plugins/caldav: new plugin

For now it can only list events for the current month.

References: https://todo.sr.ht/~sircmpwn/koushin/60

8 files changed, 235 insertions, 3 deletions

diff --git a/.gitignore b/.gitignore
index 9fbdcbb..6221491 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,5 +3,6 @@
 !/public/themes/sourcehut
 /plugins/*
 !/plugins/base
+!/plugins/caldav
 !/plugins/carddav
 !/plugins/lua
diff --git a/cmd/koushin/main.go b/cmd/koushin/main.go
index e56ed04..afdf7f3 100644
--- a/cmd/koushin/main.go
+++ b/cmd/koushin/main.go
@@ -13,6 +13,7 @@ import (
 	"github.com/labstack/gommon/log"
 
 	_ "git.sr.ht/~emersion/koushin/plugins/base"
+	_ "git.sr.ht/~emersion/koushin/plugins/caldav"
 	_ "git.sr.ht/~emersion/koushin/plugins/carddav"
 	_ "git.sr.ht/~emersion/koushin/plugins/lua"
 )
diff --git a/go.mod b/go.mod
index d89161f..c0c2992 100644
--- a/go.mod
+++ b/go.mod
@@ -13,7 +13,7 @@ require (
 	github.com/emersion/go-sasl v0.0.0-20191210011802-430746ea8b9b
 	github.com/emersion/go-smtp v0.12.1
 	github.com/emersion/go-vcard v0.0.0-20191221110513-5f81fa0d3cc7
-	github.com/emersion/go-webdav v0.2.0
+	github.com/emersion/go-webdav v0.2.1-0.20200205170548-baf63fb1b759
 	github.com/gorilla/css v1.0.0 // indirect
 	github.com/labstack/echo/v4 v4.1.15-0.20200203180927-504f39abaf32
 	github.com/labstack/gommon v0.3.0
diff --git a/go.sum b/go.sum
index fb2453d..40f9393 100644
--- a/go.sum
+++ b/go.sum
@@ -6,6 +6,7 @@ github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWR
 github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
 github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible h1:7qlOGliEKZXTDg6OTjfoBKDXWrumCAMpl/TFQ4/5kLM=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
@@ -28,14 +29,16 @@ github.com/emersion/go-textwrapper v0.0.0-20160606182133-d0e65e56babe h1:40SWqY0
 github.com/emersion/go-textwrapper v0.0.0-20160606182133-d0e65e56babe/go.mod h1:aqO8z8wPrjkscevZJFVE1wXJrLpC5LtJG7fqLOsPb2U=
 github.com/emersion/go-vcard v0.0.0-20191221110513-5f81fa0d3cc7 h1:SE+tcd+0kn0cT4MqTo66gmkjqWHF1Z+Yha5/rhLs/H8=
 github.com/emersion/go-vcard v0.0.0-20191221110513-5f81fa0d3cc7/go.mod h1:HMJKR5wlh/ziNp+sHEDV2ltblO4JD2+IdDOWtGcQBTM=
-github.com/emersion/go-webdav v0.2.0 h1:w6S3ebKLPa49uqzi5CZgV13Bxb8gPXPcaI6D3bfzcXQ=
-github.com/emersion/go-webdav v0.2.0/go.mod h1:5xPS/W9bnqkHMLtgygkgGFvm6uAsbeVRSIZk0ewu4d4=
+github.com/emersion/go-webdav v0.2.1-0.20200205170548-baf63fb1b759 h1:8joXUXgdaV935H/AUKhnyvUf754VcjmQAenNsakT4pA=
+github.com/emersion/go-webdav v0.2.1-0.20200205170548-baf63fb1b759/go.mod h1:dfzmdPRkPLLUQU00fDfwPJomgFmdblZpMoh3CaUsGCc=
 github.com/gorilla/css v1.0.0 h1:BQqNyPTi50JCFMTw/b67hByjMVXZRwGha6wxVGkeihY=
 github.com/gorilla/css v1.0.0/go.mod h1:Dn721qIggHpt4+EFCcTLTU/vk5ySda2ReITrtgBl60c=
 github.com/labstack/echo/v4 v4.1.15-0.20200203180927-504f39abaf32 h1:UiIEDYxPPmjl6mMIY4QPDguD/QAtK+gR4IRMSrjWmeA=
 github.com/labstack/echo/v4 v4.1.15-0.20200203180927-504f39abaf32/go.mod h1:mbsytw7LXzfWxMLdvzjjeERCwTL3PI03GIPpUpaMnfQ=
 github.com/labstack/gommon v0.3.0 h1:JEeO0bvc78PKdyHxloTKiF8BD5iGrH8T6MSeGvSgob0=
 github.com/labstack/gommon v0.3.0/go.mod h1:MULnywXg0yavhxWKc+lOruYdAhDwPK9wf0OL7NoOu+k=
+github.com/luxifer/ical v0.0.0-20191105105432-84b768eb6395 h1:H7Rbug09BDCzr6k/PASDjSMjbJGzXswwqesaDiBNJz8=
+github.com/luxifer/ical v0.0.0-20191105105432-84b768eb6395/go.mod h1:TGCe94U3u9fXQl4yHJ8W87z1czj057aVLxYnFYTDC08=
 github.com/martinlindhe/base36 v1.0.0 h1:eYsumTah144C0A8P1T/AVSUk5ZoLnhfYFM3OGQxB52A=
 github.com/martinlindhe/base36 v1.0.0/go.mod h1:+AtEs8xrBpCeYgSLoY/aJ6Wf37jtBuR0s35750M27+8=
 github.com/mattn/go-colorable v0.1.2/go.mod h1:U0ppj6V5qS13XJ6of8GYAs25YV2eR4EVcfRqFIhoBtE=
@@ -48,9 +51,11 @@ github.com/mattn/go-isatty v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHX
 github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
 github.com/microcosm-cc/bluemonday v1.0.2 h1:5lPfLTTAvAbtS0VqT+94yOtFnGfUWYyx0+iToC3Os3s=
 github.com/microcosm-cc/bluemonday v1.0.2/go.mod h1:iVP4YcDBq+n/5fb23BhYFvIMq/leAFZyRl6bYmGDlGc=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/valyala/bytebufferpool v1.0.0 h1:GqA5TC/0021Y/b9FG4Oi9Mr3q7XYx6KllzawFIhcdPw=
 github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
@@ -83,7 +88,9 @@ golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 layeh.com/gopher-luar v1.0.7 h1:53iv6CCkRs5wyofZ+qVXcyAYQOIG52s6pt4xkqZdq7k=
 layeh.com/gopher-luar v1.0.7/go.mod h1:TPnIVCZ2RJBndm7ohXyaqfhzjlZ+OA2SZR/YwL8tECk=
diff --git a/plugins/caldav/caldav.go b/plugins/caldav/caldav.go
new file mode 100644
index 0000000..1c043e9
--- /dev/null
+++ b/plugins/caldav/caldav.go
@@ -0,0 +1,61 @@
+package koushincaldav
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+
+	"git.sr.ht/~emersion/koushin"
+	"github.com/emersion/go-webdav/caldav"
+)
+
+var errNoCalendar = fmt.Errorf("caldav: no calendar found")
+
+type authRoundTripper struct {
+	upstream http.RoundTripper
+	session  *koushin.Session
+}
+
+func (rt *authRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	rt.session.SetHTTPBasicAuth(req)
+	return rt.upstream.RoundTrip(req)
+}
+
+func newClient(u *url.URL, session *koushin.Session) (*caldav.Client, error) {
+	rt := authRoundTripper{
+		upstream: http.DefaultTransport,
+		session:  session,
+	}
+	c, err := caldav.NewClient(&http.Client{Transport: &rt}, u.String())
+	if err != nil {
+		return nil, fmt.Errorf("failed to create CalDAV client: %v", err)
+	}
+
+	return c, nil
+}
+
+func getCalendar(u *url.URL, session *koushin.Session) (*caldav.Client, *caldav.Calendar, error) {
+	c, err := newClient(u, session)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	principal, err := c.FindCurrentUserPrincipal()
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to query CalDAV principal: %v", err)
+	}
+
+	calendarHomeSet, err := c.FindCalendarHomeSet(principal)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to query CalDAV calendar home set: %v", err)
+	}
+
+	calendars, err := c.FindCalendars(calendarHomeSet)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to find calendars: %v", err)
+	}
+	if len(calendars) == 0 {
+		return nil, nil, errNoCalendar
+	}
+	return c, &calendars[0], nil
+}
diff --git a/plugins/caldav/plugin.go b/plugins/caldav/plugin.go
new file mode 100644
index 0000000..1915646
--- /dev/null
+++ b/plugins/caldav/plugin.go
@@ -0,0 +1,71 @@
+package koushincaldav
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+
+	"git.sr.ht/~emersion/koushin"
+)
+
+func sanityCheckURL(u *url.URL) error {
+	req, err := http.NewRequest(http.MethodOptions, u.String(), nil)
+	if err != nil {
+		return err
+	}
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return err
+	}
+	resp.Body.Close()
+
+	// Servers might require authentication to perform an OPTIONS request
+	if resp.StatusCode/100 != 2 && resp.StatusCode != http.StatusUnauthorized {
+		return fmt.Errorf("HTTP request failed: %v %v", resp.StatusCode, resp.Status)
+	}
+	return nil
+}
+
+func newPlugin(srv *koushin.Server) (koushin.Plugin, error) {
+	u, err := srv.Upstream("caldavs", "caldav+insecure", "https", "http+insecure")
+	if _, ok := err.(*koushin.NoUpstreamError); ok {
+		return nil, nil
+	} else if err != nil {
+		return nil, fmt.Errorf("caldav: failed to parse upstream caldav server: %v", err)
+	}
+	switch u.Scheme {
+	case "caldavs":
+		u.Scheme = "https"
+	case "caldav+insecure", "http+insecure":
+		u.Scheme = "http"
+	}
+	if u.Scheme == "" {
+		return nil, fmt.Errorf("caldav: discovery not yet implemented") // TODO
+	}
+
+	if err := sanityCheckURL(u); err != nil {
+		return nil, fmt.Errorf("caldav: failed to connect to CalDAV server %q: %v", u, err)
+	}
+
+	srv.Logger().Printf("Configured upstream CalDAV server: %v", u)
+
+	p := koushin.GoPlugin{Name: "caldav"}
+
+	registerRoutes(&p, u)
+
+	return p.Plugin(), nil
+}
+
+func init() {
+	koushin.RegisterPluginLoader(func(s *koushin.Server) ([]koushin.Plugin, error) {
+		p, err := newPlugin(s)
+		if err != nil {
+			return nil, err
+		}
+		if p == nil {
+			return nil, nil
+		}
+		return []koushin.Plugin{p}, err
+	})
+}
diff --git a/plugins/caldav/public/calendar.html b/plugins/caldav/public/calendar.html
new file mode 100644
index 0000000..6011f9e
--- /dev/null
+++ b/plugins/caldav/public/calendar.html
@@ -0,0 +1,25 @@
+{{template "head.html"}}
+
+<h1>koushin</h1>
+
+<p>
+  <a href="/">Back</a>
+</p>
+
+<h2>Calendar: {{.Calendar.Name}}</h2>
+
+{{if .Events}}
+  <ul>
+    {{range .Events}}
+      {{$event := index .Data.Events 0}}
+      <li>
+        <a href="/calendar/{{$event.UID | pathescape}}">{{$event.Summary}}</a>
+        ({{$event.StartDate | formatdate}} — {{$event.EndDate | formatdate}})
+      </li>
+    {{end}}
+  </ul>
+{{else}}
+  <p>No events.</p>
+{{end}}
+
+{{template "foot.html"}}
diff --git a/plugins/caldav/routes.go b/plugins/caldav/routes.go
new file mode 100644
index 0000000..acc879f
--- /dev/null
+++ b/plugins/caldav/routes.go
@@ -0,0 +1,66 @@
+package koushincaldav
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+	"time"
+
+	"git.sr.ht/~emersion/koushin"
+	"github.com/emersion/go-webdav/caldav"
+)
+
+type CalendarRenderData struct {
+	koushin.BaseRenderData
+	Calendar *caldav.Calendar
+	Events   []caldav.CalendarObject
+}
+
+func registerRoutes(p *koushin.GoPlugin, u *url.URL) {
+	p.GET("/calendar", func(ctx *koushin.Context) error {
+		// TODO: multi-calendar support
+		c, calendar, err := getCalendar(u, ctx.Session)
+		if err != nil {
+			return err
+		}
+
+		now := time.Now()
+		start := time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location())
+		end := start.AddDate(0, 1, 0)
+
+		query := caldav.CalendarQuery{
+			CompRequest: caldav.CalendarCompRequest{
+				Name:  "VCALENDAR",
+				Props: []string{"VERSION"},
+				Comps: []caldav.CalendarCompRequest{{
+					Name: "VEVENT",
+					Props: []string{
+						"SUMMARY",
+						"UID",
+						"DTSTART",
+						"DTEND",
+						"DURATION",
+					},
+				}},
+			},
+			CompFilter: caldav.CompFilter{
+				Name: "VCALENDAR",
+				Comps: []caldav.CompFilter{{
+					Name:  "VEVENT",
+					Start: start,
+					End:   end,
+				}},
+			},
+		}
+		events, err := c.QueryCalendar(calendar.Path, &query)
+		if err != nil {
+			return fmt.Errorf("failed to query calendar: %v", err)
+		}
+
+		return ctx.Render(http.StatusOK, "calendar.html", &CalendarRenderData{
+			BaseRenderData: *koushin.NewBaseRenderData(ctx),
+			Calendar:       calendar,
+			Events:         events,
+		})
+	})
+}