package locator

import (
	"strings"
	"testing"

	"g.activething.com/go/DateKeys/codec"
)

func small() *Locator {
	return &Locator{Addresses: []Address{{URI: "https://ejemplo.org/b"}}, EnvelopeHeader: []byte("h\n"), RestSize: 1}
}

// Review: a reader rejects an address that breaks the rules of §44.1, not the
// locator, and uses the others; a writer never writes such an address.
func TestUsableAddresses(t *testing.T) {
	l := small()
	l.Addresses = append([]Address{{URI: "http://ejemplo.org/a"}}, l.Addresses...)
	if _, err := l.Marshal(); err == nil {
		t.Error("a writer wrote an http address")
	}
	b, err := l.marshal()
	if err != nil {
		t.Fatal(err)
	}
	back, err := Unmarshal(b)
	if err != nil || len(back.Addresses) != 2 {
		t.Fatalf("a locator with a rejected address: %v", err)
	}
	if u := back.Usable(); len(u) != 1 || u[0].URI != "https://ejemplo.org/b" {
		t.Errorf("usable: %v", u)
	}
}

// Review: the plaintext measures the least multiple of 4096 that key 6 can
// fill. A CBOR of 8192 bytes where 4096 suffice, valid in every other way, is
// not canonical.
func TestLeastMultiple(t *testing.T) {
	l := small()
	var base codec.Encoder
	l.encode(&base, -1)
	b0, err := base.Out()
	if err != nil {
		t.Fatal(err)
	}
	var e codec.Encoder
	l.encode(&e, 2*Block-len(b0)-1-3)
	b, err := e.Out()
	if err != nil || len(b) != 2*Block {
		t.Fatalf("%d bytes, %v", len(b), err)
	}
	if _, err := Unmarshal(b); err == nil || !strings.Contains(err.Error(), "least multiple") {
		t.Errorf("two blocks where one suffices: %v", err)
	}
	if want, err := l.Marshal(); err != nil || len(want) != Block {
		t.Errorf("%d bytes, %v", len(want), err)
	}
}

// Review: the bases where no length of key 6 completes a multiple are those
// where the plaintext would need 0 to 2, 26 or 259 more bytes: key 6 takes at
// least 3, and the header of its byte string grows at 24 and 256 bytes.
func TestPaddingBoundaries(t *testing.T) {
	for base := 1; base <= 3*Block; base++ {
		got := PlaintextLength(base)
		need := (Block - base%Block) % Block
		want := base + need
		switch need {
		case 0:
		case 1, 2, 26, 259:
			want += Block
		}
		if got != want {
			t.Fatalf("base %d: %d bytes, want %d", base, got, want)
		}
	}
}