/*
 * Copyright (C) 2012 Andrew Neal 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.andrew.apollo;

import android.app.PendingIntent;
import android.graphics.Bitmap;
import android.os.Looper;
import android.util.Log;

import java.lang.reflect.Field;
import java.lang.reflect.Method;

/**
 * RemoteControlClient enables exposing information meant to be consumed by
 * remote controls capable of displaying metadata, artwork and media transport
 * control buttons. A remote control client object is associated with a media
 * button event receiver. This event receiver must have been previously
 * registered with
 * {@link android.media.AudioManager#registerMediaButtonEventReceiver(android.content.ComponentName)}
 * before the RemoteControlClient can be registered through
 * {@link android.media.AudioManager#registerRemoteControlClient(android.media.RemoteControlClient)}
 * .
 */
@SuppressWarnings({
        "rawtypes", "unchecked"
})
public class RemoteControlClientCompat {

    private static final String TAG = "RemoteControlCompat";

    private static Class sRemoteControlClientClass;

    // RCC short for RemoteControlClient
    private static Method sRCCEditMetadataMethod;

    private static Method sRCCSetPlayStateMethod;

    private static Method sRCCSetTransportControlFlags;

    private static boolean sHasRemoteControlAPIs = false;

    static {
        try {
            final ClassLoader classLoader = RemoteControlClientCompat.class.getClassLoader();
            sRemoteControlClientClass = getActualRemoteControlClientClass(classLoader);
            // dynamically populate the playstate and flag values in case they
            // change
            // in future versions.
            for (final Field field : RemoteControlClientCompat.class.getFields()) {
                try {
                    final Field realField = sRemoteControlClientClass.getField(field.getName());
                    final Object realValue = realField.get(null);
                    field.set(null, realValue);
                } catch (final NoSuchFieldException e) {
                    Log.w(TAG, "Could not get real field: " + field.getName());
                } catch (final IllegalArgumentException e) {
                    Log.w(TAG,
                            "Error trying to pull field value for: " + field.getName() + " "
                                    + e.getMessage());
                } catch (final IllegalAccessException e) {
                    Log.w(TAG,
                            "Error trying to pull field value for: " + field.getName() + " "
                                    + e.getMessage());
                }
            }

            // get the required public methods on RemoteControlClient
            sRCCEditMetadataMethod = sRemoteControlClientClass.getMethod("editMetadata",
                    boolean.class);
            sRCCSetPlayStateMethod = sRemoteControlClientClass.getMethod("setPlaybackState",
                    int.class);
            sRCCSetTransportControlFlags = sRemoteControlClientClass.getMethod(
                    "setTransportControlFlags", int.class);

            sHasRemoteControlAPIs = true;
        } catch (final ClassNotFoundException e) {
            // Silently fail when running on an OS before ICS.
        } catch (final NoSuchMethodException e) {
            // Silently fail when running on an OS before ICS.
        } catch (final IllegalArgumentException e) {
            // Silently fail when running on an OS before ICS.
        } catch (final SecurityException e) {
            // Silently fail when running on an OS before ICS.
        }
    }

    public static Class getActualRemoteControlClientClass(final ClassLoader classLoader)
            throws ClassNotFoundException {
        return classLoader.loadClass("android.media.RemoteControlClient");
    }

    private Object mActualRemoteControlClient;

    public RemoteControlClientCompat(final PendingIntent pendingIntent) {
        if (!sHasRemoteControlAPIs) {
            return;
        }
        try {
            mActualRemoteControlClient = sRemoteControlClientClass.getConstructor(
                    PendingIntent.class).newInstance(pendingIntent);
        } catch (final Exception e) {
            throw new RuntimeException(e);
        }
    }

    public RemoteControlClientCompat(final PendingIntent pendingIntent, final Looper looper) {
        if (!sHasRemoteControlAPIs) {
            return;
        }

        try {
            mActualRemoteControlClient = sRemoteControlClientClass.getConstructor(
                    PendingIntent.class, Looper.class).newInstance(pendingIntent, looper);
        } catch (final Exception e) {
            Log.e(TAG, "Error creating new instance of " + sRemoteControlClientClass.getName(), e);
        }
    }

    /**
     * Class used to modify metadata in a
     * {@link android.media.RemoteControlClient} object. Use
     * {@link android.media.RemoteControlClient#editMetadata(boolean)} to create
     * an instance of an editor, on which you set the metadata for the
     * RemoteControlClient instance. Once all the information has been set, use
     * {@link #apply()} to make it the new metadata that should be displayed for
     * the associated client. Once the metadata has been "applied", you cannot
     * reuse this instance of the MetadataEditor.
     */
    public class MetadataEditorCompat {

        private Method mPutStringMethod;

        private Method mPutBitmapMethod;

        private Method mPutLongMethod;

        private Method mClearMethod;

        private Method mApplyMethod;

        private final Object mActualMetadataEditor;

        /**
         * The metadata key for the content artwork / album art.
         */
        public final static int METADATA_KEY_ARTWORK = 100;

        private MetadataEditorCompat(final Object actualMetadataEditor) {
            if (sHasRemoteControlAPIs && actualMetadataEditor == null) {
                throw new IllegalArgumentException("Remote Control API's exist, "
                        + "should not be given a null MetadataEditor");
            }
            if (sHasRemoteControlAPIs) {
                final Class metadataEditorClass = actualMetadataEditor.getClass();

                try {
                    mPutStringMethod = metadataEditorClass.getMethod("putString", int.class,
                            String.class);
                    mPutBitmapMethod = metadataEditorClass.getMethod("putBitmap", int.class,
                            Bitmap.class);
                    mPutLongMethod = metadataEditorClass
                            .getMethod("putLong", int.class, long.class);
                    mClearMethod = metadataEditorClass.getMethod("clear", new Class[] {});
                    mApplyMethod = metadataEditorClass.getMethod("apply", new Class[] {});
                } catch (final Exception e) {
                    throw new RuntimeException(e.getMessage(), e);
                }
            }
            mActualMetadataEditor = actualMetadataEditor;
        }

        /**
         * Adds textual information to be displayed. Note that none of the
         * information added after {@link #apply()} has been called, will be
         * displayed.
         * 
         * @param key The identifier of a the metadata field to set. Valid
         *            values are
         *            {@link android.media.MediaMetadataRetriever#METADATA_KEY_ALBUM}
         *            ,
         *            {@link android.media.MediaMetadataRetriever#METADATA_KEY_ALBUMARTIST}
         *            ,
         *            {@link android.media.MediaMetadataRetriever#METADATA_KEY_TITLE}
         *            ,
         *            {@link android.media.MediaMetadataRetriever#METADATA_KEY_ARTIST}
         *            ,
         *            {@link android.media.MediaMetadataRetriever#METADATA_KEY_AUTHOR}
         *            ,
         *            {@link android.media.MediaMetadataRetriever#METADATA_KEY_COMPILATION}
         *            ,
         *            {@link android.media.MediaMetadataRetriever#METADATA_KEY_COMPOSER}
         *            ,
         *            {@link android.media.MediaMetadataRetriever#METADATA_KEY_DATE}
         *            ,
         *            {@link android.media.MediaMetadataRetriever#METADATA_KEY_GENRE}
         *            ,
         *            {@link android.media.MediaMetadataRetriever#METADATA_KEY_TITLE}
         *            ,
         *            {@link android.media.MediaMetadataRetriever#METADATA_KEY_WRITER}
         *            .
         * @param value The text for the given key, or {@code null} to signify
         *            there is no valid information for the field.
         * @return Returns a reference to the same MetadataEditor object, so you
         *         can chain put calls together.
         */
        public MetadataEditorCompat putString(final int key, final String value) {
            if (sHasRemoteControlAPIs) {
                try {
                    mPutStringMethod.invoke(mActualMetadataEditor, key, value);
                } catch (final Exception e) {
                    throw new RuntimeException(e.getMessage(), e);
                }
            }
            return this;
        }

        /**
         * Sets the album / artwork picture to be displayed on the remote
         * control.
         * 
         * @param key the identifier of the bitmap to set. The only valid value
         *            is {@link #METADATA_KEY_ARTWORK}
         * @param bitmap The bitmap for the artwork, or null if there isn't any.
         * @return Returns a reference to the same MetadataEditor object, so you
         *         can chain put calls together.
         * @throws IllegalArgumentException
         * @see android.graphics.Bitmap
         */
        public MetadataEditorCompat putBitmap(final int key, final Bitmap bitmap) {
            if (sHasRemoteControlAPIs) {
                try {
                    mPutBitmapMethod.invoke(mActualMetadataEditor, key, bitmap);
                } catch (final Exception e) {
                    throw new RuntimeException(e.getMessage(), e);
                }
            }
            return this;
        }

        /**
         * Adds numerical information to be displayed. Note that none of the
         * information added after {@link #apply()} has been called, will be
         * displayed.
         * 
         * @param key the identifier of a the metadata field to set. Valid
         *            values are
         *            {@link android.media.MediaMetadataRetriever#METADATA_KEY_CD_TRACK_NUMBER}
         *            ,
         *            {@link android.media.MediaMetadataRetriever#METADATA_KEY_DISC_NUMBER}
         *            ,
         *            {@link android.media.MediaMetadataRetriever#METADATA_KEY_DURATION}
         *            (with a value expressed in milliseconds),
         *            {@link android.media.MediaMetadataRetriever#METADATA_KEY_YEAR}
         *            .
         * @param value The long value for the given key
         * @return Returns a reference to the same MetadataEditor object, so you
         *         can chain put calls together.
         * @throws IllegalArgumentException
         */
        public MetadataEditorCompat putLong(final int key, final long value) {
            if (sHasRemoteControlAPIs) {
                try {
                    mPutLongMethod.invoke(mActualMetadataEditor, key, value);
                } catch (final Exception e) {
                    throw new RuntimeException(e.getMessage(), e);
                }
            }
            return this;
        }

        /**
         * Clears all the metadata that has been set since the MetadataEditor
         * instance was created with
         * {@link android.media.RemoteControlClient#editMetadata(boolean)}.
         */
        public void clear() {
            if (sHasRemoteControlAPIs) {
                try {
                    mClearMethod.invoke(mActualMetadataEditor, (Object[])null);
                } catch (final Exception e) {
                    throw new RuntimeException(e.getMessage(), e);
                }
            }
        }

        /**
         * Associates all the metadata that has been set since the
         * MetadataEditor instance was created with
         * {@link android.media.RemoteControlClient#editMetadata(boolean)}, or
         * since {@link #clear()} was called, with the RemoteControlClient. Once
         * "applied", this MetadataEditor cannot be reused to edit the
         * RemoteControlClient's metadata.
         */
        public void apply() {
            if (sHasRemoteControlAPIs) {
                try {
                    mApplyMethod.invoke(mActualMetadataEditor, (Object[])null);
                } catch (final Exception e) {
                    throw new RuntimeException(e.getMessage(), e);
                }
            }
        }
    }

    /**
     * Creates a {@link android.media.RemoteControlClient.MetadataEditor}.
     * 
     * @param startEmpty Set to false if you want the MetadataEditor to contain
     *            the metadata that was previously applied to the
     *            RemoteControlClient, or true if it is to be created empty.
     * @return a new MetadataEditor instance.
     */
    public MetadataEditorCompat editMetadata(final boolean startEmpty) {
        Object metadataEditor;
        if (sHasRemoteControlAPIs) {
            try {
                metadataEditor = sRCCEditMetadataMethod.invoke(mActualRemoteControlClient,
                        startEmpty);
            } catch (final Exception e) {
                throw new RuntimeException(e);
            }
        } else {
            metadataEditor = null;
        }
        return new MetadataEditorCompat(metadataEditor);
    }

    /**
     * Sets the current playback state.
     * 
     * @param state The current playback state, one of the following values:
     *            {@link android.media.RemoteControlClient#PLAYSTATE_STOPPED},
     *            {@link android.media.RemoteControlClient#PLAYSTATE_PAUSED},
     *            {@link android.media.RemoteControlClient#PLAYSTATE_PLAYING},
     *            {@link android.media.RemoteControlClient#PLAYSTATE_FAST_FORWARDING}
     *            ,
     *            {@link android.media.RemoteControlClient#PLAYSTATE_REWINDING},
     *            {@link android.media.RemoteControlClient#PLAYSTATE_SKIPPING_FORWARDS}
     *            ,
     *            {@link android.media.RemoteControlClient#PLAYSTATE_SKIPPING_BACKWARDS}
     *            ,
     *            {@link android.media.RemoteControlClient#PLAYSTATE_BUFFERING},
     *            {@link android.media.RemoteControlClient#PLAYSTATE_ERROR}.
     */
    public void setPlaybackState(final int state) {
        if (sHasRemoteControlAPIs) {
            try {
                sRCCSetPlayStateMethod.invoke(mActualRemoteControlClient, state);
            } catch (final Exception e) {
                throw new RuntimeException(e);
            }
        }
    }

    /**
     * Sets the flags for the media transport control buttons that this client
     * supports.
     * 
     * @param transportControlFlags A combination of the following flags:
     *            {@link android.media.RemoteControlClient#FLAG_KEY_MEDIA_PREVIOUS}
     *            ,
     *            {@link android.media.RemoteControlClient#FLAG_KEY_MEDIA_REWIND}
     *            ,
     *            {@link android.media.RemoteControlClient#FLAG_KEY_MEDIA_PLAY},
     *            {@link android.media.RemoteControlClient#FLAG_KEY_MEDIA_PLAY_PAUSE}
     *            ,
     *            {@link android.media.RemoteControlClient#FLAG_KEY_MEDIA_PAUSE}
     *            ,
     *            {@link android.media.RemoteControlClient#FLAG_KEY_MEDIA_STOP},
     *            {@link android.media.RemoteControlClient#FLAG_KEY_MEDIA_FAST_FORWARD}
     *            ,
     *            {@link android.media.RemoteControlClient#FLAG_KEY_MEDIA_NEXT}
     */
    public void setTransportControlFlags(final int transportControlFlags) {
        if (sHasRemoteControlAPIs) {
            try {
                sRCCSetTransportControlFlags.invoke(mActualRemoteControlClient,
                        transportControlFlags);
            } catch (final Exception e) {
                throw new RuntimeException(e);
            }
        }
    }

    public final Object getActualRemoteControlClientObject() {
        return mActualRemoteControlClient;
    }
}
