package system

import (
	"context"
	"errors"
	"testing"
	"time"

	"golang.org/x/crypto/bcrypt"
)

type authenticationUserRepo struct {
	UserRepo
	user          *User
	findByUUIDErr error
}

func (r *authenticationUserRepo) FindUserByUsername(context.Context, string) (*User, error) {
	return r.user, nil
}

func (r *authenticationUserRepo) FindUserByUUID(context.Context, string) (*User, error) {
	return r.user, r.findByUUIDErr
}

func (*authenticationUserRepo) HasAuthorityMenu(context.Context, uint, string) (bool, error) {
	return true, nil
}

func (*authenticationUserRepo) FillDepartmentNamePaths(context.Context, *User) error { return nil }

type authenticationSecurityRepo struct{ SecurityRepo }

func (*authenticationSecurityRepo) SecurityConfig(context.Context) (*SecurityConfig, error) {
	return &SecurityConfig{CaptchaOpen: 2, CaptchaTimeout: 60}, nil
}

type authenticationCache struct {
	activeErr error
	getErr    error
}

func (c *authenticationCache) Get(_ context.Context, key string) (string, bool, error) {
	if key == "admin" {
		return "", false, c.activeErr
	}
	if c.getErr != nil {
		return "", false, c.getErr
	}
	return "", false, nil
}
func (*authenticationCache) Set(context.Context, string, string, time.Duration) error { return nil }
func (*authenticationCache) Delete(context.Context, string) error                     { return nil }
func (*authenticationCache) Increment(context.Context, string, time.Duration) (int64, error) {
	return 1, nil
}

type authenticationSettings struct{ RuntimeSettings }

func (*authenticationSettings) UseMultipoint() bool { return true }

type authenticationIssuer struct {
	TokenIssuer
	claims     *AuthClaims
	issuedUser *User
	issuedMust bool
}

func (i *authenticationIssuer) IssueToken(user *User, _ uint, must bool, _ time.Duration) (*IssuedToken, error) {
	i.issuedUser, i.issuedMust = user, must
	return &IssuedToken{Value: "token", ExpiresAt: time.Now().Add(time.Hour), TTL: time.Hour}, nil
}

func (i *authenticationIssuer) ParseToken(string) (*AuthClaims, error) { return i.claims, nil }

func (*authenticationIssuer) ReissueToken(claims *AuthClaims, _ uint) (*IssuedToken, error) {
	return &IssuedToken{Value: "token", ExpiresAt: claims.ExpiresAt, TTL: time.Until(claims.ExpiresAt)}, nil
}

type authenticationAudit struct {
	AuditRecordRepo
	logins []*LoginLog
}

type switchAuthorityUserRepo struct {
	UserRepo
	setUserID, setAuthorityID uint
	findCalls                 int
}

func (r *switchAuthorityUserRepo) SetUserAuthority(_ context.Context, userID, authorityID uint) error {
	r.setUserID, r.setAuthorityID = userID, authorityID
	return nil
}

func (r *switchAuthorityUserRepo) FindUserByID(context.Context, uint) (*User, error) {
	r.findCalls++
	return &User{NickName: "changed-in-database"}, nil
}

type switchAuthorityIssuer struct {
	TokenIssuer
	claims      *AuthClaims
	authorityID uint
}

func (i *switchAuthorityIssuer) ReissueToken(claims *AuthClaims, authorityID uint) (*IssuedToken, error) {
	i.claims, i.authorityID = claims, authorityID
	return &IssuedToken{Value: "switched", ExpiresAt: claims.ExpiresAt, TTL: time.Until(claims.ExpiresAt)}, nil
}

func (a *authenticationAudit) RecordLogin(_ context.Context, value *LoginLog) error {
	a.logins = append(a.logins, value)
	return nil
}

type authenticationTokenRepo struct{ APITokenRepo }

func (*authenticationTokenRepo) IsTokenDisabled(context.Context, string) (bool, error) {
	return false, nil
}

func TestLoginRecordsSuccessBeforeMultipointCacheFailure(t *testing.T) {
	hash, err := bcrypt.GenerateFromPassword([]byte("secret"), bcrypt.MinCost)
	if err != nil {
		t.Fatal(err)
	}
	users := NewUserUsecase(&authenticationUserRepo{user: &User{ID: 1, Username: "admin", Password: string(hash), AuthorityID: 888, Enable: 1}})
	cacheErr := errors.New("cache unavailable")
	security := NewSecurityUsecase(&authenticationSecurityRepo{}, &authenticationCache{activeErr: cacheErr}, &authenticationSettings{}, nil)
	audit := &authenticationAudit{}
	uc := NewAuthenticationUsecase(users, security, &authenticationIssuer{}, audit)

	_, err = uc.Login(context.Background(), &LoginAttempt{Username: "admin", Password: "secret", IP: "127.0.0.1", Agent: "test"})
	if !errors.Is(err, ErrLoginState) {
		t.Fatalf("expected login-state failure, got %v", err)
	}
	if len(audit.logins) != 1 || !audit.logins[0].Status || audit.logins[0].ErrorMessage != "登录成功" || audit.logins[0].UserID != 1 {
		t.Fatalf("expected successful login audit before cache failure, got %+v", audit.logins)
	}
}

func TestRecordLoginAllowsMissingAuditRecorder(t *testing.T) {
	uc := &AuthenticationUsecase{}
	uc.recordLogin(context.Background(), &LoginAttempt{Username: "admin"}, false, "failed", 0)
}

func TestSwitchAuthorityReissuesCurrentClaimsWithoutReloadingUser(t *testing.T) {
	repo := &switchAuthorityUserRepo{}
	issuer := &switchAuthorityIssuer{}
	uc := NewAuthenticationUsecase(NewUserUsecase(repo), nil, issuer, nil)
	expiresAt := time.Now().Add(time.Hour).Truncate(time.Second)
	claims := &AuthClaims{ID: 7, UUID: "uuid", Username: "admin", NickName: "token-nickname", AuthorityID: 888, MustChangePwd: true, ExpiresAt: expiresAt}

	result, err := uc.SwitchAuthority(context.Background(), claims, 999)
	if err != nil {
		t.Fatal(err)
	}
	if repo.setUserID != 7 || repo.setAuthorityID != 999 {
		t.Fatalf("stored authority switch = user:%d authority:%d", repo.setUserID, repo.setAuthorityID)
	}
	if repo.findCalls != 0 {
		t.Fatalf("switch reloaded user %d times", repo.findCalls)
	}
	if issuer.claims != claims || issuer.authorityID != 999 {
		t.Fatalf("reissue input = claims:%p authority:%d", issuer.claims, issuer.authorityID)
	}
	if result.User.NickName != "token-nickname" || result.User.AuthorityID != 999 || !result.NeedChangePassword || !result.ExpiresAt.Equal(expiresAt) {
		t.Fatalf("switch result = %+v", result)
	}
}

func TestLoginRejectsSecurityCacheFailure(t *testing.T) {
	cacheErr := errors.New("cache unavailable")
	security := NewSecurityUsecase(&authenticationSecurityRepo{}, &authenticationCache{getErr: cacheErr}, &authenticationSettings{}, nil)
	uc := NewAuthenticationUsecase(NewUserUsecase(&authenticationUserRepo{}), security, &authenticationIssuer{}, &authenticationAudit{})

	_, err := uc.Login(context.Background(), &LoginAttempt{Username: "admin", Password: "secret", IP: "127.0.0.1"})
	if !errors.Is(err, ErrLoginState) {
		t.Fatalf("expected login-state failure, got %v", err)
	}
}

func TestAuthenticateTokenRejectsStaleUserState(t *testing.T) {
	issuedAt := time.Now().Add(-time.Hour).Truncate(time.Second)
	baseClaims := AuthClaims{ID: 7, UUID: "uuid", Username: "admin", AuthorityID: 888, IssuedAt: issuedAt, ExpiresAt: time.Now().Add(time.Hour)}
	passwordChanged := issuedAt.Add(time.Minute)
	tests := []struct {
		name string
		user *User
		want error
	}{
		{name: "disabled", user: &User{ID: 7, UUID: "uuid", Username: "admin", AuthorityID: 888, Enable: 0}, want: ErrUserDisabled},
		{name: "role removed", user: &User{ID: 7, UUID: "uuid", Username: "admin", AuthorityID: 999, Enable: 1}, want: ErrTokenDisabled},
		{name: "password changed", user: &User{ID: 7, UUID: "uuid", Username: "admin", AuthorityID: 888, Enable: 1, PasswordUpdatedAt: &passwordChanged}, want: ErrTokenDisabled},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			claims := baseClaims
			issuer := &authenticationIssuer{claims: &claims}
			security := NewSecurityUsecase(&authenticationSecurityRepo{}, &authenticationCache{}, &authenticationSettings{}, NewTokenUsecase(&authenticationTokenRepo{}))
			uc := NewAuthenticationUsecase(NewUserUsecase(&authenticationUserRepo{user: test.user}), security, issuer, &authenticationAudit{})
			_, err := uc.AuthenticateToken(context.Background(), "token")
			if !errors.Is(err, test.want) {
				t.Fatalf("AuthenticateToken error = %v, want %v", err, test.want)
			}
		})
	}
}

func TestAuthenticateTokenRefreshesFromCurrentUser(t *testing.T) {
	issuedAt := time.Now().Add(-time.Hour).Truncate(time.Second)
	claims := &AuthClaims{ID: 7, UUID: "uuid", Username: "admin", NickName: "old", AuthorityID: 888, IssuedAt: issuedAt, BufferTime: 2 * time.Hour, ExpiresAt: time.Now().Add(time.Hour)}
	user := &User{ID: 7, UUID: "uuid", Username: "admin", NickName: "current", AuthorityID: 888, Enable: 1, MustChangePassword: true}
	issuer := &authenticationIssuer{claims: claims}
	security := NewSecurityUsecase(&authenticationSecurityRepo{}, &authenticationCache{}, &authenticationSettings{}, NewTokenUsecase(&authenticationTokenRepo{}))
	uc := NewAuthenticationUsecase(NewUserUsecase(&authenticationUserRepo{user: user}), security, issuer, &authenticationAudit{})

	result, err := uc.AuthenticateToken(context.Background(), "token")
	if err != nil {
		t.Fatal(err)
	}
	if result.Refreshed == nil || result.Claims.NickName != "current" || !result.Claims.MustChangePwd {
		t.Fatalf("unexpected authentication result: %+v", result)
	}
	if issuer.issuedUser != user || !issuer.issuedMust {
		t.Fatalf("refresh used stale user state: user=%+v must=%v", issuer.issuedUser, issuer.issuedMust)
	}
}

func TestAuthenticateTokenRejectsPasswordChangeWithinIssuedAtSecond(t *testing.T) {
	issuedAt := time.Now().Add(-time.Minute).Truncate(time.Second)
	passwordAtIssue := issuedAt.Add(100 * time.Millisecond)
	passwordChanged := issuedAt.Add(900 * time.Millisecond)
	if passwordAtIssue.Unix() != passwordChanged.Unix() {
		t.Fatal("test setup did not keep password changes in one second")
	}
	claims := &AuthClaims{
		ID:              7,
		UUID:            "uuid",
		Username:        "admin",
		AuthorityID:     888,
		IssuedAt:        issuedAt,
		ExpiresAt:       time.Now().Add(time.Hour),
		PasswordVersion: passwordAtIssue.UnixNano(),
	}
	user := &User{ID: 7, UUID: "uuid", Username: "admin", AuthorityID: 888, Enable: 1, PasswordUpdatedAt: &passwordChanged}
	issuer := &authenticationIssuer{claims: claims}
	security := NewSecurityUsecase(&authenticationSecurityRepo{}, &authenticationCache{}, &authenticationSettings{}, NewTokenUsecase(&authenticationTokenRepo{}))
	uc := NewAuthenticationUsecase(NewUserUsecase(&authenticationUserRepo{user: user}), security, issuer, &authenticationAudit{})

	if _, err := uc.AuthenticateToken(context.Background(), "token"); !errors.Is(err, ErrTokenDisabled) {
		t.Fatalf("AuthenticateToken error = %v, want ErrTokenDisabled", err)
	}
}