package card

import (
	"errors"
	"testing"
)

func TestValidate(t *testing.T) {
	tests := []struct {
		name    string
		number  string
		wantErr error
	}{
		{
			name:    "empty card number",
			number:  "",
			wantErr: ErrCardRequired,
		},
		{
			name:    "card number is too short",
			number:  "123456789",
			wantErr: ErrCardLength,
		},
		{
			name:    "card number is too long",
			number:  "12345678901234567",
			wantErr: ErrCardLength,
		},
		{
			name:    "card number contains letters",
			number:  "603799ABC4567890",
			wantErr: ErrCardNumeric,
		},
		{
			name:    "card number contains spaces",
			number:  "6037 912 3456 78",
			wantErr: ErrCardNumeric,
		},
		{
			name:    "valid card number structure",
			number:  "6037991234567890",
			wantErr: nil,
		},
	}

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

			if !errors.Is(err, tt.wantErr) {
				t.Errorf("Validate() error = %v, want %v", err, tt.wantErr)
			}
		})
	}
}

func TestMask(t *testing.T) {
	tests := []struct {
		name   string
		number string
		want   string
	}{
		{
			name:   "valid card number",
			number: "6037997512345678",
			want:   "603799******5678",
		},
		{
			name:   "invalid card number",
			number: "603799",
			want:   "",
		},
		{
			name:   "non numeric card number",
			number: "603799ABC2345678",
			want:   "",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := Mask(tt.number); got != tt.want {
				t.Errorf("Mask() = %q, want %q", got, tt.want)
			}
		})
	}
}