/*
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements.  See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License.  You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package v1

import (
	"encoding/json"
	"fmt"
)

// +kubebuilder:object:generate=false

// ErrorHandler is a generic interface that represent any type of error handler specification.
type ErrorHandler interface {
	Type() ErrorHandlerType
	Endpoint() *Endpoint
	Configuration() (map[string]interface{}, error)
	Validate() error
}

// baseErrorHandler is the base used for the Error Handler hierarchy.
type baseErrorHandler struct {
}

// Type --.
func (e *baseErrorHandler) Type() ErrorHandlerType {
	return errorHandlerTypeBase
}

// Endpoint --.
func (e *baseErrorHandler) Endpoint() *Endpoint {
	return nil
}

// Configuration --.
func (e *baseErrorHandler) Configuration() (map[string]interface{}, error) {
	return nil, nil
}

// Validate --.
func (e *baseErrorHandler) Validate() error {
	return nil
}

// ErrorHandlerNone --.
type ErrorHandlerNone struct {
	baseErrorHandler
}

// Type --.
func (e *ErrorHandlerNone) Type() ErrorHandlerType {
	return ErrorHandlerTypeNone
}

// Configuration --.
func (e *ErrorHandlerNone) Configuration() (map[string]interface{}, error) {
	return map[string]interface{}{}, nil
}

// ErrorHandlerLog represent a default (log) error handler type.
type ErrorHandlerLog struct {
	ErrorHandlerNone

	Parameters *ErrorHandlerParameters `json:"parameters,omitempty"`
}

// Type --.
func (e *ErrorHandlerLog) Type() ErrorHandlerType {
	return ErrorHandlerTypeLog
}

// Configuration --.
func (e *ErrorHandlerLog) Configuration() (map[string]interface{}, error) {
	properties, err := e.ErrorHandlerNone.Configuration()
	if err != nil {
		return nil, err
	}
	if e.Parameters != nil {
		var parameters map[string]interface{}
		err := json.Unmarshal(e.Parameters.RawMessage, &parameters)
		if err != nil {
			return nil, err
		}
	}

	return properties, nil
}

// ErrorHandlerSink represents a sink error handler type which behave like a dead letter channel.
type ErrorHandlerSink struct {
	ErrorHandlerLog

	DLCEndpoint *Endpoint `json:"endpoint,omitempty"`
}

// Type --.
func (e *ErrorHandlerSink) Type() ErrorHandlerType {
	return ErrorHandlerTypeSink
}

// Endpoint --.
func (e *ErrorHandlerSink) Endpoint() *Endpoint {
	return e.DLCEndpoint
}

// Configuration --.
func (e *ErrorHandlerSink) Configuration() (map[string]interface{}, error) {
	properties, err := e.ErrorHandlerLog.Configuration()
	if err != nil {
		return nil, err
	}

	return properties, err
}

// Validate --.
func (e *ErrorHandlerSink) Validate() error {
	if e.DLCEndpoint == nil {
		return fmt.Errorf("missing endpoint in Error Handler Sink")
	}
	return nil
}
