package wire

import (
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"
)

// Gap (e): Time.UnmarshalJSON round-trips both +00:00 and Z. The happy
// path already lives in TestTimeUnmarshalJSONAcceptsOffsetAndZ; this
// file covers null, invalid JSON, and a non-nil empty slice.

func TestTimeUnmarshalJSONNullAndInvalid(t *testing.T) {
	var tm Time
	if err := json.Unmarshal([]byte("null"), &tm); err != nil {
		t.Fatal(err)
	}
	if !tm.IsZero() {
		t.Fatalf("null must decode to zero Time, got %v", tm.Time)
	}
	if err := json.Unmarshal([]byte(`"not-a-time"`), &tm); err == nil {
		t.Fatal("invalid timestamp must fail")
	}
	if err := json.Unmarshal([]byte(`42`), &tm); err == nil {
		t.Fatal("non-string must fail")
	}
	var nilT *Time
	if err := nilT.UnmarshalJSON([]byte(`"2024-01-02T03:04:05Z"`)); err != nil {
		t.Fatalf("nil receiver: %v", err)
	}
}

func TestTimeUnmarshalJSONOffsetAndZRoundTrip(t *testing.T) {
	want := time.Date(2024, 1, 2, 3, 4, 5, 0, time.UTC)
	for _, raw := range []string{`"2024-01-02T03:04:05+00:00"`, `"2024-01-02T03:04:05Z"`} {
		var tm Time
		if err := json.Unmarshal([]byte(raw), &tm); err != nil {
			t.Fatalf("%s: %v", raw, err)
		}
		if !tm.Equal(want) {
			t.Fatalf("%s = %v", raw, tm.Time)
		}
		b, err := json.Marshal(tm)
		if err != nil {
			t.Fatal(err)
		}
		if string(b) != `"2024-01-02T03:04:05+00:00"` {
			t.Fatalf("marshal %s -> %s", raw, b)
		}
	}
}

func TestWriteJSONEncodeErrorWritesOpaque500(t *testing.T) {
	rec := httptest.NewRecorder()
	WriteJSON(rec, http.StatusOK, make(chan int))
	if rec.Code != http.StatusInternalServerError {
		t.Fatalf("status = %d", rec.Code)
	}
	if rec.Body.String() != `{"error":true,"message":"Internal server error"}` {
		t.Fatalf("body = %q", rec.Body.String())
	}
}

func TestSliceNonNilUnchanged(t *testing.T) {
	in := []int{1, 2}
	got := Slice(in)
	if len(got) != 2 || got[0] != 1 || got[1] != 2 {
		t.Fatalf("got %v", got)
	}
}