From 109f427693ed2e2282a544cd8d004a6f81276f07 Mon Sep 17 00:00:00 2001
From: dadang <dadang@pop-os.localdomain>
Date: Thu, 30 Nov 2023 09:36:05 +0700
Subject: [PATCH] feat : rotate logs

---
 README.md |   2 +-
 go.mod    |   3 ++
 rotate.go | 128 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 132 insertions(+), 1 deletion(-)
 create mode 100644 go.mod
 create mode 100644 rotate.go

diff --git a/README.md b/README.md
index b10f99e..7c94c6b 100644
--- a/README.md
+++ b/README.md
@@ -1 +1 @@
-# go-rotate-log
\ No newline at end of file
+# go-rotate-logs
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..58d8d4f
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module github.com/sutantodadang/go-rotate-logs
+
+go 1.21.4
diff --git a/rotate.go b/rotate.go
new file mode 100644
index 0000000..312ea7d
--- /dev/null
+++ b/rotate.go
@@ -0,0 +1,128 @@
+package gorotatelogs
+
+import (
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+)
+
+type Config struct {
+	Directory string
+
+	Filename string
+
+	MaxSize int // Megabyte MB
+
+	BackupName string
+
+	UsingTime bool // if true it will add "-" + FormatTime
+
+	FormatTime string // if no format it will default using rfc3399
+}
+
+type RotateLogsWriter struct {
+	config Config
+
+	mut sync.Mutex
+
+	file *os.File
+}
+
+func New(config Config) *RotateLogsWriter {
+
+	w := &RotateLogsWriter{config: config}
+
+	err := w.Rotate()
+	if err != nil {
+		return nil
+	}
+
+	return w
+
+}
+
+// write func to satisfy io.writer interface
+func (r *RotateLogsWriter) Write(output []byte) (int, error) {
+
+	r.mut.Lock()
+
+	defer r.mut.Unlock()
+
+	return r.file.Write(output)
+
+}
+
+func (r *RotateLogsWriter) Rotate() (err error) {
+
+	r.mut.Lock()
+
+	defer r.mut.Unlock()
+
+	if r.file != nil {
+
+		err = r.file.Close()
+
+		r.file = nil
+
+		if err != nil {
+			return
+		}
+
+	}
+
+	err = os.MkdirAll(r.config.Directory, os.ModePerm)
+	if err != nil {
+		return
+	}
+
+	str := strings.Split(r.config.Filename, ".log")
+
+	if r.config.UsingTime {
+
+		if r.config.FormatTime == "" {
+			r.config.FormatTime = time.RFC3339
+		}
+
+		r.config.Filename = str[0] + "-" + time.Now().Format(r.config.FormatTime) + ".log"
+
+	}
+
+	pathFile := filepath.Join(r.config.Directory, r.config.Filename)
+
+	dir, err := os.ReadDir(r.config.Filename)
+	if err != nil {
+		return
+	}
+
+	info, err := os.Stat(pathFile)
+	if err == nil {
+
+		// if file size over maxsize rename to backup and create new file
+		if (info.Size() / 1000000) > int64(r.config.MaxSize) {
+
+			newStr := strings.Split(r.config.Filename, ".log")
+
+			i := strconv.Itoa(len(dir))
+
+			err = os.Rename(pathFile, filepath.Join(r.config.Directory, newStr[0]+"-"+r.config.BackupName+"-"+i+".log"))
+			if err != nil {
+				return
+			}
+
+		}
+
+	} else {
+		return
+	}
+
+	r.file, err = os.OpenFile(pathFile, os.O_CREATE|os.O_APPEND, os.ModePerm)
+	if err != nil {
+		return
+	}
+
+	return
+
+}