package task

import (
	"database/sql"

	"github.com/samber/lo"
	"gitlink.org.cn/cloudream/db/model"
	mysql "gitlink.org.cn/cloudream/db/sql"
	"gitlink.org.cn/cloudream/scanner/internal/config"
	"gitlink.org.cn/cloudream/utils/logger"

	agtcli "gitlink.org.cn/cloudream/rabbitmq/client/agent"
	agtmsg "gitlink.org.cn/cloudream/rabbitmq/message/agent"
	agttsk "gitlink.org.cn/cloudream/rabbitmq/message/agent/task"
)

type AgentCheckCacheTask struct {
	NodeID     int
	FileHashes []string // 需要检查的FileHash列表，如果为nil（不是为空），则代表进行全量检查
}

func NewAgentCheckCacheTask(nodeID int, fileHashes []string) *AgentCheckCacheTask {
	return &AgentCheckCacheTask{
		NodeID:     nodeID,
		FileHashes: fileHashes,
	}
}

func (t *AgentCheckCacheTask) TryMerge(other Task) bool {
	task, ok := other.(*AgentCheckCacheTask)
	if !ok {
		return false
	}

	// FileHashes为nil时代表全量检查
	if task.FileHashes == nil {
		t.FileHashes = nil
	} else if t.FileHashes != nil {
		t.FileHashes = lo.Union(t.FileHashes, task.FileHashes)
	}

	return true
}

func (t *AgentCheckCacheTask) Execute(execCtx *ExecuteContext, execOpts ExecuteOption) {
	var isComplete bool
	var caches []model.Cache

	// TODO unavailable的节点需不需要发送任务？

	if t.FileHashes == nil {
		var err error
		caches, err = mysql.Cache.GetNodeCaches(execCtx.DB.SQLCtx(), t.NodeID)
		if err != nil {
			logger.WithField("NodeID", t.NodeID).Warnf("get node caches failed, err: %s", err.Error())
			return
		}
		isComplete = true

	} else {
		for _, hash := range t.FileHashes {
			ch, err := mysql.Cache.Get(execCtx.DB.SQLCtx(), hash, t.NodeID)
			// 记录不存在则跳过
			if err == sql.ErrNoRows {
				continue
			}

			if err != nil {
				logger.WithField("FileHash", hash).WithField("NodeID", t.NodeID).Warnf("get cache failed, err: %w", err)
				return
			}

			caches = append(caches, ch)
		}
		isComplete = false
	}

	// 然后向代理端发送移动文件的请求
	agentClient, err := agtcli.NewAgentClient(t.NodeID, &config.Cfg().RabbitMQ)
	if err != nil {
		logger.WithField("NodeID", t.NodeID).Warnf("create agent client failed, err: %s", err.Error())
		return
	}
	defer agentClient.Close()

	err = agentClient.PostTask(agtmsg.NewPostTaskBody(
		agttsk.NewCheckCacheTask(isComplete, caches),
		execOpts.IsEmergency, // 继承本任务的执行选项
		execOpts.DontMerge))
	if err != nil {
		logger.WithField("NodeID", t.NodeID).Warnf("request to agent failed, err: %s", err.Error())
		return
	}
}