package controller

import (
	"encoding/json"
	"errors"
	"fmt"
	"github.com/gin-gonic/gin"
	"message-pusher/channel"
	"message-pusher/common"
	"message-pusher/model"
	"net/http"
	"strconv"
	"time"
)

func keepCompatible(message *model.Message) {
	// Keep compatible with ServerChan: https://sct.ftqq.com/sendkey
	if message.Description == "" {
		message.Description = message.Short
	}
	if message.Content == "" {
		message.Content = message.Desp
	}
	if message.To == "" {
		message.To = message.OpenId
	}
}

func GetPushMessage(c *gin.Context) {
	message := model.Message{
		Title:       c.Query("title"),
		Description: c.Query("description"),
		Content:     c.Query("content"),
		URL:         c.Query("url"),
		Channel:     c.Query("channel"),
		Token:       c.Query("token"),
		To:          c.Query("to"),
		Desp:        c.Query("desp"),
		Short:       c.Query("short"),
		OpenId:      c.Query("openid"),
		Async:       c.Query("async") == "true",
	}
	keepCompatible(&message)
	pushMessageHelper(c, &message)
}

func PostPushMessage(c *gin.Context) {
	message := model.Message{
		Title:       c.PostForm("title"),
		Description: c.PostForm("description"),
		Content:     c.PostForm("content"),
		URL:         c.PostForm("url"),
		Channel:     c.PostForm("channel"),
		Token:       c.PostForm("token"),
		To:          c.PostForm("to"),
		Desp:        c.PostForm("desp"),
		Short:       c.PostForm("short"),
		OpenId:      c.PostForm("openid"),
		Async:       c.PostForm("async") == "true",
	}
	if message == (model.Message{}) {
		// Looks like the user is using JSON
		err := json.NewDecoder(c.Request.Body).Decode(&message)
		if err != nil {
			c.JSON(http.StatusOK, gin.H{
				"success": false,
				"message": "无法解析请求体，请检查其是否为合法 JSON",
			})
			return
		}
	}
	keepCompatible(&message)
	pushMessageHelper(c, &message)
}

func pushMessageHelper(c *gin.Context, message *model.Message) {
	user := model.User{Username: c.Param("username")}
	err := user.FillUserByUsername()
	if err != nil {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"message": err.Error(),
		})
		return
	}
	if user.Status == common.UserStatusNonExisted {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"message": "用户不存在",
		})
		return
	}
	if user.Status == common.UserStatusDisabled {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"message": "用户已被封禁",
		})
		return
	}
	if user.Token != "" && user.Token != " " {
		if message.Token == "" {
			message.Token = c.Request.Header.Get("Authorization")
			if message.Token == "" {
				c.JSON(http.StatusOK, gin.H{
					"success": false,
					"message": "token 为空",
				})
				return
			}
		}
		if user.Token != message.Token {
			c.JSON(http.StatusOK, gin.H{
				"success": false,
				"message": "无效的 token",
			})
			return
		}
	}
	processMessage(c, message, &user)
}

func processMessage(c *gin.Context, message *model.Message, user *model.User) {
	if message.Title == "" {
		message.Title = common.SystemName
	}
	if message.Channel == "" {
		message.Channel = user.Channel
		if message.Channel == "" {
			message.Channel = model.TypeEmail
		}
	}
	channel_, err := model.GetChannelByName(message.Channel, user.Id)
	if err != nil {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"message": "无效的渠道名称：" + message.Channel,
		})
		return
	}
	err = saveAndSendMessage(user, message, channel_)
	if err != nil {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"message": err.Error(),
		})
		return
	}
	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"message": "",
		"uuid":    message.Link,
	})
}

func saveAndSendMessage(user *model.User, message *model.Message, channel_ *model.Channel) error {
	if channel_.Status != common.ChannelStatusEnabled {
		return errors.New("该渠道已被禁用")
	}
	common.MessageCount += 1 // We don't need to use atomic here because it's not a critical value
	message.Link = common.GetUUID()
	if message.URL == "" {
		message.URL = fmt.Sprintf("%s/message/%s", common.ServerAddress, message.Link)
	}
	success := false
	if common.MessagePersistenceEnabled || user.SaveMessageToDatabase == common.SaveMessageToDatabaseAllowed {
		defer func() {
			// Update the status of the message
			status := common.MessageSendStatusFailed
			if message.Async {
				status = common.MessageSendStatusAsyncPending
			} else {
				if success {
					status = common.MessageSendStatusSent
				}
			}
			err := message.UpdateStatus(status)
			if err != nil {
				common.SysError("failed to update the status of the message: " + err.Error())
			}
			if message.Async {
				channel.AsyncMessageQueue <- message.Id
			}
		}()
		err := message.UpdateAndInsert(user.Id)
		if err != nil {
			return err
		}
		go syncMessageToUser(message, user.Id)
	} else {
		if message.Async {
			return errors.New("异步发送消息需要用户具备消息持久化的权限")
		}
		message.Link = "unsaved" // This is for user to identify whether the message is saved
		go syncMessageToUser(message, user.Id)
	}
	if !message.Async {
		err := channel.SendMessage(message, user, channel_)
		if err != nil {
			return err
		}
	}
	success = true
	return nil // After this line, the message status will be updated
}

func GetStaticFile(c *gin.Context) {
	path := c.Param("file")
	c.FileFromFS("public/static/"+path, http.FS(common.FS))
}

func RenderMessage(c *gin.Context) {
	if !common.MessageRenderEnabled {
		c.HTML(http.StatusOK, "message.html", gin.H{
			"title":       "无法渲染",
			"time":        time.Now().Format("2006-01-02 15:04:05"),
			"description": "超级管理员禁用了消息渲染",
			"content":     "很抱歉，您所使用的消息推送服务的管理员禁用了消息渲染功能，因此您的消息无法渲染。",
		})
		return
	}
	link := c.Param("link")
	if link == "unsaved" {
		c.HTML(http.StatusOK, "message.html", gin.H{
			"title":       "无法渲染",
			"time":        time.Now().Format("2006-01-02 15:04:05"),
			"description": "超级管理员禁用了消息持久化",
			"content":     "很抱歉，您所使用的消息推送服务的管理员禁用了消息持久化功能，您的消息并没有存储到数据库中，因此无法渲染。",
		})
		return
	}
	message, err := model.GetMessageByLink(link)
	if err != nil {
		c.Status(http.StatusNotFound)
		return
	}
	if message.Description != "" {
		message.Description, err = common.Markdown2HTML(message.Description)
		if err != nil {
			common.SysLog(err.Error())
		}
	}
	if message.Content != "" {
		message.HTMLContent, err = common.Markdown2HTML(message.Content)
		if err != nil {
			common.SysLog(err.Error())
		}
	}
	c.HTML(http.StatusOK, "message.html", gin.H{
		"title":       message.Title,
		"time":        time.Unix(message.Timestamp, 0).Format("2006-01-02 15:04:05"),
		"description": message.Description,
		"content":     message.HTMLContent,
	})
	return
}

func GetUserMessages(c *gin.Context) {
	userId := c.GetInt("id")
	p, _ := strconv.Atoi(c.Query("p"))
	if p < 0 {
		p = 0
	}
	messages, err := model.GetMessagesByUserId(userId, p*common.ItemsPerPage, common.ItemsPerPage)
	if err != nil {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"message": err.Error(),
		})
		return
	}
	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"message": "",
		"data":    messages,
	})
	return
}

func GetMessage(c *gin.Context) {
	messageId, _ := strconv.Atoi(c.Param("id"))
	userId := c.GetInt("id")
	message, err := model.GetMessageByIds(messageId, userId)
	if err != nil {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"message": err.Error(),
		})
		return
	}
	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"message": "",
		"data":    message,
	})
	return
}

func GetMessageStatus(c *gin.Context) {
	link := c.Param("link")
	status, err := model.GetMessageStatusByLink(link)
	if err != nil {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"message": err.Error(),
		})
		return
	}
	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"message": "",
		"status":  status,
	})
	return
}

func SearchMessages(c *gin.Context) {
	keyword := c.Query("keyword")
	messages, err := model.SearchMessages(keyword)
	if err != nil {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"message": err.Error(),
		})
		return
	}
	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"message": "",
		"data":    messages,
	})
	return
}

func ResendMessage(c *gin.Context) {
	messageId, _ := strconv.Atoi(c.Param("id"))
	userId := c.GetInt("id")
	helper := func() error {
		message, err := model.GetMessageByIds(messageId, userId)
		message.Id = 0
		if err != nil {
			return err
		}
		user, err := model.GetUserById(userId, true)
		if err != nil {
			return err
		}
		channel_, err := model.GetChannelByName(message.Channel, user.Id)
		if err != nil {
			return err
		}
		err = saveAndSendMessage(user, message, channel_)
		if err != nil {
			return err
		}
		return nil
	}
	err := helper()
	if err != nil {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"message": err.Error(),
		})
		return
	}
	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"message": "",
	})
	return
}

func DeleteMessage(c *gin.Context) {
	messageId, _ := strconv.Atoi(c.Param("id"))
	userId := c.GetInt("id")
	err := model.DeleteMessageById(messageId, userId)
	if err != nil {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"message": err.Error(),
		})
		return
	}
	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"message": "",
	})
	return
}

func DeleteAllMessages(c *gin.Context) {
	err := model.DeleteAllMessages()
	if err != nil {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"message": err.Error(),
		})
		return
	}
	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"message": "",
	})
	return
}