town/invites/invites.go

package invites

import (
	"database/sql"
	"encoding/base64"
	"math/rand"
	"strings"
	"time"

	_ "github.com/mattn/go-sqlite3"
)

const (
	dsn     = "/town/var/invites/invites.db?mode=rw"
	codeLen = 32
)

func ConnectDB() (*sql.DB, error) {
	db, err := sql.Open("sqlite3", dsn)
	if err != nil {
		return nil, err
	}

	return db, nil
}

func generateCode(email string) string {
	rand.Seed(time.Now().Unix())

	charset := "abcdefghijklmnopqrztuvwxyz"
	charset += strings.ToUpper(charset)
	charset += "0123456789"
	charset += "`~!@#$%^&*()-=_+[]{}|;:,./<>?"

	code := []byte{}

	for len(code) < codeLen {
		code = append(code, charset[rand.Intn(len(charset))])
	}

	code = append(code, ' ')

	eb := []byte(email)
	for x := 0; x < len(eb); x++ {
		code = append(code, eb[x])
	}

	return base64.StdEncoding.EncodeToString(code)
}

func Decode(code string) ([]string, error) {
	decoded, err := base64.StdEncoding.DecodeString(code)
	if err != nil {
		return nil, err
	}

	return strings.Split(string(decoded), " "), nil
}

func InsertInvite(db *sql.DB, email string) error {
	stmt, err := db.Prepare(`
		INSERT INTO invites (code, email) VALUES (?, ?)
	`)
	if err != nil {
		return err
	}

	_, err = stmt.Exec(generateCode(email), email)
	if err != nil {
		return err
	}
	defer stmt.Close()

	return nil
}

// TODO decide on rest of API (eg Validate, Use, Get, etc)