package main

import (
	"fmt"
	"log"
	"regexp"

	"gorm.io/driver/postgres"
	"gorm.io/gorm"

	"github.com/sundynix/pets-be/internal/config"
)

var databaseName = regexp.MustCompile(`^[a-zA-Z0-9_-]+$`)

// dbinit creates the configured PostgreSQL database once. It does not change other databases.
func main() {
	cfg, err := config.Load()
	if err != nil {
		log.Fatal(err)
	}
	name := cfg.Postgres.Database
	if !databaseName.MatchString(name) {
		log.Fatal("invalid database name")
	}
	maintenance := cfg.Postgres
	maintenance.Database = "postgres"
	db, err := gorm.Open(postgres.Open(maintenance.DSN()), &gorm.Config{})
	if err != nil {
		log.Fatal(err)
	}
	var count int64
	if err := db.Raw("SELECT count(*) FROM pg_database WHERE datname = ?", name).Scan(&count).Error; err != nil {
		log.Fatal(err)
	}
	if count > 0 {
		log.Printf("database %s already exists", name)
		return
	}
	if err := db.Exec(fmt.Sprintf("CREATE DATABASE \"%s\"", name)).Error; err != nil {
		log.Fatal(err)
	}
	log.Printf("created database %s", name)
}