/*************************************************************************************

Grid physics library, www.github.com/paboyle/Grid 

Source file: extras/Hadrons/Modules/MContraction/WeakHamiltonianEye.cc

Copyright (C) 2017

Author: Andrew Lawson    <andrew.lawson1991@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

See the full license in the file "LICENSE" in the top level distribution directory
*************************************************************************************/
/*  END LEGAL */

#include <Grid/Hadrons/Modules/MContraction/WeakHamiltonianEye.hpp>

using namespace Grid;
using namespace Hadrons;
using namespace MContraction;

/*
 * Weak Hamiltonian current-current contractions, Eye-type.
 * 
 * These contractions are generated by the Q1 and Q2 operators in the physical
 * basis (see e.g. Fig 3 of arXiv:1507.03094).
 * 
 * Schematics:        q4                 |                  
 *                  /-<-¬                |                             
 *                 /     \               |             q2           q3
 *                 \     /               |        /----<------*------<----¬                        
 *            q2    \   /    q3          |       /          /-*-¬          \
 *       /-----<-----* *-----<----¬      |      /          /     \          \
 *    i *            H_W           * f   |   i *           \     /  q4      * f
 *       \                        /      |      \           \->-/          /   
 *        \                      /       |       \                        /       
 *         \---------->---------/        |        \----------->----------/        
 *                   q1                  |                   q1                  
 *                                       |
 *                Saucer (S)             |                  Eye (E)
 * 
 * S: trace(q3*g5*q1*adj(q2)*g5*gL[mu][p_1]*q4*gL[mu][p_2])
 * E: trace(q3*g5*q1*adj(q2)*g5*gL[mu][p_1])*trace(q4*gL[mu][p_2])
 */

/******************************************************************************
 *                  TWeakHamiltonianEye implementation                        *
 ******************************************************************************/
// constructor /////////////////////////////////////////////////////////////////
TWeakHamiltonianEye::TWeakHamiltonianEye(const std::string name)
: Module<WeakHamiltonianPar>(name)
{}

// dependencies/products ///////////////////////////////////////////////////////
std::vector<std::string> TWeakHamiltonianEye::getInput(void)
{
    std::vector<std::string> in = {par().q1, par().q2, par().q3, par().q4};
    
    return in;
}

std::vector<std::string> TWeakHamiltonianEye::getOutput(void)
{
    std::vector<std::string> out = {getName()};
    
    return out;
}

// setup ///////////////////////////////////////////////////////////////////////
void TWeakHamiltonianEye::setup(void)
{

}

// execution ///////////////////////////////////////////////////////////////////
void TWeakHamiltonianEye::execute(void)
{

}