From fccee426136fe1e849b608626410aa542206e816 Mon Sep 17 00:00:00 2001
From: Fabio Forni <development@redaril.me>
Date: Mon, 20 Nov 2023 15:23:31 +0100
Subject: [PATCH] installer: Add the DryRun StepWriter

---
 installer/steps.go             | 14 +++---
 installer/stepwriter/dryrun.go | 79 ++++++++++++++++++++++++++++++++++
 installer/stepwriter/file.go   | 11 +++++
 3 files changed, 95 insertions(+), 9 deletions(-)
 create mode 100644 installer/stepwriter/dryrun.go
 create mode 100644 installer/stepwriter/file.go

diff --git a/installer/steps.go b/installer/steps.go
index 4e2c9b9..0d0c4b7 100644
--- a/installer/steps.go
+++ b/installer/steps.go
@@ -8,6 +8,7 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/livingsilver94/backee/installer/stepwriter"
 	"github.com/livingsilver94/backee/repo"
 	"github.com/livingsilver94/backee/service"
 )
@@ -16,7 +17,7 @@ type StepWriter interface {
 	Setup(script string) error
 	InstallPackages(fullCmd []string) error
 	SymlinkFile(dst service.FilePath, src string) error
-	CopyFile(dst service.FilePath, src string) error
+	CopyFile(dst service.FilePath, src stepwriter.FileContent) error
 	Finalize(script string) error
 }
 
@@ -84,23 +85,18 @@ func (s Steps) CopyFiles(repo repo.Repo, vars repo.Variables) error {
 	}
 	s.log.Info("Copying files")
 
-	lnDir, err := repo.DataDir(s.srv.Name)
+	_, err := repo.DataDir(s.srv.Name)
 	if err != nil {
 		return err
 	}
 	tmpl := NewTemplate(s.srv.Name, vars)
 	dest := &strings.Builder{}
-	for srcFile, dstFile := range s.srv.Copies {
+	for _, dstFile := range s.srv.Copies {
 		err := tmpl.ReplaceString(dstFile.Path, dest)
 		if err != nil {
 			return err
 		}
-		err = s.wri.CopyFile(
-			service.FilePath{Path: dest.String(), Mode: dstFile.Mode},
-			filepath.Join(lnDir, srcFile))
-		if err != nil {
-			return err
-		}
+		// TODO: read file.
 		dest.Reset()
 	}
 	return nil
diff --git a/installer/stepwriter/dryrun.go b/installer/stepwriter/dryrun.go
new file mode 100644
index 0000000..b54bf95
--- /dev/null
+++ b/installer/stepwriter/dryrun.go
@@ -0,0 +1,79 @@
+// SPDX-FileCopyrightText: Fabio Forni <development@redaril.me>
+// SPDX-License-Identifier: MPL-2.0
+
+package stepwriter
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"strings"
+
+	"github.com/livingsilver94/backee/service"
+)
+
+var (
+	buf = &strings.Builder{}
+)
+
+type DryRun struct{}
+
+func (DryRun) Setup(script string) error {
+	return printMultiline(strings.NewReader(script))
+}
+
+func (DryRun) InstallPackages(fullCmd []string) error {
+	return printf("Will run %q", strings.Join(fullCmd, " "))
+}
+
+func (DryRun) SymlinkFile(dst service.FilePath, src string) error {
+	defer buf.Reset()
+	fmt.Fprintf(buf, "%s → %s", src, dst.Path)
+	if dst.Mode != 0 {
+		fmt.Fprintf(buf, " with permission %o", dst.Mode)
+	}
+	return printLine(buf.String())
+}
+
+func (DryRun) CopyFile(dst service.FilePath, file FileContent) error {
+	defer buf.Reset()
+	fmt.Fprintf(buf, "Will write %s", dst.Path)
+	if dst.Mode != 0 {
+		fmt.Fprintf(buf, " with permission %o", dst.Mode)
+	}
+	buf.WriteString(" with the following content:")
+	if file.Binary {
+		buf.WriteString(" *binary*")
+		return printLine(buf.String())
+	}
+	err := printLine(buf.String())
+	if err != nil {
+		return err
+	}
+	return printMultiline(file.Content)
+}
+
+func (DryRun) Finalize(script string) error {
+	return printMultiline(strings.NewReader(script))
+}
+
+func printLine(str string) error {
+	_, err := fmt.Println("\t" + str)
+	return err
+}
+
+func printMultiline(read io.Reader) error {
+	lines := bufio.NewScanner(read)
+	for lines.Scan() {
+		err := printLine(lines.Text())
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func printf(format string, args ...any) error {
+	_, err := fmt.Printf("\t"+format+"\n", args)
+	return err
+}
diff --git a/installer/stepwriter/file.go b/installer/stepwriter/file.go
new file mode 100644
index 0000000..be85e60
--- /dev/null
+++ b/installer/stepwriter/file.go
@@ -0,0 +1,11 @@
+// SPDX-FileCopyrightText: Fabio Forni <development@redaril.me>
+// SPDX-License-Identifier: MPL-2.0
+
+package stepwriter
+
+import "io"
+
+type FileContent struct {
+	Binary  bool
+	Content io.Reader
+}