feat(files): implemented file permission promises

3 files changed, 153 insertions, 25 deletions

diff --git a/gonf/files.go b/gonf/files.go
index ac6a0aa..974c19c 100644
--- a/gonf/files.go
+++ b/gonf/files.go
@@ -20,20 +20,22 @@ func init() {
 
 // ----- Public ----------------------------------------------------------------
 type FilePromise struct {
-	chain    []Promise
-	contents Value
-	err      error
-	filename Value
-	status   Status
+	chain       []Promise
+	contents    Value
+	err         error
+	filename    Value
+	permissions *Permissions
+	status      Status
 }
 
 func File(filename any) *FilePromise {
 	return &FilePromise{
-		chain:    nil,
-		contents: nil,
-		err:      nil,
-		filename: interfaceToTemplateValue(filename),
-		status:   PROMISED,
+		chain:       nil,
+		contents:    nil,
+		err:         nil,
+		filename:    interfaceToTemplateValue(filename),
+		permissions: nil,
+		status:      PROMISED,
 	}
 }
 
@@ -42,6 +44,11 @@ func (f *FilePromise) Contents(contents any) *FilePromise {
 	return f
 }
 
+func (f *FilePromise) Permissions(p *Permissions) *FilePromise {
+	f.permissions = p
+	return f
+}
+
 func (f *FilePromise) Template(contents any) *FilePromise {
 	f.contents = interfaceToTemplateValue(contents)
 	return f
@@ -79,16 +86,28 @@ func (f *FilePromise) Resolve() {
 				return
 			}
 			f.status = REPAIRED
-			slog.Info("file", "filename", f.filename, "status", f.status)
-			for _, p := range f.chain {
-				p.Resolve()
-			}
 		}
 	}
-	if f.status == PROMISED {
+	if f.permissions != nil {
+		var status Status
+		status, f.err = f.permissions.resolve(filename)
+		if f.status == PROMISED || status == BROKEN {
+			f.status = status
+		}
+		if f.err != nil {
+			slog.Error("file", "filename", f.filename, "status", f.status, "error", f.err)
+			return
+		}
+	}
+	if f.status == REPAIRED {
+		slog.Info("file", "filename", f.filename, "status", f.status)
+		for _, p := range f.chain {
+			p.Resolve()
+		}
+	} else {
 		f.status = KEPT
+		slog.Debug("file", "filename", f.filename, "status", f.status)
 	}
-	slog.Debug("file", "filename", f.filename, "status", f.status)
 }
 
 // ----- Internal --------------------------------------------------------------
diff --git a/gonf/permissions.go b/gonf/permissions.go
new file mode 100644
index 0000000..2bd73a9
--- /dev/null
+++ b/gonf/permissions.go
@@ -0,0 +1,89 @@
+package gonf
+
+import (
+	"errors"
+	"io/fs"
+	"os"
+	"os/user"
+	"strconv"
+	"syscall"
+)
+
+type Permissions struct {
+	group Value
+	mode  Value
+	user  Value
+}
+
+func ModeUserGroup(mode, user, group interface{}) *Permissions {
+	return &Permissions{
+		group: interfaceToTemplateValue(group),
+		mode:  interfaceToTemplateValue(mode),
+		user:  interfaceToTemplateValue(user),
+	}
+}
+
+func (p *Permissions) resolve(filename string) (Status, error) {
+	g, ok := p.group.(*IntValue)
+	if !ok {
+		if group, err := user.LookupGroup(p.group.String()); err != nil {
+			return BROKEN, err
+		} else {
+			if groupId, err := strconv.Atoi(group.Gid); err != nil {
+				return BROKEN, err
+			} else {
+				g = &IntValue{groupId}
+				p.group = g
+			}
+		}
+	}
+	m, ok := p.mode.(*IntValue)
+	if !ok {
+		if i, err := strconv.Atoi(p.mode.String()); err != nil {
+			return BROKEN, err
+		} else {
+			m = &IntValue{i}
+			p.mode = m
+		}
+	}
+	u, ok := p.user.(*IntValue)
+	if !ok {
+		if user, err := user.Lookup(p.user.String()); err != nil {
+			return BROKEN, err
+		} else {
+			if userId, err := strconv.Atoi(user.Uid); err != nil {
+				return BROKEN, err
+			} else {
+				u = &IntValue{userId}
+				p.group = u
+			}
+		}
+	}
+	var status Status = KEPT
+	if fileInfo, err := os.Lstat(filename); err != nil {
+		return BROKEN, err
+	} else {
+		gv := g.Int()
+		mv := fs.FileMode(m.Int())
+		uv := u.Int()
+		if fileInfo.Mode() != mv {
+			if err := os.Chmod(filename, mv); err != nil {
+				return BROKEN, err
+			}
+			status = REPAIRED
+		}
+		if stat, ok := fileInfo.Sys().(*syscall.Stat_t); ok {
+			if stat.Gid != uint32(gv) || stat.Uid != uint32(uv) {
+				if err := os.Chown(filename, uv, gv); err != nil {
+					return BROKEN, err
+				}
+				status = REPAIRED
+			}
+		} else {
+			return BROKEN, errors.New("Unsupported operating system")
+		}
+		_ = gv
+		_ = uv
+	}
+	return status, nil
+}
diff --git a/gonf/values.go b/gonf/values.go
index b77e703..56743e2 100644
--- a/gonf/values.go
+++ b/gonf/values.go
@@ -11,12 +11,15 @@ type Value interface {
 }
 
 func interfaceToValue(v any) Value {
-	if vv, ok := v.(string); ok {
-		return &StringValue{vv}
-	}
 	if vv, ok := v.([]byte); ok {
 		return &BytesValue{vv}
 	}
+	if vv, ok := v.(int); ok {
+		return &IntValue{vv}
+	}
+	if vv, ok := v.(string); ok {
+		return &StringValue{vv}
+	}
 	if vv, ok := v.(*VariablePromise); ok {
 		return vv
 	}
@@ -25,12 +28,15 @@ func interfaceToValue(v any) Value {
 }
 
 func interfaceToTemplateValue(v any) Value {
-	if vv, ok := v.(string); ok {
-		return &TemplateValue{data: vv}
-	}
 	if vv, ok := v.([]byte); ok {
 		return &TemplateValue{data: string(vv)}
 	}
+	if vv, ok := v.(int); ok {
+		return &IntValue{vv}
+	}
+	if vv, ok := v.(string); ok {
+		return &TemplateValue{data: vv}
+	}
 	if vv, ok := v.(*VariablePromise); ok {
 		return vv
 	}
@@ -38,7 +44,7 @@ func interfaceToTemplateValue(v any) Value {
 	panic(fmt.Sprintf("interfaceToTemplateValue cannot take type %T as argument. Value was %#v.", v, v))
 }
 
-// ----- BytesValue -----------------------------------------------------------------
+// ----- BytesValue ------------------------------------------------------------
 type BytesValue struct {
 	value []byte
 }
@@ -46,12 +52,26 @@ type BytesValue struct {
 func (b BytesValue) Bytes() []byte {
 	return b.value
 }
-
 func (b BytesValue) String() string {
 	return string(b.value[:])
 }
 
-// ----- StringValue ----------------------------------------------------------------
+// ----- IntValue --------------------------------------------------------------
+type IntValue struct {
+	value int
+}
+
+func (i IntValue) Bytes() []byte {
+	return []byte(string(i.value))
+}
+func (i IntValue) Int() int {
+	return i.value
+}
+func (i IntValue) String() string {
+	return string(i.value)
+}
+
+// ----- StringValue -----------------------------------------------------------
 type StringValue struct {
 	value string
 }