1 files changed, 151 insertions, 4 deletions
diff --git a/server.go b/server.go
index 21fd0fa..cd03c5d 100644
--- a/server.go
+++ b/server.go
@@ -1,24 +1,171 @@
 package koushin
 
 import (
+	"fmt"
 	"net/http"
+	"net/url"
+	"time"
 
 	"github.com/labstack/echo/v4"
+	imapclient "github.com/emersion/go-imap/client"
 )
 
-func New() *echo.Echo {
-	e := echo.New()
+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
+}
+
+func (s *Server) connectIMAP() (*imapclient.Client, error) {
+	var c *imapclient.Client
 	var err error
+	if s.imap.tls {
+		c, err = imapclient.DialTLS(s.imap.host, nil)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		c, err = imapclient.Dial(s.imap.host)
+		if err != nil {
+			return nil, err
+		}
+		if !s.imap.insecure {
+			if err := c.StartTLS(nil); err != nil {
+				c.Close()
+				return nil, err
+			}
+		}
+	}
+
+	return c, err
+}
+
+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, "/")
+	}
+
+	return ctx.Render(http.StatusOK, "login.html", 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 {
+				return next(ctx)
+			} 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("/", func(c echo.Context) error {
-		return c.Render(http.StatusOK, "index.html", nil)
+	e.GET("/", func(ectx echo.Context) error {
+		ctx := ectx.(*context)
+		if ctx.conn == nil {
+			return ctx.Redirect(http.StatusFound, "/login")
+		}
+
+		return ctx.Render(http.StatusOK, "index.html", nil)
 	})
 
+	e.GET("/login", handleLogin)
+	e.POST("/login", handleLogin)
+
 	e.Static("/assets", "public/assets")
 
 	return e