feat: add implementation where you can get last track for each unique tracker id

internal/app/server/routes.go

@@ -59,6 +59,7 @@ func (a *ServerApp) RegisterRoutes() http.Handler {
 
 	// Tracks
 	r.HandleFunc("/reslevis/getTracks/{id}", controller.TracksListController(a.DB, a.ctx)).Methods("GET")
+	r.HandleFunc("/reslevis/getTracks", controller.TracksListAllController(a.DB, a.ctx)).Methods("GET")
 
 	r.HandleFunc("/reslevis/health", controller.HealthController(a.AppState, a.ctx)).Methods("GET")
 

internal/pkg/controller/tracks_controller.go

@@ -2,6 +2,7 @@ package controller
 
 import (
 	"context"
+	"log/slog"
 	"net/http"
 	"strconv"
 	"time"
@@ -42,3 +43,53 @@ func TracksListController(db *gorm.DB, context context.Context) http.HandlerFunc
 		response.JSON(w, http.StatusOK, tracks)
 	}
 }
+
+func TracksListAllController(db *gorm.DB, context context.Context) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		query := r.URL.Query()
+		lStr := query.Get("limit")
+		if lStr == "" {
+			lStr = "100"
+		}
+
+		limit, err := strconv.Atoi(lStr)
+		if err != nil {
+			slog.Error("Error in converting limit string to integer value")
+			response.InternalError(w, "internal server error", err)
+			return
+		}
+
+		offsetStr := query.Get("offset")
+		if offsetStr == "" {
+			offsetStr = "0"
+		}
+
+		offset, err := strconv.Atoi(offsetStr)
+		if err != nil {
+			slog.Error("Error in converting offset string to integer value")
+			response.InternalError(w, "internal server error", err)
+			return
+		}
+
+		var tracks []model.Tracks
+
+		// Subquery to get the latest timestamp per tracker
+		subQuery := db.Model(&model.Tracks{}).
+			Select("tracker, MAX(timestamp) AS max_timestamp").
+			Group("tracker")
+
+		if err := db.WithContext(context).
+			Table("tracks").
+			Select("tracks.*").
+			Joins("JOIN (?) AS latest ON tracks.tracker = latest.tracker AND tracks.timestamp = latest.max_timestamp", subQuery).
+			Order("tracks.timestamp DESC").
+			Limit(limit).
+			Offset(offset).
+			Find(&tracks).Error; err != nil {
+			response.InternalError(w, "failed to list tracks", err)
+			return
+		}
+
+		response.JSON(w, http.StatusOK, tracks)
+	}
+}