//
//  Copyright (C) 2004-2006 Rational Discovery LLC
//
//   @@ All Rights Reserved @@
//  This file is part of the RDKit.
//  The contents are covered by the terms of the BSD license
//  which is included in the file license.txt, found at the root
//  of the RDKit source tree.
//
#include <RDGeneral/export.h>
#ifndef __RD_MATRIX_H__
#define __RD_MATRIX_H__

#include <RDGeneral/Invariant.h>
#include "Vector.h"
#include <iostream>
#include <iomanip>
#include <cstring>
#include <boost/smart_ptr.hpp>

//#ifndef INVARIANT_SILENT_METHOD
//#define INVARIANT_SILENT_METHOD
//#endif

namespace RDNumeric {

//! A matrix class for general, non-square matrices
template <class TYPE>
class Matrix {
 public:
  typedef boost::shared_array<TYPE> DATA_SPTR;

  //! Initialize with a size.
  Matrix(unsigned int nRows, unsigned int nCols)
      : d_nRows(nRows), d_nCols(nCols), d_dataSize(nRows * nCols) {
    TYPE *data = new TYPE[d_dataSize];
    memset(static_cast<void *>(data), 0, d_dataSize * sizeof(TYPE));
    d_data.reset(data);
  }

  //! Initialize with a size and default value.
  Matrix(unsigned int nRows, unsigned int nCols, TYPE val)
      : d_nRows(nRows), d_nCols(nCols), d_dataSize(nRows * nCols) {
    TYPE *data = new TYPE[d_dataSize];
    unsigned int i;
    for (i = 0; i < d_dataSize; i++) {
      data[i] = val;
    }
    d_data.reset(data);
  }

  //! Initialize from a pointer.
  /*!
    <b>NOTE:</b> this does not take ownership of the data,
    if you delete the data externally, this Matrix will be sad.
  */
  Matrix(unsigned int nRows, unsigned int nCols, DATA_SPTR data)
      : d_nRows(nRows), d_nCols(nCols), d_dataSize(nRows * nCols) {
    d_data = data;
  }

  //! copy constructor
  /*! We make a copy of the other vector's data.
   */
  Matrix(const Matrix<TYPE> &other)
      : d_nRows(other.numRows()),
        d_nCols(other.numCols()),
        d_dataSize(d_nRows * d_nCols) {
    TYPE *data = new TYPE[d_dataSize];
    const TYPE *otherData = other.getData();
    memcpy(static_cast<void *>(data), static_cast<const void *>(otherData),
           d_dataSize * sizeof(TYPE));
    d_data.reset(data);
  }

  virtual ~Matrix() {}

  //! returns the number of rows
  inline unsigned int numRows() const { return d_nRows; }

  //! returns the number of columns
  inline unsigned int numCols() const { return d_nCols; }

  inline unsigned int getDataSize() const { return d_dataSize; }

  //! returns a particular element of the matrix
  inline virtual TYPE getVal(unsigned int i, unsigned int j) const {
    PRECONDITION(i < d_nRows, "bad index");
    PRECONDITION(j < d_nCols, "bad index");
    unsigned int id = i * d_nCols + j;
    return d_data[id];
  }

  //! sets a particular element of the matrix
  inline virtual void setVal(unsigned int i, unsigned int j, TYPE val) {
    PRECONDITION(i < d_nRows, "bad index");
    PRECONDITION(j < d_nCols, "bad index");
    unsigned int id = i * d_nCols + j;

    d_data[id] = val;
  }

  //! returns a copy of a row of the matrix
  inline virtual void getRow(unsigned int i, Vector<TYPE> &row) const {
    PRECONDITION(i < d_nRows, "bad index");
    PRECONDITION(d_nCols == row.size(), "");
    unsigned int id = i * d_nCols;
    TYPE *rData = row.getData();
    TYPE *data = d_data.get();
    memcpy(static_cast<void *>(rData), static_cast<void *>(&data[id]),
           d_nCols * sizeof(TYPE));
  }

  //! returns a copy of a column of the matrix
  inline virtual void getCol(unsigned int i, Vector<TYPE> &col) const {
    PRECONDITION(i < d_nCols, "bad index");
    PRECONDITION(d_nRows == col.size(), "");
    unsigned int j, id;
    TYPE *rData = col.getData();
    TYPE *data = d_data.get();
    for (j = 0; j < d_nRows; j++) {
      id = j * d_nCols + i;
      rData[j] = data[id];
    }
  }

  //! returns a pointer to our data array
  inline TYPE *getData() { return d_data.get(); }

  //! returns a const pointer to our data array
  inline const TYPE *getData() const { return d_data.get(); }

  //! Copy operator.
  /*! We make a copy of the other Matrix's data.
   */

  Matrix<TYPE> &assign(const Matrix<TYPE> &other) {
    PRECONDITION(d_nRows == other.numRows(),
                 "Num rows mismatch in matrix copying");
    PRECONDITION(d_nCols == other.numCols(),
                 "Num cols mismatch in matrix copying");
    const TYPE *otherData = other.getData();
    TYPE *data = d_data.get();
    memcpy(static_cast<void *>(data), static_cast<const void *>(otherData),
           d_dataSize * sizeof(TYPE));
    return *this;
  }

  //! Matrix addition.
  /*! Perform a element by element addition of other Matrix to this Matrix
   */
  virtual Matrix<TYPE> &operator+=(const Matrix<TYPE> &other) {
    PRECONDITION(d_nRows == other.numRows(),
                 "Num rows mismatch in matrix addition");
    PRECONDITION(d_nCols == other.numCols(),
                 "Num cols mismatch in matrix addition");
    const TYPE *oData = other.getData();
    unsigned int i;
    TYPE *data = d_data.get();
    for (i = 0; i < d_dataSize; i++) {
      data[i] += oData[i];
    }
    return *this;
  }

  //! Matrix subtraction.
  /*! Perform a element by element subtraction of other Matrix from this Matrix
   */
  virtual Matrix<TYPE> &operator-=(const Matrix<TYPE> &other) {
    PRECONDITION(d_nRows == other.numRows(),
                 "Num rows mismatch in matrix addition");
    PRECONDITION(d_nCols == other.numCols(),
                 "Num cols mismatch in matrix addition");
    const TYPE *oData = other.getData();
    unsigned int i;
    TYPE *data = d_data.get();
    for (i = 0; i < d_dataSize; i++) {
      data[i] -= oData[i];
    }
    return *this;
  }

  //! Multiplication by a scalar
  virtual Matrix<TYPE> &operator*=(TYPE scale) {
    unsigned int i;
    TYPE *data = d_data.get();
    for (i = 0; i < d_dataSize; i++) {
      data[i] *= scale;
    }
    return *this;
  }

  //! division by a scalar
  virtual Matrix<TYPE> &operator/=(TYPE scale) {
    unsigned int i;
    TYPE *data = d_data.get();
    for (i = 0; i < d_dataSize; i++) {
      data[i] /= scale;
    }
    return *this;
  }

  //! copies the transpose of this Matrix into another, returns the result
  /*!
    \param transpose the Matrix to store the results

    \return the transpose of this matrix.
       This is just a reference to the argument.

   */
  virtual Matrix<TYPE> &transpose(Matrix<TYPE> &transpose) const {
    unsigned int tRows = transpose.numRows();
    unsigned int tCols = transpose.numCols();
    PRECONDITION(d_nCols == tRows, "Size mismatch during transposing");
    PRECONDITION(d_nRows == tCols, "Size mismatch during transposing");
    unsigned int i, j;
    unsigned int idA, idAt, idT;
    TYPE *tData = transpose.getData();
    TYPE *data = d_data.get();
    for (i = 0; i < d_nRows; i++) {
      idA = i * d_nCols;
      for (j = 0; j < d_nCols; j++) {
        idAt = idA + j;
        idT = j * tCols + i;
        tData[idT] = data[idAt];
      }
    }
    return transpose;
  }

 protected:
  Matrix() : d_data() {}
  unsigned int d_nRows{0};
  unsigned int d_nCols{0};
  unsigned int d_dataSize{0};
  DATA_SPTR d_data;

 private:
  Matrix<TYPE> &operator=(const Matrix<TYPE> &other);
};

//! Matrix multiplication
/*!
  Multiply a Matrix A with a second Matrix B
  so the result is C = A*B

  \param A  the first Matrix used in the multiplication
  \param B  the Matrix by which to multiply
  \param C  Matrix to use for the results

  \return the results of multiplying A by B.
  This is just a reference to C.
*/
template <class TYPE>
Matrix<TYPE> &multiply(const Matrix<TYPE> &A, const Matrix<TYPE> &B,
                       Matrix<TYPE> &C) {
  unsigned int aRows = A.numRows();
  unsigned int aCols = A.numCols();
  unsigned int cRows = C.numRows();
  unsigned int cCols = C.numCols();
  unsigned int bRows = B.numRows();
  unsigned int bCols = B.numCols();
  CHECK_INVARIANT(aCols == bRows, "Size mismatch during multiplication");
  CHECK_INVARIANT(aRows == cRows, "Size mismatch during multiplication");
  CHECK_INVARIANT(bCols == cCols, "Size mismatch during multiplication");

  // we have the sizes check do do the multiplication
  TYPE *cData = C.getData();
  const TYPE *bData = B.getData();
  const TYPE *aData = A.getData();
  unsigned int i, j, k;
  unsigned int idA, idAt, idB, idC, idCt;
  for (i = 0; i < aRows; i++) {
    idC = i * cCols;
    idA = i * aCols;
    for (j = 0; j < cCols; j++) {
      idCt = idC + j;
      cData[idCt] = (TYPE)0.0;
      for (k = 0; k < aCols; k++) {
        idAt = idA + k;
        idB = k * bCols + j;
        cData[idCt] += (aData[idAt] * bData[idB]);
      }
    }
  }
  return C;
};

//! Matrix-Vector multiplication
/*!
  Multiply a Matrix A with a Vector x
  so the result is y = A*x

  \param A  the matrix used in the multiplication
  \param x  the Vector by which to multiply
  \param y  Vector to use for the results

  \return the results of multiplying x by this
  This is just a reference to y.
*/
template <class TYPE>
Vector<TYPE> &multiply(const Matrix<TYPE> &A, const Vector<TYPE> &x,
                       Vector<TYPE> &y) {
  unsigned int aRows = A.numRows();
  unsigned int aCols = A.numCols();
  unsigned int xSiz = x.size();
  unsigned int ySiz = y.size();
  CHECK_INVARIANT(aCols == xSiz, "Size mismatch during multiplication");
  CHECK_INVARIANT(aRows == ySiz, "Size mismatch during multiplication");
  unsigned int i, j;
  unsigned int idA, idAt;
  const TYPE *xData = x.getData();
  const TYPE *aData = A.getData();
  TYPE *yData = y.getData();
  for (i = 0; i < aRows; i++) {
    idA = i * aCols;
    yData[i] = (TYPE)(0.0);
    for (j = 0; j < aCols; j++) {
      idAt = idA + j;
      yData[i] += (aData[idAt] * xData[j]);
    }
  }
  return y;
};

typedef Matrix<double> DoubleMatrix;
};  // namespace RDNumeric

//! ostream operator for Matrix's
template <class TYPE>
std::ostream &operator<<(std::ostream &target,
                         const RDNumeric::Matrix<TYPE> &mat) {
  unsigned int nr = mat.numRows();
  unsigned int nc = mat.numCols();
  target << "Rows: " << mat.numRows() << " Columns: " << mat.numCols() << "\n";

  unsigned int i, j;
  for (i = 0; i < nr; i++) {
    for (j = 0; j < nc; j++) {
      target << std::setfill(' ') << std::setw(7) << std::setprecision(3)
             << mat.getVal(i, j) << " ";
    }
    target << "\n";
  }
  return target;
}

#endif