/*
 * Created on 10 nov 2009
 */

package interpreter.api;

import java.io.PrintStream;

public class ExecutionFrame
{
   public final ExecutionThread thread;
   public BytecodeMethod        method;
   public final String[]        instructions;

   public ExecutionFrame(BytecodeMethod method, ExecutionThread thread, int stacksize)
   {
      this(method, thread, new String[0], 0, stacksize);
   }

   public ExecutionFrame(BytecodeMethod method, ExecutionThread thread, String[] instructions, int localCount, int stackSize)
   {
      this.method = method;
      this.thread = thread;
      this.instructions = instructions;

      this.thread.pushFrame(this);

      this.iStack = new int[stackSize];
      this.iLocal = new int[localCount];
   }

   //

   public void print(PrintStream out, String name)
   {
      out.println("----frame[" + name + "]---");
      for (int i = 0; i < this.pStack; i++)
         out.println(" stack[" + i + "]=" + this.iStack[i]);
      for (int i = 0; i < this.iLocal.length; i++)
         out.println(" local[" + i + "]=" + this.iLocal[i]);
      out.println("----");
   }

   public int instructionPointer;

   public final void $goto(int offset)
   {
      this.instructionPointer = offset;
   }

   //

   private final int[] iStack;
   private final int[] iLocal;
   private int         pStack;

   public int stackSize()
   {
      return this.pStack;
   }

   //

   public void pushInt(int val)
   {
      this.iStack[this.pStack++] = val;
   }

   public int popInt()
   {
      return this.iStack[--this.pStack];
   }

   //

   public void pushLong(long val)
   {
      int lo = (int) ((val >> 0 * 32) & 0xFFFFFFFFL);
      int hi = (int) ((val >> 1 * 32) & 0xFFFFFFFFL);
      this.pushInt(lo);
      this.pushInt(hi);
   }

   public long popLong()
   {
      int lo = this.popInt();
      int hi = this.popInt();
      return (((long) hi) << 32) | lo;
   }

   //

   public void pushFloat(float val)
   {
      this.pushInt(Float.floatToRawIntBits(val));
   }

   public float popFloat()
   {
      return Float.intBitsToFloat(this.popInt());
   }

   //

   public void pushDouble(double val)
   {
      this.pushLong(Double.doubleToRawLongBits(val));
   }

   public double popDouble()
   {
      return Double.longBitsToDouble(this.popLong());
   }

   //

   public void pushReference(int pntr)
   {
      this.pushInt(pntr);
   }

   public int popReference()
   {
      return this.popInt();
   }

   // LOCAL

   public void storeInt(int offset, int val)
   {
      this.iLocal[offset] = val;
   }

   public int loadInt(int offset)
   {
      return this.iLocal[offset];
   }

   //

   public void storeLong(int offset, long val)
   {
      if ((offset & 1) != 0)
         throw new IllegalStateException("misaligned long");
      int lo = (int) ((val >> 0 * 32) & 0xFFFFFFFFL);
      int hi = (int) ((val >> 1 * 32) & 0xFFFFFFFFL);
      this.storeInt(offset + 0, lo);
      this.storeInt(offset + 1, hi);
   }

   public long loadLong(int offset)
   {
      if ((offset & 1) != 0)
         throw new IllegalStateException("misaligned long");
      int lo = this.loadInt(offset + 0);
      int hi = this.loadInt(offset + 1);
      return (((long) hi) << 32L) | lo;
   }

   //

   public void storeFloat(int offset, float val)
   {
      this.storeInt(offset, Float.floatToRawIntBits(val));
   }

   public float loadFloat(int offset)
   {
      return Float.intBitsToFloat(this.loadInt(offset));
   }

   //

   public void storeDouble(int offset, double val)
   {
      if ((offset & 1) != 0)
         throw new IllegalStateException("misaligned double");
      this.storeLong(offset, Double.doubleToRawLongBits(val));
   }

   public double loadDouble(int offset)
   {
      if ((offset & 1) != 0)
         throw new IllegalStateException("misaligned double");
      return Double.longBitsToDouble(this.loadLong(offset));
   }

   //

   public void storeReference(int offset, int val)
   {
      this.storeInt(offset, val);
   }

   public int loadReference(int offset)
   {
      return this.loadInt(offset);
   }

   //

   public String toString()
   {
      if (this.method == null)
         return "custom-frame";
      return this.method.toIdentifier();
   }
}