// Tests for the gRPC server package.
//
// All tests use bufconn so no network sockets are opened. TLS is omitted
// at the test layer (insecure credentials); TLS enforcement is the responsibility
// of cmd/mciassrv which wraps the listener.
package grpcserver

import (
	"context"
	"crypto/ed25519"
	"crypto/rand"
	"io"
	"log/slog"
	"net"
	"testing"
	"time"

	"google.golang.org/grpc"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/credentials/insecure"
	"google.golang.org/grpc/metadata"
	"google.golang.org/grpc/status"
	"google.golang.org/grpc/test/bufconn"

	mciasv1 "git.wntrmute.dev/kyle/mcias/gen/mcias/v1"
	"git.wntrmute.dev/kyle/mcias/internal/auth"
	"git.wntrmute.dev/kyle/mcias/internal/config"
	"git.wntrmute.dev/kyle/mcias/internal/db"
	"git.wntrmute.dev/kyle/mcias/internal/model"
	"git.wntrmute.dev/kyle/mcias/internal/token"
)

const (
	testIssuer  = "https://auth.example.com"
	bufConnSize = 1024 * 1024
)

// testEnv holds all resources for a single test's gRPC server.
type testEnv struct {
	db        *db.DB
	cfg       *config.Config
	conn      *grpc.ClientConn
	priv      ed25519.PrivateKey
	pub       ed25519.PublicKey
	masterKey []byte
}

// newTestEnv spins up an in-process gRPC server using bufconn and returns
// a client connection to it. All resources are cleaned up via t.Cleanup.
func newTestEnv(t *testing.T) *testEnv {
	t.Helper()

	pub, priv, err := ed25519.GenerateKey(rand.Reader)
	if err != nil {
		t.Fatalf("generate key: %v", err)
	}

	database, err := db.Open(":memory:")
	if err != nil {
		t.Fatalf("open db: %v", err)
	}
	if err := db.Migrate(database); err != nil {
		t.Fatalf("migrate db: %v", err)
	}

	masterKey := make([]byte, 32)
	if _, err := rand.Read(masterKey); err != nil {
		t.Fatalf("generate master key: %v", err)
	}

	cfg := config.NewTestConfig(testIssuer)
	logger := slog.New(slog.NewTextHandler(io.Discard, nil))

	srv := New(database, cfg, priv, pub, masterKey, logger)
	grpcSrv := srv.GRPCServer()

	lis := bufconn.Listen(bufConnSize)
	go func() {
		_ = grpcSrv.Serve(lis) // returns on listener close; error ignored
	}()

	conn, err := grpc.NewClient(
		"passthrough://bufnet",
		grpc.WithContextDialer(func(ctx context.Context, _ string) (net.Conn, error) {
			return lis.DialContext(ctx)
		}),
		grpc.WithTransportCredentials(insecure.NewCredentials()),
	)
	if err != nil {
		t.Fatalf("dial bufconn: %v", err)
	}

	t.Cleanup(func() {
		_ = conn.Close()
		grpcSrv.Stop()
		_ = lis.Close()
		_ = database.Close()
	})

	return &testEnv{
		db:        database,
		priv:      priv,
		pub:       pub,
		masterKey: masterKey,
		cfg:       cfg,
		conn:      conn,
	}
}

// createHumanAccount creates a human account with the given username and
// a fixed password "testpass123" directly in the database.
func (e *testEnv) createHumanAccount(t *testing.T, username string) *model.Account {
	t.Helper()
	hash, err := auth.HashPassword("testpass123", auth.ArgonParams{Time: 3, Memory: 65536, Threads: 4})
	if err != nil {
		t.Fatalf("hash password: %v", err)
	}
	acct, err := e.db.CreateAccount(username, model.AccountTypeHuman, hash)
	if err != nil {
		t.Fatalf("create account: %v", err)
	}
	return acct
}

// issueAdminToken creates an account with admin role, issues a JWT, tracks it in
// the DB, and returns the token string.
func (e *testEnv) issueAdminToken(t *testing.T, username string) (string, *model.Account) {
	t.Helper()
	acct := e.createHumanAccount(t, username)
	if err := e.db.GrantRole(acct.ID, "admin", nil); err != nil {
		t.Fatalf("grant admin role: %v", err)
	}
	tokenStr, claims, err := token.IssueToken(e.priv, testIssuer, acct.UUID, []string{"admin"}, time.Hour)
	if err != nil {
		t.Fatalf("issue token: %v", err)
	}
	if err := e.db.TrackToken(claims.JTI, acct.ID, claims.IssuedAt, claims.ExpiresAt); err != nil {
		t.Fatalf("track token: %v", err)
	}
	return tokenStr, acct
}

// issueUserToken issues a regular (non-admin) token for an account.
func (e *testEnv) issueUserToken(t *testing.T, acct *model.Account) string {
	t.Helper()
	tokenStr, claims, err := token.IssueToken(e.priv, testIssuer, acct.UUID, []string{}, time.Hour)
	if err != nil {
		t.Fatalf("issue token: %v", err)
	}
	if err := e.db.TrackToken(claims.JTI, acct.ID, claims.IssuedAt, claims.ExpiresAt); err != nil {
		t.Fatalf("track token: %v", err)
	}
	return tokenStr
}

// authCtx returns a context with the Bearer token as gRPC metadata.
func authCtx(tok string) context.Context {
	return metadata.AppendToOutgoingContext(context.Background(),
		"authorization", "Bearer "+tok)
}

// ---- AdminService tests ----

// TestHealth verifies the public Health RPC requires no auth and returns "ok".
func TestHealth(t *testing.T) {
	e := newTestEnv(t)
	cl := mciasv1.NewAdminServiceClient(e.conn)

	resp, err := cl.Health(context.Background(), &mciasv1.HealthRequest{})
	if err != nil {
		t.Fatalf("Health: %v", err)
	}
	if resp.Status != "ok" {
		t.Errorf("Health: got status %q, want %q", resp.Status, "ok")
	}
}

// TestGetPublicKey verifies the public GetPublicKey RPC returns JWK fields.
func TestGetPublicKey(t *testing.T) {
	e := newTestEnv(t)
	cl := mciasv1.NewAdminServiceClient(e.conn)

	resp, err := cl.GetPublicKey(context.Background(), &mciasv1.GetPublicKeyRequest{})
	if err != nil {
		t.Fatalf("GetPublicKey: %v", err)
	}
	if resp.Kty != "OKP" {
		t.Errorf("GetPublicKey: kty=%q, want OKP", resp.Kty)
	}
	if resp.Crv != "Ed25519" {
		t.Errorf("GetPublicKey: crv=%q, want Ed25519", resp.Crv)
	}
	if resp.X == "" {
		t.Error("GetPublicKey: x field is empty")
	}
}

// ---- Auth interceptor tests ----

// TestAuthRequired verifies that protected RPCs reject calls with no token.
func TestAuthRequired(t *testing.T) {
	e := newTestEnv(t)
	cl := mciasv1.NewAuthServiceClient(e.conn)

	// Logout requires auth; call without any metadata.
	_, err := cl.Logout(context.Background(), &mciasv1.LogoutRequest{})
	if err == nil {
		t.Fatal("Logout without token: expected error, got nil")
	}
	st, ok := status.FromError(err)
	if !ok {
		t.Fatalf("not a gRPC status error: %v", err)
	}
	if st.Code() != codes.Unauthenticated {
		t.Errorf("Logout without token: got code %v, want Unauthenticated", st.Code())
	}
}

// TestInvalidTokenRejected verifies that a malformed token is rejected.
func TestInvalidTokenRejected(t *testing.T) {
	e := newTestEnv(t)
	cl := mciasv1.NewAuthServiceClient(e.conn)

	ctx := authCtx("not.a.valid.jwt")
	_, err := cl.Logout(ctx, &mciasv1.LogoutRequest{})
	if err == nil {
		t.Fatal("Logout with invalid token: expected error, got nil")
	}
	st, _ := status.FromError(err)
	if st.Code() != codes.Unauthenticated {
		t.Errorf("got code %v, want Unauthenticated", st.Code())
	}
}

// TestRevokedTokenRejected verifies that a revoked token cannot be used.
func TestRevokedTokenRejected(t *testing.T) {
	e := newTestEnv(t)

	acct := e.createHumanAccount(t, "revokeduser")
	tokenStr, claims, err := token.IssueToken(e.priv, testIssuer, acct.UUID, []string{}, time.Hour)
	if err != nil {
		t.Fatalf("issue token: %v", err)
	}
	if err := e.db.TrackToken(claims.JTI, acct.ID, claims.IssuedAt, claims.ExpiresAt); err != nil {
		t.Fatalf("track token: %v", err)
	}
	// Revoke it before using it.
	if err := e.db.RevokeToken(claims.JTI, "test"); err != nil {
		t.Fatalf("revoke token: %v", err)
	}

	cl := mciasv1.NewAuthServiceClient(e.conn)
	ctx := authCtx(tokenStr)
	_, err = cl.Logout(ctx, &mciasv1.LogoutRequest{})
	if err == nil {
		t.Fatal("Logout with revoked token: expected error, got nil")
	}
	st, _ := status.FromError(err)
	if st.Code() != codes.Unauthenticated {
		t.Errorf("got code %v, want Unauthenticated", st.Code())
	}
}

// TestNonAdminCannotCallAdminRPC verifies that a regular user is denied access
// to admin-only RPCs (PermissionDenied, not Unauthenticated).
func TestNonAdminCannotCallAdminRPC(t *testing.T) {
	e := newTestEnv(t)
	acct := e.createHumanAccount(t, "regularuser")
	tok := e.issueUserToken(t, acct)

	cl := mciasv1.NewAccountServiceClient(e.conn)
	ctx := authCtx(tok)
	_, err := cl.ListAccounts(ctx, &mciasv1.ListAccountsRequest{})
	if err == nil {
		t.Fatal("ListAccounts as non-admin: expected error, got nil")
	}
	st, _ := status.FromError(err)
	if st.Code() != codes.PermissionDenied {
		t.Errorf("got code %v, want PermissionDenied", st.Code())
	}
}

// ---- AuthService tests ----

// TestLogin verifies successful login via gRPC.
func TestLogin(t *testing.T) {
	e := newTestEnv(t)
	_ = e.createHumanAccount(t, "loginuser")

	cl := mciasv1.NewAuthServiceClient(e.conn)
	resp, err := cl.Login(context.Background(), &mciasv1.LoginRequest{
		Username: "loginuser",
		Password: "testpass123",
	})
	if err != nil {
		t.Fatalf("Login: %v", err)
	}
	if resp.Token == "" {
		t.Error("Login: returned empty token")
	}
}

// TestLoginWrongPassword verifies that wrong-password returns Unauthenticated.
func TestLoginWrongPassword(t *testing.T) {
	e := newTestEnv(t)
	_ = e.createHumanAccount(t, "loginuser2")

	cl := mciasv1.NewAuthServiceClient(e.conn)
	_, err := cl.Login(context.Background(), &mciasv1.LoginRequest{
		Username: "loginuser2",
		Password: "wrongpassword",
	})
	if err == nil {
		t.Fatal("Login with wrong password: expected error, got nil")
	}
	st, _ := status.FromError(err)
	if st.Code() != codes.Unauthenticated {
		t.Errorf("got code %v, want Unauthenticated", st.Code())
	}
}

// TestLoginUnknownUser verifies that unknown-user returns the same error as
// wrong-password (prevents user enumeration).
func TestLoginUnknownUser(t *testing.T) {
	e := newTestEnv(t)
	cl := mciasv1.NewAuthServiceClient(e.conn)
	_, err := cl.Login(context.Background(), &mciasv1.LoginRequest{
		Username: "nosuchuser",
		Password: "whatever",
	})
	if err == nil {
		t.Fatal("Login for unknown user: expected error, got nil")
	}
	st, _ := status.FromError(err)
	if st.Code() != codes.Unauthenticated {
		t.Errorf("got code %v, want Unauthenticated", st.Code())
	}
}

// TestLogout verifies that a valid token can log itself out.
func TestLogout(t *testing.T) {
	e := newTestEnv(t)
	acct := e.createHumanAccount(t, "logoutuser")
	tok := e.issueUserToken(t, acct)

	cl := mciasv1.NewAuthServiceClient(e.conn)
	ctx := authCtx(tok)
	_, err := cl.Logout(ctx, &mciasv1.LogoutRequest{})
	if err != nil {
		t.Fatalf("Logout: %v", err)
	}

	// Second call with the same token must fail (token now revoked).
	_, err = cl.Logout(authCtx(tok), &mciasv1.LogoutRequest{})
	if err == nil {
		t.Fatal("second Logout with revoked token: expected error, got nil")
	}
}

// TestRenewToken verifies that a valid token can be renewed.
func TestRenewToken(t *testing.T) {
	e := newTestEnv(t)
	acct := e.createHumanAccount(t, "renewuser")
	tok := e.issueUserToken(t, acct)

	cl := mciasv1.NewAuthServiceClient(e.conn)
	ctx := authCtx(tok)
	resp, err := cl.RenewToken(ctx, &mciasv1.RenewTokenRequest{})
	if err != nil {
		t.Fatalf("RenewToken: %v", err)
	}
	if resp.Token == "" {
		t.Error("RenewToken: returned empty token")
	}
	if resp.Token == tok {
		t.Error("RenewToken: returned same token instead of a fresh one")
	}
}

// ---- TokenService tests ----

// TestValidateToken verifies the public ValidateToken RPC returns valid=true for
// a good token and valid=false for a garbage input (no Unauthenticated error).
func TestValidateToken(t *testing.T) {
	e := newTestEnv(t)
	acct := e.createHumanAccount(t, "validateuser")
	tok := e.issueUserToken(t, acct)

	cl := mciasv1.NewTokenServiceClient(e.conn)

	// Valid token.
	resp, err := cl.ValidateToken(context.Background(), &mciasv1.ValidateTokenRequest{Token: tok})
	if err != nil {
		t.Fatalf("ValidateToken (good): %v", err)
	}
	if !resp.Valid {
		t.Error("ValidateToken: got valid=false for a good token")
	}

	// Invalid token: should return valid=false, not an RPC error.
	resp, err = cl.ValidateToken(context.Background(), &mciasv1.ValidateTokenRequest{Token: "garbage"})
	if err != nil {
		t.Fatalf("ValidateToken (bad): unexpected RPC error: %v", err)
	}
	if resp.Valid {
		t.Error("ValidateToken: got valid=true for a garbage token")
	}
}

// TestIssueServiceTokenRequiresAdmin verifies that non-admin cannot issue tokens.
func TestIssueServiceTokenRequiresAdmin(t *testing.T) {
	e := newTestEnv(t)
	acct := e.createHumanAccount(t, "notadmin")
	tok := e.issueUserToken(t, acct)

	cl := mciasv1.NewTokenServiceClient(e.conn)
	_, err := cl.IssueServiceToken(authCtx(tok), &mciasv1.IssueServiceTokenRequest{AccountId: acct.UUID})
	if err == nil {
		t.Fatal("IssueServiceToken as non-admin: expected error, got nil")
	}
	st, _ := status.FromError(err)
	if st.Code() != codes.PermissionDenied {
		t.Errorf("got code %v, want PermissionDenied", st.Code())
	}
}

// ---- AccountService tests ----

// TestListAccountsAdminOnly verifies that ListAccounts requires admin role.
func TestListAccountsAdminOnly(t *testing.T) {
	e := newTestEnv(t)

	// Non-admin call.
	acct := e.createHumanAccount(t, "nonadmin")
	tok := e.issueUserToken(t, acct)

	cl := mciasv1.NewAccountServiceClient(e.conn)
	_, err := cl.ListAccounts(authCtx(tok), &mciasv1.ListAccountsRequest{})
	if err == nil {
		t.Fatal("ListAccounts as non-admin: expected error, got nil")
	}
	st, _ := status.FromError(err)
	if st.Code() != codes.PermissionDenied {
		t.Errorf("got code %v, want PermissionDenied", st.Code())
	}

	// Admin call.
	adminTok, _ := e.issueAdminToken(t, "adminuser")
	resp, err := cl.ListAccounts(authCtx(adminTok), &mciasv1.ListAccountsRequest{})
	if err != nil {
		t.Fatalf("ListAccounts as admin: %v", err)
	}
	if len(resp.Accounts) == 0 {
		t.Error("ListAccounts: expected at least one account")
	}
}

// TestCreateAndGetAccount exercises the full create→get lifecycle.
func TestCreateAndGetAccount(t *testing.T) {
	e := newTestEnv(t)
	adminTok, _ := e.issueAdminToken(t, "admin2")

	cl := mciasv1.NewAccountServiceClient(e.conn)

	createResp, err := cl.CreateAccount(authCtx(adminTok), &mciasv1.CreateAccountRequest{
		Username:    "newuser",
		Password:    "securepassword1",
		AccountType: "human",
	})
	if err != nil {
		t.Fatalf("CreateAccount: %v", err)
	}
	if createResp.Account == nil {
		t.Fatal("CreateAccount: returned nil account")
	}
	if createResp.Account.Id == "" {
		t.Error("CreateAccount: returned empty UUID")
	}

	// Security: credential fields must not appear in the response.
	// The Account proto has no password_hash or totp_secret fields by design.
	// Verify via GetAccount too.
	getResp, err := cl.GetAccount(authCtx(adminTok), &mciasv1.GetAccountRequest{Id: createResp.Account.Id})
	if err != nil {
		t.Fatalf("GetAccount: %v", err)
	}
	if getResp.Account.Username != "newuser" {
		t.Errorf("GetAccount: username=%q, want %q", getResp.Account.Username, "newuser")
	}
}

// TestUpdateAccount verifies that account status can be changed.
func TestUpdateAccount(t *testing.T) {
	e := newTestEnv(t)
	adminTok, _ := e.issueAdminToken(t, "admin3")

	cl := mciasv1.NewAccountServiceClient(e.conn)

	createResp, err := cl.CreateAccount(authCtx(adminTok), &mciasv1.CreateAccountRequest{
		Username:    "updateme",
		Password:    "pass12345",
		AccountType: "human",
	})
	if err != nil {
		t.Fatalf("CreateAccount: %v", err)
	}
	id := createResp.Account.Id

	_, err = cl.UpdateAccount(authCtx(adminTok), &mciasv1.UpdateAccountRequest{
		Id:     id,
		Status: "inactive",
	})
	if err != nil {
		t.Fatalf("UpdateAccount: %v", err)
	}

	getResp, err := cl.GetAccount(authCtx(adminTok), &mciasv1.GetAccountRequest{Id: id})
	if err != nil {
		t.Fatalf("GetAccount after update: %v", err)
	}
	if getResp.Account.Status != "inactive" {
		t.Errorf("after update: status=%q, want inactive", getResp.Account.Status)
	}
}

// TestSetAndGetRoles verifies that roles can be assigned and retrieved.
func TestSetAndGetRoles(t *testing.T) {
	e := newTestEnv(t)
	adminTok, _ := e.issueAdminToken(t, "admin4")

	cl := mciasv1.NewAccountServiceClient(e.conn)

	createResp, err := cl.CreateAccount(authCtx(adminTok), &mciasv1.CreateAccountRequest{
		Username:    "roleuser",
		Password:    "pass12345",
		AccountType: "human",
	})
	if err != nil {
		t.Fatalf("CreateAccount: %v", err)
	}
	id := createResp.Account.Id

	_, err = cl.SetRoles(authCtx(adminTok), &mciasv1.SetRolesRequest{
		Id:    id,
		Roles: []string{"editor", "viewer"},
	})
	if err != nil {
		t.Fatalf("SetRoles: %v", err)
	}

	getRolesResp, err := cl.GetRoles(authCtx(adminTok), &mciasv1.GetRolesRequest{Id: id})
	if err != nil {
		t.Fatalf("GetRoles: %v", err)
	}
	if len(getRolesResp.Roles) != 2 {
		t.Errorf("GetRoles: got %d roles, want 2", len(getRolesResp.Roles))
	}
}

// ---- CredentialService tests ----

// TestSetAndGetPGCreds verifies that PG credentials can be stored and retrieved.
// Security: the password is decrypted only in the GetPGCreds response; it is
// never present in account list or other responses.
func TestSetAndGetPGCreds(t *testing.T) {
	e := newTestEnv(t)
	adminTok, _ := e.issueAdminToken(t, "admin5")

	// Create a system account to hold the PG credentials.
	accCl := mciasv1.NewAccountServiceClient(e.conn)
	createResp, err := accCl.CreateAccount(authCtx(adminTok), &mciasv1.CreateAccountRequest{
		Username:    "sysaccount",
		AccountType: "system",
	})
	if err != nil {
		t.Fatalf("CreateAccount: %v", err)
	}
	accountID := createResp.Account.Id

	credCl := mciasv1.NewCredentialServiceClient(e.conn)

	_, err = credCl.SetPGCreds(authCtx(adminTok), &mciasv1.SetPGCredsRequest{
		Id: accountID,
		Creds: &mciasv1.PGCreds{
			Host:     "db.example.com",
			Port:     5432,
			Database: "mydb",
			Username: "myuser",
			Password: "supersecret",
		},
	})
	if err != nil {
		t.Fatalf("SetPGCreds: %v", err)
	}

	getResp, err := credCl.GetPGCreds(authCtx(adminTok), &mciasv1.GetPGCredsRequest{Id: accountID})
	if err != nil {
		t.Fatalf("GetPGCreds: %v", err)
	}
	if getResp.Creds == nil {
		t.Fatal("GetPGCreds: returned nil creds")
	}
	if getResp.Creds.Password != "supersecret" {
		t.Errorf("GetPGCreds: password=%q, want supersecret", getResp.Creds.Password)
	}
	if getResp.Creds.Host != "db.example.com" {
		t.Errorf("GetPGCreds: host=%q, want db.example.com", getResp.Creds.Host)
	}
}

// TestPGCredsRequireAdmin verifies that non-admin cannot access PG creds.
func TestPGCredsRequireAdmin(t *testing.T) {
	e := newTestEnv(t)
	acct := e.createHumanAccount(t, "notadmin2")
	tok := e.issueUserToken(t, acct)

	cl := mciasv1.NewCredentialServiceClient(e.conn)
	_, err := cl.GetPGCreds(authCtx(tok), &mciasv1.GetPGCredsRequest{Id: acct.UUID})
	if err == nil {
		t.Fatal("GetPGCreds as non-admin: expected error, got nil")
	}
	st, _ := status.FromError(err)
	if st.Code() != codes.PermissionDenied {
		t.Errorf("got code %v, want PermissionDenied", st.Code())
	}
}

// ---- Security: credential fields absent from responses ----

// TestCredentialFieldsAbsentFromAccountResponse verifies that account responses
// never include password_hash or totp_secret fields. The Account proto message
// does not define these fields, providing compile-time enforcement. This test
// provides a runtime confirmation by checking the returned Account struct.
func TestCredentialFieldsAbsentFromAccountResponse(t *testing.T) {
	e := newTestEnv(t)
	adminTok, _ := e.issueAdminToken(t, "admin6")

	cl := mciasv1.NewAccountServiceClient(e.conn)
	resp, err := cl.ListAccounts(authCtx(adminTok), &mciasv1.ListAccountsRequest{})
	if err != nil {
		t.Fatalf("ListAccounts: %v", err)
	}
	for _, a := range resp.Accounts {
		// Account proto only has: id, username, account_type, status,
		// totp_enabled, created_at, updated_at. No credential fields.
		// This loop body intentionally checks the fields that exist;
		// the absence of credential fields is enforced by the proto definition.
		if a.Id == "" {
			t.Error("account has empty id")
		}
	}
}