package com.comphenix.protocol.wrappers;

import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

import com.comphenix.protocol.wrappers.collection.ConvertedSet;
import com.google.common.collect.Multimap;
import com.google.common.collect.Multiset;

/**
 * Represents wrappers for Minecraft's own version of Guava.
 * @author Kristian
 */
class GuavaWrappers {
    private static volatile boolean USE_REFLECTION_FALLBACK = false;
    
    /**
     * Wrap a Bukkit multimap around Minecraft's internal multimap.
     * @param multimap - the multimap to wrap.
     * @return The Bukkit multimap.
     */
    public static <TKey, TValue> Multimap<TKey, TValue> getBukkitMultimap(
            final com.google.common.collect.Multimap<TKey, TValue> multimap) {
        
        if (USE_REFLECTION_FALLBACK) {
            return GuavaReflection.getBukkitMultimap(multimap);
        }
        
        Multimap<TKey, TValue> result = new Multimap<TKey, TValue>() {
            @Override
            public Map<TKey, Collection<TValue>> asMap() {
                return multimap.asMap();
            }

            @Override
            public void clear() {
                multimap.clear();
            }

            @Override
            public boolean containsEntry(Object arg0, Object arg1) {
                return multimap.containsEntry(arg0, arg1);
            }

            @Override
            public boolean containsKey(Object arg0) {
                return multimap.containsKey(arg0);
            }

            @Override
            public boolean containsValue(Object arg0) {
                return multimap.containsValue(arg0);
            }

            @Override
            public Collection<Entry<TKey, TValue>> entries() {
                return multimap.entries();
            }

            @Override
            public boolean equals(Object arg0) {
                return multimap.equals(arg0);
            }

            @Override
            public Collection<TValue> get(TKey arg0) {
                return multimap.get(arg0);
            }

            @Override
            public int hashCode() {
                return multimap.hashCode();
            }

            @Override
            public boolean isEmpty() {
                return multimap.isEmpty();
            }

            @Override
            public Set<TKey> keySet() {
                return multimap.keySet();
            }

            @Override
            public Multiset<TKey> keys() {
                return getBukkitMultiset(multimap.keys());
            }

            @Override
            public boolean put(TKey arg0, TValue arg1) {
                return multimap.put(arg0, arg1);
            }

            @Override
            public boolean putAll(com.google.common.collect.Multimap<? extends TKey, ? extends TValue> arg0) {
                boolean result = false;
                
                // Add each entry
                for (Entry<? extends TKey, ? extends TValue> entry : arg0.entries()) {
                    result |= multimap.put(entry.getKey(), entry.getValue());
                }
                return result;
            }

            @Override
            public boolean putAll(TKey arg0, Iterable<? extends TValue> arg1) {
                return multimap.putAll(arg0, arg1);
            }

            @Override
            public boolean remove(Object arg0, Object arg1) {
                return multimap.remove(arg0, arg1);
            }

            @Override
            public Collection<TValue> removeAll(Object arg0) {
                return multimap.removeAll(arg0);
            }

            @Override
            public Collection<TValue> replaceValues(TKey arg0, Iterable<? extends TValue> arg1) {
                return multimap.replaceValues(arg0, arg1);
            }

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

            @Override
            public Collection<TValue> values() {
                return multimap.values();
            }
        };
        
        try {
            result.size(); // Test
            return result;
        } catch (LinkageError e) {
            // Occurs on Cauldron 1.7.10
            USE_REFLECTION_FALLBACK = true;
            return GuavaReflection.getBukkitMultimap(multimap);
        }
    }
    
    public static <TValue> Multiset<TValue> getBukkitMultiset(final com.google.common.collect.Multiset<TValue> multiset) {
        if (USE_REFLECTION_FALLBACK) {
            return GuavaReflection.getBukkitMultiset(multiset);
        }
        
        Multiset<TValue> result = new Multiset<TValue>() {
            @Override
            public int add(TValue arg0, int arg1) {
                return multiset.add(arg0, arg1);
            }

            @Override
            public boolean add(TValue arg0) {
                return multiset.add(arg0);
            }

            @Override
            public boolean addAll(Collection<? extends TValue> c) {
                return multiset.addAll(c);
            }

            @Override
            public void clear() {
                multiset.clear();
            }

            @Override
            public boolean contains(Object arg0) {
                return multiset.contains(arg0);
            }

            @Override
            public boolean containsAll(Collection<?> arg0) {
                return multiset.containsAll(arg0);
            }

            @Override
            public int count(Object arg0) {
                return multiset.count(arg0);
            }

            @Override
            public Set<TValue> elementSet() {
                return multiset.elementSet();
            }

            @Override
            public Set<Multiset.Entry<TValue>> entrySet() {
                return new ConvertedSet<
                    com.google.common.collect.Multiset.Entry<TValue>,
                    Multiset.Entry<TValue>>
                (multiset.entrySet()) {
                    
                    @Override
                    protected com.google.common.collect.Multiset.Entry<TValue> toOuter(
                            com.google.common.collect.Multiset.Entry<TValue> inner) {
                        return getBukkitEntry(inner);
                    }

                    @Override
                    protected com.google.common.collect.Multiset.Entry<TValue> toInner(
                            com.google.common.collect.Multiset.Entry<TValue> outer) {
                        throw new UnsupportedOperationException("Cannot convert " + outer);
                    }
                };
            }

            @Override
            public boolean equals(Object arg0) {
                return multiset.equals(arg0);
            }

            @Override
            public int hashCode() {
                return multiset.hashCode();
            }

            @Override
            public boolean isEmpty() {
                return multiset.isEmpty();
            }

            @Override
            public Iterator<TValue> iterator() {
                return multiset.iterator();
            }

            @Override
            public int remove(Object arg0, int arg1) {
                return multiset.remove(arg0, arg1);
            }

            @Override
            public boolean remove(Object arg0) {
                return multiset.remove(arg0);
            }

            @Override
            public boolean removeAll(Collection<?> arg0) {
                return multiset.removeAll(arg0);
            }

            @Override
            public boolean retainAll(Collection<?> arg0) {
                return multiset.retainAll(arg0);
            }

            @Override
            public boolean setCount(TValue arg0, int arg1, int arg2) {
                return multiset.setCount(arg0, arg1, arg2);
            }

            @Override
            public int setCount(TValue arg0, int arg1) {
                return multiset.setCount(arg0, arg1);
            }

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

            @Override
            public Object[] toArray() {
                return multiset.toArray();
            }

            @Override
            public <T> T[] toArray(T[] a) {
                return multiset.toArray(a);
            }

            @Override
            public String toString() {
                return multiset.toString();
            }
        };
        
        try {
            result.size(); // Test
            return result;
        } catch (LinkageError e) {
            USE_REFLECTION_FALLBACK = true;
            return GuavaReflection.getBukkitMultiset(multiset);
        }
    }
    
    private static <TValue> Multiset.Entry<TValue> getBukkitEntry(final com.google.common.collect.Multiset.Entry<TValue> entry) {
        return new Multiset.Entry<TValue>() {
            @Override
            public boolean equals(Object arg0) {
                return entry.equals(arg0);
            }

            @Override
            public int getCount() {
                return entry.getCount();
            }

            @Override
            public TValue getElement() {
                return entry.getElement();
            }

            @Override
            public int hashCode() {
                return entry.hashCode();
            }

            @Override
            public String toString() {
                return entry.toString();
            }
        };
    }
}