package bencode

import "testing"

func TestDecode(t *testing.T) {
	tests := []struct {
		in   string
		want any
		err  bool
	}{
		{
			in:   "4:spam",
			want: "spam",
		},
		{
			in:   "0:",
			want: "",
		},
		{
			in:   "i42e",
			want: int64(42),
		},
		{
			in:   "i-42e",
			want: int64(-42),
		},
		{
			in:   "i0e",
			want: int64(0),
		},
		{
			in:  "",
			err: true,
		},
	}
	for _, tt := range tests {
		t.Run(tt.in, func(t *testing.T) {
			got, _, err := Decode([]byte(tt.in))
			if tt.err {
				if err == nil {
					t.Error("expected error")
				}
				return
			}
			if err != nil {
				t.Fatalf("unexpected error: %v", err)
			}
			if got != tt.want {
				t.Errorf("got %v, want %v", got, tt.want)
			}
		})
	}
}

func TestEncode(t *testing.T) {
	tests := []struct {
		name string
		in   any
		want string
	}{
		{
			name: "string",
			in:   "spam",
			want: "4:spam",
		},
		{
			name: "empty string",
			in:   "",
			want: "0:",
		},
		{
			name: "int",
			in:   int64(42),
			want: "i42e",
		},
		{
			name: "negative int",
			in:   int64(-42),
			want: "i-42e",
		},
		{
			name: "list",
			in:   []any{"a", "b"},
			want: "l1:a1:be",
		},
		{
			name: "empty list",
			in:   []any{},
			want: "le",
		},
		{
			name: "dict",
			in:   map[string]any{"b": int64(2), "a": int64(1)},
			want: "d1:ai1e1:bi2ee",
		},
		{
			name: "empty dict",
			in:   map[string]any{},
			want: "de",
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, err := Encode(tt.in)
			if err != nil {
				t.Fatalf("unexpected error: %v", err)
			}
			if string(got) != tt.want {
				t.Errorf("got %s, want %s", got, tt.want)
			}
		})
	}
}