support znc.in/playback

gencapdefs.py

@@ -165,6 +165,12 @@ CAPDEFS = [
         url="https://github.com/ircv3/ircv3-specifications/pull/362",
         standard="Proposed IRCv3",
     ),
+    CapDef(
+        identifier="ZNCPlayback",
+        name="znc.in/playback",
+        url="https://wiki.znc.in/Playback",
+        standard="ZNC vendor",
+    ),
 ]
 
 def validate_defs():

irc/caps/defs.go

@@ -7,7 +7,7 @@ package caps
 
 const (
 	// number of recognized capabilities:
-	numCapabs = 25
+	numCapabs = 26
 	// length of the uint64 array that represents the bitset:
 	bitsetLen = 1
 )
@@ -112,6 +112,10 @@ const (
 	// EventPlayback is the Proposed IRCv3 capability named "draft/event-playback":
 	// https://github.com/ircv3/ircv3-specifications/pull/362
 	EventPlayback Capability = iota
+
+	// ZNCPlayback is the ZNC vendor capability named "znc.in/playback":
+	// https://wiki.znc.in/Playback
+	ZNCPlayback Capability = iota
 )
 
 // `capabilityNames[capab]` is the string name of the capability `capab`
@@ -142,5 +146,6 @@ var (
 		"oragono.io/bnc",
 		"znc.in/self-message",
 		"draft/event-playback",
+		"znc.in/playback",
 	}
 )

irc/channel.go

@@ -620,25 +620,41 @@ func (channel *Channel) Join(client *Client, key string, isSajoin bool, rb *Resp
 	// TODO #259 can be implemented as Flush(false) (i.e., nonblocking) while holding joinPartMutex
 	rb.Flush(true)
 
-	var replayLimit int
-	customReplayLimit := client.AccountSettings().AutoreplayLines
-	if customReplayLimit != nil {
-		replayLimit = *customReplayLimit
-		maxLimit := channel.server.Config().History.ChathistoryMax
-		if maxLimit < replayLimit {
-			replayLimit = maxLimit
-		}
+	// autoreplay any messages as necessary
+	config := channel.server.Config()
+	var items []history.Item
+	if rb.session.zncPlaybackTimes != nil && (rb.session.zncPlaybackTimes.targets == nil || rb.session.zncPlaybackTimes.targets[chcfname]) {
+		items, _ = channel.history.Between(rb.session.zncPlaybackTimes.after, rb.session.zncPlaybackTimes.before, false, config.History.ChathistoryMax)
 	} else {
-		replayLimit = channel.server.Config().History.AutoreplayOnJoin
-	}
-	if 0 < replayLimit {
-		// TODO don't replay the client's own JOIN line?
-		items := channel.history.Latest(replayLimit)
-		if 0 < len(items) {
-			channel.replayHistoryItems(rb, items, true)
-			rb.Flush(true)
+		var replayLimit int
+		customReplayLimit := client.AccountSettings().AutoreplayLines
+		if customReplayLimit != nil {
+			replayLimit = *customReplayLimit
+			maxLimit := channel.server.Config().History.ChathistoryMax
+			if maxLimit < replayLimit {
+				replayLimit = maxLimit
+			}
+		} else {
+			replayLimit = channel.server.Config().History.AutoreplayOnJoin
+		}
+		if 0 < replayLimit {
+			items = channel.history.Latest(replayLimit)
 		}
 	}
+	// remove the client's own JOIN line from the replay
+	numItems := len(items)
+	for i := len(items) - 1; 0 <= i; i-- {
+		if items[i].Message.Msgid == message.Msgid {
+			// zero'ed items will not be replayed because their `Type` field is not recognized
+			items[i] = history.Item{}
+			numItems--
+			break
+		}
+	}
+	if 0 < numItems {
+		channel.replayHistoryItems(rb, items, true)
+		rb.Flush(true)
+	}
 }
 
 // plays channel join messages (the JOIN line, topic, and names) to a session.

irc/client.go

@@ -113,6 +113,8 @@ type Session struct {
 	maxlenRest   uint32
 	capState     caps.State
 	capVersion   caps.Version
+
+	zncPlaybackTimes *zncPlaybackTimes
 }
 
 // sets the session quit message, if there isn't one already

irc/commands.go

@@ -321,6 +321,10 @@ func init() {
 			handler:   whowasHandler,
 			minParams: 1,
 		},
+		"ZNC": {
+			handler:   zncHandler,
+			minParams: 1,
+		},
 	}
 
 	initializeServices()

irc/handlers.go

@@ -2001,12 +2001,16 @@ func messageHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *R
 			}
 			channel.SendSplitMessage(msg.Command, lowestPrefix, clientOnlyTags, client, splitMsg, rb)
 		} else {
-			if service, isService := OragonoServices[strings.ToLower(targetString)]; isService {
-				// NOTICE and TAGMSG to services are ignored
-				if histType == history.Privmsg {
+			// NOTICE and TAGMSG to services are ignored
+			if histType == history.Privmsg {
+				lowercaseTarget := strings.ToLower(targetString)
+				if service, isService := OragonoServices[lowercaseTarget]; isService {
 					servicePrivmsgHandler(service, server, client, message, rb)
+					continue
+				} else if _, isZNC := zncHandlers[lowercaseTarget]; isZNC {
+					zncPrivmsgHandler(client, lowercaseTarget, message, rb)
+					continue
 				}
-				continue
 			}
 
 			user := server.clients.Get(targetString)
@@ -2746,3 +2750,9 @@ func whowasHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *Re
 	}
 	return false
 }
+
+// ZNC <module> [params]
+func zncHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *ResponseBuffer) bool {
+	zncModuleHandler(client, msg.Params[0], msg.Params[1:], rb)
+	return false
+}

irc/help.go

@@ -540,6 +540,13 @@ Returns information for the given user(s).`,
 
 Returns historical information on the last user with the given nickname.`,
 	},
+	"znc": {
+		text: `ZNC <module> [params]
+
+Used to emulate features of the ZNC bouncer. This command is not intended
+for direct use by end users.`,
+		duplicate: true,
+	},
 
 	// Informational
 	"modes": {

irc/misc_test.go

@@ -0,0 +1,17 @@
+// Copyright (c) 2019 Shivaram Lingamneni <slingamn@cs.stanford.edu>
+// released under the MIT license
+
+package irc
+
+import (
+	"testing"
+	"time"
+)
+
+func TestZncTimestampParser(t *testing.T) {
+	assertEqual(zncWireTimeToTime("1558338348.988"), time.Unix(1558338348, 988000000), t)
+	assertEqual(zncWireTimeToTime("1558338348.9"), time.Unix(1558338348, 900000000), t)
+	assertEqual(zncWireTimeToTime("1558338348"), time.Unix(1558338348, 0), t)
+	assertEqual(zncWireTimeToTime(".988"), time.Unix(0, 988000000), t)
+	assertEqual(zncWireTimeToTime("garbage"), time.Unix(0, 0), t)
+}

irc/znc.go

@@ -0,0 +1,96 @@
+// Copyright (c) 2019 Shivaram Lingamneni <slingamn@cs.stanford.edu>
+// released under the MIT license
+
+package irc
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type zncCommandHandler func(client *Client, command string, params []string, rb *ResponseBuffer)
+
+var zncHandlers = map[string]zncCommandHandler{
+	"*playback": zncPlaybackHandler,
+}
+
+func zncPrivmsgHandler(client *Client, command string, privmsg string, rb *ResponseBuffer) {
+	zncModuleHandler(client, command, strings.Fields(privmsg), rb)
+}
+
+func zncModuleHandler(client *Client, command string, params []string, rb *ResponseBuffer) {
+	command = strings.ToLower(command)
+	if subHandler, ok := zncHandlers[command]; ok {
+		subHandler(client, command, params, rb)
+	} else {
+		rb.Add(nil, "*status!znc@znc.in", "NOTICE", rb.target.Nick(), fmt.Sprintf(client.t("No such module [%s]"), command))
+	}
+}
+
+// "number of seconds (floating point for millisecond precision) elapsed since January 1, 1970"
+func zncWireTimeToTime(str string) (result time.Time) {
+	var secondsPortion, fracPortion string
+	dot := strings.IndexByte(str, '.')
+	if dot == -1 {
+		secondsPortion = str
+	} else {
+		secondsPortion = str[:dot]
+		fracPortion = str[dot:]
+	}
+	seconds, _ := strconv.ParseInt(secondsPortion, 10, 64)
+	fraction, _ := strconv.ParseFloat(fracPortion, 64)
+	return time.Unix(seconds, int64(fraction*1000000000))
+}
+
+type zncPlaybackTimes struct {
+	after   time.Time
+	before  time.Time
+	targets map[string]bool // nil for "*" (everything), otherwise the channel names
+}
+
+// https://wiki.znc.in/Playback
+// PRIVMSG *playback :play <target> [lower_bound] [upper_bound]
+// e.g., PRIVMSG *playback :play * 1558374442
+func zncPlaybackHandler(client *Client, command string, params []string, rb *ResponseBuffer) {
+	if len(params) < 2 {
+		return
+	} else if strings.ToLower(params[0]) != "play" {
+		return
+	}
+	targetString := params[1]
+
+	var after, before time.Time
+	if 2 < len(params) {
+		after = zncWireTimeToTime(params[2])
+	}
+	if 3 < len(params) {
+		before = zncWireTimeToTime(params[3])
+	}
+
+	var targets map[string]bool
+
+	// OK: the user's PMs get played back immediately on receiving this,
+	// then we save the timestamps in the session to handle replay on future channel joins
+	config := client.server.Config()
+	if params[1] == "*" {
+		items, _ := client.history.Between(after, before, false, config.History.ChathistoryMax)
+		client.replayPrivmsgHistory(rb, items, true)
+	} else {
+		for _, targetName := range strings.Split(targetString, ",") {
+			if cfTarget, err := CasefoldChannel(targetName); err == nil {
+				if targets == nil {
+					targets = make(map[string]bool)
+				}
+				targets[cfTarget] = true
+			}
+		}
+	}
+
+	rb.session.zncPlaybackTimes = &zncPlaybackTimes{
+		after:   after,
+		before:  before,
+		targets: targets,
+	}
+}