package main

import (
	"context"
	"database/sql"
	"flag"
	"os"
	"time"
)

type Config struct {
	Port int
	Root string
	DB   struct {
		Scheme string
		Conn   string
	}
}

func NewConfig() (Config, error) {
	var c Config
	fs := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)

	fs.IntVar(&c.Port, "p", 8080, "port")
	fs.StringVar(&c.Root, "r", "/tmp/", "static file root")
	fs.StringVar(&c.DB.Scheme, "db-scheme", "sqlite", "sql scheme")
	fs.StringVar(&c.DB.Conn, "db-conn", "/tmp/out.sql", "sql conn string")

	err := fs.Parse(os.Args[1:])
	return c, err
}

type DB struct {
	scheme string
	conn   string
}

func NewDB(ctx context.Context, scheme, conn string) (DB, error) {
	ctx, can := context.WithTimeout(ctx, time.Second*10)
	defer can()

	db := DB{
		scheme: scheme,
		conn:   conn,
	}

	sql, err := db.dial(ctx)
	if sql != nil {
		sql.Close()
	}

	return db, err
}

func (db DB) dial(ctx context.Context) (*sql.DB, error) {
	c, err := sql.Open(db.scheme, db.conn)
	if err != nil {
		return nil, err
	}
	if err := c.PingContext(ctx); err != nil {
		return nil, err
	}
	return c, nil
}