//
// $Id: CharacterManager.java,v 1.22 2002/06/19 23:31:57 mdb Exp $

package com.threerings.cast;

import java.util.Arrays;
import java.util.Iterator;
import java.util.HashMap;

import com.samskivert.util.StringUtil;
import com.samskivert.util.Tuple;

import org.apache.commons.collections.LRUMap;

import com.threerings.media.util.Colorization;
import com.threerings.util.DirectionCodes;

import com.threerings.cast.Log;

/**
 * The character manager provides facilities for constructing sprites that
 * are used to represent characters in a scene. It also handles the
 * compositing and caching of composited character animations.
 */
public class CharacterManager
    implements DirectionCodes
{
    /**
     * Constructs the character manager.
     */
    public CharacterManager (ComponentRepository crepo)
    {
        // keep this around
        _crepo = crepo;

        // populate our actions table
        Iterator iter = crepo.enumerateActionSequences();
        while (iter.hasNext()) {
            ActionSequence action = (ActionSequence)iter.next();
            _actions.put(action.name, action);
        }
    }

    /**
     * Instructs the character manager to construct instances of this
     * derived class of {@link CharacterSprite} when creating new sprites.
     *
     * @exception IllegalArgumentException thrown if the supplied class
     * does not derive from {@link CharacterSprite}.
     */
    public void setCharacterClass (Class charClass)
    {
        // sanity check
        if (!CharacterSprite.class.isAssignableFrom(charClass)) {
            String errmsg = "Requested to use character sprite class that " + 
                "does not derive from CharacterSprite " +
                "[class=" + charClass.getName() + "].";
            throw new IllegalArgumentException(errmsg);
        }

        // make a note of it
        _charClass = charClass;
    }

    /**
     * Instructs the character manager to use the provided cache for
     * composited action animations.
     */
    public void setActionCache (ActionCache cache)
    {
        _acache = cache;
    }

    /**
     * Returns a {@link CharacterSprite} representing the character
     * described by the given {@link CharacterDescriptor}, or
     * <code>null</code> if an error occurs.
     *
     * @param desc the character descriptor.
     */
    public CharacterSprite getCharacter (CharacterDescriptor desc)
    {
        return getCharacter(desc, _charClass);
    }

    /**
     * Returns a {@link CharacterSprite} representing the character
     * described by the given {@link CharacterDescriptor}, or
     * <code>null</code> if an error occurs.
     *
     * @param desc the character descriptor.
     * @param charClass the {@link CharacterSprite} derived class that
     * should be instantiated instead of the configured default (which is
     * set via {@link #setCharacterClass}).
     */
    public CharacterSprite getCharacter (CharacterDescriptor desc,
                                         Class charClass)
    {
        try {
            CharacterSprite sprite = (CharacterSprite)
                charClass.newInstance();
            sprite.init(desc, this);
            return sprite;

        } catch (Exception e) {
            Log.warning("Failed to instantiate character sprite " +
                        "[e=" + e + "].");
            Log.logStackTrace(e);
            return null;
        }
    }

    /**
     * Informs the character manager that the action sequence for the
     * given character descriptor is likely to be needed in the near
     * future and so any efforts that can be made to load it into the
     * action sequence cache in advance should be undertaken.
     *
     * <p> This will eventually be revamped to spiffily load action
     * sequences in the background.
     */
    public void resolveActionSequence (CharacterDescriptor desc, String action)
    {
        try {
            if (getActionFrames(desc, action) == null) {
                Log.warning("Failed to resolve action sequence " +
                            "[desc=" + desc + ", action=" + action + "].");
            }

        } catch (NoSuchComponentException nsce) {
            Log.warning("Failed to resolve action sequence " +
                        "[nsce=" + nsce + "].");
        }
    }

    /**
     * Returns the action sequence instance with the specified name or
     * null if no such sequence exists.
     */
    protected ActionSequence getActionSequence (String action)
    {
        return (ActionSequence)_actions.get(action);
    }

    /**
     * Obtains the composited animation frames for the specified action
     * for a character with the specified descriptor. The resulting
     * composited animation will be cached.
     *
     * @exception NoSuchComponentException thrown if any of the components
     * in the supplied descriptor do not exist.
     * @exception IllegalArgumentException thrown if any of the components
     * referenced in the descriptor do not support the specified action.
     */
    protected ActionFrames getActionFrames (
        CharacterDescriptor descrip, String action)
        throws NoSuchComponentException
    {
        // first check the in-memory cache; which is keyed on both values
        Tuple key = new Tuple(descrip, action);
        ActionFrames frames = (ActionFrames)_frames.get(key);

        // next check the disk cache
        if (frames == null && _acache != null) {
            frames = _acache.getActionFrames(descrip, action);
            // cache the result in memory
            _frames.put(key, frames);
        }

        // if that failed, we'll just have to generate the danged things
        if (frames == null) {
            // do the compositing
            frames = createCompositeFrames(descrip, action);
            // cache the result on disk if we've got such a cache
            if (_acache != null) {
                _acache.cacheActionFrames(descrip, action, frames);
            }
            // cache the result in memory as well
            _frames.put(key, frames);
        }

        return frames;
    }

    /**
     * Generates the composited animation frames for the specified action
     * for a character with the specified descriptor.
     *
     * @exception NoSuchComponentException thrown if any of the components
     * in the supplied descriptor do not exist.
     * @exception IllegalArgumentException thrown if any of the components
     * referenced in the descriptor do not support the specified action.
     */
    protected ActionFrames createCompositeFrames (
        CharacterDescriptor descrip, String action)
        throws NoSuchComponentException
    {
        int[] cids = descrip.getComponentIds();
        int ccount = cids.length;
        Colorization[][] zations = descrip.getColorizations();

        Log.debug("Compositing action [action=" + action +
                  ", descrip=" + descrip + "].");

        // obtain the necessary components
        ColorizedComponent[] components = new ColorizedComponent[ccount];
        for (int i = 0; i < ccount; i++) {
            ColorizedComponent cc = new ColorizedComponent();
            cc.component = _crepo.getComponent(cids[i]);
            if (zations != null) {
                cc.zations = zations[i];
            }
            components[i] = cc;
        }

        // sort them into the proper rendering order
        Arrays.sort(components);

        // create colorized versions of all of the source action frames
        ActionFrames[] sources = new ActionFrames[ccount];
        for (int ii = 0; ii < ccount; ii++) {
            ActionFrames source = components[ii].component.getFrames(action);
            if (zations != null) {
                sources[ii] = source.cloneColorized(components[ii].zations);
            } else {
                sources[ii] = source;
            }
        }

        // use those to create an entity that will lazily composite things
        // together as they are needed
        return new CompositedActionFrames(sources);
    }

    /** Used when compositing component frame images. */
    protected static final class ColorizedComponent implements Comparable
    {
        /** The component to be colorized. */
        public CharacterComponent component;

        /** The colorizations to apply. */
        public Colorization[] zations;

        /** Sorts by render order. */
        public int compareTo (Object o)
        {
            ColorizedComponent co = (ColorizedComponent)o;
            return (component.componentClass.renderPriority -
                    co.component.componentClass.renderPriority);
        }
    }

    /** The component repository. */
    protected ComponentRepository _crepo;

    /** A table of our action sequences. */
    protected HashMap _actions = new HashMap();

    /** A cache of composited animation frames. */
    protected LRUMap _frames = new LRUMap(ACTION_CACHE_SIZE);

    /** The character class to be created. */
    protected Class _charClass = CharacterSprite.class;

    /** The action animation cache, if we have one. */
    protected ActionCache _acache;

    /** The number of actions to cache before we start clearing them
     * out. */
    protected static final int ACTION_CACHE_SIZE = 30;
}