Extract HTTP handlers in separate file

1 files changed, 275 insertions, 0 deletions

diff --git a/handlers.go b/handlers.go
new file mode 100644
index 0000000..21873a7
--- /dev/null
+++ b/handlers.go
@@ -0,0 +1,275 @@
+package koushin
+
+import (
+	"fmt"
+	"io/ioutil"
+	"mime"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+
+	"github.com/emersion/go-imap"
+	imapclient "github.com/emersion/go-imap/client"
+	"github.com/emersion/go-message"
+	"github.com/emersion/go-sasl"
+	"github.com/labstack/echo/v4"
+)
+
+func handleGetMailbox(ectx echo.Context) error {
+	ctx := ectx.(*context)
+
+	mboxName, err := url.PathUnescape(ctx.Param("mbox"))
+	if err != nil {
+		return echo.NewHTTPError(http.StatusBadRequest, err)
+	}
+
+	page := 0
+	if pageStr := ctx.QueryParam("page"); pageStr != "" {
+		var err error
+		if page, err = strconv.Atoi(pageStr); err != nil || page < 0 {
+			return echo.NewHTTPError(http.StatusBadRequest, "invalid page index")
+		}
+	}
+
+	var mailboxes []*imap.MailboxInfo
+	var msgs []imapMessage
+	var mbox *imap.MailboxStatus
+	err = ctx.session.Do(func(c *imapclient.Client) error {
+		var err error
+		if mailboxes, err = listMailboxes(c); err != nil {
+			return err
+		}
+		if msgs, err = listMessages(c, mboxName, page); err != nil {
+			return err
+		}
+		mbox = c.Mailbox()
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	prevPage, nextPage := -1, -1
+	if page > 0 {
+		prevPage = page - 1
+	}
+	if (page+1)*messagesPerPage < int(mbox.Messages) {
+		nextPage = page + 1
+	}
+
+	return ctx.Render(http.StatusOK, "mailbox.html", map[string]interface{}{
+		"Mailbox":   mbox,
+		"Mailboxes": mailboxes,
+		"Messages":  msgs,
+		"PrevPage":  prevPage,
+		"NextPage":  nextPage,
+	})
+}
+
+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, username, password)
+		if err != nil {
+			return fmt.Errorf("failed to put connection in pool: %v", err)
+		}
+		ctx.setToken(token)
+
+		return ctx.Redirect(http.StatusFound, "/mailbox/INBOX")
+	}
+
+	return ctx.Render(http.StatusOK, "login.html", nil)
+}
+
+func handleLogout(ectx echo.Context) error {
+	ctx := ectx.(*context)
+
+	err := ctx.session.Do(func(c *imapclient.Client) error {
+		return c.Logout()
+	})
+	if err != nil {
+		return fmt.Errorf("failed to logout: %v", err)
+	}
+
+	ctx.setToken("")
+	return ctx.Redirect(http.StatusFound, "/login")
+}
+
+func handleGetPart(ctx *context, raw bool) error {
+	mboxName, uid, err := parseMboxAndUid(ctx.Param("mbox"), ctx.Param("uid"))
+	if err != nil {
+		return echo.NewHTTPError(http.StatusBadRequest, err)
+	}
+	partPathString := ctx.QueryParam("part")
+	partPath, err := parsePartPath(partPathString)
+	if err != nil {
+		return echo.NewHTTPError(http.StatusBadRequest, err)
+	}
+
+	var msg *imapMessage
+	var part *message.Entity
+	var mbox *imap.MailboxStatus
+	err = ctx.session.Do(func(c *imapclient.Client) error {
+		var err error
+		msg, part, err = getMessagePart(c, mboxName, uid, partPath)
+		mbox = c.Mailbox()
+		return err
+	})
+	if err != nil {
+		return err
+	}
+
+	mimeType, _, err := part.Header.ContentType()
+	if err != nil {
+		return fmt.Errorf("failed to parse part Content-Type: %v", err)
+	}
+	if len(partPath) == 0 {
+		mimeType = "message/rfc822"
+	}
+
+	if raw {
+		disp, dispParams, _ := part.Header.ContentDisposition()
+		filename := dispParams["filename"]
+
+		// TODO: set Content-Length if possible
+
+		if !strings.EqualFold(mimeType, "text/plain") || strings.EqualFold(disp, "attachment") {
+			dispParams := make(map[string]string)
+			if filename != "" {
+				dispParams["filename"] = filename
+			}
+			disp := mime.FormatMediaType("attachment", dispParams)
+			ctx.Response().Header().Set("Content-Disposition", disp)
+		}
+		return ctx.Stream(http.StatusOK, mimeType, part.Body)
+	}
+
+	var body string
+	if strings.HasPrefix(strings.ToLower(mimeType), "text/") {
+		b, err := ioutil.ReadAll(part.Body)
+		if err != nil {
+			return fmt.Errorf("failed to read part body: %v", err)
+		}
+		body = string(b)
+	}
+
+	return ctx.Render(http.StatusOK, "message.html", map[string]interface{}{
+		"Mailbox":     mbox,
+		"Message":     msg,
+		"Body":        body,
+		"PartPath":    partPathString,
+		"MailboxPage": (mbox.Messages - msg.SeqNum) / messagesPerPage,
+	})
+}
+
+func handleCompose(ectx echo.Context) error {
+	ctx := ectx.(*context)
+
+	var msg OutgoingMessage
+	if strings.ContainsRune(ctx.session.username, '@') {
+		msg.From = ctx.session.username
+	}
+
+	if ctx.Request().Method == http.MethodGet && ctx.Param("uid") != "" {
+		// This is a reply
+		mboxName, uid, err := parseMboxAndUid(ctx.Param("mbox"), ctx.Param("uid"))
+		if err != nil {
+			return echo.NewHTTPError(http.StatusBadRequest, err)
+		}
+		partPath, err := parsePartPath(ctx.QueryParam("part"))
+		if err != nil {
+			return echo.NewHTTPError(http.StatusBadRequest, err)
+		}
+
+		var inReplyTo *imapMessage
+		var part *message.Entity
+		err = ctx.session.Do(func(c *imapclient.Client) error {
+			var err error
+			inReplyTo, part, err = getMessagePart(c, mboxName, uid, partPath)
+			return err
+		})
+		if err != nil {
+			return err
+		}
+
+		mimeType, _, err := part.Header.ContentType()
+		if err != nil {
+			return fmt.Errorf("failed to parse part Content-Type: %v", err)
+		}
+
+		if !strings.HasPrefix(strings.ToLower(mimeType), "text/") {
+			err := fmt.Errorf("cannot reply to \"%v\" part", mimeType)
+			return echo.NewHTTPError(http.StatusBadRequest, err)
+		}
+
+		msg.Text, err = quote(part.Body)
+		if err != nil {
+			return err
+		}
+
+		msg.InReplyTo = inReplyTo.Envelope.MessageId
+		// TODO: populate From from known user addresses and inReplyTo.Envelope.To
+		replyTo := inReplyTo.Envelope.ReplyTo
+		if len(replyTo) == 0 {
+			replyTo = inReplyTo.Envelope.From
+		}
+		if len(replyTo) > 0 {
+			msg.To = make([]string, len(replyTo))
+			for i, to := range replyTo {
+				msg.To[i] = to.MailboxName + "@" + to.HostName
+			}
+		}
+		msg.Subject = inReplyTo.Envelope.Subject
+		if !strings.HasPrefix(strings.ToLower(msg.Subject), "re:") {
+			msg.Subject = "Re: " + msg.Subject
+		}
+	}
+
+	if ctx.Request().Method == http.MethodPost {
+		msg.From = ctx.FormValue("from")
+		msg.To = parseAddressList(ctx.FormValue("to"))
+		msg.Subject = ctx.FormValue("subject")
+		msg.Text = ctx.FormValue("text")
+		msg.InReplyTo = ctx.FormValue("in_reply_to")
+
+		c, err := ctx.server.connectSMTP()
+		if err != nil {
+			return err
+		}
+		defer c.Close()
+
+		auth := sasl.NewPlainClient("", ctx.session.username, ctx.session.password)
+		if err := c.Auth(auth); err != nil {
+			return echo.NewHTTPError(http.StatusForbidden, err)
+		}
+
+		if err := sendMessage(c, &msg); err != nil {
+			return err
+		}
+
+		if err := c.Quit(); err != nil {
+			return fmt.Errorf("QUIT failed: %v", err)
+		}
+
+		// TODO: append to IMAP Sent mailbox
+
+		return ctx.Redirect(http.StatusFound, "/mailbox/INBOX")
+	}
+
+	return ctx.Render(http.StatusOK, "compose.html", map[string]interface{}{
+		"Message": &msg,
+	})
+}