package auth

import (
	"crypto/hmac"
	"crypto/sha256"
	"encoding/base64"
	"encoding/hex"
	"strconv"
	"testing"
	"time"

	"github.com/google/uuid"
)

func TestIssueAndParseSetPasswordToken(t *testing.T) {
	t.Parallel()
	const secret = "test-signing-secret-not-for-prod"
	uid := uuid.MustParse("aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa")

	token, err := IssueSetPasswordToken(secret, uid, time.Hour)
	if err != nil {
		t.Fatalf("IssueSetPasswordToken: %v", err)
	}
	got, err := ParseSetPasswordToken(secret, token)
	if err != nil {
		t.Fatalf("ParseSetPasswordToken: %v", err)
	}
	if got != uid {
		t.Fatalf("user id = %s, want %s", got, uid)
	}
}

func TestParseSetPasswordTokenRejectsWrongSecret(t *testing.T) {
	t.Parallel()
	uid := uuid.New()
	token, err := IssueSetPasswordToken("secret-a", uid, time.Hour)
	if err != nil {
		t.Fatalf("IssueSetPasswordToken: %v", err)
	}
	if _, err := ParseSetPasswordToken("secret-b", token); err == nil {
		t.Fatal("expected invalid token for wrong secret")
	}
}

func TestParseSetPasswordTokenRejectsExpired(t *testing.T) {
	t.Parallel()
	uid := uuid.New()
	const secret = "secret"
	// Build an already-expired signed token (IssueSetPasswordToken coerces ttl<=0 to 72h).
	exp := time.Now().Add(-time.Hour).Unix()
	nonce := "deadbeefdeadbeef"
	payload := uid.String() + "." + strconv.FormatInt(exp, 10) + "." + nonce
	mac := hmac.New(sha256.New, []byte(secret))
	_, _ = mac.Write([]byte(payload))
	sig := hex.EncodeToString(mac.Sum(nil))
	token := base64.RawURLEncoding.EncodeToString([]byte(payload + "." + sig))
	if _, err := ParseSetPasswordToken(secret, token); err == nil {
		t.Fatal("expected expired token to fail")
	}
}

func TestIssueSetPasswordTokenRequiresSecret(t *testing.T) {
	t.Parallel()
	if _, err := IssueSetPasswordToken("", uuid.New(), time.Hour); err == nil {
		t.Fatal("expected error when secret is empty")
	}
}