package at.yawk.numaec;

import org.eclipse.collections.api.ByteIterable;
import org.eclipse.collections.api.bag.MutableBag;
import org.eclipse.collections.api.bag.primitive.MutableShortBag;
import org.eclipse.collections.api.block.function.primitive.ShortFunction;
import org.eclipse.collections.api.block.function.primitive.ShortFunction0;
import org.eclipse.collections.api.block.function.primitive.ShortToShortFunction;
import org.eclipse.collections.api.block.function.primitive.ShortToObjectFunction;
import org.eclipse.collections.api.block.function.primitive.ByteShortToShortFunction;
import org.eclipse.collections.api.block.function.primitive.ByteToShortFunction;
import org.eclipse.collections.api.block.predicate.primitive.ShortPredicate;
import org.eclipse.collections.api.block.predicate.primitive.ByteShortPredicate;
import org.eclipse.collections.api.iterator.MutableShortIterator;
import org.eclipse.collections.api.map.primitive.MutableShortByteMap;
import org.eclipse.collections.api.map.primitive.MutableByteShortMap;
import org.eclipse.collections.api.map.primitive.ByteShortMap;

public class ByteShortBTreeMap extends BaseByteShortMap implements ByteShortBufferMap {
    protected final BTree bTree;
    protected int size = 0;

    ByteShortBTreeMap(LargeByteBufferAllocator allocator, BTreeConfig config) {
        int leafSize = Byte.BYTES + Short.BYTES;
        int branchSize = config.entryMustBeInLeaf ? Byte.BYTES : leafSize;
        this.bTree = new BTree(allocator, config, branchSize, leafSize) {
            @Override
            protected void writeBranchEntry(LargeByteBuffer lbb, long address, long key, long value) {
                lbb.setByte(address, fromKey(key));
                if (!config.entryMustBeInLeaf) {
                    lbb.setShort(address + Byte.BYTES, fromValue(value));
                }
            }

            @Override
            protected void writeLeafEntry(LargeByteBuffer lbb, long address, long key, long value) {
                lbb.setByte(address, fromKey(key));
                lbb.setShort(address + Byte.BYTES, fromValue(value));
            }

            @Override
            protected long readBranchKey(LargeByteBuffer lbb, long address) {
                return toKey(lbb.getByte(address));
            }

            @Override
            protected long readBranchValue(LargeByteBuffer lbb, long address) {
                if (config.entryMustBeInLeaf) {
                    throw new AssertionError();
                } else {
                    return toValue(lbb.getShort(address + Byte.BYTES));
                }
            }

            @Override
            protected long readLeafKey(LargeByteBuffer lbb, long address) {
                return toKey(lbb.getByte(address));
            }

            @Override
            protected long readLeafValue(LargeByteBuffer lbb, long address) {
                return toValue(lbb.getShort(address + Byte.BYTES));
            }
        };
    }

    @Override
    protected MapStoreCursor iterationCursor() {
        BTree.Cursor cursor = bTree.allocateCursor();
        cursor.descendToStart();
        return cursor;
    }

    @Override
    protected MapStoreCursor keyCursor(byte key) {
        BTree.Cursor cursor = bTree.allocateCursor();
        cursor.descendToKey(toKey(key));
        return cursor;
    }

    @DoNotMutate
    @Override
    void checkInvariants() {
        super.checkInvariants();
        bTree.checkInvariants();
    }

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

    @Override
    public void close() {
        bTree.close();
    }

    public static class Mutable extends ByteShortBTreeMap implements MutableByteShortBufferMap {
        Mutable(LargeByteBufferAllocator allocator, BTreeConfig config) {
            super(allocator, config);
        }

        @Override
        public void put(byte key, short value) {
            long k = toKey(key);
            long v = toValue(value);
            try (BTree.Cursor cursor = bTree.allocateCursor()) {
                cursor.descendToKey(k);
                if (cursor.elementFound()) {
                    cursor.setValue(v);
                } else {
                    cursor.simpleInsert(k, v);
                    cursor.balance();
                    size++;
                }
            }
        }

        @Override
        public void putAll(ByteShortMap map) {
            map.forEachKeyValue(this::put);
        }

        @Override
        public void updateValues(ByteShortToShortFunction function) {
            try (BTree.Cursor cursor = bTree.allocateCursor()) {
                cursor.descendToStart();
                while (cursor.next()) {
                    short updated = function.valueOf(fromKey(cursor.getKey()), fromValue(cursor.getValue()));
                    cursor.setValue(toValue(updated));
                }
            }
        }

        @Override
        public void removeKey(byte key) {
            long k = toKey(key);
            try (BTree.Cursor cursor = bTree.allocateCursor()) {
                cursor.descendToKey(k);
                if (cursor.elementFound()) {
                    cursor.simpleRemove();
                    cursor.balance();
                    size--;
                }
            }
        }

        @Override
        public void remove(byte key) {
            removeKey(key);
        }

        @Override
        public short removeKeyIfAbsent(byte key, short value) {
            long k = toKey(key);
            try (BTree.Cursor cursor = bTree.allocateCursor()) {
                cursor.descendToKey(k);
                if (cursor.elementFound()) {
                    short v = fromValue(cursor.getValue());
                    cursor.simpleRemove();
                    cursor.balance();
                    size--;
                    return v;
                } else {
                    return value;
                }
            }
        }

        @Override
        public short getIfAbsentPut(byte key, short value) {
            long k = toKey(key);
            try (BTree.Cursor cursor = bTree.allocateCursor()) {
                cursor.descendToKey(k);
                if (cursor.elementFound()) {
                    return fromValue(cursor.getValue());
                } else {
                    cursor.simpleInsert(k, toValue(value));
                    cursor.balance();
                    size++;
                    return value;
                }
            }
        }

        @Override
        public short getIfAbsentPut(byte key, ShortFunction0 function) {
            long k = toKey(key);
            try (BTree.Cursor cursor = bTree.allocateCursor()) {
                cursor.descendToKey(k);
                if (cursor.elementFound()) {
                    return fromValue(cursor.getValue());
                } else {
                    short v = function.value();
                    cursor.simpleInsert(k, toValue(v));
                    cursor.balance();
                    size++;
                    return v;
                }
            }
        }

        @Override
        public short getIfAbsentPutWithKey(byte key, ByteToShortFunction function) {
            long k = toKey(key);
            try (BTree.Cursor cursor = bTree.allocateCursor()) {
                cursor.descendToKey(k);
                if (cursor.elementFound()) {
                    return fromValue(cursor.getValue());
                } else {
                    short v = function.valueOf(key);
                    cursor.simpleInsert(k, toValue(v));
                    cursor.balance();
                    size++;
                    return v;
                }
            }
        }

        @Override
        public <P> short getIfAbsentPutWith(byte key, ShortFunction<? super P> function, P parameter) {
            long k = toKey(key);
            try (BTree.Cursor cursor = bTree.allocateCursor()) {
                cursor.descendToKey(k);
                if (cursor.elementFound()) {
                    return fromValue(cursor.getValue());
                } else {
                    short v = function.shortValueOf(parameter);
                    cursor.simpleInsert(k, toValue(v));
                    cursor.balance();
                    size++;
                    return v;
                }
            }
        }

        @Override
        public short updateValue(byte key, short initialValueIfAbsent, ShortToShortFunction function) {
            long k = toKey(key);
            try (BTree.Cursor cursor = bTree.allocateCursor()) {
                cursor.descendToKey(k);
                if (cursor.elementFound()) {
                    short updated = function.valueOf(fromValue(cursor.getValue()));
                    cursor.setValue(toValue(updated));
                    return updated;
                } else {
                    short updated = function.valueOf(initialValueIfAbsent);
                    cursor.simpleInsert(k, toValue(updated));
                    cursor.balance();
                    size++;
                    return updated;
                }
            }
        }

        @Override
        public MutableByteShortMap withKeyValue(byte key, short value) {
            put(key, value);
            return this;
        }

        @Override
        public MutableByteShortMap withoutKey(byte key) {
            removeKey(key);
            return this;
        }

        @Override
        public MutableByteShortMap withoutAllKeys(ByteIterable keys) {
            keys.forEach(this::removeKey);
            return this;
        }

        @Override
        public MutableByteShortMap asUnmodifiable() {
            throw new UnsupportedOperationException("Mutable.asUnmodifiable not implemented yet");
        }

        @Override
        public MutableByteShortMap asSynchronized() {
            throw new UnsupportedOperationException("Mutable.asSynchronized not implemented yet");
        }

        @Override
        public short addToValue(byte key, short toBeAdded) {
            long k = toKey(key);
            try (BTree.Cursor cursor = bTree.allocateCursor()) {
                cursor.descendToKey(k);
                if (cursor.elementFound()) {
                    short updated = (short) (fromValue(cursor.getValue()) + toBeAdded);
                    cursor.setValue(toValue(updated));
                    return updated;
                } else {
                    cursor.simpleInsert(k, toValue(toBeAdded));
                    cursor.balance();
                    size++;
                    return toBeAdded;
                }
            }
        }

        @Override
        public void clear() {
            bTree.clear();
            size = 0;
        }

        @Override
        public MutableShortByteMap flipUniqueValues() {
            throw new UnsupportedOperationException("ByteShortBufferMap.Mutable.flipUniqueValues not implemented yet");
        }

        @Override
        public MutableByteShortMap select(ByteShortPredicate predicate) {
            throw new UnsupportedOperationException("ByteShortBufferMap.Mutable.select not implemented yet");
        }

        @Override
        public MutableShortBag select(ShortPredicate predicate) {
            throw new UnsupportedOperationException("ByteShortBufferMap.Mutable.select not implemented yet");
        }

        @Override
        public MutableByteShortMap reject(ByteShortPredicate predicate) {
            throw new UnsupportedOperationException("ByteShortBufferMap.Mutable.reject not implemented yet");
        }

        @Override
        public MutableShortBag reject(ShortPredicate predicate) {
            throw new UnsupportedOperationException("ByteShortBufferMap.Mutable.reject not implemented yet");
        }

        @Override
        public <V> MutableBag<V> collect(ShortToObjectFunction<? extends V> function) {
            throw new UnsupportedOperationException("ByteShortBufferMap.Mutable.collect not implemented yet");
        }

        @Override
        public MutableShortIterator shortIterator() {
            return super.shortIterator();
        }
    }
}