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/*
 * Copyright 2019 and onwards Makoto Yui
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package matrix4j.matrix.builders;

import matrix4j.matrix.Matrix;

import javax.annotation.Nonnegative;
import javax.annotation.Nonnull;

public abstract class MatrixBuilder {

    public MatrixBuilder() {}

    protected static final void checkColIndex(final int col) {
        if (col < 0) {
            throw new IllegalArgumentException("Found negative column index: " + col);
        }
    }

    public void nextRow(@Nonnull final double[] row) {
        for (int col = 0; col < row.length; col++) {
            nextColumn(col, row[col]);
        }
        nextRow();
    }

    public void nextRow(@Nonnull final String[] row) {
        for (String col : row) {
            if (col == null) {
                continue;
            }
            nextColumn(col);
        }
        nextRow();
    }

    @Nonnull
    public abstract MatrixBuilder nextRow();

    @Nonnull
    public abstract MatrixBuilder nextColumn(@Nonnegative int col, double value);

    /**
     * @throws IllegalArgumentException
     * @throws NumberFormatException
     */
    @Nonnull
    public MatrixBuilder nextColumn(@Nonnull final String col) {
        final int pos = col.indexOf(':');
        if (pos == 0) {
            throw new IllegalArgumentException("Invalid feature value representation: " + col);
        }

        final String feature;
        final double value;
        if (pos > 0) {
            feature = col.substring(0, pos);
            String s2 = col.substring(pos + 1);
            value = Double.parseDouble(s2);
        } else {
            feature = col;
            value = 1.d;
        }

        if (feature.indexOf(':') != -1) {
            throw new IllegalArgumentException("Invalid feature format `:`: " + col);
        }

        int colIndex = Integer.parseInt(feature);
        if (colIndex < 0) {
            throw new IllegalArgumentException(
                "Col index MUST be greater than or equals to 0: " + colIndex);
        }

        return nextColumn(colIndex, value);
    }

    @Nonnull
    public abstract Matrix buildMatrix();

}