From 8f93fa1f891d6dda43297f4fc4f50c9baee87394 Mon Sep 17 00:00:00 2001
From: Dan Engelbrecht <dan@engelbrecht.com>
Date: Sun, 29 May 2022 23:42:34 +0200
Subject: [PATCH] pop command

---
 commands/cmd_pop.go  | 105 +++++++++++++++++++++++++++++++++++++++++++
 commands/cmd_push.go |  26 ++++++++++-
 commands/commands.go |   2 +-
 3 files changed, 131 insertions(+), 2 deletions(-)
 create mode 100644 commands/cmd_pop.go

diff --git a/commands/cmd_pop.go b/commands/cmd_pop.go
new file mode 100644
index 00000000..3d3466cf
--- /dev/null
+++ b/commands/cmd_pop.go
@@ -0,0 +1,105 @@
+package commands
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/DanEngelbrecht/golongtail/longtailutils"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+func pop(
+	numWorkerCount int,
+	stackOffset uint32,
+	retainPermissions bool,
+	enableFileMapping bool) ([]longtailutils.StoreStat, []longtailutils.TimeStat, error) {
+	const fname = "get"
+	log := logrus.WithFields(logrus.Fields{
+		"fname":             fname,
+		"stackOffset":       stackOffset,
+		"numWorkerCount":    numWorkerCount,
+		"retainPermissions": retainPermissions,
+		"enableFileMapping": enableFileMapping,
+	})
+	log.Debug(fname)
+
+	storeStats := []longtailutils.StoreStat{}
+	timeStats := []longtailutils.TimeStat{}
+
+	setupStartTime := time.Now()
+
+	logFile := ".longtail/log"
+	targetFolderPath := "."
+	excludeFilterRegEx := "^\\.longtail(/|$)"
+	blobStoreURI := ".longtail/store"
+
+	history := ""
+	_, err := os.Stat(logFile)
+	if err == nil {
+		historyBytes, err := ioutil.ReadFile(logFile)
+		if err != nil {
+			return storeStats, timeStats, errors.Wrap(err, fname)
+		}
+		history = string(historyBytes)
+	} else if !os.IsNotExist(err) {
+		return storeStats, timeStats, errors.Wrap(err, fname)
+	}
+
+	historyLines := make([]string, 0)
+	if history != "" {
+		historyLines = strings.Split(string(history), "\n")
+	}
+
+	if len(historyLines) < int(stackOffset+1) {
+		err = fmt.Errorf("stack offset out of bounds for `%s`, log contains `%d` entries, need `%d` entries", logFile, len(historyLines), int(stackOffset+1))
+		return storeStats, timeStats, errors.Wrap(err, fname)
+	}
+
+	sourceFilePath := historyLines[len(historyLines)-int(stackOffset+1)]
+	versionLocalStoreIndexPath := sourceFilePath[:len(sourceFilePath)-3] + "lsi"
+
+	setupTime := time.Since(setupStartTime)
+	timeStats = append(timeStats, longtailutils.TimeStat{"Setup", setupTime})
+
+	downSyncStoreStats, downSyncTimeStats, err := downsync(
+		numWorkerCount,
+		blobStoreURI,
+		sourceFilePath,
+		targetFolderPath,
+		"",
+		"",
+		retainPermissions,
+		false,
+		versionLocalStoreIndexPath,
+		"",
+		excludeFilterRegEx,
+		true,
+		false,
+		enableFileMapping)
+
+	storeStats = append(storeStats, downSyncStoreStats...)
+	timeStats = append(timeStats, downSyncTimeStats...)
+
+	return storeStats, timeStats, errors.Wrap(err, fname)
+}
+
+type PopCmd struct {
+	StackOffset uint32 `name:"offset" help:"Offset into log, zero equals top of stack (latest push)" default:"0"`
+	RetainPermissionsOption
+	EnableFileMappingOption
+}
+
+func (r *PopCmd) Run(ctx *Context) error {
+	storeStats, timeStats, err := pop(
+		ctx.NumWorkerCount,
+		r.StackOffset,
+		r.RetainPermissions,
+		r.EnableFileMapping)
+	ctx.StoreStats = append(ctx.StoreStats, storeStats...)
+	ctx.TimeStats = append(ctx.TimeStats, timeStats...)
+	return err
+}
diff --git a/commands/cmd_push.go b/commands/cmd_push.go
index f17ad45a..fdcd72ef 100644
--- a/commands/cmd_push.go
+++ b/commands/cmd_push.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"strings"
 	"time"
 
 	"github.com/DanEngelbrecht/golongtail/longtailutils"
@@ -40,7 +41,8 @@ func push(
 	storeStats := []longtailutils.StoreStat{}
 	timeStats := []longtailutils.TimeStat{}
 
-	excludeFilterRegEx := ".longtail/*."
+	logFile := ".longtail/log"
+	excludeFilterRegEx := "^\\.longtail(/|$)"
 	sourceFolderPath := ""
 	targetFilePath := ".longtail/tmp.lvi"
 	blobStoreURI := ".longtail/store"
@@ -93,6 +95,28 @@ func push(
 		return storeStats, timeStats, errors.Wrap(err, fname)
 	}
 
+	history := ""
+	_, err = os.Stat(logFile)
+	if err == nil {
+		historyBytes, err := ioutil.ReadFile(logFile)
+		if err != nil {
+			return storeStats, timeStats, errors.Wrap(err, fname)
+		}
+		history = string(historyBytes)
+	} else if !os.IsNotExist(err) {
+		return storeStats, timeStats, errors.Wrap(err, fname)
+	}
+
+	historyLines := make([]string, 0)
+	if history != "" {
+		historyLines = strings.Split(string(history), "\n")
+	}
+
+	historyLines = append(historyLines, hashedVersionFilePath)
+	history = strings.Join(historyLines, "\n")
+
+	ioutil.WriteFile(logFile, []byte(history), 0666)
+
 	storeStats = append(storeStats, upSyncStoreStats...)
 	timeStats = append(timeStats, upSyncTimeStats...)
 
diff --git a/commands/commands.go b/commands/commands.go
index 75701874..199b7b60 100644
--- a/commands/commands.go
+++ b/commands/commands.go
@@ -30,5 +30,5 @@ var Cli struct {
 	Unpack                  UnpackCmd                  `cmd:"" name:"unpack" help:"Unpack an archive"`
 	Put                     PutCmd                     `cmd:"" name:"put" help:"Upload a folder"`
 	Push                    PushCmd                    `cmd:"" name:"push" help:"Makes a snapshot of the current folder and store in .longtail folder"`
-	//	Pop                     PopCmd                     `cmd:"" name:"pop" help:"Restores the most current snapshot to the current folder from store in .longtail folder"`
+	Pop                     PopCmd                     `cmd:"" name:"pop" help:"Restores the most current snapshot to the current folder from store in .longtail folder"`
 }