[Backend] Refactor the GetMyMarkers and NearbyMarkers functions to im…

…plement pagination

backend/dto/marker_dto.go

@@ -25,9 +25,16 @@ type QueryParams struct {
 	Longitude float64 `query:"longitude"`
 	Distance  int     `query:"distance"`
 	N         int     `query:"n"`
+	Page      int     `query:"page"`
 }
 
 type MarkerWithDistance struct {
 	models.Marker
 	Distance float64 `db:"distance"` // Distance in meters
 }
+
+type MarkerWithDislike struct {
+	models.Marker
+	Username     string `db:"Username"`
+	DislikeCount int    `db:"DislikeCount"`
+}

backend/handlers/marker_api.go

@@ -4,6 +4,7 @@ import (
 	"chulbong-kr/dto"
 	"chulbong-kr/services"
 	"chulbong-kr/utils"
+	"math"
 	"strconv"
 
 	"github.com/gofiber/fiber/v2"
@@ -270,21 +271,32 @@ func UndoDislikeHandler(c *fiber.Ctx) error {
 }
 
 func GetUserMarkersHandler(c *fiber.Ctx) error {
-	// Retrieve userID from c.Locals, which is set during authentication
 	userID, ok := c.Locals("userID").(int)
 	if !ok {
-		// If userID is not available, return an error response
 		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "User not authenticated"})
 	}
 
-	// Call the modified service function with the userID
-	markersWithPhotos, err := services.GetAllMarkersByUser(userID)
+	// Parse query parameters for pagination
+	page, err := strconv.Atoi(c.Query("page", "1"))
+	if err != nil || page < 1 {
+		page = 1 // default to first page
+	}
+	pageSize := 4
+
+	markersWithPhotos, total, err := services.GetAllMarkersByUserWithPagination(userID, page, pageSize)
 	if err != nil {
 		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": err.Error()})
 	}
 
-	// Return the filtered markers
-	return c.JSON(markersWithPhotos)
+	totalPages := int(math.Ceil(float64(total) / float64(pageSize)))
+
+	// Return the filtered markers with pagination info
+	return c.JSON(fiber.Map{
+		"markers":      markersWithPhotos,
+		"currentPage":  page,
+		"totalPages":   totalPages,
+		"totalMarkers": total,
+	})
 }
 
 // CheckDislikeStatus handler
@@ -318,8 +330,9 @@ func CheckDislikeStatus(c *fiber.Ctx) error {
 // @Param		longitude	query	number	true	"Longitude of the location (float)"
 // @Param		distance	query	int		true	"Search radius distance (meters)"
 // @Param		N			query	int		true	"Number of markers to return"
+// @Param		page			query	int		true	"Page Index number"
 // @Security	ApiKeyAuth
-// @Success	200	{array}	dto.MarkerWithDistance	"Markers found successfully (with distance)"
+// @Success	200	{object}	map[string]interface{}	"Markers found successfully (with distance) in pages"
 // @Failure	400	{object}	map[string]interface{}	"Invalid query parameters"
 // @Failure	404	{object}	map[string]interface{}	"No markers found within the specified distance"
 // @Failure	500	{object}	map[string]interface{}	"Internal server error"
@@ -334,16 +347,35 @@ func FindCloseMarkersHandler(c *fiber.Ctx) error {
 		return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": "Distance cannot be greater than 3,000m (3km)"})
 	}
 
-	// Find nearby markers within the specified distance
-	markers, err := services.FindClosestNMarkersWithinDistance(params.Latitude, params.Longitude, params.Distance, params.N)
+	// Set default page to 1 if not specified
+	if params.Page < 1 {
+		params.Page = 1
+	}
+
+	pageSize := 4 // Define page size
+	offset := (params.Page - 1) * pageSize
+
+	// Find nearby markers within the specified distance and page
+	markers, total, err := services.FindClosestNMarkersWithinDistance(params.Latitude, params.Longitude, params.Distance, pageSize, offset)
 	if err != nil {
 		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": err.Error()})
 	}
 
-	if len(markers) == 0 {
-		return c.Status(fiber.StatusNotFound).JSON(fiber.Map{"message": "No markers found within the specified distance"})
+	// if len(markers) == 0 {
+	// 	return c.Status(fiber.StatusNotFound).JSON(fiber.Map{"message": "No markers found within the specified distance"})
+	// }
+
+	// Calculate total pages
+	totalPages := total / pageSize
+	if total%pageSize != 0 {
+		totalPages++
 	}
 
-	// Return the found markers
-	return c.JSON(markers)
+	// Return the found markers along with pagination info
+	return c.JSON(fiber.Map{
+		"markers":      markers,
+		"currentPage":  params.Page,
+		"totalPages":   totalPages,
+		"totalMarkers": total,
+	})
 }

backend/services/marker_service.go

@@ -7,6 +7,8 @@ import (
 	"chulbong-kr/database"
 	"chulbong-kr/dto"
 	"chulbong-kr/models"
+
+	"github.com/jmoiron/sqlx"
 )
 
 func CreateMarkerWithPhotos(markerDto *dto.MarkerRequest, userID int, form *multipart.Form) (*dto.MarkerResponse, error) {
@@ -119,34 +121,37 @@ GROUP BY Markers.MarkerID, Users.Username, Markers.CreatedAt, Markers.UpdatedAt`
 	return markersWithPhotos, nil
 }
 
-func GetAllMarkersByUser(userID int) ([]models.MarkerWithPhotos, error) {
-	// Query to select markers created by a specific user
-	const markerQuery = `
+func GetAllMarkersByUserWithPagination(userID, page, pageSize int) ([]models.MarkerWithPhotos, int, error) {
+	offset := (page - 1) * pageSize
+
+	// Query to select markers created by a specific user with LIMIT and OFFSET for pagination
+	markerQuery := `
 SELECT Markers.MarkerID, Markers.UserID, ST_Y(Location) AS Latitude, ST_X(Location) AS Longitude, 
 Markers.Description, Users.Username, Markers.CreatedAt, Markers.UpdatedAt, 
 COUNT(MarkerDislikes.DislikeID) AS DislikeCount
 FROM Markers
 JOIN Users ON Markers.UserID = Users.UserID
 LEFT JOIN MarkerDislikes ON Markers.MarkerID = MarkerDislikes.MarkerID
 WHERE Markers.UserID = ?
-GROUP BY Markers.MarkerID, Users.Username, Markers.CreatedAt, Markers.UpdatedAt`
+GROUP BY Markers.MarkerID, Users.Username, Markers.CreatedAt, Markers.UpdatedAt
+LIMIT ? OFFSET ?`
 
-	var markersWithUsernames []struct {
-		models.Marker
-		Username     string `db:"Username"`
-		DislikeCount int    `db:"DislikeCount"`
-	}
-	err := database.DB.Select(&markersWithUsernames, markerQuery, userID)
+	var markersWithUsernames []dto.MarkerWithDislike
+	err := database.DB.Select(&markersWithUsernames, markerQuery, userID, pageSize, offset)
 	if err != nil {
-		return nil, err
+		return nil, 0, err
 	}
 
 	// Fetch all photos at once
-	const photoQuery = `SELECT * FROM Photos`
+	photoQuery := `SELECT * FROM Photos WHERE MarkerID IN (?)`
+	query, args, err := sqlx.In(photoQuery, getMarkerIDs(markersWithUsernames))
+	if err != nil {
+		return nil, 0, err
+	}
 	var allPhotos []models.Photo
-	err = database.DB.Select(&allPhotos, photoQuery)
+	err = database.DB.Select(&allPhotos, database.DB.Rebind(query), args...)
 	if err != nil {
-		return nil, err
+		return nil, 0, err
 	}
 
 	// Map photos to their markers
@@ -166,7 +171,15 @@ GROUP BY Markers.MarkerID, Users.Username, Markers.CreatedAt, Markers.UpdatedAt`
 		})
 	}
 
-	return markersWithPhotos, nil
+	// Query to get the total count of markers for the user
+	countQuery := `SELECT COUNT(DISTINCT Markers.MarkerID) FROM Markers WHERE Markers.UserID = ?`
+	var total int
+	err = database.DB.Get(&total, countQuery, userID)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	return markersWithPhotos, total, nil
 }
 
 // GetMarker retrieves a single marker and its associated photo by the marker's ID
@@ -316,22 +329,43 @@ SELECT EXISTS (
 }
 
 // FindClosestNMarkersWithinDistance
-func FindClosestNMarkersWithinDistance(lat, long float64, distance, n int) ([]dto.MarkerWithDistance, error) {
-	point := fmt.Sprintf("POINT(%f %f)", long, lat) // Note: MySQL expects longitude first
+func FindClosestNMarkersWithinDistance(lat, long float64, distance, pageSize, offset int) ([]dto.MarkerWithDistance, int, error) {
+	point := fmt.Sprintf("POINT(%f %f)", long, lat)
 
-	// Modify the query to also select the distance
+	// Query to find markers within N meters and calculate total
 	query := `
-SELECT MarkerID, UserID, ST_Y(Location) AS Latitude, ST_X(Location) AS Longitude, Description, CreatedAt, UpdatedAt, ST_Distance_Sphere(Location, ST_GeomFromText(?)) AS distance 
+SELECT MarkerID, UserID, ST_Y(Location) AS Latitude, ST_X(Location) AS Longitude, Description, CreatedAt, UpdatedAt, ST_Distance_Sphere(Location, ST_GeomFromText(?)) AS distance
 FROM Markers
 WHERE ST_Distance_Sphere(Location, ST_GeomFromText(?)) <= ?
 ORDER BY distance ASC
-LIMIT ?`
+LIMIT ? OFFSET ?`
 
 	var markers []dto.MarkerWithDistance
-	err := database.DB.Select(&markers, query, point, point, distance, n)
+	err := database.DB.Select(&markers, query, point, point, distance, pageSize, offset)
+	if err != nil {
+		return nil, 0, fmt.Errorf("error checking for nearby markers: %w", err)
+	}
+
+	// Query to get total count of markers within distance
+	countQuery := `
+SELECT COUNT(*)
+FROM Markers
+WHERE ST_Distance_Sphere(Location, ST_GeomFromText(?)) <= ?`
+
+	var total int
+	err = database.DB.Get(&total, countQuery, point, distance)
 	if err != nil {
-		return nil, fmt.Errorf("error checking for nearby markers: %w", err)
+		return nil, 0, fmt.Errorf("error getting total markers count: %w", err)
 	}
 
-	return markers, nil
+	return markers, total, nil
+}
+
+// Helper function to extract marker IDs
+func getMarkerIDs(markers []dto.MarkerWithDislike) []interface{} {
+	ids := make([]interface{}, len(markers))
+	for i, marker := range markers {
+		ids[i] = marker.MarkerID
+	}
+	return ids
 }