feat: add total player count and total playtime logic

- Implemented TotalPlayerCountLogic to retrieve the total number of unique players within a specified time range.
- Implemented TotalPlayTimeLogic to calculate the total playtime of players within a specified time range.
- Created ServiceContext to manage database connections and initialize necessary tables.
- Added types for total player count and total playtime requests and responses.
- Set up the main server file to start the application with the necessary configurations.
- Updated go.mod and go.sum for new dependencies.

app/internal/logic/topkillerlogic.go

@@ -0,0 +1,60 @@
+package logic
+
+import (
+	"context"
+
+	"git.cialloo.com/CiallooWeb/ServerStatistics/app/internal/svc"
+	"git.cialloo.com/CiallooWeb/ServerStatistics/app/internal/types"
+
+	"github.com/zeromicro/go-zero/core/logx"
+)
+
+type TopKillerLogic struct {
+	logx.Logger
+	ctx    context.Context
+	svcCtx *svc.ServiceContext
+}
+
+// Get top players by kill count within a specified time range
+func NewTopKillerLogic(ctx context.Context, svcCtx *svc.ServiceContext) *TopKillerLogic {
+	return &TopKillerLogic{
+		Logger: logx.WithContext(ctx),
+		ctx:    ctx,
+		svcCtx: svcCtx,
+	}
+}
+
+func (l *TopKillerLogic) TopKiller(req *types.TopKillerReq) (resp *types.TopKillerResp, err error) {
+	query := `
+		SELECT attacker_steamid64, attacker_name,
+			COUNT(*) as kill_count
+		FROM steam_union.event_player_death_log
+		WHERE event_player_death_time >= TO_TIMESTAMP($1 / 1000.0)
+			AND event_player_death_time <= TO_TIMESTAMP($2 / 1000.0)
+			AND attacker_steamid64 > 1
+		GROUP BY attacker_steamid64, attacker_name
+		ORDER BY kill_count DESC
+		LIMIT $3
+	`
+
+	rows, err := l.svcCtx.DB.QueryContext(l.ctx, query, req.TimeRangeStart, req.TimeRangeEnd, req.Limit)
+	if err != nil {
+		l.Errorf("Failed to query top killers: %v", err)
+		return nil, err
+	}
+	defer rows.Close()
+
+	var players []types.TopKillerRespPlayer
+	for rows.Next() {
+		var player types.TopKillerRespPlayer
+		if err := rows.Scan(&player.SteamID64, &player.UserName, &player.KillCount); err != nil {
+			l.Errorf("Failed to scan top killer: %v", err)
+			continue
+		}
+		players = append(players, player)
+	}
+
+	return &types.TopKillerResp{
+		Players: players,
+	}, nil
+}