package dns

import (
	"time"

	"github.com/TeaOSLab/EdgeAPI/internal/errors"
	_ "github.com/go-sql-driver/mysql"
	"github.com/iwind/TeaGo/Tea"
	"github.com/iwind/TeaGo/dbs"
	"github.com/iwind/TeaGo/maps"
)

type DNSTaskType = string

const (
	DNSTaskTypeClusterChange       DNSTaskType = "clusterChange"       // 集群节点、服务发生变化
	DNSTaskTypeClusterNodesChange  DNSTaskType = "clusterNodesChange"  // 集群中节点发生变化
	DNSTaskTypeClusterRemoveDomain DNSTaskType = "clusterRemoveDomain" // 从集群中移除域名
	DNSTaskTypeNodeChange          DNSTaskType = "nodeChange"
	DNSTaskTypeServerChange        DNSTaskType = "serverChange"
	DNSTaskTypeDomainChange        DNSTaskType = "domainChange"
)

var DNSTasksNotifier = make(chan bool, 2)

type DNSTaskDAO dbs.DAO

func NewDNSTaskDAO() *DNSTaskDAO {
	return dbs.NewDAO(&DNSTaskDAO{
		DAOObject: dbs.DAOObject{
			DB:     Tea.Env,
			Table:  "edgeDNSTasks",
			Model:  new(DNSTask),
			PkName: "id",
		},
	}).(*DNSTaskDAO)
}

var SharedDNSTaskDAO *DNSTaskDAO

func init() {
	dbs.OnReady(func() {
		SharedDNSTaskDAO = NewDNSTaskDAO()
	})
}

// CreateDNSTask 生成任务
func (this *DNSTaskDAO) CreateDNSTask(tx *dbs.Tx, clusterId int64, serverId int64, nodeId int64, domainId int64, recordName string, taskType string) error {
	if clusterId <= 0 && serverId <= 0 && nodeId <= 0 && domainId <= 0 {
		return nil
	}
	err := this.Query(tx).InsertOrUpdateQuickly(maps.Map{
		"clusterId":  clusterId,
		"serverId":   serverId,
		"nodeId":     nodeId,
		"domainId":   domainId,
		"recordName": recordName,
		"updatedAt":  time.Now().Unix(),
		"type":       taskType,
		"isDone":     false,
		"isOk":       false,
		"error":      "",
		"version":    time.Now().UnixNano(),
	}, maps.Map{
		"updatedAt":  time.Now().Unix(),
		"isDone":     false,
		"isOk":       false,
		"error":      "",
		"version":    time.Now().UnixNano(),
		"countFails": 0,
	})
	if err != nil {
		return err
	}

	// 通知更新
	select {
	case DNSTasksNotifier <- true:
	default:
	}

	return nil
}

// CreateClusterTask 生成集群变更任务
func (this *DNSTaskDAO) CreateClusterTask(tx *dbs.Tx, clusterId int64, taskType DNSTaskType) error {
	return this.CreateDNSTask(tx, clusterId, 0, 0, 0, "", taskType)
}

// CreateClusterRemoveTask 生成集群删除域名任务
func (this *DNSTaskDAO) CreateClusterRemoveTask(tx *dbs.Tx, clusterId int64, domainId int64, recordName string) error {
	return this.CreateDNSTask(tx, clusterId, 0, 0, domainId, recordName, DNSTaskTypeClusterRemoveDomain)
}

// CreateNodeTask 生成节点任务
func (this *DNSTaskDAO) CreateNodeTask(tx *dbs.Tx, clusterId int64, nodeId int64, taskType DNSTaskType) error {
	return this.CreateDNSTask(tx, clusterId, 0, nodeId, 0, "", taskType)
}

// CreateServerTask 生成服务任务
func (this *DNSTaskDAO) CreateServerTask(tx *dbs.Tx, clusterId int64, serverId int64, taskType DNSTaskType) error {
	return this.CreateDNSTask(tx, clusterId, serverId, 0, 0, "", taskType)
}

// CreateDomainTask 生成域名更新任务
func (this *DNSTaskDAO) CreateDomainTask(tx *dbs.Tx, domainId int64, taskType DNSTaskType) error {
	return this.CreateDNSTask(tx, 0, 0, 0, domainId, "", taskType)
}

// FindAllDoingTasks 查找所有正在执行的任务
func (this *DNSTaskDAO) FindAllDoingTasks(tx *dbs.Tx) (result []*DNSTask, err error) {
	_, err = this.Query(tx).
		Where("(isDone=0 OR (isDone=1 AND isOk=0 AND countFails<3))"). // 3 = retry times
		Asc("version").
		AscPk().
		Slice(&result).
		FindAll()
	return
}

// FindAllDoingOrErrorTasks 查找正在执行的和错误的任务
func (this *DNSTaskDAO) FindAllDoingOrErrorTasks(tx *dbs.Tx, nodeClusterId int64) (result []*DNSTask, err error) {
	var query = this.Query(tx)
	if nodeClusterId > 0 {
		query.Attr("clusterId", nodeClusterId)
	}
	_, err = query.
		Where("(isDone=0 OR (isDone=1 AND isOk=0))").
		Asc("updatedAt").
		Asc("version").
		AscPk().
		Slice(&result).
		FindAll()
	return
}

// ExistDoingTasks 检查是否有正在执行的任务
func (this *DNSTaskDAO) ExistDoingTasks(tx *dbs.Tx) (bool, error) {
	return this.Query(tx).
		Attr("isDone", 0).
		Exist()
}

// ExistErrorTasks 检查是否有错误的任务
func (this *DNSTaskDAO) ExistErrorTasks(tx *dbs.Tx) (bool, error) {
	return this.Query(tx).
		Attr("isDone", 1).
		Attr("isOk", 0).
		Exist()
}

// DeleteDNSTask 删除任务
func (this *DNSTaskDAO) DeleteDNSTask(tx *dbs.Tx, taskId int64) error {
	_, err := this.Query(tx).
		Pk(taskId).
		Delete()
	return err
}

// DeleteAllDNSTasks 删除所有任务
func (this *DNSTaskDAO) DeleteAllDNSTasks(tx *dbs.Tx) error {
	return this.Query(tx).
		DeleteQuickly()
}

// UpdateDNSTaskError 设置任务错误
func (this *DNSTaskDAO) UpdateDNSTaskError(tx *dbs.Tx, taskId int64, err string) error {
	if taskId <= 0 {
		return errors.New("invalid taskId")
	}
	var op = NewDNSTaskOperator()
	op.Id = taskId
	op.IsDone = true
	op.Error = err
	op.IsOk = false
	op.CountFails = dbs.SQL("countFails+1")
	return this.Save(tx, op)
}

// UpdateDNSTaskDone 设置任务完成
func (this *DNSTaskDAO) UpdateDNSTaskDone(tx *dbs.Tx, taskId int64, taskVersion int64) error {
	if taskId <= 0 {
		return errors.New("invalid taskId")
	}

	currentVersion, err := this.Query(tx).
		Pk(taskId).
		Result("version").
		FindInt64Col(0)
	if err != nil {
		return err
	}

	// 如果版本号发生变化，则说明有新的要执行的任务
	if taskVersion > 0 && currentVersion > 0 && currentVersion != taskVersion {
		return nil
	}

	var op = NewDNSTaskOperator()
	op.Id = taskId
	op.IsDone = true
	op.IsOk = true
	op.CountFails = 0
	op.Error = ""
	return this.Save(tx, op)
}

// GenerateVersion 生成最新的版本号
func (this *DNSTaskDAO) GenerateVersion() int64 {
	return time.Now().UnixNano()
}

// UpdateClusterDNSTasksDone 设置所有集群任务完成
func (this *DNSTaskDAO) UpdateClusterDNSTasksDone(tx *dbs.Tx, clusterId int64, maxVersion int64) error {
	if clusterId <= 0 || maxVersion <= 0 {
		return nil
	}

	return this.Query(tx).
		Attr("clusterId", clusterId).
		Attr("isOk", false).
		Lte("version", maxVersion).
		Set("isDone", true).
		Set("isOk", true).
		Set("error", "").
		Set("countFails", 0).
		UpdateQuickly()
}

// DeleteDNSTasksWithClusterId 删除集群相关任务
func (this *DNSTaskDAO) DeleteDNSTasksWithClusterId(tx *dbs.Tx, clusterId int64) error {
	if clusterId <= 0 {
		return nil
	}
	return this.Query(tx).
		Attr("clusterId", clusterId).
		DeleteQuickly()
}