import type { DoubleMatrix } from 'cheminfo-types';

import type {
  DoubleArrayConstructor,
  DoubleArrayType,
} from '../utils/index.ts';

import { matrixCreateEmpty } from './matrixCreateEmpty.ts';
import { matrixMinMaxZ } from './matrixMinMaxZ.ts';

export interface MatrixZRescaleOptions<
  ArrayConstructorType extends DoubleArrayConstructor = Float64ArrayConstructor,
> {
  /**
   * min
   * @default 0
   */
  min?: number;

  /**
   * max
   * @default 1
   */
  max?: number;

  /**
   * Allows to specify the type of array to use.
   * @default Float64Array
   */
  ArrayConstructor?: ArrayConstructorType;
}

/**
 * Rescale a matrix between min and max values.
 * @param matrix - matrix [rows][cols].
 * @param options - Options.
 */
export function matrixZRescale<
  ArrayConstructorType extends DoubleArrayConstructor = Float64ArrayConstructor,
>(
  matrix: DoubleMatrix,
  options: MatrixZRescaleOptions<ArrayConstructorType> = {},
): Array<DoubleArrayType<DoubleArrayConstructor>> {
  const { min = 0, max = 1, ArrayConstructor } = options;
  const nbColumns = matrix[0].length;
  const nbRows = matrix.length;
  const newMatrix = matrixCreateEmpty({ nbColumns, nbRows, ArrayConstructor });

  const { min: currentMin, max: currentMax } = matrixMinMaxZ(matrix);
  const factor = (max - min) / (currentMax - currentMin);

  for (let column = 0; column < nbColumns; column++) {
    for (let row = 0; row < nbRows; row++) {
      newMatrix[row][column] =
        (matrix[row][column] - currentMin) * factor + min;
    }
  }
  return newMatrix;
}