package waf

import (
	"context"
	"fmt"
	"sort"
	v1 "github.com/go-nunu/nunu-layout-advanced/api/v1"
	"github.com/go-nunu/nunu-layout-advanced/internal/model"
	"github.com/go-nunu/nunu-layout-advanced/internal/repository"
	"github.com/go-nunu/nunu-layout-advanced/internal/repository/api/waf"
	"github.com/go-nunu/nunu-layout-advanced/internal/service"
	"github.com/go-nunu/nunu-layout-advanced/internal/service/api/flexCdn"
	"golang.org/x/sync/errgroup"
)

type TcpforwardingService interface {
	GetTcpforwarding(ctx context.Context, req v1.GetForwardingRequest) (v1.TcpForwardingDataRequest, error)
	AddTcpForwarding(ctx context.Context, req *v1.TcpForwardingRequest) (int, error)
	EditTcpForwarding(ctx context.Context, req *v1.TcpForwardingRequest) error
	DeleteTcpForwarding(ctx context.Context, req v1.DeleteTcpForwardingRequest) error
	GetTcpForwardingAllIpsByHostId(ctx context.Context, req v1.GetForwardingRequest) ([]v1.TcpForwardingDataRequest, error)
}

func NewTcpforwardingService(
	service *service.Service,
	tcpforwardingRepository waf.TcpforwardingRepository,
	parser service.ParserService,
	required service.RequiredService,
	crawler service.CrawlerService,
	globalRep waf.GlobalLimitRepository,
	hostRep repository.HostRepository,
	wafformatter WafFormatterService,
	cdn flexCdn.CdnService,
	proxy flexCdn.ProxyService,
	aidedTcp AidedTcpService,
) TcpforwardingService {
	return &tcpforwardingService{
		Service:                 service,
		tcpforwardingRepository: tcpforwardingRepository,
		parser:                  parser,
		required:                required,
		crawler:                 crawler,
		globalRep:               globalRep,
		hostRep:                 hostRep,
		wafformatter:            wafformatter,
		cdn:                     cdn,
		proxy:                   proxy,
		aidedTcp:                aidedTcp,
	}
}

type tcpforwardingService struct {
	*service.Service
	tcpforwardingRepository waf.TcpforwardingRepository
	parser                  service.ParserService
	required                service.RequiredService
	crawler                 service.CrawlerService
	globalRep               waf.GlobalLimitRepository
	hostRep                 repository.HostRepository
	wafformatter            WafFormatterService
	cdn                     flexCdn.CdnService
	proxy                   flexCdn.ProxyService
	aidedTcp                AidedTcpService
}

// GetTcpforwarding 获取单个TCP转发配置详情
// 该函数根据ID同时查询主记录和规则记录，并合并返回完整的配置信息
func (s *tcpforwardingService) GetTcpforwarding(ctx context.Context, req v1.GetForwardingRequest) (v1.TcpForwardingDataRequest, error) {
	// 参数验证
	if req.Id <= 0 {
		return v1.TcpForwardingDataRequest{}, fmt.Errorf("非法的ID参数: %d", req.Id)
	}

	var tcpForwarding model.Tcpforwarding
	var backend model.TcpForwardingRule
	var err error

	// 并发查询主记录和规则记录以提高性能
	g, gCtx := errgroup.WithContext(ctx)
	g.Go(func() error {
		res, e := s.tcpforwardingRepository.GetTcpforwarding(gCtx, int64(req.Id))
		if e != nil {
			return fmt.Errorf("查询TCP转发主记录失败 ID:%d, %w", req.Id, e)
		}
		if res != nil {
			tcpForwarding = *res
		}
		return nil
	})

	g.Go(func() error {
		res, e := s.tcpforwardingRepository.GetTcpForwardingIpsByID(gCtx, req.Id)
		if e != nil {
			return fmt.Errorf("查询TCP转发规则记录失败 ID:%d, %w", req.Id, e)
		}
		if res != nil {
			backend = *res
		}
		return nil
	})

	if err = g.Wait(); err != nil {
		return v1.TcpForwardingDataRequest{}, err
	}

	// 检查是否找到主记录
	if tcpForwarding.Id == 0 {
		return v1.TcpForwardingDataRequest{}, fmt.Errorf("TCP转发配置不存在 ID:%d", req.Id)
	}

	return v1.TcpForwardingDataRequest{
		Id:          tcpForwarding.Id,
		Port:        tcpForwarding.Port,
		Comment:     tcpForwarding.Comment,
		Proxy:       tcpForwarding.Proxy,
		BackendList: backend.BackendList,
	}, nil
}


// AddTcpForwarding 添加 TCP 转发配置
// 该函数完成 TCP 转发的完整创建流程：验证、创建 CDN、添加源站、配置代理、保存数据、处理异步任务
func (s *tcpforwardingService) AddTcpForwarding(ctx context.Context, req *v1.TcpForwardingRequest) (int, error) {
	// 1. 数据准备和验证
	require, formData, err := s.aidedTcp.PrepareWafData(ctx, req)
	if err != nil {
		return 0, err
	}

	if err := s.aidedTcp.ValidateAddRequest(ctx, req, require); err != nil {
		return 0, err
	}

	// 2. 创建CDN网站
	tcpId, err := s.aidedTcp.CreateCdnWebsite(ctx, formData)
	if err != nil {
		return 0, err
	}

	// 3. 添加源站
	cdnOriginIds, err := s.aidedTcp.AddOriginsToWebsite(ctx, req, tcpId)
	if err != nil {
		return 0, err
	}

	// 4. 配置代理协议
	if err := s.aidedTcp.ConfigureProxyProtocol(ctx, req, tcpId); err != nil {
		return 0, err
	}

	// 5. 保存到数据库
	id, err := s.aidedTcp.SaveToDatabase(ctx, req, require, tcpId, cdnOriginIds)
	if err != nil {
		return 0, err
	}

	// 6. 处理异步任务
	s.aidedTcp.ProcessAsyncTasks(req)

	return id, nil
}


// EditTcpForwarding 编辑 TCP 转发配置
// 该函数完成 TCP 转发的完整编辑流程：验证、更新 CDN、处理IP白名单、更新源站、更新数据库
func (s *tcpforwardingService) EditTcpForwarding(ctx context.Context, req *v1.TcpForwardingRequest) error {
	// 1. 数据准备和验证
	require, formData, err := s.aidedTcp.PrepareWafData(ctx, req)
	if err != nil {
		return err
	}

	oldData, err := s.tcpforwardingRepository.GetTcpforwarding(ctx, int64(req.TcpForwardingData.Id))
	if err != nil {
		return fmt.Errorf("获取原始数据失败: %w", err)
	}

	if err := s.aidedTcp.ValidateEditRequest(ctx, req, require, oldData); err != nil {
		return err
	}

	// 2. 更新CDN配置
	if err := s.aidedTcp.UpdateCdnConfiguration(ctx, req, oldData, require, formData); err != nil {
		return err
	}

	// 3. 获取IP数据并处理白名单
	ipData, err := s.tcpforwardingRepository.GetTcpForwardingIpsByID(ctx, req.TcpForwardingData.Id)
	if err != nil {
		return fmt.Errorf("获取IP数据失败: %w", err)
	}

	if err := s.aidedTcp.ProcessIpWhitelistChanges(ctx, req, ipData); err != nil {
		return err
	}

	// 4. 更新源站配置
	if err := s.aidedTcp.UpdateOriginServers(ctx, req, oldData, ipData); err != nil {
		return err
	}

	// 5. 更新数据库记录
	if err := s.aidedTcp.UpdateDatabaseRecords(ctx, req, oldData, require, ipData); err != nil {
		return err
	}

	return nil
}


// DeleteTcpForwarding 批量删除 TCP 转发配置
// 该函数支持批量删除多个 TCP 转发配置，对每个配置都执行完整的删除流程
func (s *tcpforwardingService) DeleteTcpForwarding(ctx context.Context, req v1.DeleteTcpForwardingRequest) error {
	// 批量删除处理
	for _, id := range req.Ids {
		if err := s.deleteSingleTcpForwarding(ctx, id, req.HostId); err != nil {
			return fmt.Errorf("删除TCP转发配置失败 ID:%d, %w", id, err)
		}
	}
	return nil
}

// deleteSingleTcpForwarding 删除单个 TCP 转发配置
// 该函数完成单个配置的完整删除流程：权限验证、删除 CDN、清理IP白名单、清理数据库
func (s *tcpforwardingService) deleteSingleTcpForwarding(ctx context.Context, id int, hostId int) error {
	// 1. 获取原始数据并验证权限
	oldData, err := s.tcpforwardingRepository.GetTcpforwarding(ctx, int64(id))
	if err != nil {
		return fmt.Errorf("获取TCP转发数据失败: %w", err)
	}

	if err := s.aidedTcp.ValidateDeletePermission(oldData, hostId); err != nil {
		return err
	}

	// 2. 删除CDN服务器
	if err := s.aidedTcp.DeleteCdnServer(ctx, oldData.CdnWebId); err != nil {
		return err
	}

	// 3. 处理IP白名单清理
	if err := s.aidedTcp.ProcessDeleteIpWhitelist(ctx, id); err != nil {
		return err
	}

	// 4. 清理数据库记录
	if err := s.aidedTcp.CleanupDatabaseRecords(ctx, id); err != nil {
		return err
	}

	return nil
}


// GetTcpForwardingAllIpsByHostId 获取指定主机的所有 TCP 转发配置列表
// 该函数使用并发查询优化性能，同时获取多个配置的详细信息并按ID降序排列
func (s *tcpforwardingService) GetTcpForwardingAllIpsByHostId(ctx context.Context, req v1.GetForwardingRequest) ([]v1.TcpForwardingDataRequest, error) {
	type CombinedResult struct {
		Id          int
		Forwarding  *model.Tcpforwarding
		BackendRule *model.TcpForwardingRule
		Err         error
	}
	g, gCtx := errgroup.WithContext(ctx)
	ids, err := s.tcpforwardingRepository.GetTcpForwardingAllIdsByID(gCtx, req.HostId)
	if err != nil {
		return nil, fmt.Errorf("GetTcpForwardingAllIds failed: %w", err)
	}
	if len(ids) == 0 {
		return nil, nil
	}
	resChan := make(chan CombinedResult, len(ids))
	g.Go(func() error {
		for _, idVal := range ids {
			currentID := idVal
			g.Go(func() error {
				var wf *model.Tcpforwarding
				var bk *model.TcpForwardingRule
				var localErr error
				wf, localErr = s.tcpforwardingRepository.GetTcpforwarding(gCtx, int64(currentID))
				if localErr != nil {
					resChan <- CombinedResult{Id: currentID, Err: localErr}
					return localErr
				}
				bk, localErr = s.tcpforwardingRepository.GetTcpForwardingIpsByID(gCtx, currentID)
				if localErr != nil {
					resChan <- CombinedResult{Id: currentID, Err: localErr}
					return localErr
				}
				resChan <- CombinedResult{Id: currentID, Forwarding: wf, BackendRule: bk}
				return nil
			})
		}
		return nil
	})
	groupErr := g.Wait()
	close(resChan)
	if groupErr != nil {
		return nil, groupErr
	}
	res := make([]v1.TcpForwardingDataRequest, 0, len(ids))
	for r := range resChan {
		if r.Err != nil {
			return nil, fmt.Errorf("received error from goroutine for ID %d: %w", r.Id, r.Err)
		}
		if r.Forwarding == nil {
			return nil, fmt.Errorf("received nil forwarding from goroutine for ID %d", r.Id)
		}

		dataReq := v1.TcpForwardingDataRequest{
			Id:      r.Forwarding.Id,
			Port:    r.Forwarding.Port,
			Comment: r.Forwarding.Comment,
			Proxy:   r.Forwarding.Proxy,
		}
		if r.BackendRule != nil {
			dataReq.BackendList = r.BackendRule.BackendList
		}
		res = append(res, dataReq)
	}

	sort.Slice(res, func(i, j int) bool {
		return res[i].Id > res[j].Id
	})
	return res, nil
}