#! /usr/bin/env bash
set -e -u
# -----------------------------------------------------------------------------
#
# xad.git
if [ ! -e xad.git ]
then
   git clone https://github.com/auto-differentiation/xad.git xad.git
fi
cd xad.git
#
# xad.git/build
if [ ! -e build ]
then
   mkdir build
fi
cd build
#
# xad.git/build/CMakeCache.txt
if [ -e CMakeCache.txt ]
then
   rm CMakeCache.txt
fi
#
# prefix
prefix=$(pwd)/prefix
#
#
# xad.git/build/cmake.out
# run cmake and put stdout and stderr in cmake.out
cmake -D CMAKE_INSTALL_PREFIX="$prefix" .. >& cmake.out
#
# xad.git/build/install.out
# run make install and stdout and stderr in install.out
make install >& install.out
#
# library_list
# find all the static libraries that have been installed
library_list=$(find $prefix -name '*.a')
echo "library_list = $library_list"
#
# xad.git/build/my_test.cpp
# creagte my_test.cpp, a simple program that uses xad
cat << EOF > my_test.cpp

# include <iostream>
# include <XAD/XAD.hpp>

template <class T>
T f(const T& x0)
{ return x0 * x0; }

int main()
{
    // input values
    double x0 = 2.0;

    // tape and active data type for 1st order adjoint computation
    typedef xad::adj<double> mode;
    typedef mode::tape_type tape_type;
    typedef mode::active_type AD;

    // initialize tape
    tape_type tape;

    // set independent variables
    AD x0_ad = x0;

    // and register them
    tape.registerInput(x0_ad);

    // start recording derivatives
    tape.newRecording();

    AD y = f(x0_ad);

    // register and seed adjoint of output
    tape.registerOutput(y);
    derivative(y) = 1.0;

    // compute all other adjoints
    tape.computeAdjoints();

    // output results
    std::cout << "y = " << value(y) << "\n"
              << "\nfirst order derivatives:\n"
              << "dy/dx0 = " << derivative(x0_ad) << "\n";
}
EOF
#
# xad.git/build/my_test.out
# attempt to compile and link the program above
if ! g++ \
   -g \
   -I $prefix/include \
   $library_list \
   -o my_test \
   my_test.cpp  >& my_test.out
then
   head my_test.out
   echo 'my_test.sh: Error'
   exit 1
fi
./my_test
echo 'my_test.sh: OK'