package handlers

import (
	"fmt"
	"net/http"
	"strconv"
	"strings"
	"time"

	"game-admin/internal/models"

	"github.com/gin-gonic/gin"
	"github.com/uptrace/bun"
)

func (h *GameHandler) ListLeaderboards(c *gin.Context) {
	gameID, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid game id"})
		return
	}
	if err := h.ensureLeaderboardModuleEnabled(c, gameID); err != nil {
		renderLeaderboardModuleError(c, err)
		return
	}

	var leaderboards []models.Leaderboard
	err = h.db.NewSelect().
		Model(&leaderboards).
		Relation("Groups", func(q *bun.SelectQuery) *bun.SelectQuery {
			return q.OrderExpr("lbg.id ASC")
		}).
		Where("lb.game_id = ?", gameID).
		OrderExpr("lb.id DESC").
		Scan(c)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, leaderboards)
}

func (h *GameHandler) GetLeaderboard(c *gin.Context) {
	gameID, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid game id"})
		return
	}
	leaderboardID, err := strconv.ParseInt(c.Param("leaderboard_id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid leaderboard id"})
		return
	}
	if err := h.ensureLeaderboardModuleEnabled(c, gameID); err != nil {
		renderLeaderboardModuleError(c, err)
		return
	}

	leaderboard, err := h.getLeaderboard(c, gameID, leaderboardID)
	if err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "Leaderboard not found"})
		return
	}

	c.JSON(http.StatusOK, leaderboard)
}

func (h *GameHandler) CreateLeaderboard(c *gin.Context) {
	gameID, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid game id"})
		return
	}

	var req models.UpsertLeaderboardRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	if err := validateUpsertLeaderboardRequest(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	if err := h.ensureLeaderboardModuleEnabled(c, gameID); err != nil {
		renderLeaderboardModuleError(c, err)
		return
	}

	isActive := true
	if req.IsActive != nil {
		isActive = *req.IsActive
	}

	leaderboard := &models.Leaderboard{
		GameID:     gameID,
		Key:        strings.TrimSpace(req.Key),
		Name:       strings.TrimSpace(req.Name),
		SortOrder:  req.SortOrder,
		PeriodType: req.PeriodType,
		IsActive:   isActive,
		CreatedAt:  time.Now(),
		UpdatedAt:  time.Now(),
	}
	_, err = h.db.NewInsert().Model(leaderboard).Exec(c)
	if err != nil {
		c.JSON(http.StatusConflict, gin.H{"error": "Leaderboard key already exists"})
		return
	}

	created, err := h.getLeaderboard(c, gameID, leaderboard.ID)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusCreated, created)
}

func (h *GameHandler) UpdateLeaderboard(c *gin.Context) {
	gameID, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid game id"})
		return
	}
	leaderboardID, err := strconv.ParseInt(c.Param("leaderboard_id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid leaderboard id"})
		return
	}

	var req models.UpsertLeaderboardRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	if err := validateUpsertLeaderboardRequest(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	if err := h.ensureLeaderboardModuleEnabled(c, gameID); err != nil {
		renderLeaderboardModuleError(c, err)
		return
	}
	current, err := h.getLeaderboard(c, gameID, leaderboardID)
	if err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "Leaderboard not found"})
		return
	}

	isActive := current.IsActive
	if req.IsActive != nil {
		isActive = *req.IsActive
	}

	_, err = h.db.NewUpdate().
		Model((*models.Leaderboard)(nil)).
		Set(`"key" = ?`, strings.TrimSpace(req.Key)).
		Set("name = ?", strings.TrimSpace(req.Name)).
		Set("sort_order = ?", req.SortOrder).
		Set("period_type = ?", req.PeriodType).
		Set("is_active = ?", isActive).
		Set("updated_at = ?", time.Now()).
		Where("id = ? AND game_id = ?", leaderboardID, gameID).
		Exec(c)
	if err != nil {
		c.JSON(http.StatusConflict, gin.H{"error": "Could not update leaderboard"})
		return
	}

	updated, err := h.getLeaderboard(c, gameID, leaderboardID)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, updated)
}

func (h *GameHandler) DeleteLeaderboard(c *gin.Context) {
	gameID, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid game id"})
		return
	}
	leaderboardID, err := strconv.ParseInt(c.Param("leaderboard_id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid leaderboard id"})
		return
	}
	if err := h.ensureLeaderboardModuleEnabled(c, gameID); err != nil {
		renderLeaderboardModuleError(c, err)
		return
	}
	if _, err := h.getLeaderboard(c, gameID, leaderboardID); err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "Leaderboard not found"})
		return
	}

	tx, err := h.db.BeginTx(c, nil)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	committed := false
	defer func() {
		if !committed {
			_ = tx.Rollback()
		}
	}()

	var groups []models.LeaderboardGroup
	if err := tx.NewSelect().Model(&groups).Where("leaderboard_id = ?", leaderboardID).Scan(c); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	if len(groups) > 0 {
		groupIDs := make([]int64, 0, len(groups))
		for _, group := range groups {
			groupIDs = append(groupIDs, group.ID)
		}
		if _, err := tx.NewDelete().Model((*models.LeaderboardGroupMember)(nil)).Where("group_id IN (?)", bun.In(groupIDs)).Exec(c); err != nil {
			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
			return
		}
	}

	if _, err := tx.NewDelete().Model((*models.LeaderboardGroup)(nil)).Where("leaderboard_id = ?", leaderboardID).Exec(c); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	if _, err := tx.NewDelete().Model((*models.LeaderboardScore)(nil)).Where("leaderboard_id = ?", leaderboardID).Exec(c); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	if _, err := tx.NewDelete().Model((*models.Leaderboard)(nil)).Where("id = ? AND game_id = ?", leaderboardID, gameID).Exec(c); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	if err := tx.Commit(); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	committed = true

	c.JSON(http.StatusOK, gin.H{"message": "Leaderboard deleted"})
}

func (h *GameHandler) ListLeaderboardGroups(c *gin.Context) {
	leaderboardID, err := strconv.ParseInt(c.Param("leaderboard_id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid leaderboard id"})
		return
	}
	leaderboard, err := h.getLeaderboardByID(c, leaderboardID)
	if err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "Leaderboard not found"})
		return
	}
	if err := h.ensureLeaderboardModuleEnabled(c, leaderboard.GameID); err != nil {
		renderLeaderboardModuleError(c, err)
		return
	}

	var groups []models.LeaderboardGroup
	err = h.db.NewSelect().
		Model(&groups).
		Relation("Members", func(q *bun.SelectQuery) *bun.SelectQuery {
			return q.OrderExpr("lbgm.id ASC")
		}).
		Where("lbg.leaderboard_id = ?", leaderboardID).
		OrderExpr("lbg.id ASC").
		Scan(c)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, groups)
}

func (h *GameHandler) CreateLeaderboardGroup(c *gin.Context) {
	leaderboardID, err := strconv.ParseInt(c.Param("leaderboard_id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid leaderboard id"})
		return
	}
	leaderboard, err := h.getLeaderboardByID(c, leaderboardID)
	if err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "Leaderboard not found"})
		return
	}

	var req models.UpsertLeaderboardGroupRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	if err := validateUpsertLeaderboardGroupRequest(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	if err := h.ensureLeaderboardModuleEnabled(c, leaderboard.GameID); err != nil {
		renderLeaderboardModuleError(c, err)
		return
	}

	isDefault := false
	if req.IsDefault != nil {
		isDefault = *req.IsDefault
	}

	group := &models.LeaderboardGroup{
		LeaderboardID: leaderboardID,
		Key:           strings.TrimSpace(req.Key),
		Name:          strings.TrimSpace(req.Name),
		IsDefault:     isDefault,
		CreatedAt:     time.Now(),
		UpdatedAt:     time.Now(),
	}
	_, err = h.db.NewInsert().Model(group).Exec(c)
	if err != nil {
		c.JSON(http.StatusConflict, gin.H{"error": "Leaderboard group key already exists"})
		return
	}

	c.JSON(http.StatusCreated, group)
}

func (h *GameHandler) UpdateLeaderboardGroup(c *gin.Context) {
	groupID, err := strconv.ParseInt(c.Param("group_id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid group id"})
		return
	}

	group, leaderboard, err := h.getLeaderboardGroup(c, groupID)
	if err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "Leaderboard group not found"})
		return
	}

	var req models.UpsertLeaderboardGroupRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	if err := validateUpsertLeaderboardGroupRequest(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	if err := h.ensureLeaderboardModuleEnabled(c, leaderboard.GameID); err != nil {
		renderLeaderboardModuleError(c, err)
		return
	}

	isDefault := group.IsDefault
	if req.IsDefault != nil {
		isDefault = *req.IsDefault
	}

	_, err = h.db.NewUpdate().
		Model((*models.LeaderboardGroup)(nil)).
		Set(`"key" = ?`, strings.TrimSpace(req.Key)).
		Set("name = ?", strings.TrimSpace(req.Name)).
		Set("is_default = ?", isDefault).
		Set("updated_at = ?", time.Now()).
		Where("id = ?", groupID).
		Exec(c)
	if err != nil {
		c.JSON(http.StatusConflict, gin.H{"error": "Could not update leaderboard group"})
		return
	}

	updated, _, err := h.getLeaderboardGroup(c, groupID)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, updated)
}

func (h *GameHandler) DeleteLeaderboardGroup(c *gin.Context) {
	groupID, err := strconv.ParseInt(c.Param("group_id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid group id"})
		return
	}
	_, leaderboard, err := h.getLeaderboardGroup(c, groupID)
	if err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "Leaderboard group not found"})
		return
	}
	if err := h.ensureLeaderboardModuleEnabled(c, leaderboard.GameID); err != nil {
		renderLeaderboardModuleError(c, err)
		return
	}

	tx, err := h.db.BeginTx(c, nil)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	committed := false
	defer func() {
		if !committed {
			_ = tx.Rollback()
		}
	}()

	if _, err := tx.NewDelete().Model((*models.LeaderboardGroupMember)(nil)).Where("group_id = ?", groupID).Exec(c); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	if _, err := tx.NewDelete().Model((*models.LeaderboardGroup)(nil)).Where("id = ?", groupID).Exec(c); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	if err := tx.Commit(); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	committed = true

	c.JSON(http.StatusOK, gin.H{"message": "Leaderboard group deleted"})
}

func (h *GameHandler) AddLeaderboardGroupMember(c *gin.Context) {
	groupID, err := strconv.ParseInt(c.Param("group_id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid group id"})
		return
	}
	group, leaderboard, err := h.getLeaderboardGroup(c, groupID)
	if err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "Leaderboard group not found"})
		return
	}
	if err := h.ensureLeaderboardModuleEnabled(c, leaderboard.GameID); err != nil {
		renderLeaderboardModuleError(c, err)
		return
	}

	var req models.AddLeaderboardGroupMemberRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	if err := h.ensureUserBelongsToGame(c, req.UserID, leaderboard.GameID); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	member := &models.LeaderboardGroupMember{
		GroupID:   group.ID,
		UserID:    req.UserID,
		CreatedAt: time.Now(),
	}
	_, err = h.db.NewInsert().Model(member).Exec(c)
	if err != nil {
		c.JSON(http.StatusConflict, gin.H{"error": "User already in group"})
		return
	}
	c.JSON(http.StatusCreated, member)
}

func (h *GameHandler) DeleteLeaderboardGroupMember(c *gin.Context) {
	groupID, err := strconv.ParseInt(c.Param("group_id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid group id"})
		return
	}
	userID, err := strconv.ParseInt(c.Param("user_id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid user id"})
		return
	}
	_, leaderboard, err := h.getLeaderboardGroup(c, groupID)
	if err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "Leaderboard group not found"})
		return
	}
	if err := h.ensureLeaderboardModuleEnabled(c, leaderboard.GameID); err != nil {
		renderLeaderboardModuleError(c, err)
		return
	}

	res, err := h.db.NewDelete().Model((*models.LeaderboardGroupMember)(nil)).Where("group_id = ? AND user_id = ?", groupID, userID).Exec(c)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	if affected, _ := res.RowsAffected(); affected == 0 {
		c.JSON(http.StatusNotFound, gin.H{"error": "Group member not found"})
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": "Group member deleted"})
}

func (h *GameHandler) UpsertLeaderboardScore(c *gin.Context) {
	leaderboardID, err := strconv.ParseInt(c.Param("leaderboard_id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid leaderboard id"})
		return
	}
	leaderboard, err := h.getLeaderboardByID(c, leaderboardID)
	if err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "Leaderboard not found"})
		return
	}
	if err := h.ensureLeaderboardModuleEnabled(c, leaderboard.GameID); err != nil {
		renderLeaderboardModuleError(c, err)
		return
	}

	var req models.UpsertLeaderboardScoreRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	if err := h.ensureUserGameBelongsToGame(c, req.UserGameID, leaderboard.GameID); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	now := time.Now()
	score := &models.LeaderboardScore{
		LeaderboardID: leaderboardID,
		UserGameID:    req.UserGameID,
		Score:         req.Score,
		CreatedAt:     now,
		UpdatedAt:     now,
	}
	_, err = h.db.NewInsert().Model(score).
		On("CONFLICT (leaderboard_id, user_game_id) DO UPDATE").
		Set("score = EXCLUDED.score").
		Set("updated_at = EXCLUDED.updated_at").
		Exec(c)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": "Leaderboard score saved"})
}

func (h *GameHandler) GetLeaderboardRankings(c *gin.Context) {
	leaderboardID, err := strconv.ParseInt(c.Param("leaderboard_id"), 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid leaderboard id"})
		return
	}
	leaderboard, err := h.getLeaderboardByID(c, leaderboardID)
	if err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "Leaderboard not found"})
		return
	}
	if err := h.ensureLeaderboardModuleEnabled(c, leaderboard.GameID); err != nil {
		renderLeaderboardModuleError(c, err)
		return
	}

	limit := 50
	if rawLimit := c.Query("limit"); rawLimit != "" {
		parsed, err := strconv.Atoi(rawLimit)
		if err != nil || parsed <= 0 {
			c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid limit"})
			return
		}
		if parsed > 200 {
			parsed = 200
		}
		limit = parsed
	}

	query := h.db.NewSelect().
		TableExpr("leaderboard_scores AS lbs").
		ColumnExpr("lbs.user_game_id AS user_game_id").
		ColumnExpr("ug.user_id AS user_id").
		ColumnExpr("u.username AS username").
		ColumnExpr("lbs.score AS score").
		Join("JOIN user_games AS ug ON ug.id = lbs.user_game_id").
		Join("JOIN users AS u ON u.id = ug.user_id").
		Where("lbs.leaderboard_id = ?", leaderboardID)

	if rawGroupID := c.Query("group_id"); rawGroupID != "" {
		groupID, err := strconv.ParseInt(rawGroupID, 10, 64)
		if err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid group_id"})
			return
		}
		group, _, err := h.getLeaderboardGroup(c, groupID)
		if err != nil || group.LeaderboardID != leaderboardID {
			c.JSON(http.StatusNotFound, gin.H{"error": "Leaderboard group not found"})
			return
		}
		query = query.Join("JOIN leaderboard_group_members AS lbgm ON lbgm.user_id = ug.user_id").
			Where("lbgm.group_id = ?", groupID)
	}

	switch leaderboard.SortOrder {
	case models.LeaderboardSortOrderAsc:
		query = query.OrderExpr("lbs.score ASC, lbs.updated_at ASC")
	default:
		query = query.OrderExpr("lbs.score DESC, lbs.updated_at ASC")
	}

	var rows []models.LeaderboardRankItem
	if err := query.Limit(limit).Scan(c, &rows); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	for i := range rows {
		rows[i].Rank = int64(i + 1)
	}

	c.JSON(http.StatusOK, gin.H{
		"leaderboard": leaderboard,
		"items":       rows,
	})
}

func (h *GameHandler) ensureLeaderboardModuleEnabled(c *gin.Context, gameID int64) error {
	exists, err := h.gameExists(c, gameID)
	if err != nil {
		return err
	}
	if !exists {
		return fmt.Errorf("game_not_found")
	}
	hasModule, err := h.gameHasModule(c, gameID, "leaderboard")
	if err != nil {
		return err
	}
	if !hasModule {
		return fmt.Errorf("leaderboard_module_disabled")
	}
	return nil
}

func renderLeaderboardModuleError(c *gin.Context, err error) {
	switch err.Error() {
	case "game_not_found":
		c.JSON(http.StatusNotFound, gin.H{"error": "Game not found"})
	case "leaderboard_module_disabled":
		c.JSON(http.StatusForbidden, gin.H{"error": "Leaderboard module is not enabled for this game"})
	default:
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
	}
}

func validateUpsertLeaderboardRequest(req *models.UpsertLeaderboardRequest) error {
	req.Key = strings.TrimSpace(req.Key)
	req.Name = strings.TrimSpace(req.Name)
	if req.Key == "" {
		return fmt.Errorf("key is required")
	}
	if req.Name == "" {
		return fmt.Errorf("name is required")
	}
	if req.SortOrder != models.LeaderboardSortOrderAsc && req.SortOrder != models.LeaderboardSortOrderDesc {
		return fmt.Errorf("sort_order must be asc or desc")
	}
	switch req.PeriodType {
	case models.LeaderboardPeriodAllTime, models.LeaderboardPeriodDaily, models.LeaderboardPeriodWeekly, models.LeaderboardPeriodMonthly:
	default:
		return fmt.Errorf("unsupported period_type")
	}
	return nil
}

func validateUpsertLeaderboardGroupRequest(req *models.UpsertLeaderboardGroupRequest) error {
	req.Key = strings.TrimSpace(req.Key)
	req.Name = strings.TrimSpace(req.Name)
	if req.Key == "" {
		return fmt.Errorf("key is required")
	}
	if req.Name == "" {
		return fmt.Errorf("name is required")
	}
	return nil
}

func (h *GameHandler) getLeaderboard(c *gin.Context, gameID, leaderboardID int64) (*models.Leaderboard, error) {
	leaderboard := new(models.Leaderboard)
	err := h.db.NewSelect().
		Model(leaderboard).
		Relation("Groups", func(q *bun.SelectQuery) *bun.SelectQuery {
			return q.OrderExpr("lbg.id ASC")
		}).
		Where("lb.id = ? AND lb.game_id = ?", leaderboardID, gameID).
		Scan(c)
	if err != nil {
		return nil, err
	}
	return leaderboard, nil
}

func (h *GameHandler) getLeaderboardByID(c *gin.Context, leaderboardID int64) (*models.Leaderboard, error) {
	leaderboard := new(models.Leaderboard)
	err := h.db.NewSelect().
		Model(leaderboard).
		Where("id = ?", leaderboardID).
		Scan(c)
	if err != nil {
		return nil, err
	}
	return leaderboard, nil
}

func (h *GameHandler) getLeaderboardGroup(c *gin.Context, groupID int64) (*models.LeaderboardGroup, *models.Leaderboard, error) {
	group := new(models.LeaderboardGroup)
	err := h.db.NewSelect().Model(group).Where("id = ?", groupID).Scan(c)
	if err != nil {
		return nil, nil, err
	}
	leaderboard, err := h.getLeaderboardByID(c, group.LeaderboardID)
	if err != nil {
		return nil, nil, err
	}
	return group, leaderboard, nil
}

func (h *GameHandler) ensureUserBelongsToGame(c *gin.Context, userID, gameID int64) error {
	exists, err := h.db.NewSelect().
		Model((*models.UserGame)(nil)).
		Where("user_id = ? AND game_id = ?", userID, gameID).
		Exists(c)
	if err != nil {
		return err
	}
	if !exists {
		return fmt.Errorf("user is not connected to this game")
	}
	return nil
}

func (h *GameHandler) ensureUserGameBelongsToGame(c *gin.Context, userGameID, gameID int64) error {
	exists, err := h.db.NewSelect().
		Model((*models.UserGame)(nil)).
		Where("id = ? AND game_id = ?", userGameID, gameID).
		Exists(c)
	if err != nil {
		return err
	}
	if !exists {
		return fmt.Errorf("user_game does not belong to this game")
	}
	return nil
}