/*
 * 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.camera.data;

import android.app.Activity;
import android.content.ContentResolver;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.AsyncTask;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;

import com.android.camera.SDCard;
import com.android.camera.Storage;
import com.android.camera.app.PlaceholderManager;
import com.android.camera.ui.FilmStripView.ImageData;

import java.util.ArrayList;
import java.util.Comparator;

/**
 * A {@link LocalDataAdapter} that provides data in the camera folder.
 */
public class CameraDataAdapter implements LocalDataAdapter {
    private static final String TAG = "CAM_CameraDataAdapter";

    private static final int DEFAULT_DECODE_SIZE = 1600;

    private LocalDataList mImages;

    private Listener mListener;
    private final int mPlaceHolderResourceId;

    private int mSuggestedWidth = DEFAULT_DECODE_SIZE;
    private int mSuggestedHeight = DEFAULT_DECODE_SIZE;

    private LocalData mLocalDataToDelete;
    private QueryTask mQueryTask;

    public CameraDataAdapter(int placeholderResource) {
        mImages = new LocalDataList();
        mPlaceHolderResourceId = placeholderResource;
    }

    @Override
    public void requestLoad(ContentResolver resolver) {
        mQueryTask = new QueryTask();
        mQueryTask.execute(resolver);
    }

    @Override
    public void stopLoading() {
        if (mQueryTask != null) {
            mQueryTask.cancel(true);
        }
    }

    @Override
    public LocalData getLocalData(int dataID) {
        if (dataID < 0 || dataID >= mImages.size()) {
            return null;
        }

        return mImages.get(dataID);
    }

    @Override
    public int getTotalNumber() {
        return mImages.size();
    }

    @Override
    public ImageData getImageData(int id) {
        return getLocalData(id);
    }

    @Override
    public void suggestViewSizeBound(int w, int h) {
        if (w <= 0 || h <= 0) {
            mSuggestedWidth  = mSuggestedHeight = DEFAULT_DECODE_SIZE;
        } else {
            mSuggestedWidth = (w < DEFAULT_DECODE_SIZE ? w : DEFAULT_DECODE_SIZE);
            mSuggestedHeight = (h < DEFAULT_DECODE_SIZE ? h : DEFAULT_DECODE_SIZE);
        }
    }

    @Override
    public View getView(Activity activity, int dataID, boolean inFullScreen) {
        if (dataID >= mImages.size() || dataID < 0) {
            return null;
        }

        return mImages.get(dataID).getView(
                activity, mSuggestedWidth, mSuggestedHeight,
                mPlaceHolderResourceId, this, inFullScreen);
    }

    @Override
    public void setListener(Listener listener) {
        mListener = listener;
        if (mImages != null) {
            mListener.onDataLoaded();
        }
    }

    @Override
    public boolean canSwipeInFullScreen(int dataID) {
        if (dataID < mImages.size() && dataID > 0) {
            return mImages.get(dataID).canSwipeInFullScreen();
        }
        return true;
    }

    @Override
    public void removeData(Context c, int dataID) {
        if (dataID >= mImages.size()) return;
        LocalData d = mImages.remove(dataID);
        // Delete previously removed data first.
        executeDeletion(c);
        mLocalDataToDelete = d;
        mListener.onDataRemoved(dataID, d);
    }

    // TODO: put the database query on background thread
    @Override
    public void addNewVideo(ContentResolver cr, Uri uri) {
        Cursor c = cr.query(uri,
                LocalMediaData.VideoData.QUERY_PROJECTION,
                MediaStore.Video.Media.DATA + " like ? or " +
                MediaStore.Video.Media.DATA + " like ? ", getCameraPath(),
                LocalMediaData.VideoData.QUERY_ORDER);
        if (c == null || !c.moveToFirst()) {
            return;
        }
        int pos = findDataByContentUri(uri);
        LocalMediaData.VideoData newData = LocalMediaData.VideoData.buildFromCursor(c);
        if (newData != null) {
            if (pos != -1) {
                // A duplicate one, just do a substitute.
                updateData(pos, newData);
            } else {
                // A new data.
                insertData(newData);
            }
        } else {
            Log.e(TAG, "video data not found");
        }
        c.close();
    }

    // TODO: put the database query on background thread
    @Override
    public void addNewPhoto(ContentResolver cr, Uri uri) {
        Cursor c = cr.query(uri,
                LocalMediaData.PhotoData.QUERY_PROJECTION,
                MediaStore.Images.Media.DATA + " like ? or " +
                MediaStore.Images.Media.DATA + " like ? ", getCameraPath(),
                LocalMediaData.PhotoData.QUERY_ORDER);
        if (c == null || !c.moveToFirst()) {
            return;
        }
        int pos = findDataByContentUri(uri);
        LocalMediaData.PhotoData newData = LocalMediaData.PhotoData.buildFromCursor(c);
        if (pos != -1) {
            // a duplicate one, just do a substitute.
            Log.v(TAG, "found duplicate photo");
            updateData(pos, newData);
        } else {
            // a new data.
            insertData(newData);
        }
        c.close();
    }

    @Override
    public int findDataByContentUri(Uri uri) {
        // LocalDataList will return in O(1) if the uri is not contained.
        // Otherwise the performance is O(n), but this is acceptable as we will
        // most often call this to find an element at the beginning of the list.
        return mImages.indexOf(uri);
    }

    @Override
    public boolean undoDataRemoval() {
        if (mLocalDataToDelete == null) return false;
        LocalData d = mLocalDataToDelete;
        mLocalDataToDelete = null;
        insertData(d);
        return true;
    }

    @Override
    public boolean executeDeletion(Context c) {
        if (mLocalDataToDelete == null) return false;

        DeletionTask task = new DeletionTask(c);
        task.execute(mLocalDataToDelete);
        mLocalDataToDelete = null;
        return true;
    }

    @Override
    public void flush() {
        replaceData(new LocalDataList());
    }

    @Override
    public void refresh(ContentResolver resolver, Uri contentUri) {
        int pos = findDataByContentUri(contentUri);
        if (pos == -1) {
            return;
        }

        LocalData data = mImages.get(pos);
        LocalData refreshedData = data.refresh(resolver);
        if (refreshedData != null) {
            updateData(pos, refreshedData);
        }
    }

    @Override
    public void updateData(final int pos, LocalData data) {
        mImages.set(pos, data);
        if (mListener != null) {
            mListener.onDataUpdated(new UpdateReporter() {
                @Override
                public boolean isDataRemoved(int dataID) {
                    return false;
                }

                @Override
                public boolean isDataUpdated(int dataID) {
                    return (dataID == pos);
                }
            });
        }
    }

    @Override
    public void insertData(LocalData data) {
        // Since this function is mostly for adding the newest data,
        // a simple linear search should yield the best performance over a
        // binary search.
        int pos = 0;
        Comparator<LocalData> comp = new LocalData.NewestFirstComparator();
        for (; pos < mImages.size()
                && comp.compare(data, mImages.get(pos)) > 0; pos++);
        mImages.add(pos, data);
        if (mListener != null) {
            mListener.onDataInserted(pos, data);
        }
    }

    /** Update all the data */
    private void replaceData(LocalDataList list) {
        if (list.size() == 0 && mImages.size() == 0) {
            return;
        }
        mImages = list;
        if (mListener != null) {
            mListener.onDataLoaded();
        }
    }

    private static String[] getCameraPath() {
        String[] cameraPath =
                {Storage.DIRECTORY + "/%", SDCard.instance().getDirectory() + "/%"};
        return cameraPath;
    }

    private class QueryTask extends AsyncTask<ContentResolver, Void, LocalDataList> {

        /**
         * Loads all the photo and video data in the camera folder in background
         * and combine them into one single list.
         *
         * @param resolver {@link ContentResolver} to load all the data.
         * @return An {@link ArrayList} of all loaded data.
         */
        @Override
        protected LocalDataList doInBackground(ContentResolver... resolver) {
            LocalDataList l = new LocalDataList();
            // Photos
            Cursor c = resolver[0].query(
                    LocalMediaData.PhotoData.CONTENT_URI,
                    LocalMediaData.PhotoData.QUERY_PROJECTION,
                    MediaStore.Images.Media.DATA + " like ? or " +
                    MediaStore.Images.Media.DATA + " like ? ", getCameraPath(),
                    LocalMediaData.PhotoData.QUERY_ORDER);
            if (c != null && c.moveToFirst()) {
                // build up the list.
                while (true) {
                    LocalData data = LocalMediaData.PhotoData.buildFromCursor(c);
                    if (data != null) {
                        if (data.getMimeType().equals(PlaceholderManager.PLACEHOLDER_MIME_TYPE)) {
                            l.add(new InProgressDataWrapper(data, true));
                        } else {
                            l.add(data);
                        }
                    } else {
                        Log.e(TAG, "Error loading data:"
                                + c.getString(LocalMediaData.PhotoData.COL_DATA));
                    }
                    if (c.isLast()) {
                        break;
                    }
                    c.moveToNext();
                }
            }
            if (c != null) {
                c.close();
            }

            c = resolver[0].query(
                    LocalMediaData.VideoData.CONTENT_URI,
                    LocalMediaData.VideoData.QUERY_PROJECTION,
                    MediaStore.Video.Media.DATA + " like ? or " +
                    MediaStore.Video.Media.DATA + " like ? ", getCameraPath(),
                    LocalMediaData.VideoData.QUERY_ORDER);
            if (c != null && c.moveToFirst()) {
                // build up the list.
                c.moveToFirst();
                while (!isCancelled()) {
                    LocalData data = LocalMediaData.VideoData.buildFromCursor(c);
                    if (data != null) {
                        l.add(data);
                    } else {
                        Log.e(TAG, "Error loading data:"
                                + c.getString(LocalMediaData.VideoData.COL_DATA));
                    }
                    if (!c.isLast()) {
                        c.moveToNext();
                    } else {
                        break;
                    }
                }
            }
            if (c != null) {
                c.close();
            }

            if (l.size() != 0) {
                l.sort(new LocalData.NewestFirstComparator());
            }

            return l;
        }

        @Override
        protected void onPostExecute(LocalDataList l) {
            if (!isCancelled()) {
                replaceData(l);
            }
            if (mQueryTask == this) {
                mQueryTask = null;
            }
        }
    }

    private class DeletionTask extends AsyncTask<LocalData, Void, Void> {
        Context mContext;

        DeletionTask(Context context) {
            mContext = context;
        }

        @Override
        protected Void doInBackground(LocalData... data) {
            for (int i = 0; i < data.length; i++) {
                if (!data[i].isDataActionSupported(LocalData.ACTION_DELETE)) {
                    Log.v(TAG, "Deletion is not supported:" + data[i]);
                    continue;
                }
                data[i].delete(mContext);
            }
            return null;
        }
    }
}