Created StatListWriter and tests

Additional testing required, but workable code

core/src/com/riiablo/attributes/StatListWriter.java

@@ -0,0 +1,56 @@
+package com.riiablo.attributes;
+
+import java.util.Iterator;
+
+import com.riiablo.codec.excel.ItemStatCost;
+import com.riiablo.io.BitOutput;
+import com.riiablo.logger.LogManager;
+import com.riiablo.logger.Logger;
+import com.riiablo.logger.MDC;
+
+public class StatListWriter {
+  private static final Logger log = LogManager.getLogger(StatListWriter.class);
+
+  public void write(StatListGetter stats, StatGetter stat, BitOutput bits) {
+    log.traceEntry("write(stats: {}, stat: {}, bits: {})", stats, stat, bits);
+    final ItemStatCost.Entry entry = stat.entry();
+    if (entry.Saved) {
+      if (log.traceEnabled()) log.trace("Writing character save stat {}", stat.debugString());
+      assert !entry.CSvSigned : "entry.CSvSigned(" + entry.CSvSigned + ") unsupported";
+      bits.write63u(stat.param(), entry.CSvParam);
+      bits.write63u(stat.value(), entry.CSvBits);
+    } else {
+      if (log.traceEnabled()) log.trace("Writing stat {}", stat.debugString());
+      bits.write63u(stat.param(), entry.Save_Param_Bits);
+      bits.write63u(stat.value() + entry.Save_Add, entry.Save_Bits);
+    }
+  }
+
+  public void write(StatListGetter stats, BitOutput bits) {
+    for (Iterator<StatGetter> it = stats.iterator(); it.hasNext();) {
+      final StatGetter stat = it.next();
+      final short id = stat.id();
+      try {
+        MDC.put("stat", id);
+        bits.write15u(id, Stat.BITS);
+        final byte numEncoded = Stat.getNumEncoded(id);
+        try {
+          if (numEncoded > 1) MDC.put("numEncoded", numEncoded);
+          write(stats, stat, bits);
+          for (short j = 1; j < numEncoded; j++) {
+            final StatGetter next = it.next();
+            assert next.id() == id + j : String.format(
+                "it.next(%s) != %d : getNumEncoded(%s)[%d..%d]", next, id + j, id + j, id, id + numEncoded - 1);
+            write(stats, stat, bits);
+          }
+        } finally {
+          MDC.remove("numEncoded");
+        }
+      } finally {
+        MDC.remove("stat");
+      }
+    }
+
+    bits.write15u(Stat.NONE, Stat.BITS);
+  }
+}

core/test/com/riiablo/attributes/StatListWriterTest.java

@@ -0,0 +1,69 @@
+package com.riiablo.attributes;
+
+import io.netty.buffer.ByteBufUtil;
+import io.netty.buffer.Unpooled;
+import org.junit.AfterClass;
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import com.badlogic.gdx.ApplicationAdapter;
+import com.badlogic.gdx.Gdx;
+import com.badlogic.gdx.backends.headless.HeadlessApplication;
+
+import com.riiablo.Files;
+import com.riiablo.Riiablo;
+import com.riiablo.codec.StringTBLs;
+import com.riiablo.io.BitInput;
+import com.riiablo.io.BitOutput;
+import com.riiablo.io.ByteInput;
+import com.riiablo.io.ByteOutput;
+import com.riiablo.logger.Level;
+import com.riiablo.logger.LogManager;
+import com.riiablo.mpq.MPQFileHandleResolver;
+
+public class StatListWriterTest {
+  @BeforeClass
+  public static void setup() {
+    Gdx.app = new HeadlessApplication(new ApplicationAdapter() {});
+    Riiablo.home = Gdx.files.absolute("C:\\Program Files (x86)\\Steam\\steamapps\\common\\Diablo II");
+    Riiablo.mpqs = new MPQFileHandleResolver();
+    Riiablo.string = new StringTBLs(Riiablo.mpqs);
+    Riiablo.files = new Files();
+  }
+
+  @AfterClass
+  public static void teardown() {
+    Gdx.app.exit();
+  }
+
+  @BeforeClass
+  public static void before() {
+    LogManager.setLevel("com.riiablo.attributes", Level.TRACE);
+  }
+
+  private void testItem(byte[] data, long bitsToSkip, int length) {
+    final int offset = (int) (bitsToSkip >> 3);
+    final int bitOffset = (int) (bitsToSkip & 0x7);
+    ByteInput in = ByteInput.wrap(Unpooled.wrappedBuffer(data, offset, length));
+    BitInput bitInput = in.unalign().skipBits(bitOffset);
+    StatListReader reader = new StatListReader();
+    final StatListGetter stats = reader.read(StatList.obtain().buildList(), bitInput);
+    System.out.println(ByteBufUtil.prettyHexDump(in.buffer(), 0, in.buffer().readerIndex()));
+
+    ByteOutput out = ByteOutput.wrap(Unpooled.buffer(length, length));
+    BitOutput bitOutput = out.unalign().writeRaw(data[offset], bitOffset);
+    System.out.println(ByteBufUtil.prettyHexDump(out.buffer()));
+    StatListWriter writer = new StatListWriter();
+    writer.write(stats, bitOutput);
+    bitOutput.flush();
+    System.out.println(ByteBufUtil.prettyHexDump(out.buffer()));
+
+    Assert.assertTrue(ByteBufUtil.equals(in.buffer(), 0, out.buffer(), 0, in.buffer().readerIndex()));
+  }
+
+  @Test
+  public void read_item_grief_stats() {
+    testItem(Gdx.files.internal("test/Grief.d2i").readBytes(), 197, 0x12);
+  }
+}