From d6cba44b604b3e744b5076fe5cbff192e0262444 Mon Sep 17 00:00:00 2001
From: Vasiliy Tolstov <v.tolstov@unistack.org>
Date: Wed, 15 Mar 2023 00:53:26 +0300
Subject: [PATCH] allow to override Struct on Save/Load/Init

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
---
 flag.go | 48 +++++++++++++++++++++++++++++++++++++++++++++---
 go.mod  |  4 +++-
 2 files changed, 48 insertions(+), 4 deletions(-)

diff --git a/flag.go b/flag.go
index a98e11d..b89a278 100644
--- a/flag.go
+++ b/flag.go
@@ -43,11 +43,24 @@ func (c *flagConfig) Init(opts ...config.Option) error {
 	for _, o := range opts {
 		o(&c.opts)
 	}
+
+	if err := config.DefaultBeforeInit(c.opts.Context, c); err != nil && !c.opts.AllowFail {
+		return err
+	}
+
 	c.configure()
 
 	fields, err := rutil.StructFields(c.opts.Struct)
 	if err != nil {
-		return err
+		if !c.opts.AllowFail {
+			return err
+		}
+
+		if err := config.DefaultAfterInit(c.opts.Context, c); err != nil && !c.opts.AllowFail {
+			return err
+		}
+
+		return nil
 	}
 
 	for _, sf := range fields {
@@ -84,10 +97,13 @@ func (c *flagConfig) Init(opts ...config.Option) error {
 		}
 
 		if err != nil {
-			c.opts.Logger.Errorf(c.opts.Context, "flag init error: %v", err)
 			if !c.opts.AllowFail {
 				return err
 			}
+			if err := config.DefaultAfterInit(c.opts.Context, c); err != nil && !c.opts.AllowFail {
+				return err
+			}
+
 			return nil
 		}
 
@@ -120,26 +136,52 @@ func (c *flagConfig) Init(opts ...config.Option) error {
 			err = c.flagMap(sf.Value, fn, fv, fd)
 		}
 		if err != nil {
-			c.opts.Logger.Errorf(c.opts.Context, "flag init error: %v", err)
 			if !c.opts.AllowFail {
 				return err
 			}
+
+			if err := config.DefaultAfterInit(c.opts.Context, c); err != nil && !c.opts.AllowFail {
+				return err
+			}
+
 			return nil
 		}
 	}
 
+	if err := config.DefaultAfterInit(c.opts.Context, c); err != nil && !c.opts.AllowFail {
+		return err
+	}
+
 	return nil
 }
 
 func (c *flagConfig) Load(ctx context.Context, opts ...config.LoadOption) error {
 	options := config.NewLoadOptions(opts...)
 	_ = options
+
+	if err := config.DefaultBeforeLoad(ctx, c); err != nil && !c.opts.AllowFail {
+		return err
+	}
+
+	if err := config.DefaultAfterLoad(ctx, c); err != nil && !c.opts.AllowFail {
+		return err
+	}
+
 	// TODO: allow merge, append and so
 	flag.Parse()
+
 	return nil
 }
 
 func (c *flagConfig) Save(ctx context.Context, opts ...config.SaveOption) error {
+	if err := config.DefaultBeforeSave(ctx, c); err != nil && !c.opts.AllowFail {
+		return err
+	}
+
+	if err := config.DefaultAfterSave(ctx, c); err != nil && !c.opts.AllowFail {
+		return err
+	}
+
 	return nil
 }
 
diff --git a/go.mod b/go.mod
index 4e9709f..19bf822 100644
--- a/go.mod
+++ b/go.mod
@@ -1,5 +1,7 @@
 module go.unistack.org/micro-config-flag/v3
 
-go 1.16
+go 1.18
 
 require go.unistack.org/micro/v3 v3.10.16
+
+require github.com/imdario/mergo v0.3.13 // indirect