better error management + shortcode overflow control

client/config.go

@@ -3,6 +3,7 @@ package client
 import (
 	"encoding/json"
 	"errors"
+	"fmt"
 	"os"
 	"sync"
 
@@ -65,6 +66,18 @@ func GetConfig() *Config {
 	return instance
 }
 
+func (c *Config) Validate() error {
+	if c.StoragePath == "" {
+		return errors.New("storage_path is required")
+	}
+
+	if c.Chunksize < 1024 || c.Chunksize > 10*1024*1024 {
+		return fmt.Errorf("chunksize must be between 1KB and 10MB, got %d", c.Chunksize)
+	}
+
+	return nil
+}
+
 func (c *Config) Load(filename string) error {
 	data, err := os.ReadFile(filename)
 	if err != nil {
@@ -74,6 +87,9 @@ func (c *Config) Load(filename string) error {
 	if err != nil {
 		return err
 	}
+	if err := c.Validate(); err != nil {
+		return fmt.Errorf("invalid config: %w", err)
+	}
 	// override values if not set or wrong
 	if c.HttpTimeOut <= 0 {
 		c.HttpTimeOut = 10