// Transactional executes the given function in a transaction. If todo returns an error, the transaction is rolled back
func Transactional(db DB, todo func(f Application) error) error {
	var tx Transaction
	var err error
	if tx, err = db.BeginTransaction(); err != nil {
		log.Error(nil, map[string]interface{}{
			"err": err,
		}, "database BeginTransaction failed!")

		return errors.WithStack(err)
	}

	if err := todo(tx); err != nil {
		log.Debug(nil, map[string]interface{}{
			"pkg": "application",
		}, "Rolling back the transaction...")

		tx.Rollback()

		log.Error(nil, map[string]interface{}{
			"err": err,
		}, "database transaction failed!")
		return errors.WithStack(err)
	}

	log.Debug(nil, map[string]interface{}{
		"pkg": "application",
	}, "Commit the transaction!")

	return tx.Commit()
}

// Delete deletes the space with the given id
// returns NotFoundError or InternalError
func (r *GormRepository) Delete(ctx context.Context, ID satoriuuid.UUID) error {
	if ID == satoriuuid.Nil {
		log.Error(ctx, map[string]interface{}{
			"spaceID": ID.String(),
		}, "unable to find the space by ID")
		return errors.NewNotFoundError("space", ID.String())
	}
	space := Space{ID: ID}
	tx := r.db.Delete(space)

	if err := tx.Error; err != nil {
		log.Error(ctx, map[string]interface{}{
			"spaceID": ID.String(),
		}, "unable to delete the space")
		return errors.NewInternalError(err.Error())
	}
	if tx.RowsAffected == 0 {
		log.Error(ctx, map[string]interface{}{
			"spaceID": ID.String(),
		}, "none row was affected by the deletion operation")
		return errors.NewNotFoundError("space", ID.String())
	}

	return nil
}

// Save updates the given iteration in the db. Version must be the same as the one in the stored version
// returns NotFoundError, VersionConflictError or InternalError
func (m *GormIterationRepository) Save(ctx context.Context, i Iteration) (*Iteration, error) {
	itr := Iteration{}
	tx := m.db.Where("id=?", i.ID).First(&itr)
	if tx.RecordNotFound() {
		log.Error(ctx, map[string]interface{}{
			"iterationID": i.ID,
		}, "iteration cannot be found")
		// treating this as a not found error: the fact that we're using number internal is implementation detail
		return nil, errors.NewNotFoundError("iteration", i.ID.String())
	}
	if err := tx.Error; err != nil {
		log.Error(ctx, map[string]interface{}{
			"iterationID": i.ID,
			"err":         err,
		}, "unknown error happened when searching the iteration")
		return nil, errors.NewInternalError(err.Error())
	}
	tx = tx.Save(&i)
	if err := tx.Error; err != nil {
		log.Error(ctx, map[string]interface{}{
			"iterationID": i.ID,
			"err":         err,
		}, "unable to save the iterations")
		return nil, errors.NewInternalError(err.Error())
	}
	return &i, nil
}

// Migrate executes the required migration of the database on startup.
// For each successful migration, an entry will be written into the "version"
// table, that states when a certain version was reached.
func Migrate(db *sql.DB) error {
	var err error

	if db == nil {
		return errs.Errorf("Database handle is nil\n")
	}

	m := getMigrations()

	var tx *sql.Tx
	for nextVersion := int64(0); nextVersion < int64(len(m)) && err == nil; nextVersion++ {

		tx, err = db.Begin()
		if err != nil {
			return errs.Errorf("Failed to start transaction: %s\n", err)
		}

		err = migrateToNextVersion(tx, &nextVersion, m)

		if err != nil {
			oldErr := err
			log.Info(nil, map[string]interface{}{
				"pkg":         "migration",
				"nextVersion": nextVersion,
				"migrations":  m,
				"err":         err,
			}, "Rolling back transaction due to: ", err)

			if err = tx.Rollback(); err != nil {
				log.Error(nil, map[string]interface{}{
					"nextVersion": nextVersion,
					"migrations":  m,
					"err":         err,
				}, "error while rolling back transaction: ", err)
				return errs.Errorf("Error while rolling back transaction: %s\n", err)
			}
			return oldErr
		}

		if err = tx.Commit(); err != nil {
			log.Error(nil, map[string]interface{}{
				"migrations": m,
				"err":        err,
			}, "error during transaction commit: ", err)
			return errs.Errorf("Error during transaction commit: %s\n", err)
		}

	}

	if err != nil {
		log.Error(nil, map[string]interface{}{
			"migrations": m,
			"err":        err,
		}, "migration failed with error: ", err)
		return errs.Errorf("Migration failed with error: %s\n", err)
	}

	return nil
}

// Save updates the given tracker in storage.
// returns NotFoundError, ConversionError or InternalError
func (r *GormTrackerRepository) Save(ctx context.Context, t app.Tracker) (*app.Tracker, error) {
	res := Tracker{}
	id, err := strconv.ParseUint(t.ID, 10, 64)
	if err != nil || id == 0 {
		return nil, NotFoundError{entity: "tracker", ID: t.ID}
	}

	log.Info(ctx, map[string]interface{}{
		"pkg":       "remoteworkitem",
		"trackerID": id,
	}, "Looking for a tracker repository with id ", id)

	tx := r.db.First(&res, id)
	if tx.RecordNotFound() {
		log.Error(ctx, map[string]interface{}{
			"trackerID": id,
		}, "tracker repository not found")

		return nil, NotFoundError{entity: "tracker", ID: t.ID}
	}
	_, present := RemoteWorkItemImplRegistry[t.Type]
	// Ensure we support this remote tracker.
	if present != true {
		return nil, BadParameterError{parameter: "type", value: t.Type}
	}

	newT := Tracker{
		ID:   id,
		URL:  t.URL,
		Type: t.Type}

	if err := tx.Save(&newT).Error; err != nil {
		log.Error(ctx, map[string]interface{}{
			"trackerID": newT.ID,
			"err":       err,
		}, "unable to save tracker repository")
		return nil, InternalError{simpleError{err.Error()}}
	}

	log.Info(ctx, map[string]interface{}{
		"pkg":     "remoteworkitem",
		"tracker": newT.ID,
	}, "Tracker repository successfully updated")

	t2 := app.Tracker{
		ID:   strconv.FormatUint(id, 10),
		URL:  t.URL,
		Type: t.Type}

	return &t2, nil
}

// Load returns the work item link type for the given ID.
// Returns NotFoundError, ConversionError or InternalError
func (r *GormWorkItemLinkTypeRepository) Load(ctx context.Context, ID string) (*app.WorkItemLinkTypeSingle, error) {
	id, err := satoriuuid.FromString(ID)
	if err != nil {
		// treat as not found: clients don't know it must be a UUID
		return nil, errors.NewNotFoundError("work item link type", ID)
	}
	log.Info(ctx, map[string]interface{}{
		"pkg":    "link",
		"wiltID": ID,
	}, "Loading work item link type")
	res := WorkItemLinkType{}
	db := r.db.Model(&res).Where("id=?", ID).First(&res)
	if db.RecordNotFound() {
		log.Error(ctx, map[string]interface{}{
			"wiltID": ID,
		}, "work item link type not found")
		return nil, errors.NewNotFoundError("work item link type", id.String())
	}
	if db.Error != nil {
		return nil, errors.NewInternalError(db.Error.Error())
	}
	// Convert the created link type entry into a JSONAPI response
	result := ConvertLinkTypeFromModel(res)

	return &result, nil
}

// Delete deletes the work item link with the given id
// returns NotFoundError or InternalError
func (r *GormWorkItemLinkRepository) Delete(ctx context.Context, ID string) error {
	id, err := satoriuuid.FromString(ID)
	if err != nil {
		// treat as not found: clients don't know it must be a UUID
		return errors.NewNotFoundError("work item link", ID)
	}
	var link = WorkItemLink{
		ID: id,
	}
	log.Info(ctx, map[string]interface{}{
		"pkg":   "link",
		"wilID": ID,
	}, "Deleting the work item link repository")

	db := r.db.Delete(&link)
	if db.Error != nil {
		log.Error(ctx, map[string]interface{}{
			"wilID": ID,
			"err":   db.Error,
		}, "unable to delete work item link repository")
		return errors.NewInternalError(db.Error.Error())
	}
	if db.RowsAffected == 0 {
		return errors.NewNotFoundError("work item link", id.String())
	}
	return nil
}

// Show returns the authorized user based on the provided Token
func (c *UserController) Show(ctx *app.ShowUserContext) error {
	id, err := c.tokenManager.Locate(ctx)
	if err != nil {
		jerrors, _ := jsonapi.ErrorToJSONAPIErrors(goa.ErrBadRequest(err.Error()))
		return ctx.BadRequest(jerrors)
	}

	return application.Transactional(c.db, func(appl application.Application) error {
		identity, err := appl.Identities().Load(ctx, id)
		if err != nil || identity == nil {
			log.Error(ctx, map[string]interface{}{
				"identityID": id,
			}, "auth token containers id %s of unknown Identity", id)
			jerrors, _ := jsonapi.ErrorToJSONAPIErrors(goa.ErrUnauthorized(fmt.Sprintf("Auth token contains id %s of unknown Identity\n", id)))
			return ctx.Unauthorized(jerrors)
		}

		var user *account.User
		userID := identity.UserID
		if userID.Valid {
			user, err = appl.Users().Load(ctx.Context, userID.UUID)
			if err != nil {
				return jsonapi.JSONErrorResponse(ctx, errors.Wrap(err, fmt.Sprintf("Can't load user with id %s", userID.UUID)))
			}
		}

		return ctx.OK(ConvertUser(ctx.RequestData, identity, user))
	})
}

// Load returns the tracker configuration for the given id
// returns NotFoundError, ConversionError or InternalError
func (r *GormTrackerRepository) Load(ctx context.Context, ID string) (*app.Tracker, error) {
	id, err := strconv.ParseUint(ID, 10, 64)
	if err != nil || id == 0 {
		// treating this as a not found error: the fact that we're using number internal is implementation detail
		return nil, NotFoundError{"tracker", ID}
	}

	log.Info(ctx, map[string]interface{}{
		"pkg":       "remoteworkitem",
		"trackerID": id,
	}, "Loading tracker repository...")

	res := Tracker{}
	tx := r.db.First(&res, id)
	if tx.RecordNotFound() {
		log.Error(ctx, map[string]interface{}{
			"trackerID": ID,
		}, "tracker repository not found")

		return nil, NotFoundError{"tracker", ID}
	}
	if tx.Error != nil {
		return nil, InternalError{simpleError{fmt.Sprintf("error while loading: %s", tx.Error.Error())}}
	}
	t := app.Tracker{
		ID:   strconv.FormatUint(res.ID, 10),
		URL:  res.URL,
		Type: res.Type}

	return &t, nil
}

// Load returns the tracker query for the given id
// returns NotFoundError, ConversionError or InternalError
func (r *GormTrackerQueryRepository) Load(ctx context.Context, ID string) (*app.TrackerQuery, error) {
	id, err := strconv.ParseUint(ID, 10, 64)
	if err != nil || id == 0 {
		// treating this as a not found error: the fact that we're using number internal is implementation detail
		return nil, NotFoundError{"tracker query", ID}
	}

	log.Info(ctx, map[string]interface{}{
		"pkg":            "remoteworkitem",
		"trackerQueryid": id,
	}, "Loading the tracker query")

	res := TrackerQuery{}
	if r.db.First(&res, id).RecordNotFound() {
		log.Error(ctx, map[string]interface{}{
			"trackerID": id,
		}, "tracker resource not found")
		return nil, NotFoundError{"tracker query", ID}
	}
	tq := app.TrackerQuery{
		ID:        strconv.FormatUint(res.ID, 10),
		Query:     res.Query,
		Schedule:  res.Schedule,
		TrackerID: strconv.FormatUint(res.TrackerID, 10)}

	return &tq, nil
}

// LoadTypeFromDB return work item type for the given id
func (r *GormWorkItemTypeRepository) LoadTypeFromDB(ctx context.Context, name string) (*WorkItemType, error) {
	log.Logger().Infoln("Loading work item type", name)
	res, ok := cache.Get(name)
	if !ok {
		log.Info(ctx, map[string]interface{}{
			"pkg":  "workitem",
			"type": name,
		}, "Work item type doesn't exist in the cache. Loading from DB...")
		res = WorkItemType{}

		db := r.db.Model(&res).Where("name=?", name).First(&res)
		if db.RecordNotFound() {
			log.Error(ctx, map[string]interface{}{
				"witName": name,
			}, "work item type repository not found")
			return nil, errors.NewNotFoundError("work item type", name)
		}
		if err := db.Error; err != nil {
			return nil, errors.NewInternalError(err.Error())
		}
		cache.Put(res)
	}

	return &res, nil
}

// Save updates the given work item link in storage. Version must be the same as the one int the stored version.
// returns NotFoundError, VersionConflictError, ConversionError or InternalError
func (r *GormWorkItemLinkRepository) Save(ctx context.Context, lt app.WorkItemLinkSingle) (*app.WorkItemLinkSingle, error) {
	res := WorkItemLink{}
	if lt.Data.ID == nil {
		return nil, errors.NewBadParameterError("work item link", nil)
	}
	db := r.db.Model(&res).Where("id=?", *lt.Data.ID).First(&res)
	if db.RecordNotFound() {
		log.Error(ctx, map[string]interface{}{
			"wilID": *lt.Data.ID,
		}, "work item link not found")
		return nil, errors.NewNotFoundError("work item link", *lt.Data.ID)
	}
	if db.Error != nil {
		log.Error(ctx, map[string]interface{}{
			"wilID": *lt.Data.ID,
			"err":   db.Error,
		}, "unable to find work item link")
		return nil, errors.NewInternalError(db.Error.Error())
	}
	if lt.Data.Attributes.Version == nil || res.Version != *lt.Data.Attributes.Version {
		return nil, errors.NewVersionConflictError("version conflict")
	}
	if err := ConvertLinkToModel(lt, &res); err != nil {
		return nil, errs.WithStack(err)
	}
	res.Version = res.Version + 1
	if err := r.ValidateCorrectSourceAndTargetType(ctx, res.SourceID, res.TargetID, res.LinkTypeID); err != nil {
		return nil, errs.WithStack(err)
	}
	db = r.db.Save(&res)
	if db.Error != nil {
		log.Error(ctx, map[string]interface{}{
			"wilID": res.ID,
			"err":   db.Error,
		}, "unable to save work item link")
		return nil, errors.NewInternalError(db.Error.Error())
	}

	log.Info(ctx, map[string]interface{}{
		"pkg":   "link",
		"wilID": res.ID,
	}, "Work item link updated")
	result := ConvertLinkFromModel(res)
	return &result, nil
}

func fetchTrackerQueries(db *gorm.DB) []trackerSchedule {
	tsList := []trackerSchedule{}
	err := db.Table("tracker_queries").Select("trackers.id as tracker_id, trackers.url, trackers.type as tracker_type, tracker_queries.query, tracker_queries.schedule").Joins("left join trackers on tracker_queries.tracker_id = trackers.id").Where("trackers.deleted_at is NULL AND tracker_queries.deleted_at is NULL").Scan(&tsList).Error
	if err != nil {
		log.Error(nil, map[string]interface{}{
			"err": err,
		}, "fetch operation failed for tracker queries")
	}
	return tsList
}

// Generate obtain the access token from Keycloak for the test user
func (c *LoginController) Generate(ctx *app.GenerateLoginContext) error {
	if !configuration.IsPostgresDeveloperModeEnabled() {
		log.Error(ctx, map[string]interface{}{
			"method": "Generate",
		}, "Postgres developer mode not enabled")
		jerrors, _ := jsonapi.ErrorToJSONAPIErrors(goa.ErrUnauthorized("Postgres developer mode not enabled"))
		return ctx.Unauthorized(jerrors)
	}

	var scopes []account.Identity
	scopes = append(scopes, test.TestIdentity)
	scopes = append(scopes, test.TestObserverIdentity)

	client := &http.Client{Timeout: 10 * time.Second}

	username := configuration.GetKeycloakTestUserName()
	res, err := client.PostForm(configuration.GetKeycloakEndpointToken(), url.Values{
		"client_id":     {configuration.GetKeycloakClientID()},
		"client_secret": {configuration.GetKeycloakSecret()},
		"username":      {username},
		"password":      {configuration.GetKeycloakTestUserSecret()},
		"grant_type":    {"password"},
	})
	if err != nil {
		return jsonapi.JSONErrorResponse(ctx, errors.NewInternalError("error when obtaining token "+err.Error()))
	}

	token, err := readToken(res, ctx)
	if err != nil {
		log.Error(ctx, map[string]interface{}{
			"tokenEndpoint": res,
			"err":           err,
		}, "Error when unmarshal json with access token")
		return jsonapi.JSONErrorResponse(ctx, e.Wrap(err, "Error when unmarshal json with access token"))
	}

	var tokens app.AuthTokenCollection
	tokens = append(tokens, &app.AuthToken{Token: token})
	// Creates the testuser user and identity if they don't yet exist
	c.auth.CreateKeycloakUser(*token.AccessToken, ctx)

	return ctx.OK(tokens)
}

// Create creates a new work item in the repository
// returns BadParameterError, ConversionError or InternalError
func (r *GormWorkItemTypeRepository) Create(ctx context.Context, extendedTypeName *string, name string, fields map[string]app.FieldDefinition) (*app.WorkItemType, error) {
	existing, _ := r.LoadTypeFromDB(ctx, name)
	if existing != nil {
		log.Error(ctx, map[string]interface{}{"witName": name}, "unable to create new work item type")
		return nil, errors.NewBadParameterError("name", name)
	}
	allFields := map[string]FieldDefinition{}
	path := name
	if extendedTypeName != nil {
		extendedType := WorkItemType{}
		db := r.db.First(&extendedType, "name = ?", extendedTypeName)
		if db.RecordNotFound() {
			return nil, errors.NewBadParameterError("extendedTypeName", *extendedTypeName)
		}
		if err := db.Error; err != nil {
			return nil, errors.NewInternalError(err.Error())
		}
		// copy fields from extended type
		for key, value := range extendedType.Fields {
			allFields[key] = value
		}
		path = extendedType.Path + pathSep + name
	}

	// now process new fields, checking whether they are ok to add.
	for field, definition := range fields {
		existing, exists := allFields[field]
		ct, err := convertFieldTypeToModels(*definition.Type)
		if err != nil {
			return nil, errs.WithStack(err)
		}
		converted := FieldDefinition{
			Required: definition.Required,
			Type:     ct,
		}
		if exists && !compatibleFields(existing, converted) {
			return nil, fmt.Errorf("incompatible change for field %s", field)
		}
		allFields[field] = converted
	}

	created := WorkItemType{
		Version: 0,
		Name:    name,
		Path:    path,
		Fields:  allFields,
	}

	if err := r.db.Save(&created).Error; err != nil {
		return nil, errors.NewInternalError(err.Error())
	}

	result := convertTypeFromModels(&created)
	return &result, nil
}

// Load a single Iteration regardless of parent
func (m *GormIterationRepository) Load(ctx context.Context, id uuid.UUID) (*Iteration, error) {
	defer goa.MeasureSince([]string{"goa", "db", "iteration", "get"}, time.Now())
	var obj Iteration

	tx := m.db.Where("id = ?", id).First(&obj)
	if tx.RecordNotFound() {
		log.Error(ctx, map[string]interface{}{
			"iterationID": id.String(),
		}, "iteration cannot be found")
		return nil, errors.NewNotFoundError("Iteration", id.String())
	}
	if tx.Error != nil {
		log.Error(ctx, map[string]interface{}{
			"iterationID": id.String(),
			"err":         tx.Error,
		}, "unable to load the iteration")
		return nil, errors.NewInternalError(tx.Error.Error())
	}
	return &obj, nil
}

// CanStartIteration checks the rule - Only one iteration from a space can have state=start at a time.
// More rules can be added as needed in this function
func (m *GormIterationRepository) CanStartIteration(ctx context.Context, i *Iteration) (bool, error) {
	var count int64
	m.db.Model(&Iteration{}).Where("space_id=? and state=?", i.SpaceID, IterationStateStart).Count(&count)
	if count != 0 {
		log.Error(ctx, map[string]interface{}{
			"iterationID": i.ID,
			"spaceID":     i.SpaceID,
		}, "one iteration from given space is already running!")
		return false, errors.NewBadParameterError("state", "One iteration from given space is already running")
	}
	return true, nil
}

// Save a single comment
func (m *GormCommentRepository) Save(ctx context.Context, comment *Comment) (*Comment, error) {
	c := Comment{}
	tx := m.db.Where("id=?", comment.ID).First(&c)
	if tx.RecordNotFound() {
		log.Error(ctx, map[string]interface{}{
			"commentID": comment.ID,
		}, "comment not found!")
		// treating this as a not found error: the fact that we're using number internal is implementation detail
		return nil, errors.NewNotFoundError("comment", comment.ID.String())
	}
	if err := tx.Error; err != nil {
		log.Error(ctx, map[string]interface{}{
			"commentID": comment.ID,
			"err":       err,
		}, "comment search operation failed!")

		return nil, errors.NewInternalError(err.Error())
	}
	// make sure no comment is created with an empty 'markup' value
	if comment.Markup == "" {
		comment.Markup = rendering.SystemMarkupDefault
	}
	tx = tx.Save(comment)
	if err := tx.Error; err != nil {
		log.Error(ctx, map[string]interface{}{
			"commentID": comment.ID,
			"err":       err,
		}, "unable to save the comment!")

		return nil, errors.NewInternalError(err.Error())
	}

	log.Debug(ctx, map[string]interface{}{
		"pkg":       "comment",
		"commentID": comment.ID,
	}, "Comment updated!")

	return comment, nil
}

// Load a single comment regardless of parent
func (m *GormCommentRepository) Load(ctx context.Context, id uuid.UUID) (*Comment, error) {
	defer goa.MeasureSince([]string{"goa", "db", "comment", "get"}, time.Now())
	var obj Comment

	tx := m.db.Where("id=?", id).First(&obj)
	if tx.RecordNotFound() {
		log.Error(ctx, map[string]interface{}{
			"commentID": id.String(),
		}, "comment search operation failed!")

		return nil, errors.NewNotFoundError("comment", id.String())
	}
	if tx.Error != nil {
		log.Error(ctx, map[string]interface{}{
			"commentID": id.String(),
			"err":       tx.Error,
		}, "unable to load the comment")

		return nil, errors.NewInternalError(tx.Error.Error())
	}
	return &obj, nil
}

// ContextIdentity returns the identity's ID found in given context
// Uses tokenManager.Locate to fetch the identity of currently logged in user
func ContextIdentity(ctx context.Context) (string, error) {
	tm := ReadTokenManagerFromContext(ctx)
	if tm == nil {
		log.Error(ctx, map[string]interface{}{
			"token": tm,
		}, "missing token manager")

		return "", errs.New("Missing token manager")
	}
	uuid, err := tm.Locate(ctx)
	if err != nil {
		// TODO : need a way to define user as Guest
		log.Error(ctx, map[string]interface{}{
			"uuid": uuid,
			"tm":   tm,
			"err":  err,
		}, "identity belongs to a Guest User")

		return "", errs.WithStack(err)
	}
	return uuid.String(), nil
}