// SPDX-License-Identifier: Apache-2.0
// 
// Copyright 2015 Conrad Sanderson (http://conradsanderson.id.au)
// Copyright 2015 National ICT Australia (NICTA)
// 
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ------------------------------------------------------------------------


#include <armadillo>
#include "catch.hpp"
#include "utils.hpp"

using namespace arma;


TEST_CASE("fn_interp1_1", "[interp1]")
  {
  mat A = 
    "\
     0.061198   0.201990   0.019678  -0.493936  -0.126745   0.051408;\
     0.437242   0.058956  -0.149362  -0.045465   0.296153   0.035437;\
    -0.492474  -0.031309   0.314156   0.419733   0.068317  -0.454499;\
     0.336352   0.411541   0.458476  -0.393139  -0.135040   0.373833;\
     0.239585  -0.428913  -0.406953  -0.291020  -0.353768   0.258704;\
    ";
  
  vec x = vectorise(A(0,0,size(5,3)));
  vec y = vectorise(A(0,3,size(5,3)));
  
  vec xi_a = linspace<vec>( x.min(), x.max(), 10 );
  vec xi_b = flipud( linspace<vec>( x.min(), x.max(), 11 ) );
  
  vec yi_a;
  vec yi_b;
  
  interp1(x, y, xi_a, yi_a);
  interp1(x, y, xi_b, yi_b);
  
  vec yi_a_gt = { 0.419733, 0.241248, 0.149666, 0.058084, 0.057588, 0.152062, -0.284524, -0.307613, -0.336627, 0.373833 };
  vec yi_b_gt = { 0.373833, -0.300357, -0.353940, -0.201854, -0.449865, 0.063571, 0.045817, 0.085559, 0.167982, 0.250406, 0.419733 };
  
  REQUIRE( accu(abs( yi_a - yi_a_gt )) == Approx(0.0).margin(0.001) );
  REQUIRE( accu(abs( yi_b - yi_b_gt )) == Approx(0.0).margin(0.001) );
  
  // REQUIRE_THROWS(  );
  }



TEMPLATE_TEST_CASE("fn_interp1_fp_randu", "[interp1]", TEST_FLOAT_TYPES)
  {
  typedef TestType eT;

  Col<eT> x = linspace<Col<eT>>(0, 1, 101);
  Col<eT> y = square(x);
  Col<eT> x2 = linspace<Col<eT>>(0, 2, 201);
  Col<eT> z1, z2, z3, z4;

  vec x_ref = conv_to<vec>::from(x);
  vec y_ref = conv_to<vec>::from(y);
  vec x2_ref = conv_to<vec>::from(x2);
  vec z1_ref, z2_ref, z3_ref, z4_ref;

  interp1(x, y, x2, z1, "nearest", eT(5));
  interp1(x, y, x2, z2, "linear", eT(5));
  interp1(x, y, x2, z3, "*nearest", eT(5));
  interp1(x, y, x2, z4, "*linear", eT(5));

  interp1(x_ref, y_ref, x2_ref, z1_ref, "nearest", 5.0);
  interp1(x_ref, y_ref, x2_ref, z2_ref, "linear", 5.0);
  interp1(x_ref, y_ref, x2_ref, z3_ref, "*nearest", 5.0);
  interp1(x_ref, y_ref, x2_ref, z4_ref, "*linear", 5.0);

  constexpr const eT margin = is_blas_real<eT>::value ? eT(0.001) : eT(0.1);

  REQUIRE( z1.n_elem == z1_ref.n_elem );
  REQUIRE( z2.n_elem == z2_ref.n_elem );
  REQUIRE( z3.n_elem == z3_ref.n_elem );
  REQUIRE( z4.n_elem == z4_ref.n_elem );

  for (uword i = 0; i < z1.n_elem; ++i)
    {
    REQUIRE( z1[i] == Approx(eT(z1_ref[i])).margin(margin) );
    REQUIRE( z2[i] == Approx(eT(z2_ref[i])).margin(margin) );
    REQUIRE( z3[i] == Approx(eT(z3_ref[i])).margin(margin) );
    REQUIRE( z4[i] == Approx(eT(z4_ref[i])).margin(margin) );
    }
  }
