package config

import (
	"database/sql"
	"fmt"
	"time"

	_ "github.com/lib/pq"
)

// DB global var (may be nil if connection fails)
var DB *sql.DB

// Use the credentials you provided
const (
	host     = "202.46.28.160"
	port     = 45432
	user     = "5803024022"
	password = "pw5803024022"
	dbname   = "tgs03_5803024022"
)

// InitDB attempts to open a connection pool to Postgres.
// It returns error if ping fails.
func InitDB() (*sql.DB, error) {
	dsn := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s sslmode=disable",
		host, port, user, password, dbname)
	db, err := sql.Open("postgres", dsn)
	if err != nil {
		return nil, err
	}
	// reasonable settings
	db.SetMaxOpenConns(10)
	db.SetMaxIdleConns(5)
	db.SetConnMaxLifetime(time.Minute * 5)

	// Ping with timeout
	done := make(chan error, 1)
	go func() {
		done <- db.Ping()
	}()
	select {
	case err := <-done:
		if err != nil {
			return nil, err
		}
	case <-time.After(2 * time.Second):
		return nil, fmt.Errorf("db ping timeout")
	}
	return db, nil
}