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/svc/servicecontext.go

@@ -0,0 +1,64 @@
+package svc
+
+import (
+	"database/sql"
+	"log"
+
+	"git.cialloo.com/CiallooWeb/ServerStatistics/app/internal/config"
+
+	_ "github.com/lib/pq" // PostgreSQL driver
+)
+
+type ServiceContext struct {
+	Config config.Config
+	DB     *sql.DB
+}
+
+func NewServiceContext(c config.Config) *ServiceContext {
+	// Initialize database connection
+	db, err := sql.Open("postgres", c.Database.DSN)
+	if err != nil {
+		log.Fatalf("Failed to connect to database: %v", err)
+	}
+
+	// Test the connection
+	if err := db.Ping(); err != nil {
+		log.Fatalf("Failed to ping database: %v", err)
+	}
+
+	log.Println("Database connection established successfully")
+
+	// Create tables if they don't exist
+	if err := createTables(db); err != nil {
+		log.Fatalf("Failed to create tables: %v", err)
+	}
+
+	return &ServiceContext{
+		Config: c,
+		DB:     db,
+	}
+}
+
+func createTables(db *sql.DB) error {
+	// Create server table
+	serverTableQuery := `
+	CREATE TABLE IF NOT EXISTS server (
+		id SERIAL PRIMARY KEY,
+		name VARCHAR(64) NOT NULL,
+		ip VARCHAR(64) NOT NULL,
+		port INTEGER NOT NULL,
+		category VARCHAR(64) NOT NULL,
+		bot_count INTEGER NOT NULL,
+		human_count INTEGER NOT NULL,
+		mapname VARCHAR(64) NOT NULL,
+		last_update TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+		UNIQUE (ip, port)
+	);`
+
+	if _, err := db.Exec(serverTableQuery); err != nil {
+		return err
+	}
+
+	log.Println("Database tables created successfully")
+	return nil
+}