// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2010, 2011, 2012 Google Inc. All rights reserved.
// http://code.google.com/p/ceres-solver/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
//   this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
//   this list of conditions and the following disclaimer in the documentation
//   and/or other materials provided with the distribution.
// * Neither the name of Google Inc. nor the names of its contributors may be
//   used to endorse or promote products derived from this software without
//   specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Author: sameeragarwal@google.com (Sameer Agarwal)

#include "ceres/residual_block_utils.h"

#include <cmath>
#include <cstddef>
#include <limits>
#include <glog/logging.h>
#include "ceres/residual_block.h"
#include "ceres/parameter_block.h"
#include "ceres/stringprintf.h"
#include "ceres/internal/eigen.h"
#include "ceres/internal/port.h"

namespace ceres {
namespace internal {

// It is a near impossibility that user code generates this exact
// value in normal operation, thus we will use it to fill arrays
// before passing them to user code. If on return an element of the
// array still contains this value, we will assume that the user code
// did not write to that memory location.
static const double kImpossibleValue = 1e302;

bool IsArrayValid(const int size, const double* x) {
  if (x != NULL) {
    for (int i = 0; i < size; ++i) {
      if (!isfinite(x[i]) || (x[i] == kImpossibleValue))  {
        return false;
      }
    }
  }
  return true;
}

void InvalidateArray(const int size, double* x) {
  if (x != NULL) {
    for (int i = 0; i < size; ++i) {
      x[i] = kImpossibleValue;
    }
  }
}

void InvalidateEvaluation(const ResidualBlock& block,
                          double* cost,
                          double* residuals,
                          double** jacobians) {
  const int num_parameter_blocks = block.NumParameterBlocks();
  const int num_residuals = block.NumResiduals();

  InvalidateArray(1, cost);
  InvalidateArray(num_residuals, residuals);
  if (jacobians != NULL) {
    for (int i = 0; i < num_parameter_blocks; ++i) {
      const int parameter_block_size = block.parameter_blocks()[i]->Size();
      InvalidateArray(num_residuals * parameter_block_size, jacobians[i]);
    }
  }
}

// Utility routine to print an array of doubles to a string. If the
// array pointer is NULL, it is treated as an array of zeros.
void AppendArrayToString(const int size, const double* x, string* result) {
  for (int i = 0; i < size; ++i) {
    if (x == NULL) {
      StringAppendF(result, "Not Computed  ");
    } else {
      if (x[i] == kImpossibleValue) {
        StringAppendF(result, "Uninitialized ");
      } else {
        StringAppendF(result, "%12g ", x[i]);
      }
    }
  }
}

string EvaluationToString(const ResidualBlock& block,
                          double const* const* parameters,
                          double* cost,
                          double* residuals,
                          double** jacobians) {
  CHECK_NOTNULL(cost);
  CHECK_NOTNULL(residuals);

  const int num_parameter_blocks = block.NumParameterBlocks();
  const int num_residuals = block.NumResiduals();
  string result = "";

  StringAppendF(&result,
                "Residual Block size: %d parameter blocks x %d residuals\n\n",
                num_parameter_blocks, num_residuals);
  result +=
      "For each parameter block, the value of the parameters are printed in the first column   \n"  // NOLINT
      "and the value of the jacobian under the corresponding residual. If a ParameterBlock was \n"  // NOLINT
      "held constant then the corresponding jacobian is printed as 'Not Computed'. If an entry \n"  // NOLINT
      "of the Jacobian/residual array was requested but was not written to by user code, it is \n"  // NOLINT
      "indicated by 'Uninitialized'. This is an error. Residuals or Jacobian values evaluating \n"  // NOLINT
      "to Inf or NaN is also an error.  \n\n"; // NOLINT

  string space = "Residuals:     ";
  result += space;
  AppendArrayToString(num_residuals, residuals, &result);
  StringAppendF(&result, "\n\n");

  for (int i = 0; i < num_parameter_blocks; ++i) {
    const int parameter_block_size = block.parameter_blocks()[i]->Size();
    StringAppendF(
        &result, "Parameter Block %d, size: %d\n", i, parameter_block_size);
    StringAppendF(&result, "\n");
    for (int j = 0; j < parameter_block_size; ++j) {
      AppendArrayToString(1, parameters[i] + j, &result);
      StringAppendF(&result, "| ");
      for (int k = 0; k < num_residuals; ++k) {
        AppendArrayToString(1,
                            (jacobians != NULL && jacobians[i] != NULL)
                            ? jacobians[i] + k * parameter_block_size + j
                            : NULL,
                            &result);
      }
      StringAppendF(&result, "\n");
    }
    StringAppendF(&result, "\n");
  }
  StringAppendF(&result, "\n");
  return result;
}

bool IsEvaluationValid(const ResidualBlock& block,
                       double const* const* parameters,
                       double* cost,
                       double* residuals,
                       double** jacobians) {
  const int num_parameter_blocks = block.NumParameterBlocks();
  const int num_residuals = block.NumResiduals();

  if (!IsArrayValid(num_residuals, residuals)) {
    return false;
  }

  if (jacobians != NULL) {
    for (int i = 0; i < num_parameter_blocks; ++i) {
      const int parameter_block_size = block.parameter_blocks()[i]->Size();
      if (!IsArrayValid(num_residuals * parameter_block_size, jacobians[i])) {
        return false;
      }
    }
  }

  return true;
}

}  // namespace internal
}  // namespace ceres