From 1a957145e803e6e655dd9a25b7574b26f0a16c54 Mon Sep 17 00:00:00 2001
From: Bhasher <github.it@bhasher.com>
Date: Thu, 4 Jan 2024 16:20:00 +0100
Subject: [PATCH] Projects list cache

---
 backend/handlers/projects.go | 14 +++++++++-----
 backend/main.go              |  2 +-
 backend/utils/cache.go       | 14 ++++++++++----
 3 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/backend/handlers/projects.go b/backend/handlers/projects.go
index 2c67c70..94f0eed 100644
--- a/backend/handlers/projects.go
+++ b/backend/handlers/projects.go
@@ -23,29 +23,27 @@ func projectsRouter(router fiber.Router) error {
 	return nil
 }
 
-var projectsLastEdit time.Time;
+var projectsLastEdit time.Time = time.Now().Truncate(time.Second);
 
 func GetAllProjects(c *fiber.Ctx) error {
-	isCached, err := utils.Cache(c, projectsLastEdit);
+	isCached, err := utils.Cache(c, &projectsLastEdit);
 	if err == nil && isCached {
 		return nil;
 	}
 
 	projects, err := db.GetAllProjects()
-	currentTime := time.Now();
 	if err != nil {
 		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{
 			"error": "Cannot retrieve projects",
 			"trace": fmt.Sprint(err),
 		})
 	}
-
+	
 	err = c.Status(fiber.StatusOK).JSON(projects)
 	if err != nil {
 		return err;
 	}
 
-	projectsLastEdit = currentTime;
 	return nil;
 }
 
@@ -83,6 +81,8 @@ func CreateProject(c *fiber.Ctx) error {
 		})
 	}
 
+	projectsLastEdit = time.Now().Truncate(time.Second);
+
 	return c.Status(fiber.StatusCreated).JSON(fiber.Map{
 		"id": id,
 	})
@@ -111,6 +111,8 @@ func UpdateProject(c *fiber.Ctx) error {
 		return c.SendStatus(fiber.StatusNotFound)
 	}
 
+	projectsLastEdit = time.Now().Truncate(time.Second);
+
 	return c.SendStatus(fiber.StatusNoContent)
 }
 
@@ -132,6 +134,8 @@ func DeleteProject(c *fiber.Ctx) error {
 		return c.SendStatus(fiber.StatusNotFound)
 	}
 
+	projectsLastEdit = time.Now().Truncate(time.Second);
+
 	return c.SendStatus(fiber.StatusNoContent)
 }
 
diff --git a/backend/main.go b/backend/main.go
index a8a9727..b0223a3 100644
--- a/backend/main.go
+++ b/backend/main.go
@@ -33,7 +33,7 @@ func main() {
 	app.Use(cors.New(cors.Config{
 		AllowOrigins: origins,
 		AllowMethods: "GET,POST,PUT,DELETE",
-		AllowHeaders: "Origin, Content-Type, Accept",
+		AllowHeaders: "Origin, Content-Type, Accept, Cache-Control, Pragma,Expires, If-Modified-Since",
 	}))
 
 	// app.Use(cache.New())
diff --git a/backend/utils/cache.go b/backend/utils/cache.go
index 280cb64..f083470 100644
--- a/backend/utils/cache.go
+++ b/backend/utils/cache.go
@@ -6,16 +6,22 @@ import (
 	"github.com/gofiber/fiber/v2"
 )
 
-func Cache(c *fiber.Ctx, lastEdit time.Time) (bool, error) {
-	clientLast, err := time.Parse(time.RFC1123, c.Get("If-Modified-Since"))
+func Cache(c *fiber.Ctx, lastEdit *time.Time) (bool, error) {
+	ifModifiedSince := c.Get("If-Modified-Since")
+	if ifModifiedSince == "" {
+		return false, nil
+	}
+
+	clientLast, err := time.Parse(time.RFC1123, ifModifiedSince)
 	if err != nil {
 		return false, err
 	}
-	
-	if clientLast.Before(lastEdit) {
+
+	if !lastEdit.After(clientLast) {
 		c.SendStatus(fiber.StatusNotModified)
 		return true, nil
 	}
 
+	c.Set("Last-Modified", lastEdit.Format(time.RFC1123))
 	return false, nil
 }
\ No newline at end of file