package io.trygvis.btree;

import java.io.Closeable;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.Iterator;

public class BtreeFile implements Closeable {
    private final HeapFile heap;
    private final int keySize;
    private final int itemsPerPage;

    public BtreeFile(HeapFile heap, int keySize) throws IOException {
        this.heap = heap;
        this.keySize = keySize;
        itemsPerPage = heap.PAGE_SIZE / keySize;

        // Make sure we always have a page #0.
        if (heap.pageCount() == 0) {
            HeapPage root = heap.blankPage();
            heap.writePage(root);
        }
    }

    public void add(byte[] key, byte[] value) throws IOException {
        HeapPage page = heap.loadPage(0);

        ByteBuffer k = ByteBuffer.wrap(key);
        ByteBuffer current;
        ByteBuffer smaller;

        Iterator<ByteBuffer> it = page.items().iterator();

        int position = 0;

        while(it.hasNext()) {
            current = it.next();

            int diff = k.compareTo(current);

            if(diff < 0) {
                break;
            }
        }

//        page.prepend();
    }

    @Override
    public void close() throws IOException {
        heap.close();
    }

    public static class BtreeItem {
        private final byte[] from;
        private final int page;

        public BtreeItem(byte[] from, int page) {
            this.from = from;
            this.page = page;
        }
    }
}