model: Replace global db variable by custom type

Reducing global variables makes it easier to understand functions
independently of the rest of the code.

Adding the new model.DB type as a custom variant of the sql.DB type
makes it possible to write methods for the database which makes the code
way more readable.

1 files changed, 68 insertions, 62 deletions

diff --git a/controller/recipe.go b/controller/recipe.go
index b0a81d9..aec7144 100644
--- a/controller/recipe.go
+++ b/controller/recipe.go
@@ -12,74 +12,80 @@ import (
 	"github.com/gorilla/mux"
 )
 
-func RecipeCreate(w http.ResponseWriter, r *http.Request) {
-	buf, err := io.ReadAll(r.Body)
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
+func RecipeCreate(db *model.DB) func(http.ResponseWriter, *http.Request) {
+	return func(w http.ResponseWriter, r *http.Request) {
+		buf, err := io.ReadAll(r.Body)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		recipe := model.Recipe{}
+		err = json.Unmarshal(buf, &recipe)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+
+		recipe.LastChanged = fmt.Sprint(time.Now().Unix())
+		recipe.Created = recipe.LastChanged
+
+		var obj model.Object = &recipe
+		err = db.Transaction(obj.Create)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		http.Redirect(w, r, "/recipe/"+recipe.Id, http.StatusSeeOther)
 	}
-
-	recipe := model.Recipe{}
-	err = json.Unmarshal(buf, &recipe)
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusBadRequest)
-		return
-	}
-
-	recipe.LastChanged = fmt.Sprint(time.Now().Unix())
-	recipe.Created = recipe.LastChanged
-
-	var obj model.Object = &recipe
-	err = model.Transaction(obj.Create)
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
-
-	http.Redirect(w, r, "/recipe/"+recipe.Id, http.StatusSeeOther)
 }
 
-func RecipeUpdate(w http.ResponseWriter, r *http.Request) {
-	buf, err := io.ReadAll(r.Body)
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
-
-	recipe := model.Recipe{}
-	err = json.Unmarshal(buf, &recipe)
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusBadRequest)
-		return
+func RecipeUpdate(db *model.DB) func(http.ResponseWriter, *http.Request) {
+	return func(w http.ResponseWriter, r *http.Request) {
+		buf, err := io.ReadAll(r.Body)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		recipe := model.Recipe{}
+		err = json.Unmarshal(buf, &recipe)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+
+		if recipe.Id != mux.Vars(r)[`id`] {
+			http.Error(w, "IDs in URL and JSON do not match", http.StatusBadRequest)
+			return
+		}
+
+		recipe.LastChanged = fmt.Sprint(time.Now().Unix())
+
+		var obj model.Object = &recipe
+		err = db.Transaction(obj.Update)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		http.Redirect(w, r, "/recipe/"+recipe.Id, http.StatusSeeOther)
 	}
-
-	if recipe.Id != mux.Vars(r)[`id`] {
-		http.Error(w, "IDs in URL and JSON do not match", http.StatusBadRequest)
-		return
-	}
-
-	recipe.LastChanged = fmt.Sprint(time.Now().Unix())
-
-	var obj model.Object = &recipe
-	err = model.Transaction(obj.Update)
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
-
-	http.Redirect(w, r, "/recipe/"+recipe.Id, http.StatusSeeOther)
 }
 
-func RecipeDelete(w http.ResponseWriter, r *http.Request) {
-	recipe := model.Recipe{}
-	recipe.Id = mux.Vars(r)[`id`]
+func RecipeDelete(db *model.DB) func(http.ResponseWriter, *http.Request) {
+	return func(w http.ResponseWriter, r *http.Request) {
+		recipe := model.Recipe{}
+		recipe.Id = mux.Vars(r)[`id`]
 
-	var obj model.Object = &recipe
-	err := model.Transaction(obj.Delete)
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
+		var obj model.Object = &recipe
+		err := db.Transaction(obj.Delete)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
 
-	http.Redirect(w, r, "/recipes", http.StatusSeeOther)
+		http.Redirect(w, r, "/recipes", http.StatusSeeOther)
+	}
 }