(mContext,
                    R.layout.phone_favorite_tile_view, null);
        }
        tileView.setPhotoManager(mPhotoManager);
        tileView.setListener(mListener);
        tileView.loadFromContact(getItem(position));
        return tileView;
    }

    @Override
    public int getViewTypeCount() {
        return ViewTypes.COUNT;
    }

    @Override
    public int getItemViewType(int position) {
        return ViewTypes.TILE;
    }

    /**
     * Temporarily removes a contact from the list for UI refresh. Stores data for this contact
     * in the back-up variable.
     *
     * @param index Position of the contact to be removed.
     */
    public void popContactEntry(int index) {
        if (isIndexInBound(index)) {
            mDraggedEntry = mContactEntries.get(index);
            mDraggedEntryIndex = index;
            mDragEnteredEntryIndex = index;
            markDropArea(mDragEnteredEntryIndex);
        }
    }

    /**
     * @param itemIndex Position of the contact in {@link #mContactEntries}.
     * @return True if the given index is valid for {@link #mContactEntries}.
     */
    public boolean isIndexInBound(int itemIndex) {
        return itemIndex >= 0 && itemIndex < mContactEntries.size();
    }

    /**
     * Mark the tile as drop area by given the item index in {@link #mContactEntries}.
     *
     * @param itemIndex Position of the contact in {@link #mContactEntries}.
     */
    private void markDropArea(int itemIndex) {
        if (mDraggedEntry != null && isIndexInBound(mDragEnteredEntryIndex) &&
                isIndexInBound(itemIndex)) {
            mDataSetChangedListener.cacheOffsetsForDatasetChange();
            // Remove the old placeholder item and place the new placeholder item.
            final int oldIndex = mDragEnteredEntryIndex;
            mContactEntries.remove(mDragEnteredEntryIndex);
            mDragEnteredEntryIndex = itemIndex;
            mContactEntries.add(mDragEnteredEntryIndex, ContactEntry.BLANK_ENTRY);
            ContactEntry.BLANK_ENTRY.id = mDraggedEntry.id;
            mDataSetChangedListener.onDataSetChangedForAnimation();
            notifyDataSetChanged();
        }
    }

    /**
     * Drops the temporarily removed contact to the desired location in the list.
     */
    public void handleDrop() {
        boolean changed = false;
        if (mDraggedEntry != null) {
            if (isIndexInBound(mDragEnteredEntryIndex) &&
                    mDragEnteredEntryIndex != mDraggedEntryIndex) {
                // Don't add the ContactEntry here (to prevent a double animation from occuring).
                // When we receive a new cursor the list of contact entries will automatically be
                // populated with the dragged ContactEntry at the correct spot.
                mDropEntryIndex = mDragEnteredEntryIndex;
                mContactEntries.set(mDropEntryIndex, mDraggedEntry);
                mDataSetChangedListener.cacheOffsetsForDatasetChange();
                changed = true;
            } else if (isIndexInBound(mDraggedEntryIndex)) {
                // If {@link #mDragEnteredEntryIndex} is invalid,
                // falls back to the original position of the contact.
                mContactEntries.remove(mDragEnteredEntryIndex);
                mContactEntries.add(mDraggedEntryIndex, mDraggedEntry);
                mDropEntryIndex = mDraggedEntryIndex;
                notifyDataSetChanged();
            }

            if (changed && mDropEntryIndex < PIN_LIMIT) {
                final ArrayList<ContentProviderOperation> operations =
                        getReflowedPinningOperations(mContactEntries, mDraggedEntryIndex,
                                mDropEntryIndex);
                if (!operations.isEmpty()) {
                    // update the database here with the new pinned positions
                    try {
                        mContext.getContentResolver().applyBatch(ContactsContract.AUTHORITY,
                                operations);
                    } catch (RemoteException | OperationApplicationException e) {
                        Log.e(TAG, "Exception thrown when pinning contacts", e);
                    }
                }
            }
            mDraggedEntry = null;
        }
    }

    /**
     * Invoked when the dragged item is dropped to unsupported location. We will then move the
     * contact back to where it was dragged from.
     */
    public void dropToUnsupportedView() {
        if (isIndexInBound(mDragEnteredEntryIndex)) {
            mContactEntries.remove(mDragEnteredEntryIndex);
            mContactEntries.add(mDraggedEntryIndex, mDraggedEntry);
            notifyDataSetChanged();
        }
    }

    /**
     * Clears all temporary variables at a new interaction.
     */
    public void cleanTempVariables() {
        mDraggedEntryIndex = -1;
        mDropEntryIndex = -1;
        mDragEnteredEntryIndex = -1;
        mDraggedEntry = null;
    }

    /**
     * Used when a contact is removed from speeddial. This will both unstar and set pinned position
     * of the contact to PinnedPosition.DEMOTED so that it doesn't show up anymore in the favorites
     * list.
     */
    private void unstarAndUnpinContact(Uri contactUri) {
        final ContentValues values = new ContentValues(2);
        values.put(Contacts.STARRED, false);
        values.put(Contacts.PINNED, PinnedPositions.DEMOTED);
        mContext.getContentResolver().update(contactUri, values, null, null);
    }

    /**
     * Given a list of contacts that each have pinned positions, rearrange the list (destructive)
     * such that all pinned contacts are in their defined pinned positions, and unpinned contacts
     * take the spaces between those pinned contacts. Demoted contacts should not appear in the
     * resulting list.
     *
     * This method also updates the pinned positions of pinned contacts so that they are all
     * unique positive integers within range from 0 to toArrange.size() - 1. This is because
     * when the contact entries are read from the database, it is possible for them to have
     * overlapping pin positions due to sync or modifications by third party apps.
     */
    @VisibleForTesting
    /* package */ void arrangeContactsByPinnedPosition(ArrayList<ContactEntry> toArrange) {
        final PriorityQueue<ContactEntry> pinnedQueue =
                new PriorityQueue<ContactEntry>(PIN_LIMIT, mContactEntryComparator);

        final List<ContactEntry> unpinnedContacts = new LinkedList<ContactEntry>();

        final int length = toArrange.size();
        for (int i = 0; i < length; i++) {
            final ContactEntry contact = toArrange.get(i);
            // Decide whether the contact is hidden(demoted), pinned, or unpinned
            if (contact.pinned > PIN_LIMIT || contact.pinned == PinnedPositions.UNPINNED) {
                unpinnedContacts.add(contact);
            } else if (contact.pinned > PinnedPositions.DEMOTED) {
                // Demoted or contacts with negative pinned positions are ignored.
                // Pinned contacts go into a priority queue where they are ranked by pinned
                // position. This is required because the contacts provider does not return
                // contacts ordered by pinned position.
                pinnedQueue.add(contact);
            }
        }

        final int maxToPin = Math.min(PIN_LIMIT, pinnedQueue.size() + unpinnedContacts.size());

        toArrange.clear();
        for (int i = 1; i < maxToPin + 1; i++) {
            if (!pinnedQueue.isEmpty() && pinnedQueue.peek().pinned <= i) {
                final ContactEntry toPin = pinnedQueue.poll();
                toPin.pinned = i;
                toArrange.add(toPin);
            } else if (!unpinnedContacts.isEmpty()) {
                toArrange.add(unpinnedContacts.remove(0));
            }
        }

        // If there are still contacts in pinnedContacts at this point, it means that the pinned
        // positions of these pinned contacts exceed the actual number of contacts in the list.
        // For example, the user had 10 frequents, starred and pinned one of them at the last spot,
        // and then cleared frequents. Contacts in this situation should become unpinned.
        while (!pinnedQueue.isEmpty()) {
            final ContactEntry entry = pinnedQueue.poll();
            entry.pinned = PinnedPositions.UNPINNED;
            toArrange.add(entry);
        }

        // Any remaining unpinned contacts that weren't in the gaps between the pinned contacts
        // now just get appended to the end of the list.
        toArrange.addAll(unpinnedContacts);
    }

    /**
     * Given an existing list of contact entries and a single entry that is to be pinned at a
     * particular position, return a list of {@link ContentProviderOperation}s that contains new
     * pinned positions for all contacts that are forced to be pinned at new positions, trying as
     * much as possible to keep pinned contacts at their original location.
     *
     * At this point in time the pinned position of each contact in the list has already been
     * updated by {@link #arrangeContactsByPinnedPosition}, so we can assume that all pinned
     * positions(within {@link #PIN_LIMIT} are unique positive integers.
     */
    @VisibleForTesting
    /* package */ ArrayList<ContentProviderOperation> getReflowedPinningOperations(
            ArrayList<ContactEntry> list, int oldPos, int newPinPos) {
        final ArrayList<ContentProviderOperation> positions = Lists.newArrayList();
        final int lowerBound = Math.min(oldPos, newPinPos);
        final int upperBound = Math.max(oldPos, newPinPos);
        for (int i = lowerBound; i <= upperBound; i++) {
            final ContactEntry entry = list.get(i);

            // Pinned positions in the database start from 1 instead of being zero-indexed like
            // arrays, so offset by 1.
            final int databasePinnedPosition = i + 1;
            if (entry.pinned == databasePinnedPosition) continue;

            final Uri uri = Uri.withAppendedPath(Contacts.CONTENT_URI, String.valueOf(entry.id));
            final ContentValues values = new ContentValues();
            values.put(Contacts.PINNED, databasePinnedPosition);
            positions.add(ContentProviderOperation.newUpdate(uri).withValues(values).build());
        }
        return positions;
    }

    protected static class ViewTypes {
        public static final int TILE = 0;
        public static final int COUNT = 1;
    }

    @Override
    public void onDragStarted(int x, int y, PhoneFavoriteSquareTileView view) {
        setInDragging(true);
        final int itemIndex = mContactEntries.indexOf(view.getContactEntry());
        popContactEntry(itemIndex);
    }

    @Override
    public void onDragHovered(int x, int y, PhoneFavoriteSquareTileView view) {
        if (view == null) {
            // The user is hovering over a view that is not a contact tile, no need to do
            // anything here.
            return;
        }
        final int itemIndex = mContactEntries.indexOf(view.getContactEntry());
        if (mInDragging &&
                mDragEnteredEntryIndex != itemIndex &&
                isIndexInBound(itemIndex) &&
                itemIndex < PIN_LIMIT &&
                itemIndex >= 0) {
            markDropArea(itemIndex);
        }
    }

    @Override
    public void onDragFinished(int x, int y) {
        setInDragging(false);
        // A contact has been dragged to the RemoveView in order to be unstarred,  so simply wait
        // for the new contact cursor which will cause the UI to be refreshed without the unstarred
        // contact.
        if (!mAwaitingRemove) {
            handleDrop();
        }
    }

    @Override
    public void onDroppedOnRemove() {
        if (mDraggedEntry != null) {
            unstarAndUnpinContact(mDraggedEntry.lookupUri);
            mAwaitingRemove = true;
        }
    }
}