package main

import (
	"fmt"
	"log"
	"net/http"
	"time"

	"github.com/bwmarrin/snowflake"

	"github.com/gin-gonic/gin"
)

var taskQueue = NewQueue()
var waitQueue = NewQueue()
var readyQueue = NewQueue()
var errorQueue = NewQueue()

var snowNode *snowflake.Node

func initSnowflake() {
	if snowNode == nil {
		node, err := snowflake.NewNode(1)
		if err != nil {
			panic(err)
		}
		snowNode = node
	}
}

func init() {

	log.SetFlags(log.Llongfile | log.LstdFlags)
	initOplog()
	initSnowflake()

	engine.GET("/", func(c *gin.Context) {
		c.JSON(200, Response{Code: 200, Message: "Home Page"})
	})

	task := engine.Group("/task")
	task.GET("/get", GetTask)
	task.POST("/put", PutTask)

	task.POST("/content", ContentTask)

	task.POST("/error", ErrorTask)

	task.GET("/ready", ReadyTask)
	task.POST("/ack", AckTask)
}

// GetTask 获取当前一条任务列表
func GetTask(c *gin.Context) {
	if itask, ok := taskQueue.Pop(); ok {
		task := itask.(*Task)
		waitQueue.Push(task.data["taskid"], task)
		c.JSON(http.StatusOK, Response{Code: 200, Message: "", Data: task})
		return
	}
	c.JSON(http.StatusOK, Response{Code: 204, Message: "No Task"})
}

// PutTask 把一条任务放入队列
func PutTask(c *gin.Context) {

	u := c.PostForm("url")
	if u != "" {
		data := NewTask()
		now := time.Now()
		tid := snowNode.Generate().Base64()
		label := c.PostForm("label")
		data.Store("taskid", tid)
		data.Store("url", u)
		data.Store("ts", now.UnixNano())
		data.Store("label", label)

		if callback := c.PostForm("callback"); callback != "" {
			data.Store("callback", callback)
		}
		taskQueue.Push(tid, data)
		oplog.Write(data)
		c.JSON(http.StatusOK, Response{Code: 200, Message: "ok", Data: data})
		return
	}

	c.JSON(http.StatusOK, Response{Code: 400, Message: "url 不错在"})
	return
}

// ContentTask 把一条任务放入队列
func ContentTask(c *gin.Context) {
	var err error
	tid, ok := c.GetPostForm("taskid")
	if !ok {
		c.JSON(http.StatusOK, Response{Code: 404, Message: "taskid is not set"})
	}

	if iv, ok := waitQueue.Remove(tid); ok {
		if content, ok := c.GetPostForm("content"); ok {
			task := iv.(*Task)
			task.Store("content", content)
			task.Store("status", "ready")
			readyQueue.Push(tid, task) // 进入回调发送队列.TODO: 内容持久化
			c.JSON(200, Response{Code: 200, Data: task})
			// log.Println("start callback")
			if label, ok := task.Load("label"); ok {
				log.Println(label.(string), tid)
			}
			go CallbackServer(task)
			return
		}
	}

	c.JSON(200, Response{Code: 404, Message: fmt.Sprintln("response: ", err)})
}

// AckTask 确认整个任务流程完成.
func AckTask(c *gin.Context) {
	tid := c.PostForm("taskid")
	if tid != "" {
		if itask, ok := readyQueue.Get(tid); ok {
			task := itask.(*Task)
			if status, ok := task.Load("status"); ok {
				if status.(string) == "readying" {
					task.Store("status", "readied")
					c.JSON(http.StatusOK, Response{Code: 200, Message: fmt.Sprintf("task %s readied", tid)})
					return
				}
				c.JSON(http.StatusOK, Response{Code: 200, Message: fmt.Sprintf("task %s is not readying", tid)})
				return
			}
		}
	} else {
		c.JSON(http.StatusOK, Response{Code: 404, Message: fmt.Sprintf("query taskid params must exist")})
		return
	}
	c.JSON(http.StatusOK, Response{Code: 404, Message: fmt.Sprintf("taskid: %s is not found", tid)})
}

// ReadyTask 已完成的任务. 读取期间为readying状态.
func ReadyTask(c *gin.Context) {
	tid := c.Query("taskid")
	if tid != "" {
		if itask, ok := readyQueue.Get(tid); ok {
			task := itask.(*Task)
			task.Store("status", "readying")
			c.JSON(http.StatusOK, Response{Code: 200, Data: task})
			return
		}
	} else {
		c.JSON(http.StatusOK, Response{Code: 404, Message: fmt.Sprintf("query taskid params must exist")})
		return
	}
	c.JSON(http.StatusOK, Response{Code: 404, Message: fmt.Sprintf("taskid: %s is not found", tid)})
}

// ErrorTask 任务错误无法完成
func ErrorTask(c *gin.Context) {
	tid := c.PostForm("taskid")
	errorStr := c.PostForm("error")
	if itask, ok := waitQueue.Remove(tid); ok {
		task := itask.(*Task)
		task.Store("error", errorStr)
		errorQueue.Push(tid, task) // 进入回调发送队列.TODO: 内容持久化
		c.JSON(http.StatusOK, Response{Code: 200})
		return
	}
	c.JSON(http.StatusOK, Response{Code: 404})
	return
}