Notes/session.go

package main

import (
	// Standard
	"database/sql"
	"errors"
	"fmt"
	"net/http"
	"time"
)

type Session struct {
	UUID    string
	UserID  int
	Created time.Time
}

func CreateSession() (session Session, err error) {// {{{
	var rows *sql.Rows
	if rows, err = db.Query(`
		INSERT INTO public.session(uuid)
		VALUES(gen_random_uuid())
		RETURNING uuid, created`,
	); err != nil {
		return
	}
	defer rows.Close()

	if rows.Next() {
		rows.Scan(&session.UUID, &session.Created)
	}

	return
}// }}}

func sessionUUID(r *http.Request) (string, error) {// {{{
	headers := r.Header["X-Session-Id"]
	if len(headers) > 0 {
		return headers[0], nil
	}
	return "", errors.New("Invalid session")
}// }}}
func ValidateSession(r *http.Request, notFoundIsError bool) (session Session, found bool, err error) {// {{{
	var uuid string
	if uuid, err = sessionUUID(r); err != nil {
		return
	}

	session.UUID = uuid
	if found, err = session.Retrieve(); err != nil {
		return
	}

	if notFoundIsError && !found {
		err = errors.New("Invalid session")
		return
	}

	return
}// }}}

func (session *Session) Retrieve() (found bool, err error) {// {{{
	var rows *sql.Rows
	if rows, err = db.Query(`
		SELECT
			uuid, user_id, created
		FROM public.session
		WHERE
			uuid = $1 AND
			created + $2::interval >= NOW()
		`,
		session.UUID,
		fmt.Sprintf("%d days", config.Session.DaysValid),
	); err != nil {
		return
	}
	defer rows.Close()

	found = false
	if rows.Next() {
		found = true
		rows.Scan(&session.UUID, &session.UserID, &session.Created)
	}

	return
}// }}}
func (session *Session) Authenticate(username, password string) (authenticated bool, err error) {// {{{
	var rows *sql.Rows
	if rows, err = db.Query(`
		SELECT id
		FROM public.user
		WHERE
			username=$1 AND
			password=password_hash(SUBSTRING(password FROM 1 FOR 32), $2::bytea)
		`,
		username,
		password,
	); err != nil {
		return
	}
	defer rows.Close()

	if rows.Next() {
		rows.Scan(&session.UserID)
		authenticated = session.UserID > 0
	}

	if authenticated {
		_, err = db.Exec("UPDATE public.session SET user_id=$1 WHERE uuid=$2", session.UserID, session.UUID)
		if err != nil {
			return
		}
	}

	return 
}// }}}


// vim: foldmethod=marker