res_levis_backend/internal/pkg/controller/tracks_controller.go

package controller

import (
	"context"
	"log/slog"
	"net/http"
	"strconv"
	"time"

	"github.com/AFASystems/presence/internal/pkg/api/response"
	"github.com/AFASystems/presence/internal/pkg/model"
	"github.com/gorilla/mux"
	"gorm.io/gorm"
)

func TracksListController(db *gorm.DB, context context.Context) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		id := mux.Vars(r)["id"]
		var tracks []model.Tracks

		query := r.URL.Query()
		lStr := query.Get("limit")

		parseTime := func(key string, defaultTime time.Time) time.Time {
			t, err := time.Parse(time.RFC3339, query.Get(key))
			if err != nil {
				return defaultTime
			}
			return t
		}

		limit, _ := strconv.Atoi(lStr)
		if limit == 0 {
			limit = 10
		}
		from := parseTime("from", time.Now().AddDate(0, 0, -1))
		to := parseTime("to", time.Now())

		if err := db.WithContext(context).Where("uuid = ? AND timestamp BETWEEN ? AND ?", id, from, to).Order("timestamp DESC").Limit(limit).Find(&tracks).Error; err != nil {
			response.InternalError(w, "failed to list tracks", err)
			return
		}
		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)
	}
}