/**
 * Copyright 2017-2023 by XGBoost contributors
 */
#include <gtest/gtest.h>
#include <xgboost/context.h>
#include <xgboost/json.h>
#include <xgboost/objective.h>

#include "../../../src/common/linalg_op.h"  // for begin, end
#include "../../../src/objective/adaptive.h"
#include "../../../src/tree/param.h"        // for TrainParam
#include "../helpers.h"
#include "xgboost/base.h"
#include "xgboost/data.h"
#include "xgboost/linalg.h"

#include "test_regression_obj.h"

namespace xgboost {

void TestLinearRegressionGPair(const Context* ctx) {
  std::string obj_name = "reg:squarederror";

  std::vector<std::pair<std::string, std::string>> args;
  std::unique_ptr<ObjFunction> obj{ObjFunction::Create(obj_name, ctx)};

  obj->Configure(args);
  CheckObjFunction(obj,
                   {0, 0.1f, 0.9f,   1,    0,  0.1f, 0.9f,  1},
                   {0,   0,   0,   0,    1,    1,    1, 1},
                   {1,   1,   1,   1,    1,    1,    1, 1},
                   {0, 0.1f, 0.9f, 1.0f, -1.0f, -0.9f, -0.1f, 0},
                   {1,   1,   1,   1,    1,    1,    1, 1});
  CheckObjFunction(obj,
                   {0, 0.1f, 0.9f,   1,    0,  0.1f, 0.9f,  1},
                   {0,   0,   0,   0,    1,    1,    1, 1},
                   {},  // empty weight
                   {0, 0.1f, 0.9f, 1.0f, -1.0f, -0.9f, -0.1f, 0},
                   {1,   1,   1,   1,    1,    1,    1, 1});
  ASSERT_NO_THROW(obj->DefaultEvalMetric());
}

void TestSquaredLog(const Context* ctx) {
  std::string obj_name = "reg:squaredlogerror";
  std::vector<std::pair<std::string, std::string>> args;

  std::unique_ptr<ObjFunction> obj{ObjFunction::Create(obj_name, ctx)};
  obj->Configure(args);
  CheckConfigReload(obj, obj_name);

  CheckObjFunction(obj,
                   {0.1f, 0.2f, 0.4f, 0.8f, 1.6f},  // pred
                   {1.0f, 1.0f, 1.0f, 1.0f, 1.0f},  // labels
                   {1.0f, 1.0f, 1.0f, 1.0f, 1.0f},  // weights
                   {-0.5435f, -0.4257f, -0.25475f, -0.05855f, 0.1009f},
                   { 1.3205f,  1.0492f,  0.69215f,  0.34115f, 0.1091f});
  CheckObjFunction(obj,
                   {0.1f, 0.2f, 0.4f, 0.8f, 1.6f},  // pred
                   {1.0f, 1.0f, 1.0f, 1.0f, 1.0f},  // labels
                   {},                              // empty weights
                   {-0.5435f, -0.4257f, -0.25475f, -0.05855f, 0.1009f},
                   { 1.3205f,  1.0492f,  0.69215f,  0.34115f, 0.1091f});
  ASSERT_EQ(obj->DefaultEvalMetric(), std::string{"rmsle"});
}

void TestLogisticRegressionGPair(const Context* ctx) {
  std::string obj_name = "reg:logistic";
  std::vector<std::pair<std::string, std::string>> args;
  std::unique_ptr<ObjFunction> obj{ObjFunction::Create(obj_name, ctx)};

  obj->Configure(args);
  CheckConfigReload(obj, obj_name);

  CheckObjFunction(obj,
                   {   0,  0.1f,  0.9f,    1,    0,   0.1f,  0.9f,      1}, // preds
                   {   0,    0,    0,    0,    1,     1,     1,     1}, // labels
                   {   1,    1,    1,    1,    1,     1,     1,     1}, // weights
                   { 0.5f, 0.52f, 0.71f, 0.73f, -0.5f, -0.47f, -0.28f, -0.26f}, // out_grad
                   {0.25f, 0.24f, 0.20f, 0.19f, 0.25f,  0.24f,  0.20f,  0.19f}); // out_hess
}

void TestLogisticRegressionBasic(const Context* ctx) {
  std::string obj_name = "reg:logistic";
  std::vector<std::pair<std::string, std::string>> args;
  std::unique_ptr<ObjFunction> obj{ObjFunction::Create(obj_name, ctx)};

  obj->Configure(args);
  CheckConfigReload(obj, obj_name);

  // test label validation
  EXPECT_ANY_THROW(CheckObjFunction(obj, {0}, {10}, {1}, {0}, {0}))
    << "Expected error when label not in range [0,1f] for LogisticRegression";

  // test ProbToMargin
  EXPECT_NEAR(obj->ProbToMargin(0.1f), -2.197f, 0.01f);
  EXPECT_NEAR(obj->ProbToMargin(0.5f), 0, 0.01f);
  EXPECT_NEAR(obj->ProbToMargin(0.9f), 2.197f, 0.01f);
  EXPECT_ANY_THROW((void)obj->ProbToMargin(10))
      << "Expected error when base_score not in range [0,1f] for LogisticRegression";

  // test PredTransform
  HostDeviceVector<bst_float> io_preds = {0, 0.1f, 0.5f, 0.9f, 1};
  std::vector<bst_float> out_preds = {0.5f, 0.524f, 0.622f, 0.710f, 0.731f};
  obj->PredTransform(&io_preds);
  auto& preds = io_preds.HostVector();
  for (int i = 0; i < static_cast<int>(io_preds.Size()); ++i) {
    EXPECT_NEAR(preds[i], out_preds[i], 0.01f);
  }
}

void TestsLogisticRawGPair(const Context* ctx) {
  std::string obj_name = "binary:logitraw";
  std::vector<std::pair<std::string, std::string>> args;
  std::unique_ptr<ObjFunction>  obj {ObjFunction::Create(obj_name, ctx)};
  obj->Configure(args);

  CheckObjFunction(obj,
                   {   0,  0.1f,  0.9f,    1,    0,   0.1f,   0.9f,     1},
                   {   0,    0,    0,    0,    1,     1,     1,     1},
                   {   1,    1,    1,    1,    1,     1,     1,     1},
                   { 0.5f, 0.52f, 0.71f, 0.73f, -0.5f, -0.47f, -0.28f, -0.26f},
                   {0.25f, 0.24f, 0.20f, 0.19f, 0.25f,  0.24f,  0.20f,  0.19f});
}

}  // namespace xgboost