package timestamp

import (
	"encoding/binary"
	"testing"
	"time"
)

func TestNewAndAccessors(t *testing.T) {
	tv := New(1700000000)
	if tv.I64() != 1700000000 || tv.U64() != 1700000000 || tv.Int() != 1700000000 {
		t.Fatal("New accessors disagree")
	}
	if tv.Time().Unix() != 1700000000 {
		t.Fatal("Time")
	}
	if tv.String() != "1700000000" {
		t.Fatalf("String: got %s", tv.String())
	}
	var nilT *T
	if nilT.U64() != 0 || nilT.I64() != 0 || nilT.Int() != 0 {
		t.Fatal("a nil timestamp should read as zero")
	}
}

func TestBytesRoundTrip(t *testing.T) {
	tv := New(1700000000)
	back := FromBytes(tv.Bytes())
	if back.I64() != tv.I64() {
		t.Fatal("Bytes/FromBytes roundtrip")
	}
}

func TestMarshalUnmarshal(t *testing.T) {
	tv := New(1700000000)
	buf := tv.Marshal(nil)
	if string(buf) != "1700000000" {
		t.Fatalf("Marshal: got %s", string(buf))
	}
	back := New(0)
	rem, err := back.Unmarshal(buf)
	if err != nil {
		t.Fatal(err)
	}
	if back.I64() != 1700000000 || len(rem) != 0 {
		t.Fatal("Unmarshal")
	}
	js, err := tv.MarshalJSON()
	if err != nil {
		t.Fatal(err)
	}
	if string(js) != "1700000000" {
		t.Fatalf("MarshalJSON: got %s", string(js))
	}
}

// TestFromVarint pins the encoding FromVarint decodes: it reads Go's zigzag
// varint (encoding/binary), one value, and hands back what follows it.
func TestFromVarint(t *testing.T) {
	b := []byte{:11}
	n := binary.PutVarint(b, 300)
	b[n] = 0xff
	tv, rem, err := FromVarint(b[:n+1])
	if err != nil {
		t.Fatal(err)
	}
	if tv.I64() != 300 {
		t.Fatalf("value: got %d", tv.I64())
	}
	if string(rem) != string([]byte{0xff}) {
		t.Fatal("remainder should be the byte after the varint")
	}
	if _, _, err = FromVarint(nil); err == nil {
		t.Fatal("an empty varint should fail")
	}
}

func TestConversions(t *testing.T) {
	if FromTime(time.Unix(1700000001, 0)).I64() != 1700000001 {
		t.Fatal("FromTime")
	}
	if FromUnix(1700000002).I64() != 1700000002 {
		t.Fatal("FromUnix")
	}
	var tv T
	tv.FromInt(7)
	if tv.I64() != 7 {
		t.Fatal("FromInt")
	}
	if Now().I64() < 1600000000 {
		t.Fatal("Now is not a unix timestamp")
	}
}