package config_test

import (
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"sneak.berlin/go/dnswatcher/internal/config"
)

func TestParseCSV(t *testing.T) {
	t.Parallel()

	tests := []struct {
		name  string
		input string
		want  []string
	}{
		{"empty string", "", nil},
		{"single value", "a", []string{"a"}},
		{"multiple values", "a,b,c", []string{"a", "b", "c"}},
		{"whitespace trimmed", " a , b ", []string{"a", "b"}},
		{"trailing comma", "a,b,", []string{"a", "b"}},
		{"leading comma", ",a,b", []string{"a", "b"}},
		{"consecutive commas", "a,,b", []string{"a", "b"}},
		{"all empty segments", ",,,", nil},
		{"whitespace only", " , , ", nil},
		{"tabs", "\ta\t,\tb\t", []string{"a", "b"}},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()

			got := config.ParseCSVForTest(tt.input)
			require.Len(t, got, len(tt.want))

			for i, w := range tt.want {
				assert.Equal(t, w, got[i])
			}
		})
	}
}