package aliyunnlb

import (
	"context"
	"errors"
	"fmt"
	"log/slog"
	"strings"

	aliopen "github.com/alibabacloud-go/darabonba-openapi/v2/client"
	alinlb "github.com/alibabacloud-go/nlb-20220430/v4/client"
	"github.com/alibabacloud-go/tea/tea"
	"github.com/samber/lo"

	"github.com/certimate-go/certimate/pkg/core"
	sslmgrsp "github.com/certimate-go/certimate/pkg/core/ssl-manager/providers/aliyun-cas"
)

type SSLDeployerProviderConfig struct {
	// 阿里云 AccessKeyId。
	AccessKeyId string `json:"accessKeyId"`
	// 阿里云 AccessKeySecret。
	AccessKeySecret string `json:"accessKeySecret"`
	// 阿里云资源组 ID。
	ResourceGroupId string `json:"resourceGroupId,omitempty"`
	// 阿里云地域。
	Region string `json:"region"`
	// 部署资源类型。
	ResourceType ResourceType `json:"resourceType"`
	// 负载均衡实例 ID。
	// 部署资源类型为 [RESOURCE_TYPE_LOADBALANCER] 时必填。
	LoadbalancerId string `json:"loadbalancerId,omitempty"`
	// 负载均衡监听 ID。
	// 部署资源类型为 [RESOURCE_TYPE_LISTENER] 时必填。
	ListenerId string `json:"listenerId,omitempty"`
}

type SSLDeployerProvider struct {
	config     *SSLDeployerProviderConfig
	logger     *slog.Logger
	sdkClient  *alinlb.Client
	sslManager core.SSLManager
}

var _ core.SSLDeployer = (*SSLDeployerProvider)(nil)

func NewSSLDeployerProvider(config *SSLDeployerProviderConfig) (*SSLDeployerProvider, error) {
	if config == nil {
		return nil, errors.New("the configuration of the ssl deployer provider is nil")
	}

	client, err := createSDKClient(config.AccessKeyId, config.AccessKeySecret, config.Region)
	if err != nil {
		return nil, fmt.Errorf("could not create sdk client: %w", err)
	}

	sslmgr, err := sslmgrsp.NewSSLManagerProvider(&sslmgrsp.SSLManagerProviderConfig{
		AccessKeyId:     config.AccessKeyId,
		AccessKeySecret: config.AccessKeySecret,
		ResourceGroupId: config.ResourceGroupId,
		Region: lo.
			If(config.Region == "" || strings.HasPrefix(config.Region, "cn-"), "cn-hangzhou").
			Else("ap-southeast-1"),
	})
	if err != nil {
		return nil, fmt.Errorf("could not create ssl manager: %w", err)
	}

	return &SSLDeployerProvider{
		config:     config,
		logger:     slog.Default(),
		sdkClient:  client,
		sslManager: sslmgr,
	}, nil
}

func (d *SSLDeployerProvider) SetLogger(logger *slog.Logger) {
	if logger == nil {
		d.logger = slog.New(slog.DiscardHandler)
	} else {
		d.logger = logger
	}

	d.sslManager.SetLogger(logger)
}

func (d *SSLDeployerProvider) Deploy(ctx context.Context, certPEM string, privkeyPEM string) (*core.SSLDeployResult, error) {
	// 上传证书
	upres, err := d.sslManager.Upload(ctx, certPEM, privkeyPEM)
	if err != nil {
		return nil, fmt.Errorf("failed to upload certificate file: %w", err)
	} else {
		d.logger.Info("ssl certificate uploaded", slog.Any("result", upres))
	}

	// 根据部署资源类型决定部署方式
	switch d.config.ResourceType {
	case RESOURCE_TYPE_LOADBALANCER:
		if err := d.deployToLoadbalancer(ctx, upres.ExtendedData["CertIdentifier"].(string)); err != nil {
			return nil, err
		}

	case RESOURCE_TYPE_LISTENER:
		if err := d.deployToListener(ctx, upres.ExtendedData["CertIdentifier"].(string)); err != nil {
			return nil, err
		}

	default:
		return nil, fmt.Errorf("unsupported resource type '%s'", d.config.ResourceType)
	}

	return &core.SSLDeployResult{}, nil
}

func (d *SSLDeployerProvider) deployToLoadbalancer(ctx context.Context, cloudCertId string) error {
	if d.config.LoadbalancerId == "" {
		return errors.New("config `loadbalancerId` is required")
	}

	// 查询负载均衡实例的详细信息
	// REF: https://help.aliyun.com/zh/slb/network-load-balancer/developer-reference/api-nlb-2022-04-30-getloadbalancerattribute
	getLoadBalancerAttributeReq := &alinlb.GetLoadBalancerAttributeRequest{
		LoadBalancerId: tea.String(d.config.LoadbalancerId),
	}
	getLoadBalancerAttributeResp, err := d.sdkClient.GetLoadBalancerAttribute(getLoadBalancerAttributeReq)
	d.logger.Debug("sdk request 'nlb.GetLoadBalancerAttribute'", slog.Any("request", getLoadBalancerAttributeReq), slog.Any("response", getLoadBalancerAttributeResp))
	if err != nil {
		return fmt.Errorf("failed to execute sdk request 'nlb.GetLoadBalancerAttribute': %w", err)
	}

	// 查询 TCPSSL 监听列表
	// REF: https://help.aliyun.com/zh/slb/network-load-balancer/developer-reference/api-nlb-2022-04-30-listlisteners
	listenerIds := make([]string, 0)
	listListenersLimit := int32(100)
	var listListenersToken *string = nil
	for {
		select {
		case <-ctx.Done():
			return ctx.Err()
		default:
		}

		listListenersReq := &alinlb.ListListenersRequest{
			MaxResults:       tea.Int32(listListenersLimit),
			NextToken:        listListenersToken,
			LoadBalancerIds:  []*string{tea.String(d.config.LoadbalancerId)},
			ListenerProtocol: tea.String("TCPSSL"),
		}
		listListenersResp, err := d.sdkClient.ListListeners(listListenersReq)
		d.logger.Debug("sdk request 'nlb.ListListeners'", slog.Any("request", listListenersReq), slog.Any("response", listListenersResp))
		if err != nil {
			return fmt.Errorf("failed to execute sdk request 'nlb.ListListeners': %w", err)
		}

		if listListenersResp.Body.Listeners != nil {
			for _, listener := range listListenersResp.Body.Listeners {
				listenerIds = append(listenerIds, tea.StringValue(listener.ListenerId))
			}
		}

		if len(listListenersResp.Body.Listeners) == 0 || listListenersResp.Body.NextToken == nil {
			break
		} else {
			listListenersToken = listListenersResp.Body.NextToken
		}
	}

	// 遍历更新监听证书
	if len(listenerIds) == 0 {
		d.logger.Info("no nlb listeners to deploy")
	} else {
		d.logger.Info("found tcpssl listeners to deploy", slog.Any("listenerIds", listenerIds))
		var errs []error

		for _, listenerId := range listenerIds {
			select {
			case <-ctx.Done():
				return ctx.Err()
			default:
				if err := d.updateListenerCertificate(ctx, listenerId, cloudCertId); err != nil {
					errs = append(errs, err)
				}
			}
		}

		if len(errs) > 0 {
			return errors.Join(errs...)
		}
	}

	return nil
}

func (d *SSLDeployerProvider) deployToListener(ctx context.Context, cloudCertId string) error {
	if d.config.ListenerId == "" {
		return errors.New("config `listenerId` is required")
	}

	// 更新监听
	if err := d.updateListenerCertificate(ctx, d.config.ListenerId, cloudCertId); err != nil {
		return err
	}

	return nil
}

func (d *SSLDeployerProvider) updateListenerCertificate(ctx context.Context, cloudListenerId string, cloudCertId string) error {
	// 查询监听的属性
	// REF: https://help.aliyun.com/zh/slb/network-load-balancer/developer-reference/api-nlb-2022-04-30-getlistenerattribute
	getListenerAttributeReq := &alinlb.GetListenerAttributeRequest{
		ListenerId: tea.String(cloudListenerId),
	}
	getListenerAttributeResp, err := d.sdkClient.GetListenerAttribute(getListenerAttributeReq)
	d.logger.Debug("sdk request 'nlb.GetListenerAttribute'", slog.Any("request", getListenerAttributeReq), slog.Any("response", getListenerAttributeResp))
	if err != nil {
		return fmt.Errorf("failed to execute sdk request 'nlb.GetListenerAttribute': %w", err)
	}

	// 修改监听的属性
	// REF: https://help.aliyun.com/zh/slb/network-load-balancer/developer-reference/api-nlb-2022-04-30-updatelistenerattribute
	updateListenerAttributeReq := &alinlb.UpdateListenerAttributeRequest{
		ListenerId:     tea.String(cloudListenerId),
		CertificateIds: []*string{tea.String(cloudCertId)},
	}
	updateListenerAttributeResp, err := d.sdkClient.UpdateListenerAttribute(updateListenerAttributeReq)
	d.logger.Debug("sdk request 'nlb.UpdateListenerAttribute'", slog.Any("request", updateListenerAttributeReq), slog.Any("response", updateListenerAttributeResp))
	if err != nil {
		return fmt.Errorf("failed to execute sdk request 'nlb.UpdateListenerAttribute': %w", err)
	}

	return nil
}

func createSDKClient(accessKeyId, accessKeySecret, region string) (*alinlb.Client, error) {
	// 接入点一览 https://api.aliyun.com/product/Nlb
	var endpoint string
	switch region {
	case "":
		endpoint = "nlb.cn-hangzhou.aliyuncs.com"
	default:
		endpoint = fmt.Sprintf("nlb.%s.aliyuncs.com", region)
	}

	config := &aliopen.Config{
		AccessKeyId:     tea.String(accessKeyId),
		AccessKeySecret: tea.String(accessKeySecret),
		Endpoint:        tea.String(endpoint),
	}

	client, err := alinlb.NewClient(config)
	if err != nil {
		return nil, err
	}

	return client, nil
}
