// Copyright (c) 2021 Quan guanyu
// randomness is licensed under Mulan PSL v2.
// You can use this software according to the terms and conditions of the Mulan PSL v2.
// You may obtain a copy of Mulan PSL v2 at:
//          http://license.coscl.org.cn/MulanPSL2
// THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
// EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
// MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
// See the Mulan PSL v2 for more details.

package randomness

import (
	"math"
)

// MatrixRank 矩阵秩检测,M=Q=32
func MatrixRank(data []byte) *TestResult {
	p, q := MatrixRankTestBytes(data, 32, 32)
	return &TestResult{Name: "矩阵秩检测", P: p, Q: q, Pass: p >= Alpha}
}

// MatrixRankTest 矩阵秩检测,M=Q=32
func MatrixRankTest(bits []bool) (float64, float64) {
	return MatrixRankProto(bits, 32, 32)
}

// MatrixRankTestBytes 矩阵秩检测
func MatrixRankTestBytes(data []byte, M, Q int) (float64, float64) {
	return MatrixRankProto(B2bitArr(data), M, Q)
}

// MatrixRankProto 矩阵秩检测
// bits: 待检测序列
// M: 矩阵行数
// Q: 矩阵列隶属
func MatrixRankProto(bits []bool, M, Q int) (float64, float64) {
	n := len(bits)

	N := n / (M * Q)
	if N == 0 {
		panic("please provide valid test bits")
	}
	//int n_disc = n % (M * Q);
	var Fm, Fm1, Fr = 0, 0, 0
	var matrix = make([][]int, 32)
	for i := 0; i < 32; i++ {
		matrix[i] = make([]int, 32)
	}
	var V, P float64
	var r int
	var b bool

	for i := 0; i < N; i++ {
		for j := 0; j < M; j++ {
			for k := 0; k < Q; k++ {
				b, bits = bits[0], bits[1:]
				if b {
					matrix[j][k] = 1
				} else {
					matrix[j][k] = 0
				}
			}
		}
		r = rank(matrix, M)

		if r == min(M, Q) {
			Fm++
		} else if r == (min(M, Q) - 1) {
			Fm1++
		} else {
			Fr++
		}
	}
	_N := float64(N)
	V = math.Pow(float64(Fm)-0.2888*_N, 2.0)/(0.2888*_N) +
		math.Pow(float64(Fm1)-0.5776*_N, 2.0)/(0.5776*_N) +
		math.Pow(float64(Fr)-0.1336*_N, 2.0)/(0.1336*_N)

	P = igamc(1, V/2.0)

	return P, P
}