package bt

import (
	"reflect"
	"testing"
)

func TestParsePorts(t *testing.T) {
	tests := []struct {
		spec string
		want []int
	}{
		// port spec examples.
		{"6881,6885", []int{6881, 6885}},
		{"6881-6999", rangeInts(6881, 6999)},
		{"7000-7001,8000", []int{7000, 7001, 8000}},
		{"6881-6889,6999", append(rangeInts(6881, 6889), 6999)},
		// single bare port.
		{"6881", []int{6881}},
		// whitespace and empty fields are tolerated.
		{" 6881 , 6885 ", []int{6881, 6885}},
		{"6881,,6885", []int{6881, 6885}},
		// empty / all-bad specs yield nil.
		{"", nil},
		{",", nil},
		{"abc", nil},
		// out-of-range ports are dropped.
		{"0", nil},
		{"70000", nil},
		// a range that overruns 65535 keeps only the valid part.
		{"65534-65540", []int{65534, 65535}},
	}
	for _, tt := range tests {
		got := ParsePorts(tt.spec)
		if !reflect.DeepEqual(got, tt.want) {
			t.Errorf("ParsePorts(%q) = %v, want %v", tt.spec, got, tt.want)
		}
	}
}

func rangeInts(a, b int) []int {
	out := make([]int, 0, b-a+1)
	for i := a; i <= b; i++ {
		out = append(out, i)
	}
	return out
}