%global __brp_check_rpaths %{nil}
%global __requires_exclude ^libmpi
%global packname  LangevinFlow
%global packver   0.1.0
%global rlibdir   /usr/local/lib/R/library

Name:             R-CRAN-%{packname}
Version:          0.1.0
Release:          1%{?dist}%{?buildtag}
Summary:          Langevin Diffusion Samplers with a C++ Backend

License:          MIT + file LICENSE
URL:              https://cran.r-project.org/package=%{packname}
Source0:          %{url}&version=%{packver}#/%{packname}_%{packver}.tar.gz


BuildRequires:    R-devel >= 3.5.0
Requires:         R-core >= 3.5.0
BuildRequires:    R-CRAN-Rcpp >= 1.0.0
BuildRequires:    R-stats 
BuildRequires:    R-graphics 
BuildRequires:    R-CRAN-RcppArmadillo 
Requires:         R-CRAN-Rcpp >= 1.0.0
Requires:         R-stats 
Requires:         R-graphics 

%description
Provides lightweight, dependency-minimal implementations of Langevin
diffusion based Markov chain Monte Carlo samplers, including the
Unadjusted Langevin Algorithm (ULA) and the Metropolis-Adjusted Langevin
Algorithm (MALA). The core sampling loops are written in C++ via 'Rcpp'
and 'RcppArmadillo' for performance, while exposing a simple R-level
interface where the user supplies the gradient of the negative log-density
(and, for MALA, the negative log-density itself). Intended as a building
block for Bayesian inference and stochastic optimization rather than a
full probabilistic programming framework. Methods follow Roberts and
Tweedie (1996) <doi:10.2307/3318418> and Roberts and Rosenthal (1998)
<doi:10.1111/1467-9868.00123>.

%prep
%setup -q -c -n %{packname}

# fix end of executable files
find -type f -executable -exec grep -Iq . {} \; -exec sed -i -e '$a\' {} \;
# prevent binary stripping
[ -d %{packname}/src ] && find %{packname}/src -type f -exec \
  sed -i 's@/usr/bin/strip@/usr/bin/true@g' {} \; || true
[ -d %{packname}/src ] && find %{packname}/src/Make* -type f -exec \
  sed -i 's@-g0@@g' {} \; || true
# don't allow local prefix in executable scripts
find -type f -executable -exec sed -Ei 's@#!( )*/usr/local/bin@#!/usr/bin@g' {} \;

%build

%install

mkdir -p %{buildroot}%{rlibdir}
%{_bindir}/R CMD INSTALL -l %{buildroot}%{rlibdir} %{packname}
test -d %{packname}/src && (cd %{packname}/src; rm -f *.o *.so)
rm -f %{buildroot}%{rlibdir}/R.css
# remove buildroot from installed files
find %{buildroot}%{rlibdir} -type f -exec sed -i "s@%{buildroot}@@g" {} \;

%files
%{rlibdir}/%{packname}