/**
* @Author: zou.yingbin
* @Create  : 2021/10/18 9:52
* @Modify  : 2021/10/18 9:52
* @note    : 查看日志文件内容
 */

package other

import (
	"bufio"
	"github.com/gin-gonic/gin"
	"html/template"
	"mtp2_if/config"
	"net/http"
	"os"
)

// LogView 查看日志文件内容
func LogView(c *gin.Context) {
	// 最多显示最新100行, 如果要查看更多, 请下载文件
	filename := c.DefaultQuery("filename", "")
	if filename == "" {
		c.JSON(http.StatusBadRequest, gin.H{"message": "param error"})
		return
	}
	str := getFileContent(filename, 200)
	//c.String(http.StatusOK,  str)

	const templateText = `
<p>
<h1></h1>
<h3> 日志文件内容(只显示最新的n行) </h3>
-------------------<br>
</p>
<p>
{{.data}}
</p>
`
	if tmpl, err := template.New("index").Parse(templateText); err == nil {
		_ = tmpl.Execute(c.Writer, gin.H{"data": template.HTML(str)})
	} else {
		c.String(400, "template err")
	}
}

// getFileContent 获取文件内容
func getFileContent(filename string, nLines int) string {
	fileDir := config.SerCfg.LogCfg.LogPath
	if len(fileDir) > 0 {
		if nLen := len(fileDir); fileDir[nLen-1] != '/' {
			fileDir += "/"
		}
	}
	file, err := os.Open(fileDir + filename)
	if err != nil {
		return "file not found"
	}
	scanner := bufio.NewScanner(file)
	total := 0
	for scanner.Scan() {
		total++
	}
	readPos := 0
	if total > nLines {
		readPos = total - nLines
	}
	txt := ""
	file.Seek(0, 0)
	index := 0
	s := bufio.NewScanner(file)
	for s.Scan() {
		if index >= readPos {
			txt += s.Text() + "<br>"
		}
		index++
	}

	return txt
}