package authtokens

import (
	"golang.org/x/crypto/bcrypt"
	"src.dualinventive.com/go/authentication-service/internal/domain"
	"src.dualinventive.com/go/authentication-service/internal/pwreset"
	"src.dualinventive.com/go/authentication-service/internal/storage"
	"src.dualinventive.com/go/lib/dilog"
)

//Service contains token related operations.
type Service struct {
	Logger                dilog.Logger
	CredentialsRepository storage.CredentialsRepository
	TokenRepository       storage.TokenRepository
	ResetCodeRepository   storage.ResetCodeRepository
	TemplateRepository    pwreset.TemplateRepository
	EmailSender           pwreset.EmailSender
}

//NewService creates an authtokens.Service
func NewService(
	logger dilog.Logger,
	credentialsrepository storage.CredentialsRepository,
	tokenrepository storage.TokenRepository,
	resetcoderepository storage.ResetCodeRepository,
	templaterepository pwreset.TemplateRepository,
	emailsender pwreset.EmailSender,
) *Service {
	service := &Service{
		Logger:                logger,
		CredentialsRepository: credentialsrepository,
		TokenRepository:       tokenrepository,
		ResetCodeRepository:   resetcoderepository,
		TemplateRepository:    templaterepository,
		EmailSender:           emailsender,
	}

	return service
}

//CreateToken is used to create a new token for user
func (s *Service) CreateToken(
	credentials domain.Credentials,
	userAgent string,
) (token *domain.Token, err error) {
	user, err := s.CredentialsRepository.GetUserByUserName(credentials.User, credentials.CompanyCode)
	if err != nil {
		s.Logger.WithError(err).WithField("user", credentials.User).WithField("company", credentials.CompanyCode).
			Error("CredentialsRepository.GetUserByUserName returned error")
		return nil, &ErrInvalidCredentials{}
	}
	if !validatePassword(credentials.Password, user.PasswordHash) {
		return nil, &ErrInvalidCredentials{}
	}

	token, err = s.TokenRepository.
		CreateToken(credentials.User, credentials.CompanyCode, userAgent, resolveRights(user)...)
	if err != nil {
		s.Logger.WithError(err).WithField("user", credentials.User).
			WithField("company", credentials.CompanyCode).WithField("agent", userAgent).
			Error("TokenRepository.CreateToken returned error")
		return nil, NewErrRepositoryConnectionFailure("TokenRepository")
	}

	s.Logger.WithField("user", credentials.User).WithField("company", credentials.CompanyCode).
		WithField("agent", userAgent).WithField("token", token.Secret[:20]+"...").
		Debug("Service.CreateToken returned successful")
	return token, nil
}

//resolveRights deduplicates rights of a user by turning them into a set-like map.
//This set is then returned as an array.
func resolveRights(user *domain.User) []string {
	set := make(map[string]bool)
	for _, role := range user.Roles {
		for _, right := range role.Rights {
			set[right.Code] = true
		}
	}

	rights := make([]string, len(set))
	for right := range set {
		rights = append(rights, right)
	}

	return rights
}

//VerifyToken is used to verify if token is valid
func (s *Service) VerifyToken(
	token *domain.Token,
	rights ...string,
) (*domain.Token, error) {
	if token == nil {
		s.Logger.Warning("Service.VerifyToken got nil token")
		return nil, &ErrNilToken{}
	}

	isValid, isAuthorized, err := s.TokenRepository.IsValid(token, rights...)
	if !isValid {
		switch err {
		case storage.ErrTokenNotFound:
			s.Logger.WithField("token", token).
				Error("TokenRepository.IsValid returned ErrTokenNotFound")
			return nil, &ErrInvalidToken{}
		case storage.ErrTokenInvalid:
			s.Logger.WithField("token", token).
				Error("TokenRepository.IsValid returned ErrTokenInvalid")
			return nil, &ErrInvalidToken{}
		default:
			s.Logger.WithField("token", token).
				Error("TokenRepository.IsValid returned false")
			return nil, &ErrInvalidToken{}
		}
	}
	if isValid && !isAuthorized {
		return nil, &ErrUnauthorized{}
	}

	s.Logger.WithField("token", token.Secret[:20]+"...").
		Debug("Service.VerifyToken returned successful")
	return token, nil
}

//DeleteToken is used to remove the token for user
func (s *Service) DeleteToken(
	token *domain.Token,
) error {
	if token == nil {
		s.Logger.Warning("Service.DeleteToken got nil token")
		return &ErrNilToken{}
	}
	err := s.TokenRepository.DeleteToken(token)
	if err != nil {
		s.Logger.WithError(err).WithField("token", token).
			Error("TokenRepository.DeleteToken returned error")
		return &ErrTokenNotFound{}
	}

	s.Logger.WithField("token", token.Secret[:20]+"...").
		Debug("Service.DeleteToken returned successful")
	return nil
}

//GetUserByToken is used to retrieve user information based on the given token.
func (s *Service) GetUserByToken(
	token *domain.Token,
) (*domain.User, error) {
	if token == nil {
		s.Logger.Warning("Service.GetUserByToken got nil token")
		return nil, &ErrNilToken{}
	}

	userName, companyCode, err := s.TokenRepository.GetUserNameByToken(token)
	if err != nil {
		s.Logger.WithError(err).WithField("token", token).
			Error("TokenRepository.GetUserNameByToken returned error")
		return nil, &ErrTokenNotFound{}
	}

	user, err := s.CredentialsRepository.GetUserByUserName(userName, companyCode)
	if err != nil {
		s.Logger.WithError(err).WithField("user", userName).WithField("company", companyCode).
			Error("CredentialsRepository.GetUserByUserName returned error")
		return nil, NewErrUserNotFound(userName)
	}
	if user == nil {
		s.Logger.WithField("user", userName).WithField("company", companyCode).
			Warning("CredentialsRepository.GetUserByUserName returned nil")
		return nil, NewErrUserNotFound(userName)
	}

	s.Logger.WithField("token", token.Secret[:20]+"...").WithField("user", user).
		Debug("Service.GetUserByToken returned successful")
	return user, nil
}

//GetTokensByUser returns a list of currently active tokens by the given username.
func (s *Service) GetTokensByUser(userName string, companyCode string) ([]*domain.Token, error) {
	if userName == "" {
		s.Logger.WithField("user", userName).WithField("company", companyCode).
			Warning("Service.GetTokensByUser got empty userName")
		return nil, NewErrUserNotFound(userName)
	}
	if companyCode == "" {
		s.Logger.WithField("user", userName).WithField("company", companyCode).
			Warning("Service.GetTokensByUser got empty companyCode")
		return nil, NewErrUserNotFound(userName)
	}

	tokens, err := s.TokenRepository.GetTokens(userName, companyCode)
	if err != nil {
		s.Logger.WithError(err).WithField("user", userName).WithField("company", companyCode).
			Error("TokenRepository.GetTokens returned error")
		return nil, NewErrFailedToGetTokens(userName, err)
	}

	s.Logger.WithField("user", userName).WithField("company", companyCode).WithField("token", tokens).
		Debug("Service.GetTokensByUser returned successful")
	return tokens, nil
}

//GetOpaqueTokensByToken returns a list of active session for the current user.
func (s *Service) GetOpaqueTokensByToken(token *domain.Token) (map[string]string, error) {
	opaqueTokens := make(map[string]string)

	if token == nil {
		s.Logger.Warning("Service.GetOpaqueTokensByToken got nil token")
		return nil, &ErrNilToken{}
	}

	isValid, _, err := s.TokenRepository.IsValid(token)
	if err != nil {
		s.Logger.WithError(err).WithField("token", token).
			Error("TokenRepository.IsValid returned error")
		return nil, &ErrInvalidToken{}
	}
	if !isValid {
		s.Logger.WithField("token", token).
			Warning("TokenRepository.IsValid returned false")
		return nil, &ErrInvalidToken{}
	}

	userName, companyCode, err := s.TokenRepository.GetUserNameByToken(token)
	if err != nil {
		s.Logger.WithError(err).WithField("token", token).
			Error("TokenRepository.GetUserNameByToken returned error")
		return nil, NewErrRepositoryConnectionFailure("TokenRepository")
	}

	tokens, err := s.GetTokensByUser(userName, companyCode)
	if err != nil {
		s.Logger.WithError(err).WithField("user", userName).WithField("company", companyCode).
			Error("GetTokensByUser returned error")
		// err is NewErrUserNotFound or NewErrFailedToGetTokens
		return nil, err
	}

	for _, token := range tokens {
		opaqueID, userAgent, err := s.TokenRepository.GetTokenPayload(token)
		if err != nil {
			s.Logger.WithError(err).WithField("token", token).
				Error("TokenRepository.GetTokenPayload returned error")
		} else {
			opaqueTokens[opaqueID] = userAgent
		}
	}

	s.Logger.WithField("token", token.Secret[:20]+"...").WithField("opaque", opaqueTokens).
		Debug("Service.GetOpaqueTokensByToken returned successful")
	return opaqueTokens, nil
}

//DeleteTokenByOpaqueID removes a token by reference of it's opaque id.
func (s *Service) DeleteTokenByOpaqueID(token *domain.Token, opaqueTokenID string) error {
	if token == nil {
		s.Logger.Warning("Service.DeleteTokenByOpaqueID got nil token")
		return &ErrNilToken{}
	}

	isValid, _, err := s.TokenRepository.IsValid(token)
	if err != nil {
		s.Logger.WithError(err).WithField("token", token).
			Error("TokenRepository.IsValid returned error")
		return &ErrInvalidToken{}
	}
	if !isValid {
		s.Logger.WithField("token", token).
			Warning("TokenRepository.IsValid returned false")
		return &ErrInvalidToken{}
	}

	tokenMap := make(map[string]*domain.Token)
	userName, companyCode, err := s.TokenRepository.GetUserNameByToken(token)
	if err != nil {
		s.Logger.WithError(err).WithField("token", token).
			Error("TokenRepository.GetUserNameByToken returned error")
		return NewErrRepositoryConnectionFailure("TokenRepository")
	}

	tokens, err := s.GetTokensByUser(userName, companyCode)
	if err != nil {
		s.Logger.WithError(err).WithField("user", userName).WithField("company", companyCode).
			Error("TokenRepository.GetTokensByUser returned error")
		// err is NewErrUserNotFound or NewErrFailedToGetTokens
		return err
	}

	for _, token := range tokens {
		opaqueID, _, err := s.TokenRepository.GetTokenPayload(token) //nolint: vetshadow
		if err != nil {
			s.Logger.WithError(err).WithField("token", token).
				Error("TokenRepository.GetTokenPayload returned error")
		} else {
			tokenMap[opaqueID] = token
		}
	}

	token, ok := tokenMap[opaqueTokenID]
	if !ok {
		s.Logger.Warning("Service.DeleteTokenByOpaqueID token not found")
		return &ErrTokenNotFound{}
	}

	err = s.DeleteToken(token)
	if err != nil {
		// err is ErrNilToken or ErrTokenNotFound
		return err
	}

	s.Logger.WithField("token", token.Secret[:20]+"...").WithField("opaque", opaqueTokenID).
		Debug("Service.DeleteTokenByOpaqueID returned successful")
	return nil
}

func validatePassword(password string, hash string) bool {
	err := bcrypt.CompareHashAndPassword([]byte(hash), []byte(password))
	return err == nil
}