From b71ede4c1ba09c700c1c58a4c0617be3f961f627 Mon Sep 17 00:00:00 2001
From: mahdi <dev@meta-tech.academy>
Date: Tue, 21 Nov 2023 17:08:40 +0100
Subject: [PATCH] sys/ssh - add DownloadFile

---
 ssh/ssh.go | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 sys/sys.go | 21 ++++++++++++++++++++
 2 files changed, 77 insertions(+)

diff --git a/ssh/ssh.go b/ssh/ssh.go
index 5ff63c0..a552473 100644
--- a/ssh/ssh.go
+++ b/ssh/ssh.go
@@ -8,8 +8,11 @@ import (
 	"net"
 	"os"
 	"os/user"
+	"strings"
 
 	"gitea.meta-tech.academy/go/core/echo"
+	"gitea.meta-tech.academy/go/core/sys"
+	"gitea.meta-tech.academy/go/core/util"
 	"github.com/pkg/sftp"
 	"golang.org/x/crypto/ssh"
 	"golang.org/x/crypto/ssh/agent"
@@ -115,6 +118,59 @@ func (s *Ssh) Scp() *sftp.Client {
 	return scp
 }
 
+type ApplyOnSize func(s *Ssh, size int64)
+
+func (s *Ssh) DownloadFile(remoteFile string, localFile string, display bool, close bool, fn ...ApplyOnSize) bool {
+	done := false
+	alreadyDownload := false
+	checksum := ""
+	buf := s.Exec(fmt.Sprintf("du --apparent-size --block-size=1  \"%s\" | awk '{ print $1}'", remoteFile), false)
+	size := util.Str2int64(buf.String(), 10, -1)
+	buf.Reset()
+	if len(fn) > 0 {
+		fn[0](s, size)
+	}
+	buf = s.Exec(fmt.Sprintf("sha256sum \"%s\" | cut -d' ' -f1", remoteFile), false)
+	checksum = strings.TrimSuffix(buf.String(), "\n")
+	buf.Reset()
+	if sys.CheckFileSize(size, localFile) {
+		if display {
+			echo.Cstyle("usageCom").Echo("    already downloaded\n")
+		}
+		alreadyDownload = sys.CheckSumFile(checksum, localFile)
+		if display {
+			if alreadyDownload {
+				echo.Cstyle("usageCom").Echo("    file integrity confirmed\n")
+			} else {
+				echo.Cstyle("podFullName").Echo("    file seems corrupt, retry download\n")
+			}
+		}
+	} else if display {
+		echo.Cstyle("podFullName").Echo("    file seems corrupt, retry download\n")
+	}
+	if !alreadyDownload {
+		scp := s.Scp()
+		if close {
+			defer scp.Close()
+		}
+		if err := s.downloadFile(size, scp, remoteFile, localFile); err != nil {
+			done = sys.CheckSumFile(checksum, localFile)
+			if display {
+				echo.Cstyle("usageCom").Echo("    file downloaded !\n")
+				if done {
+					echo.Cstyle("usageCom").Echo("    file integrity confirmed\n")
+				} else {
+					echo.Cstyle("usageCom").Echo("    file seems corrupt, abort\n")
+				}
+				echo.State(done)
+			}
+		} else {
+			log.Fatal(err)
+		}
+	}
+	return done
+}
+
 func (s *Ssh) ScpDownload(size int64, remoteFile string, localFile string, close bool) bool {
 	var done bool = false
 	scp := s.Scp()
diff --git a/sys/sys.go b/sys/sys.go
index 6f9944e..2d7f0ab 100644
--- a/sys/sys.go
+++ b/sys/sys.go
@@ -8,6 +8,7 @@ import (
 	"os"
 	"os/exec"
 	"os/signal"
+	"strings"
 	"syscall"
 
 	"golang.org/x/sys/unix"
@@ -156,3 +157,23 @@ func IsFileExists(path string) bool {
 	}
 	return exists
 }
+
+func CheckFileSize(remoteSize int64, path string) bool {
+	var size int64 = -1
+	if IsFileExists(path) {
+		if infos, err := os.Stat(path); err == nil {
+			size = infos.Size()
+		}
+	}
+	return size == remoteSize
+}
+
+func CheckSumFile(remoteChecksum string, path string) bool {
+	var checksum string = ""
+	if IsFileExists(path) {
+		var buf bytes.Buffer
+		RunBufferedCmd(exec.Command("sha256sum", path), &buf)
+		checksum = strings.Split(buf.String(), " ")[0]
+	}
+	return checksum == remoteChecksum
+}