package fr.lifl.stc.stan.dsl;

import org.apache.bcel.generic.ObjectType;
import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.generic.Type;
import org.apache.bcel.classfile.Method;

class FlowSpecialType extends Type
{
    public static final FlowSpecialType IO = new FlowSpecialType((byte)1337, "IO");
    public static final FlowSpecialType STATIC = new FlowSpecialType((byte)123, "STATIC");
    public static final FlowSpecialType EXCEPTION = new FlowSpecialType((byte)542, "EXCEPTION");

    protected FlowSpecialType(byte x, String name)
    {
        super(x, name);
    }
}


public class Flow
{
    public int src, dst, link;
    public Type srcType, dstType;
    
    private Method m;
    private JavaClass c;

    /* Flow endpoints */
    public final static int FLOW_R = 0;
    public final static int FLOW_E = 1;
    public final static int FLOW_S = 2;
    public final static int FLOW_F = 3;
    public final static int FLOW_THIS = 4;

    /*
     * bit	            7	6	5	4	3	2	1	0
     * entity a (from)	S	S	p	p	S	S	p	p
     * entity b (to)	S	p	S	p	S	p	S	p
     * type of link  	V	V	V	V	R	R	R	R
     */
    public final static int RPP = 1;
    public final static int RPS = 2;
    public final static int RSP = 4;
    public final static int RSS = 8;
    public final static int VPP = 16;
    public final static int VPS = 32;
    public final static int VSP = 64;
    public final static int VSS = 128;

    
    public Flow(JavaClass c, Method m, int src, int dst, int link)
    {
        this.src = src;
        this.dst = dst;
        this.m = m;
        this.c = c;
        this.link = link;

        this.srcType = codeToType(src);
        this.dstType = codeToType(dst);

        //System.out.println(srcType + "<->" + dstType);
    }

    private Type codeToType(int code)
    {
        switch (code)
		{
			case FLOW_E:
                return FlowSpecialType.EXCEPTION;
			case FLOW_S:
                return FlowSpecialType.STATIC;
			case FLOW_F:
                return FlowSpecialType.IO;
			case FLOW_R:
				return m.getReturnType();
			case FLOW_THIS:
				return new ObjectType(this.c.getClassName());
			default:
                if ( (code-5) <= m.getArgumentTypes().length )
                    return this.m.getArgumentTypes()[code-5];
                else
                {
                    System.out.println("IMPLEMENTTTTTT");
                    return new ObjectType("null");
                }
		}
    }

    private String pos2Str(int pos)
    {
        switch (pos)
		{
			case FLOW_E:
                return "Exception";
			case FLOW_S:
                return "Static";
			case FLOW_F:
                return "I/O";
			case FLOW_R:
				return "Return";
			case FLOW_THIS:
				return "This";
			default:
				return "Argument #" + (pos-5);
		}

    }
    
    public String toString()
    {
        return srcType + "(" + pos2Str(src) + ") -> " + dstType + "(" + pos2Str(dst) + ")";
    }
    
}