////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2016-2022 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Octave is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <cinttypes>
#include <cmath>

#include <limits>
#include <sstream>

#include "lo-array-errwarn.h"
#include "lo-error.h"

namespace octave
{
  // Text constants used to shorten code below.

  static const char *error_id_nonconformant_args
    = "Octave:nonconformant-args";

  static const char *error_id_index_out_of_bounds
    = "Octave:index-out-of-bounds";

  static const char *error_id_invalid_index = "Octave:invalid-index";

  static const char *warning_id_nearly_singular_matrix
    = "Octave:nearly-singular-matrix";

  static const char *warning_id_singular_matrix = "Octave:singular-matrix";

  void
  err_nan_to_logical_conversion (void)
  {
    (*current_liboctave_error_handler)
      ("invalid conversion from NaN to logical");
  }

  void
  err_nan_to_character_conversion (void)
  {
    (*current_liboctave_error_handler)
      ("invalid conversion from NaN to character");
  }

  void
  err_nonconformant (const char *op,
                     octave_idx_type op1_len, octave_idx_type op2_len)
  {
    const char *err_id = error_id_nonconformant_args;

    (*current_liboctave_error_with_id_handler)
      (err_id, "%s: nonconformant arguments (op1 len: %" OCTAVE_IDX_TYPE_FORMAT
       ", op2 len: % " OCTAVE_IDX_TYPE_FORMAT ")",
       op, op1_len, op2_len);
  }

  void
  err_nonconformant (const char *op,
                     octave_idx_type op1_nr, octave_idx_type op1_nc,
                     octave_idx_type op2_nr, octave_idx_type op2_nc)
  {
    const char *err_id = error_id_nonconformant_args;

    (*current_liboctave_error_with_id_handler)
      (err_id, "%s: nonconformant arguments "
       "(op1 is %" OCTAVE_IDX_TYPE_FORMAT "x%" OCTAVE_IDX_TYPE_FORMAT ", "
       "op2 is %" OCTAVE_IDX_TYPE_FORMAT"x%" OCTAVE_IDX_TYPE_FORMAT ")",
       op, op1_nr, op1_nc, op2_nr, op2_nc);
  }

  void
  err_nonconformant (const char *op,
                     const dim_vector& op1_dims, const dim_vector& op2_dims)
  {
    const char *err_id = error_id_nonconformant_args;

    std::string op1_dims_str = op1_dims.str ();
    std::string op2_dims_str = op2_dims.str ();

    (*current_liboctave_error_with_id_handler)
      (err_id, "%s: nonconformant arguments (op1 is %s, op2 is %s)",
       op, op1_dims_str.c_str (), op2_dims_str.c_str ());
  }

  void
  err_del_index_out_of_range (bool is1d, octave_idx_type idx,
                              octave_idx_type ext)
  {
    const char *err_id = error_id_index_out_of_bounds;

    (*current_liboctave_error_with_id_handler)
      (err_id, "A(%s) = []: index out of bounds: value %" OCTAVE_IDX_TYPE_FORMAT
       " out of bound %" OCTAVE_IDX_TYPE_FORMAT,
       is1d ? "I" : "..,I,..", idx, ext);
  }

  // Show the expression that caused the error, e.g.,  "A(-1,_)",
  // "A(0+1i)", "A(_,3)".  Show how many indices come before/after the
  // offending one, e.g., (<error>), (<error>,_), or (_,<error>,...[x5]...)

  std::string
  index_exception::expression (void) const
  {
    std::ostringstream buf;

    if (m_var.empty () || m_var == "<unknown>")
      buf << "index ";
    else
      buf << m_var;

    bool show_parens = m_dim > 0;

    if (show_parens)
      {
        if (m_dim < 5)
          {
            buf << '(';

            for (octave_idx_type i = 1; i < m_dim; i++)
              buf << "_,";
          }
        else
          buf << "(...[x" << m_dim - 1 << "]...";
      }

    buf << m_index;

    if (show_parens)
      {
        if (m_nd - m_dim < 5)
          {
            for (octave_idx_type i = 0; i < m_nd - m_dim; i++)
              buf << ",_";

            if (m_nd >= m_dim)
              buf << ')';
          }
        else
          buf << "...[x" << m_nd - m_dim << "]...)";
      }

    return buf.str ();
  }

  class invalid_index : public index_exception
  {
  public:

    invalid_index (const std::string& value, octave_idx_type ndim,
                   octave_idx_type dimen)
      : index_exception (value, ndim, dimen)
    {
      // Virtual, but the one we want to call is defined in this class.
      update_message ();
    }

    void update_message (void)
    {
      static std::string exp
        = std::to_string (std::numeric_limits<octave_idx_type>::digits);

      set_message (expression ()
                   + ": subscripts must be either integers 1 to (2^" + exp
                   + ")-1 or logicals");
    }

    // ID of error to throw
    const char * err_id (void) const
    {
      return error_id_invalid_index;
    }
  };

  // Complain if an index is negative, fractional, or too big.

  void
  err_invalid_index (const std::string& idx, octave_idx_type nd,
                     octave_idx_type dim, const std::string&)
  {
    invalid_index e (idx, nd, dim);

    throw e;
  }

  void
  err_invalid_index (octave_idx_type n, octave_idx_type nd,
                     octave_idx_type dim, const std::string& var)
  {
    err_invalid_index (std::to_string (n + 1), nd, dim, var);
  }

  void
  err_invalid_index (double n, octave_idx_type nd, octave_idx_type dim,
                     const std::string& var)
  {
    std::ostringstream buf;
    buf << n + 1;

    if (! std::isnan (n))
      {
        // if  n  not an integer, but would be printed as one, show diff
        double nearest = std::floor (n + 1.5);
        if (n + 1 != nearest && (buf.str ().find ('.') == std::string::npos))
          buf << std::showpos << (n + 1 - nearest);
      }

    err_invalid_index (buf.str (), nd, dim, var);
  }

  // Complain for read access beyond the bounds of an array.

  class out_of_range : public index_exception
  {
  public:

    out_of_range (const std::string& value, octave_idx_type nd,
                  octave_idx_type dim, octave_idx_type ext,
                  const dim_vector& size)
      : index_exception (value, nd, dim), m_size (size), m_extent (ext)
    {
      // Virtual, but the one we want to call is defined in this class.
      update_message ();
    }

    void update_message (void)
    {
      set_message (expression () + ": out of bound "
                   + std::to_string (m_extent)
                   + " (dimensions are " + m_size.str ('x') + ")");
    }

    // ID of error to throw.
    const char * err_id (void) const
    {
      return error_id_index_out_of_bounds;
    }

  private:

    // Dimension of object being accessed.
    dim_vector m_size;

    // Length of dimension being accessed.
    octave_idx_type m_extent;
  };

  // Complain of an index that is out of range
  void
  err_index_out_of_range (int nd, int dim, octave_idx_type idx,
                          octave_idx_type ext, const dim_vector& dv)
  {
    throw out_of_range (std::to_string (idx), nd, dim, ext, dv);
  }

  void
  err_invalid_resize (void)
  {
    (*current_liboctave_error_with_id_handler)
      ("Octave:invalid-resize",
       "Invalid resizing operation or ambiguous assignment to an out-of-bounds array element");
  }

  void
  warn_singular_matrix (double rcond)
  {
    if (rcond == 0.0)
      {
        (*current_liboctave_warning_with_id_handler)
          (warning_id_singular_matrix,
           "matrix singular to machine precision");
      }
    else
      {
        (*current_liboctave_warning_with_id_handler)
          (warning_id_nearly_singular_matrix,
           "matrix singular to machine precision, rcond = %g", rcond);
      }
  }

  // DEPRECATED in Octave 6.

  // Complain of an index that is out of range, but we don't know matrix size
  void
  err_index_out_of_range (int nd, int dim, octave_idx_type idx,
                          octave_idx_type ext)
  {
    // The dim_vector setting here doesn't really make sense.  However,
    // this function has been deprecated and will be removed in version
    // 8, so there's no need to attempt to fix it.

    throw out_of_range (std::to_string (idx), nd, dim, ext,
                        dim_vector (1, 1, 1, 1, 1, 1, 1));
  }
}

/* Tests in test/index.tst */