/*
 * MIT License
 *
 * Copyright (c) 2019 Tatyana Borisova <tanusshhka@mail.ru>
 *
 * This file is part of NeuralNetwork project https://git.semlanik.org/semlanik/NeuralNetwork
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this
 * software and associated documentation files (the "Software"), to deal in the Software
 * without restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software, and
 * to permit persons to whom the Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies
 * or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
 * FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

package neuralnetwork

import (
	"encoding/binary"
	"fmt"
	"io"

	mat "gonum.org/v1/gonum/mat"
)

func saveDense(writer io.Writer, matrix *mat.Dense) {
	buffer, _ := matrix.MarshalBinary()
	// Save 4-bytes little-endian size of Dense buffer
	bufferSize := make([]byte, 4)
	binary.LittleEndian.PutUint32(bufferSize, uint32(len(buffer)))
	writer.Write(bufferSize)
	_, err := writer.Write(buffer)
	check(err)
	// fmt.Printf("wrote array size %d count of bytes %d \n", len(buffer), bufferCount)
	printMatDense(matrix)
}

func printMatDense(matrix *mat.Dense) {
	// Print the result using the formatter.
	// fc := mat.Formatted(matrix, mat.Prefix("    "), mat.Squeeze())
	// fmt.Printf("c = %v \n\n", fc)
}

func readDense(reader io.Reader, matrix *mat.Dense) *mat.Dense {
	count := readInt(reader)
	// fmt.Printf("%d \n\n", count)
	matrix = &mat.Dense{}
	matrix.UnmarshalBinary(readByteArray(reader, count))
	printMatDense(matrix)
	return matrix
}

func readByteArray(reader io.Reader, size int) []byte {
	// Read an input array
	sizeBuffer := make([]byte, size)
	n1, err := reader.Read(sizeBuffer)
	check(err)

	fmt.Printf("readByteArray: size = %d \n", n1)

	return sizeBuffer
}

func readInt(reader io.Reader) int {
	// Reade int
	count := make([]byte, 4)
	_, err := reader.Read(count)
	check(err)

	return int(binary.LittleEndian.Uint32(count))
}

func check(e error) {
	if e != nil {
		panic(e)
	}
}