/*
 * Copyright (c) 2017, MegaEase
 * All rights reserved.
 *
 * Licensed 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 consulserviceregistry

import (
	"fmt"

	"github.com/hashicorp/consul/api"
)

type (
	// consulClient is the common client interface for consul.
	consulClient interface {
		ServiceRegister(registration *api.AgentServiceRegistration) error
		ServiceDeregister(instanceID string) error
		ListServiceInstances(serviceName string) ([]*api.CatalogService, error)
		ListAllServiceInstances() ([]*api.CatalogService, error)
	}

	consulAPIClient struct {
		client *api.Client
	}
)

func newConsulAPIClient(client *api.Client) *consulAPIClient {
	return &consulAPIClient{
		client: client,
	}
}

func (c *consulAPIClient) ServiceRegister(registration *api.AgentServiceRegistration) error {
	return c.client.Agent().ServiceRegister(registration)
}

func (c *consulAPIClient) ServiceDeregister(instanceID string) error {
	return c.client.Agent().ServiceDeregister(instanceID)
}

func (c *consulAPIClient) ListServiceInstances(serviceName string) ([]*api.CatalogService, error) {
	resp, _, err := c.client.Catalog().Service(serviceName, "", &api.QueryOptions{})
	if err != nil {
		return nil, err
	}
	return resp, nil
}

func (c *consulAPIClient) ListAllServiceInstances() ([]*api.CatalogService, error) {
	resp, _, err := c.client.Catalog().Services(&api.QueryOptions{})
	if err != nil {
		return nil, fmt.Errorf("pull catalog services failed: %v", err)
	}

	catalogServices := []*api.CatalogService{}
	for serviceName := range resp {
		services, _, err := c.client.Catalog().Service(serviceName, "", &api.QueryOptions{})
		if err != nil {
			return nil, fmt.Errorf("pull catalog service %s failed: %v", serviceName, err)
		}

		catalogServices = append(catalogServices, services...)
	}

	return catalogServices, nil
}