package flow

import (
	"log"
	"time"
)

// FlowContext 流程的上下文, 用于传递每个流程之间的参数
type FlowContext struct {
	RootFlow    *Flow
	CurrentFlow *FlowNode

	CurrentWrite []byte // 8 byte
	CurrentRead  []byte // 14 byte
}

// FlowNode 流程节点
type FlowNode struct {
	Name string
	Path string

	prev *FlowNode
	next *FlowNode

	Task func(cxt *FlowContext) int
}

// Write 该写入函数包含了 自动封装日志格式
func (cxt *FlowContext) Write(flag OperatorFlag) {

	operator.portWriterLock.Lock()
	wbuf := OperatorOption(flag)
	operator.port.Write(wbuf)
	operator.port.Flush()
	cxt.CurrentWrite = wbuf
	operator.portWriterLock.Unlock()

	if len(wbuf) == 8 {
		flowpath := cxt.CurrentFlow.Path + ">" + cxt.CurrentFlow.Name // 路径
		_, err := operator.oplog.Exec("insert into operator(ts , rootflow, flowpath, writelog, readlog) values(?,?,?,?,?)", time.Now().Unix(), cxt.RootFlow.Name, flowpath, cxt.CurrentWrite, cxt.CurrentRead)
		if err != nil {
			log.Println("日志写入错误: ", err)
		}
	} else {
		log.Println("write buffer len is not equal to 8, now is", len(wbuf), "buf: ", wbuf)
	}

}

// Sensor 返回传感器数值, 每次调用都是最新的.
func (cxt *FlowContext) Sensor() *Sensor {
	buf := make([]byte, 14)

	operator.portReaderLock.Lock()
	n, err := operator.port.Read(buf)
	cxt.CurrentRead = buf
	operator.portReaderLock.Unlock()
	if err != nil {
		log.Println("read bufferr is error:", err)
	} else {

		if n == 14 {
			return NewSensor(buf)
		}
		//TODO: 断包, 沾包 处理
		log.Println("读取长度不等于14, len = ", n)
	}

	return nil
}

// Flow 流程
type Flow struct {
	Name string

	Context *FlowContext // 执行流程时候的上下文

	Head *FlowNode
	Tail *FlowNode
}

// Add 添加
func (flow *Flow) Add(name string, task func(cxt *FlowContext) int) {

	node := &FlowNode{Name: name, Task: task}

	if flow.Head == nil {
		flow.Head = node
		flow.Tail = node

		node.Path = node.Name
		return
	}

	node.Path = flow.Tail.Path + ">" + flow.Tail.Name

	flow.Tail.next = node
	flow.Tail = node

	if node.next != nil {
		panic("tail next is not nil")
	}
}