/**
* @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"
	"fmt"
	"github.com/gin-gonic/gin"
	"html/template"
	"mtp2_if/config"
	"net/http"
	"os"
	"strings"
)

// 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"
	}
	// bufio.Scan默认缓冲区大小只有40000, 如果不设置缓存区, 遇到数据大于40000的将返回false
	const maxCapacity = 512 * 1024
	buf := make([]byte, maxCapacity)
	scanner := bufio.NewScanner(file)
	scanner.Buffer(buf, maxCapacity)
	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)
	s.Buffer(buf, maxCapacity)
	for s.Scan() {
		if index >= readPos {
			str := s.Text()
			if strings.Contains(str, "[SQL]") {
				p1 := strings.Index(str, "[SQL]")
				p2 := strings.LastIndex(str, "[")
				if p1 != -1 && p2 != -1 {
					if p1+5 < len(str) {
						p1 += 5 // 往前移5个字符, 不包含[SQL]
					}
					if p2 > p1 {
						str1 := str[0:p1]
						str2 := str[p1:p2]
						str3 := str[p2:]
						str = str1 + setFontColor(str2, "#FF00FF") + str3
						txt += str + "<br>"
					} else {
						str = setFontColor(str, "#FF00FF")
						txt += str + "<br>"
					}
				} else {
					// #FF00FF 紫色
					str = setFontColor(str, "#FF00FF")
					txt += str + "<br>"
				}
			} else if strings.Contains(str, `GET /api/`) {
				// #0000FF 蓝色
				str = setFontColor(str, "#0000FF")
				txt += str + "<br>"
			} else {
				txt += str + "<br>"
			}
		}
		index++
	}

	txt = setColorForSubString(txt, "FROM", "#DC143C")
	txt = setColorForSubString(txt, "from", "#DC143C")

	return txt
}

// 设置字体颜色
func setFontColor(str string, clr string) string {
	return fmt.Sprintf(`<font color="%v">%v</font>`, clr, str)
}

// 为某个子串设置颜色
func setColorForSubString(str string, subStr string, clr string) string {
	newStr := setFontColor(subStr, clr)
	return strings.ReplaceAll(str, subStr, newStr)
}