Added skeleton code for register endpoint (#2)

Reviewed-on: phoenix/textsender-auth#2
Co-authored-by: phoenix <kundeng00@pm.me>
Co-committed-by: phoenix <kundeng00@pm.me>

internal/db/connection.go

@@ -0,0 +1,113 @@
+// db/connection.go
+package db
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+var Pool *pgxpool.Pool
+
+type Database struct {
+	Pool *pgxpool.Pool
+}
+
+func NewDatabase(connString string) (*Database, error) {
+	ctx := context.Background()
+	// Parse the connection string and create pool configuration
+	config, err := pgxpool.ParseConfig(connString)
+	if err != nil {
+		return nil, fmt.Errorf("unable to parse DSN: %v", err)
+	}
+
+	// Configure connection pool settings
+	config.MaxConns = 25
+	config.MinConns = 5
+	config.MaxConnLifetime = time.Hour
+	config.MaxConnIdleTime = 30 * time.Minute
+	config.HealthCheckPeriod = time.Minute
+
+	// Configure connection timeouts
+	config.ConnConfig.ConnectTimeout = 10 * time.Second
+	config.ConnConfig.RuntimeParams["timezone"] = "UTC"
+
+	// Create the connection pool
+	pool, err := pgxpool.NewWithConfig(ctx, config)
+	if err != nil {
+		return nil, fmt.Errorf("unable to create connection pool: %v", err)
+	}
+
+	// Test the connection with a short timeout
+
+	if err := pool.Ping(ctx); err != nil {
+		pool.Close()
+		return nil, fmt.Errorf("unable to ping database: %v", err)
+	}
+
+	log.Printf("Successfully connected to database")
+	return &Database{Pool: pool}, nil
+}
+
+func (db *Database) Close() {
+	if db.Pool != nil {
+		db.Pool.Close()
+		log.Println("Database connection pool closed")
+	}
+}
+
+// HealthCheck verifies the database connection is still alive
+func (db *Database) HealthCheck(ctx context.Context) error {
+	return db.Pool.Ping(ctx)
+}
+
+// GetPoolStats returns connection pool statistics
+func (db *Database) GetPoolStats() string {
+	stats := db.Pool.Stat()
+	return fmt.Sprintf("TotalConns: %d, IdleConns: %d, AcquiredConns: %d",
+		stats.TotalConns(), stats.IdleConns(), stats.AcquiredConns())
+}
+
+func (db *Database) ResetDatabase(ctx context.Context) error {
+	tx, err := db.Pool.Begin(ctx)
+	if err != nil {
+		return fmt.Errorf("Transaction unable to begin: %v", err)
+	}
+	defer tx.Rollback(ctx)
+
+	schemaContent, err := os.ReadFile("migrations/schema.sql")
+	if err != nil {
+		return fmt.Errorf("error reading schema file: %v", err)
+	}
+
+	statements := strings.Split(string(schemaContent), ";")
+
+	for _, stmt := range statements {
+		stmt = strings.TrimSpace(stmt)
+		if stmt == "" {
+			continue
+		}
+
+		if strings.HasPrefix(stmt, "--") {
+			continue
+		}
+
+		_, err := tx.Exec(ctx, stmt)
+		if err != nil {
+			return fmt.Errorf("error executing SQL statement: %v\nStatement: %s", err, stmt)
+		}
+	}
+
+	if err := tx.Commit(ctx); err != nil {
+		return fmt.Errorf("unable to commit transaction: %v", err)
+	}
+
+	log.Println("Database schema applied successfully")
+
+	return nil
+}