// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package storageclass

import (
	"errors"
	"reflect"
	"testing"
)

func TestParseStorageClass(t *testing.T) {
	tests := []struct {
		storageClassEnv string
		wantSc          StorageClass
		expectedError   error
	}{
		{
			"EC:3",
			StorageClass{
				Parity: 3,
			},
			nil,
		},
		{
			"EC:4",
			StorageClass{
				Parity: 4,
			},
			nil,
		},
		{
			"AB:4",
			StorageClass{
				Parity: 4,
			},
			errors.New("Unsupported scheme AB. Supported scheme is EC"),
		},
		{
			"EC:4:5",
			StorageClass{
				Parity: 4,
			},
			errors.New("Too many sections in EC:4:5"),
		},
		{
			"EC:A",
			StorageClass{
				Parity: 4,
			},
			errors.New(`strconv.Atoi: parsing "A": invalid syntax`),
		},
		{
			"AB",
			StorageClass{
				Parity: 4,
			},
			errors.New("Too few sections in AB"),
		},
	}
	for i, tt := range tests {
		gotSc, err := parseStorageClass(tt.storageClassEnv)
		if err != nil && tt.expectedError == nil {
			t.Errorf("Test %d, Expected %s, got %s", i+1, tt.expectedError, err)
			return
		}
		if err == nil && tt.expectedError != nil {
			t.Errorf("Test %d, Expected %s, got %s", i+1, tt.expectedError, err)
			return
		}
		if tt.expectedError == nil && !reflect.DeepEqual(gotSc, tt.wantSc) {
			t.Errorf("Test %d, Expected %v, got %v", i+1, tt.wantSc, gotSc)
			return
		}
		if tt.expectedError != nil && err.Error() != tt.expectedError.Error() {
			t.Errorf("Test %d, Expected `%v`, got `%v`", i+1, tt.expectedError, err)
		}
	}
}

func TestValidateParity(t *testing.T) {
	tests := []struct {
		rrsParity     int
		ssParity      int
		success       bool
		setDriveCount int
	}{
		{2, 4, true, 16},
		{3, 3, true, 16},
		{0, 0, true, 16},
		{1, 4, true, 16},
		{0, 4, true, 16},
		{7, 6, false, 16},
		{9, 0, false, 16},
		{9, 9, false, 16},
		{2, 9, false, 16},
		{9, 2, false, 16},
	}
	for i, tt := range tests {
		err := validateParity(tt.ssParity, tt.rrsParity, tt.setDriveCount)
		if err != nil && tt.success {
			t.Errorf("Test %d, Expected success, got %s", i+1, err)
		}
		if err == nil && !tt.success {
			t.Errorf("Test %d, Expected failure, got success", i+1)
		}
	}
}

func TestParityCount(t *testing.T) {
	tests := []struct {
		sc             string
		disksCount     int
		expectedData   int
		expectedParity int
	}{
		{RRS, 16, 14, 2},
		{STANDARD, 16, 8, 8},
		{"", 16, 8, 8},
		{RRS, 16, 9, 7},
		{STANDARD, 16, 10, 6},
		{"", 16, 9, 7},
	}
	for i, tt := range tests {
		scfg := Config{
			Standard: StorageClass{
				Parity: 8,
			},
			RRS: StorageClass{
				Parity: 2,
			},
		}
		// Set env var for test case 4
		if i+1 == 4 {
			scfg.RRS.Parity = 7
		}
		// Set env var for test case 5
		if i+1 == 5 {
			scfg.Standard.Parity = 6
		}
		// Set env var for test case 6
		if i+1 == 6 {
			scfg.Standard.Parity = 7
		}
		parity := scfg.GetParityForSC(tt.sc)
		if (tt.disksCount - parity) != tt.expectedData {
			t.Errorf("Test %d, Expected data disks %d, got %d", i+1, tt.expectedData, tt.disksCount-parity)
			continue
		}
		if parity != tt.expectedParity {
			t.Errorf("Test %d, Expected parity disks %d, got %d", i+1, tt.expectedParity, parity)
		}
	}
}

// Test IsValid method with valid and invalid inputs
func TestIsValidStorageClassKind(t *testing.T) {
	tests := []struct {
		sc   string
		want bool
	}{
		{"STANDARD", true},
		{"REDUCED_REDUNDANCY", true},
		{"", false},
		{"INVALID", false},
		{"123", false},
		{"MINIO_STORAGE_CLASS_RRS", false},
		{"MINIO_STORAGE_CLASS_STANDARD", false},
	}
	for i, tt := range tests {
		if got := IsValid(tt.sc); got != tt.want {
			t.Errorf("Test %d, Expected Storage Class to be %t, got %t", i+1, tt.want, got)
		}
	}
}