alps/server.go
2019-12-02 19:53:09 +01:00

219 lines
4.3 KiB
Go

package koushin
import (
"fmt"
"net/http"
"net/url"
"strconv"
"strings"
"time"
"github.com/labstack/echo/v4"
imapclient "github.com/emersion/go-imap/client"
)
const cookieName = "koushin_session"
type Server struct {
imap struct {
host string
tls bool
insecure bool
pool *ConnPool
}
}
func NewServer(imapURL string) (*Server, error) {
u, err := url.Parse(imapURL)
if err != nil {
return nil, err
}
s := &Server{}
s.imap.host = u.Host
switch u.Scheme {
case "imap":
// This space is intentionally left blank
case "imaps":
s.imap.tls = true
case "imap+insecure":
s.imap.insecure = true
default:
return nil, fmt.Errorf("unrecognized IMAP URL scheme: %s", u.Scheme)
}
s.imap.pool = NewConnPool()
return s, nil
}
type context struct {
echo.Context
server *Server
conn *imapclient.Client
}
var aLongTimeAgo = time.Unix(233431200, 0)
func (c *context) setToken(token string) {
cookie := http.Cookie{
Name: cookieName,
Value: token,
HttpOnly: true,
// TODO: domain, secure
}
if token == "" {
cookie.Expires = aLongTimeAgo // unset the cookie
}
c.SetCookie(&cookie)
}
func handleLogin(ectx echo.Context) error {
ctx := ectx.(*context)
username := ctx.FormValue("username")
password := ctx.FormValue("password")
if username != "" && password != "" {
conn, err := ctx.server.connectIMAP()
if err != nil {
return err
}
if err := conn.Login(username, password); err != nil {
conn.Logout()
return ctx.Render(http.StatusOK, "login.html", nil)
}
token, err := ctx.server.imap.pool.Put(conn)
if err != nil {
return err
}
ctx.setToken(token)
return ctx.Redirect(http.StatusFound, "/mailbox/INBOX")
}
return ctx.Render(http.StatusOK, "login.html", nil)
}
func parseUid(s string) (uint32, error) {
uid, err := strconv.ParseUint(s, 10, 32)
if err != nil {
return 0, err
}
if uid == 0 {
return 0, fmt.Errorf("UID must be non-zero")
}
return uint32(uid), nil
}
func parsePartPath(s string) ([]int, error) {
l := strings.Split(s, ".")
path := make([]int, len(l))
for i, s := range l {
var err error
path[i], err = strconv.Atoi(s)
if err != nil {
return nil, err
}
if path[i] <= 0 {
return nil, fmt.Errorf("part num must be strictly positive")
}
}
return path, nil
}
func New(imapURL string) *echo.Echo {
e := echo.New()
s, err := NewServer(imapURL)
if err != nil {
e.Logger.Fatal(err)
}
e.Use(func(next echo.HandlerFunc) echo.HandlerFunc {
return func(ectx echo.Context) error {
ctx := &context{Context: ectx, server: s}
cookie, err := ctx.Cookie(cookieName)
if err == http.ErrNoCookie {
// Require auth for all pages except /login
if ctx.Path() == "/login" {
return next(ctx)
} else {
return ctx.Redirect(http.StatusFound, "/login")
}
} else if err != nil {
return err
}
ctx.conn, err = ctx.server.imap.pool.Get(cookie.Value)
if err == ErrSessionExpired {
ctx.setToken("")
return ctx.Redirect(http.StatusFound, "/login")
} else if err != nil {
return err
}
return next(ctx)
}
})
e.Renderer, err = loadTemplates()
if err != nil {
e.Logger.Fatal("Failed to load templates:", err)
}
e.GET("/mailbox/:mbox", func(ectx echo.Context) error {
ctx := ectx.(*context)
mailboxes, err := listMailboxes(ctx.conn)
if err != nil {
return err
}
msgs, err := listMessages(ctx.conn, ctx.Param("mbox"))
if err != nil {
return err
}
return ctx.Render(http.StatusOK, "mailbox.html", map[string]interface{}{
"Mailbox": ctx.conn.Mailbox(),
"Mailboxes": mailboxes,
"Messages": msgs,
})
})
e.GET("/message/:mbox/:uid", func(ectx echo.Context) error {
ctx := ectx.(*context)
uid, err := parseUid(ctx.Param("uid"))
if err != nil {
return echo.NewHTTPError(http.StatusBadRequest, err)
}
// TODO: handle messages without a text part
part, err := parsePartPath(ctx.QueryParam("part"))
if err != nil {
return echo.NewHTTPError(http.StatusBadRequest, err)
}
msg, body, err := getMessage(ctx.conn, ctx.Param("mbox"), uid, part)
if err != nil {
return err
}
return ctx.Render(http.StatusOK, "message.html", map[string]interface{}{
"Mailbox": ctx.conn.Mailbox(),
"Message": msg,
"Body": body,
})
})
e.GET("/login", handleLogin)
e.POST("/login", handleLogin)
e.Static("/assets", "public/assets")
return e
}