model: Rework recipe validation

This reduces code duplication and enforces time stamps.

2 files changed, 44 insertions, 27 deletions

diff --git a/model/recipe.go b/model/recipe.go
index 4594287..a9bd0fe 100644
--- a/model/recipe.go
+++ b/model/recipe.go
@@ -5,7 +5,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"strconv"
 )
 
 type Recipe struct {
@@ -25,14 +24,12 @@ func (r Recipe) String() string {
 }
 
 func (r *Recipe) Validate() error {
+	var err error
+
 	if r.Id != "" {
-		id, err := strconv.Atoi(r.Id)
+		err = isPositiveOrZeroInt(r.Id)
 		if err != nil {
-			return fmt.Errorf("Recipe has non-empty ID which is no integer: %w", err)
-		}
-
-		if id < 0 {
-			return fmt.Errorf("Recipes has negative ID: %d", id)
+			return fmt.Errorf("Invalid recipe ID: %w", err)
 		}
 	}
 
@@ -41,28 +38,20 @@ func (r *Recipe) Validate() error {
 	}
 
 	if r.Portions != "" {
-		portions, err := strconv.Atoi(r.Portions)
+		err = isPositiveOrZeroInt(r.Portions)
 		if err != nil {
-			return fmt.Errorf("Recipe has non-empty portions which is no integer: %w", err)
-		}
-
-		if portions < 0 {
-			return fmt.Errorf("Recipes has negative number of portions: %d", portions)
+			return fmt.Errorf("Invalid recipe portions: %w", err)
 		}
 	}
 
-	if r.Created != "" {
-		_, err := strconv.Atoi(r.Created)
-		if err != nil {
-			return fmt.Errorf("Recipe has non-empty time stamp 'created' which is no integer: %w", err)
-		}
+	err = isInt(r.Created)
+	if err != nil {
+		return fmt.Errorf("Invalid creation time stamp: %w", err)
 	}
 
-	if r.LastChanged != "" {
-		_, err := strconv.Atoi(r.LastChanged)
-		if err != nil {
-			return fmt.Errorf("Recipe has non-empty time stamp 'last_changed' which is no integer: %w", err)
-		}
+	err = isInt(r.LastChanged)
+	if err != nil {
+		return fmt.Errorf("Invalid last changed time stamp: %w", err)
 	}
 
 	return nil
@@ -288,8 +277,8 @@ func RecipeTestData() []Recipe {
 			Portions:    "4",
 			Url:         "https://example.org",
 			Notes:       "Very fluffy",
-			Created:     "",
-			LastChanged: "",
+			Created:     "1715957069",
+			LastChanged: "1715958069",
 			Steps: []Step{
 				{
 					Text: "Stir the dough",
@@ -313,8 +302,8 @@ func RecipeTestData() []Recipe {
 			Portions:    "2",
 			Url:         "https://xengineering.eu/git/ceres",
 			Notes:       "Delicious!",
-			Created:     "",
-			LastChanged: "",
+			Created:     "1715658069",
+			LastChanged: "1715958070",
 			Steps: []Step{},
 		},
 	}
diff --git a/model/validation.go b/model/validation.go
new file mode 100644
index 0000000..d49141d
--- /dev/null
+++ b/model/validation.go
@@ -0,0 +1,28 @@
+package model
+
+import (
+	"fmt"
+	"strconv"
+)
+
+func isInt(s string) error {
+	_, err := strconv.Atoi(s)
+	if err != nil {
+		return fmt.Errorf("'%s' cannot be casted to integer", s)
+	}
+
+	return nil
+}
+
+func isPositiveOrZeroInt(s string) error {
+	i, err := strconv.Atoi(s)
+	if err != nil {
+		return fmt.Errorf("'%s' cannot be casted to integer", s)
+	}
+
+	if i < 0 {
+		return fmt.Errorf("'%s' is negative", s)
+	}
+
+	return nil
+}