package azure

import (

	"encoding/json"

	"fmt"

	"io/ioutil"

	"net/http"

	"strings"

	"github.com/Azure/go-autorest/autorest"

)

// Copyright 2017 Microsoft Corporation

//

//  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.

type audience []string

type authentication struct {

	LoginEndpoint string   `json:"loginEndpoint"`

	Audiences     audience `json:"audiences"`

}

type environmentMetadataInfo struct {

	GalleryEndpoint string         `json:"galleryEndpoint"`

	GraphEndpoint   string         `json:"graphEndpoint"`

	PortalEndpoint  string         `json:"portalEndpoint"`

	Authentication  authentication `json:"authentication"`

}

// EnvironmentProperty represent property names that clients can override

type EnvironmentProperty string

const (

	// EnvironmentName ...

	EnvironmentName EnvironmentProperty = "name"

	// EnvironmentManagementPortalURL ..

	EnvironmentManagementPortalURL EnvironmentProperty = "managementPortalURL"

	// EnvironmentPublishSettingsURL ...

	EnvironmentPublishSettingsURL EnvironmentProperty = "publishSettingsURL"

	// EnvironmentServiceManagementEndpoint ...

	EnvironmentServiceManagementEndpoint EnvironmentProperty = "serviceManagementEndpoint"

	// EnvironmentResourceManagerEndpoint ...

	EnvironmentResourceManagerEndpoint EnvironmentProperty = "resourceManagerEndpoint"

	// EnvironmentActiveDirectoryEndpoint ...

	EnvironmentActiveDirectoryEndpoint EnvironmentProperty = "activeDirectoryEndpoint"

	// EnvironmentGalleryEndpoint ...

	EnvironmentGalleryEndpoint EnvironmentProperty = "galleryEndpoint"

	// EnvironmentKeyVaultEndpoint ...

	EnvironmentKeyVaultEndpoint EnvironmentProperty = "keyVaultEndpoint"

	// EnvironmentGraphEndpoint ...

	EnvironmentGraphEndpoint EnvironmentProperty = "graphEndpoint"

	// EnvironmentServiceBusEndpoint ...

	EnvironmentServiceBusEndpoint EnvironmentProperty = "serviceBusEndpoint"

	// EnvironmentBatchManagementEndpoint ...

	EnvironmentBatchManagementEndpoint EnvironmentProperty = "batchManagementEndpoint"

	// EnvironmentStorageEndpointSuffix ...

	EnvironmentStorageEndpointSuffix EnvironmentProperty = "storageEndpointSuffix"

	// EnvironmentSQLDatabaseDNSSuffix ...

	EnvironmentSQLDatabaseDNSSuffix EnvironmentProperty = "sqlDatabaseDNSSuffix"

	// EnvironmentTrafficManagerDNSSuffix ...

	EnvironmentTrafficManagerDNSSuffix EnvironmentProperty = "trafficManagerDNSSuffix"

	// EnvironmentKeyVaultDNSSuffix ...

	EnvironmentKeyVaultDNSSuffix EnvironmentProperty = "keyVaultDNSSuffix"

	// EnvironmentServiceBusEndpointSuffix ...

	EnvironmentServiceBusEndpointSuffix EnvironmentProperty = "serviceBusEndpointSuffix"

	// EnvironmentServiceManagementVMDNSSuffix ...

	EnvironmentServiceManagementVMDNSSuffix EnvironmentProperty = "serviceManagementVMDNSSuffix"

	// EnvironmentResourceManagerVMDNSSuffix ...

	EnvironmentResourceManagerVMDNSSuffix EnvironmentProperty = "resourceManagerVMDNSSuffix"

	// EnvironmentContainerRegistryDNSSuffix ...

	EnvironmentContainerRegistryDNSSuffix EnvironmentProperty = "containerRegistryDNSSuffix"

	// EnvironmentTokenAudience ...

	EnvironmentTokenAudience EnvironmentProperty = "tokenAudience"

)

// OverrideProperty represents property name and value that clients can override

type OverrideProperty struct {

	Key   EnvironmentProperty

	Value string

}

// EnvironmentFromURL loads an Environment from a URL

// This function is particularly useful in the Hybrid Cloud model, where one may define their own

// endpoints.

func EnvironmentFromURL(resourceManagerEndpoint string, properties ...OverrideProperty) (environment Environment, err error) {

	var metadataEnvProperties environmentMetadataInfo

	if resourceManagerEndpoint == "" {

		return environment, fmt.Errorf("Metadata resource manager endpoint is empty")

	}

	if metadataEnvProperties, err = retrieveMetadataEnvironment(resourceManagerEndpoint); err != nil {

		return environment, err

	}

	// Give priority to user's override values

	overrideProperties(&environment, properties)

	if environment.Name == "" {

		environment.Name = "HybridEnvironment"

	}

	stampDNSSuffix := environment.StorageEndpointSuffix

	if stampDNSSuffix == "" {

		stampDNSSuffix = strings.TrimSuffix(strings.TrimPrefix(strings.Replace(resourceManagerEndpoint, strings.Split(resourceManagerEndpoint, ".")[0], "", 1), "."), "/")

		environment.StorageEndpointSuffix = stampDNSSuffix

	}

	if environment.KeyVaultDNSSuffix == "" {

		environment.KeyVaultDNSSuffix = fmt.Sprintf("%s.%s", "vault", stampDNSSuffix)

	}

	if environment.KeyVaultEndpoint == "" {

		environment.KeyVaultEndpoint = fmt.Sprintf("%s%s", "https://", environment.KeyVaultDNSSuffix)

	}

	if environment.TokenAudience == "" {

		environment.TokenAudience = metadataEnvProperties.Authentication.Audiences[0]

	}

	if environment.ActiveDirectoryEndpoint == "" {

		environment.ActiveDirectoryEndpoint = metadataEnvProperties.Authentication.LoginEndpoint

	}

	if environment.ResourceManagerEndpoint == "" {

		environment.ResourceManagerEndpoint = resourceManagerEndpoint

	}

	if environment.GalleryEndpoint == "" {

		environment.GalleryEndpoint = metadataEnvProperties.GalleryEndpoint

	}

	if environment.GraphEndpoint == "" {

		environment.GraphEndpoint = metadataEnvProperties.GraphEndpoint

	}

	return environment, nil

}

func overrideProperties(environment *Environment, properties []OverrideProperty) {

	for _, property := range properties {

		switch property.Key {

		case EnvironmentName:

			{

				environment.Name = property.Value

			}

		case EnvironmentManagementPortalURL:

			{

				environment.ManagementPortalURL = property.Value

			}

		case EnvironmentPublishSettingsURL:

			{

				environment.PublishSettingsURL = property.Value

			}

		case EnvironmentServiceManagementEndpoint:

			{

				environment.ServiceManagementEndpoint = property.Value

			}

		case EnvironmentResourceManagerEndpoint:

			{

				environment.ResourceManagerEndpoint = property.Value

			}

		case EnvironmentActiveDirectoryEndpoint:

			{

				environment.ActiveDirectoryEndpoint = property.Value

			}

		case EnvironmentGalleryEndpoint:

			{

				environment.GalleryEndpoint = property.Value

			}

		case EnvironmentKeyVaultEndpoint:

			{

				environment.KeyVaultEndpoint = property.Value

			}

		case EnvironmentGraphEndpoint:

			{

				environment.GraphEndpoint = property.Value

			}

		case EnvironmentServiceBusEndpoint:

			{

				environment.ServiceBusEndpoint = property.Value

			}

		case EnvironmentBatchManagementEndpoint:

			{

				environment.BatchManagementEndpoint = property.Value

			}

		case EnvironmentStorageEndpointSuffix:

			{

				environment.StorageEndpointSuffix = property.Value

			}

		case EnvironmentSQLDatabaseDNSSuffix:

			{

				environment.SQLDatabaseDNSSuffix = property.Value

			}

		case EnvironmentTrafficManagerDNSSuffix:

			{

				environment.TrafficManagerDNSSuffix = property.Value

			}

		case EnvironmentKeyVaultDNSSuffix:

			{

				environment.KeyVaultDNSSuffix = property.Value

			}

		case EnvironmentServiceBusEndpointSuffix:

			{

				environment.ServiceBusEndpointSuffix = property.Value

			}

		case EnvironmentServiceManagementVMDNSSuffix:

			{

				environment.ServiceManagementVMDNSSuffix = property.Value

			}

		case EnvironmentResourceManagerVMDNSSuffix:

			{

				environment.ResourceManagerVMDNSSuffix = property.Value

			}

		case EnvironmentContainerRegistryDNSSuffix:

			{

				environment.ContainerRegistryDNSSuffix = property.Value

			}

		case EnvironmentTokenAudience:

			{

				environment.TokenAudience = property.Value

			}

		}

	}

}

func retrieveMetadataEnvironment(endpoint string) (environment environmentMetadataInfo, err error) {

	client := autorest.NewClientWithUserAgent("")

	managementEndpoint := fmt.Sprintf("%s%s", strings.TrimSuffix(endpoint, "/"), "/metadata/endpoints?api-version=1.0")

	req, _ := http.NewRequest("GET", managementEndpoint, nil)

	response, err := client.Do(req)

	if err != nil {

		return environment, err

	}

	defer response.Body.Close()

	jsonResponse, err := ioutil.ReadAll(response.Body)

	if err != nil {

		return environment, err

	}

	err = json.Unmarshal(jsonResponse, &environment)

	return environment, err

}