Merge pull request #19 from RianIhsan/feature/pagination-get-campaigns

feature:pagination get campaigns

campaign/repository.go

@@ -13,6 +13,10 @@ type Repository interface {
 	Update(campaign Campaign) (Campaign, error)
 	CreateImage(campaignImage CampaignImage) (CampaignImage, error)
 	MarkAllImagesAsNonPrimary(campaignID int) (bool, error)
+	GetTotalCampaigns() (int64, error)
+	GetPaginatedCampaigns(offset, limit int) ([]Campaign, error)
+	GetTotalCampaignsByUserID(userID int) (int64, error)
+	GetPaginatedCampaignsByUserID(userID, offset, limit int) ([]Campaign, error)
 }
 
 type repository struct {
@@ -90,3 +94,42 @@ func (r *repository) MarkAllImagesAsNonPrimary(campaignID int) (bool, error) {
 	}
 	return true, nil
 }
+
+func (r *repository) GetTotalCampaigns() (int64, error) {
+	var total int64
+	if err := r.db.Model(&Campaign{}).Count(&total).Error; err != nil {
+		return 0, err
+	}
+	return total, nil
+}
+
+func (r *repository) GetPaginatedCampaigns(offset, limit int) ([]Campaign, error) {
+	var campaigns []Campaign
+	err := r.db.Offset(offset).Limit(limit).Preload("CampaignImages", "campaign_images.is_primary = 1").Find(&campaigns).Error
+	if err != nil {
+		return campaigns, err
+	}
+
+	return campaigns, nil
+}
+
+func (r *repository) GetTotalCampaignsByUserID(userID int) (int64, error) {
+	var total int64
+	if err := r.db.Model(&Campaign{}).Where("user_id = ?", userID).Count(&total).Error; err != nil {
+		return 0, err
+	}
+	return total, nil
+}
+
+func (r *repository) GetPaginatedCampaignsByUserID(userID, offset, limit int) ([]Campaign, error) {
+	var campaigns []Campaign
+	err := r.db.Where("user_id = ?", userID).
+		Offset(offset).
+		Limit(limit).
+		Preload("CampaignImages", "campaign_images.is_primary = 1").
+		Find(&campaigns).Error
+	if err != nil {
+		return campaigns, err
+	}
+	return campaigns, nil
+}

campaign/service.go

@@ -1,13 +1,18 @@
 package campaign
 
-import "errors"
+import (
+	"errors"
+	"math"
+)
 
 type Service interface {
 	FindCampaigns(userID int) ([]Campaign, error)
 	FindCampaignByID(input GetCampaignDetailInput) (Campaign, error)
 	CreateCampaign(input CreateCampaignInput) (Campaign, error)
 	UpdateCampaign(inputID GetCampaignDetailInput, data CreateCampaignInput) (Campaign, error)
 	SaveCampaignImage(input CreateCampaignImageInput, file string) (CampaignImage, error)
+	GetPaginatedCampaigns(page, pageSize int) ([]Campaign, int, int, int, int, error)
+	GetPaginatedCampaignsByUserID(userID, page, pageSize int) ([]Campaign, int, int, int, int, error)
 }
 
 type service struct {
@@ -102,3 +107,63 @@ func (s *service) SaveCampaignImage(input CreateCampaignImageInput, file string)
 
 	return newCampaignImage, nil
 }
+
+func (s *service) GetPaginatedCampaigns(page, pageSize int) ([]Campaign, int, int, int, int, error) {
+	totalCampaigns, err := s.repository.GetTotalCampaigns()
+	if err != nil {
+		return nil, 0, 0, 0, 0, err
+	}
+
+	totalPages := int(math.Ceil(float64(totalCampaigns) / float64(pageSize)))
+	if page < 1 {
+		page = 1
+	}
+	if page > totalPages {
+		page = totalPages
+	}
+	offset := (page - 1) * pageSize
+	campaigns, err := s.repository.GetPaginatedCampaigns(offset, pageSize)
+	if err != nil {
+		return nil, 0, 0, 0, 0, err
+	}
+	var nextPage, prevPage int
+	if page < totalPages {
+		nextPage = page + 1
+	}
+	if page > 1 {
+		prevPage = page - 1
+	}
+
+	return campaigns, totalPages, page, nextPage, prevPage, nil
+}
+
+func (s *service) GetPaginatedCampaignsByUserID(userID, page, pageSize int) ([]Campaign, int, int, int, int, error) {
+	totalCampaigns, err := s.repository.GetTotalCampaignsByUserID(userID)
+	if err != nil {
+		return nil, 0, 0, 0, 0, err
+	}
+
+	totalPages := int(math.Ceil(float64(totalCampaigns) / float64(pageSize)))
+	if page < 1 {
+		page = 1
+	}
+	if page > totalPages {
+		page = totalPages
+	}
+
+	offset := (page - 1) * pageSize
+	campaigns, err := s.repository.GetPaginatedCampaignsByUserID(userID, offset, pageSize)
+	if err != nil {
+		return nil, 0, 0, 0, 0, err
+	}
+	var nextPage, prevPage int
+	if page < totalPages {
+		nextPage = page + 1
+	}
+
+	if page > 1 {
+		prevPage = page - 1
+	}
+
+	return campaigns, totalPages, page, nextPage, prevPage, nil
+}

handler/campaign.go

@@ -22,15 +22,39 @@ func NewCampaignHandler(service campaign.Service) *campaignHandler {
 }
 
 func (h *campaignHandler) GetCampaigns(c *gin.Context) {
-	userID, _ := strconv.Atoi(c.Query("user_id"))
-
-	campaigns, err := h.service.FindCampaigns(userID)
+	userID, _ := strconv.Atoi(c.DefaultQuery("user_id", "0"))
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "10"))
+
+	var campaigns []campaign.Campaign
+	var totalPages, currentPage, nextPage, prevPage int
+	var err error
+
+	if userID != 0 {
+		campaigns, totalPages, currentPage, nextPage, prevPage, err = h.service.GetPaginatedCampaignsByUserID(userID, page, pageSize)
+	} else {
+		campaigns, totalPages, currentPage, nextPage, prevPage, err = h.service.GetPaginatedCampaigns(page, pageSize)
+	}
 	if err != nil {
 		response := helper.ErrorResponse("Error to get campaigns", err)
 		c.JSON(http.StatusBadRequest, response)
 		return
 	}
-	response := helper.ResponseWithData("List of campaigns", campaign.FormatCampaigns(campaigns))
+
+	if totalPages > 1 {
+		if currentPage < totalPages {
+			nextPage = currentPage + 1
+		} else {
+			nextPage = -1
+		}
+		if currentPage > 1 {
+			prevPage = currentPage - 1
+		} else {
+			prevPage = -1
+		}
+	}
+
+	response := helper.ResponseWithPaginationAndNextPrev("List of campaigns", campaign.FormatCampaigns(campaigns), currentPage, totalPages, nextPage, prevPage)
 	c.JSON(http.StatusOK, response)
 
 }
@@ -76,7 +100,7 @@ func (h *campaignHandler) CreateCampaign(c *gin.Context) {
 		return
 	}
 
-	response := helper.ErrorResponse("Success creating campaign", campaign.FormatCampaign(newCampaign))
+	response := helper.ResponseWithData("Success creating campaign", campaign.FormatCampaign(newCampaign))
 	c.JSON(http.StatusOK, response)
 }
 

helper/helper.go

@@ -129,5 +129,31 @@ func GenerateRandomOTP(otpLent int) string {
 	}
 
 	return string(otp)
+}
 
+type PaginationMeta struct {
+	CurrentPage int `json:"current_page"`
+	TotalPage   int `json:"total_page"`
+	NextPage    int `json:"next_page"`
+	PrevPage    int `json:"prev_page"`
+}
+type TResponseWithPaginationAndNextPrev struct {
+	Message string         `json:"message"`
+	Data    interface{}    `json:"data"`
+	Meta    PaginationMeta `json:"meta"`
+}
+
+func ResponseWithPaginationAndNextPrev(message string, data interface{}, currentPage, totalPages, nextPage, prevPage int) TResponseWithPaginationAndNextPrev {
+	meta := PaginationMeta{
+		CurrentPage: currentPage,
+		TotalPage:   totalPages,
+		NextPage:    nextPage,
+		PrevPage:    prevPage,
+	}
+
+	return TResponseWithPaginationAndNextPrev{
+		Message: message,
+		Data:    data,
+		Meta:    meta,
+	}
 }