From 6a6d2c7042103b17f1bdd47def6cedccf37bb970 Mon Sep 17 00:00:00 2001
From: alex <alex@roese.dev>
Date: Fri, 13 Oct 2023 08:49:38 +0200
Subject: [PATCH] add pagination

---
 go.mod                       |  3 +++
 go.sum                       |  6 ++++++
 rspagination/rspagination.go | 35 +++++++++++++++++++++++++++++++++++
 3 files changed, 44 insertions(+)
 create mode 100644 rspagination/rspagination.go

diff --git a/go.mod b/go.mod
index 7345106..9dd094c 100644
--- a/go.mod
+++ b/go.mod
@@ -10,6 +10,8 @@ require (
 	github.com/go-playground/validator/v10 v10.15.5 // indirect
 	github.com/gofiber/fiber/v2 v2.49.2 // indirect
 	github.com/google/uuid v1.3.1 // indirect
+	github.com/jinzhu/inflection v1.0.0 // indirect
+	github.com/jinzhu/now v1.1.5 // indirect
 	github.com/klauspost/compress v1.16.7 // indirect
 	github.com/leodido/go-urn v1.2.4 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
@@ -24,4 +26,5 @@ require (
 	golang.org/x/net v0.8.0 // indirect
 	golang.org/x/sys v0.12.0 // indirect
 	golang.org/x/text v0.8.0 // indirect
+	gorm.io/gorm v1.25.5 // indirect
 )
diff --git a/go.sum b/go.sum
index 602d1ed..8e9589d 100644
--- a/go.sum
+++ b/go.sum
@@ -16,6 +16,10 @@ github.com/gofiber/fiber/v2 v2.49.2 h1:ONEN3/Vc+dUCxxDgZZwpqvhISgHqb+bu+isBiEyKE
 github.com/gofiber/fiber/v2 v2.49.2/go.mod h1:gNsKnyrmfEWFpJxQAV0qvW6l70K1dZGno12oLtukcts=
 github.com/google/uuid v1.3.1 h1:KjJaJ9iWZ3jOFZIf1Lqf4laDRCasjl0BCmnEGxkdLb4=
 github.com/google/uuid v1.3.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/jinzhu/inflection v1.0.0 h1:K317FqzuhWc8YvSVlFMCCUb36O/S9MCKRDI7QkRKD/E=
+github.com/jinzhu/inflection v1.0.0/go.mod h1:h+uFLlag+Qp1Va5pdKtLDYj+kHp5pxUVkryuEj+Srlc=
+github.com/jinzhu/now v1.1.5 h1:/o9tlHleP7gOFmsnYNz3RGnqzefHA47wQpKrrdTIwXQ=
+github.com/jinzhu/now v1.1.5/go.mod h1:d3SSVoowX0Lcu0IBviAWJpolVfI5UJVZZ7cO71lE/z8=
 github.com/klauspost/compress v1.16.7 h1:2mk3MPGNzKyxErAw8YaohYh69+pa4sIQSC0fPGCFR9I=
 github.com/klauspost/compress v1.16.7/go.mod h1:ntbaceVETuRiXiv4DpjP66DpAtAGkEQskQzEyD//IeE=
 github.com/leodido/go-urn v1.2.4 h1:XlAE/cm/ms7TE/VMVoduSpNBoyc2dOxHs5MZSwAN63Q=
@@ -60,3 +64,5 @@ golang.org/x/text v0.8.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gorm.io/gorm v1.25.5 h1:zR9lOiiYf09VNh5Q1gphfyia1JpiClIWG9hQaxB/mls=
+gorm.io/gorm v1.25.5/go.mod h1:hbnx/Oo0ChWMn1BIhpy1oYozzpM15i4YPuHDmfYtwg8=
diff --git a/rspagination/rspagination.go b/rspagination/rspagination.go
new file mode 100644
index 0000000..61e7c04
--- /dev/null
+++ b/rspagination/rspagination.go
@@ -0,0 +1,35 @@
+package rspagination
+
+import (
+	"math"
+
+	"gorm.io/gorm"
+)
+
+// GetTotalPages returns total pages for pagination
+// Example whereQuery = "stock_item_id = ?" and args = stockItemId is Where("stock_item_id = ?", stockItemId)
+func GetTotalPages(database *gorm.DB, paginationLimit int, any interface{}, whereQuery interface{}, args ...interface{}) int {
+	var totalPages int64
+
+	database.Model(any).
+		Where(whereQuery, args).
+		Count(&totalPages)
+
+	return int(math.Ceil(float64(totalPages) / float64(paginationLimit)))
+}
+
+func GetPageOffset(page int, paginationLimit int) int {
+	return (page - 1) * paginationLimit
+}
+
+type PageQuery struct {
+	Page int
+}
+
+func DbPageQuery(database *gorm.DB, query PageQuery, paginationLimit int, result any, orderBy, whereQuery interface{}, args ...interface{}) *gorm.DB {
+	return database.Limit(paginationLimit).
+		Offset(GetPageOffset(query.Page, paginationLimit)).
+		Where(whereQuery, args).
+		Order(orderBy).
+		Find(result)
+}