From a31da73f39500c17036cabc850d3721bb48d4dbf Mon Sep 17 00:00:00 2001
From: Matthieu Grieger <matthieugrieger@gmail.com>
Date: Sat, 10 Jan 2015 13:03:52 -0800
Subject: [PATCH] Add request
 https://github.com/matthieugrieger/mumbledj/issues/15: numsongs command

---
 commands.go    | 18 ++++++++++++++++++
 mumbledj.gcfg  |  8 ++++++++
 parseconfig.go |  2 ++
 songqueue.go   | 15 +++++++++++++++
 strings.go     |  5 +++++
 5 files changed, 48 insertions(+)

diff --git a/commands.go b/commands.go
index 034abfa..4fdd055 100644
--- a/commands.go
+++ b/commands.go
@@ -95,6 +95,13 @@ func parseCommand(user *gumble.User, username, command string) {
 		} else {
 			user.Send(NO_PERMISSION_MSG)
 		}
+	// Numsongs command
+	case dj.conf.Aliases.NumSongsAlias:
+		if dj.HasPermission(username, dj.conf.Permissions.AdminNumSongs) {
+			numSongs()
+		} else {
+			user.Send(NO_PERMISSION_MSG)
+		}
 	// Kill command
 	case dj.conf.Aliases.KillAlias:
 		if dj.HasPermission(username, dj.conf.Permissions.AdminKill) {
@@ -284,6 +291,17 @@ func reset(username string) {
 	}
 }
 
+// Performs numsongs functionality. Uses the SongQueue traversal function to traverse the
+// queue with a function call that increments a counter. Once finished, the bot outputs
+// the number of songs in the queue to chat.
+func numSongs() {
+	songCount := 0
+	dj.queue.Traverse(func(i int, item QueueItem) {
+		songCount += 1
+	})
+	dj.client.Self().Channel().Send(fmt.Sprintf(NUM_SONGS_HTML, songCount), false)
+}
+
 // Performs kill functionality. First cleans the ~/.mumbledj/songs directory to get rid of any
 // excess m4a files. The bot then safely disconnects from the server.
 func kill() {
diff --git a/mumbledj.gcfg b/mumbledj.gcfg
index 7db62e4..f9be6cc 100644
--- a/mumbledj.gcfg
+++ b/mumbledj.gcfg
@@ -67,6 +67,10 @@ ReloadAlias = "reload"
 # DEFAULT VALUE: "reset"
 ResetAlias = "reset"
 
+# Alias used for numsongs command
+# DEFAULT VALUE: "numsongs"
+NumSongsAlias = "numsongs"
+
 # Alias used for kill command
 # DEFAULT VALUE: "kill"
 KillAlias = "kill"
@@ -115,6 +119,10 @@ AdminReload = true
 # DEFAULT VALUE: true
 AdminReset = true
 
+# Make numsongs an admin command?
+# DEFAULT VALUE: false
+AdminNumSongs = false
+
 # Make kill an admin command?
 # DEFAULT VALUE: true (I recommend never changing this to false)
 AdminKill = true
diff --git a/parseconfig.go b/parseconfig.go
index dcd407d..3a0e2be 100644
--- a/parseconfig.go
+++ b/parseconfig.go
@@ -35,6 +35,7 @@ type DjConfig struct {
 		MoveAlias              string
 		ReloadAlias            string
 		ResetAlias             string
+		NumSongsAlias          string
 		KillAlias              string
 	}
 	Permissions struct {
@@ -47,6 +48,7 @@ type DjConfig struct {
 		AdminMove         bool
 		AdminReload       bool
 		AdminReset        bool
+		AdminNumSongs     bool
 		AdminKill         bool
 	}
 }
diff --git a/songqueue.go b/songqueue.go
index bce90e2..f1bc082 100644
--- a/songqueue.go
+++ b/songqueue.go
@@ -58,6 +58,21 @@ func (q *SongQueue) Len() int {
 	return len(q.queue)
 }
 
+// A traversal function for SongQueue. Allows a visit function to be passed in which performs
+// the specified action on each queue item. Traverses all individual songs, and all songs
+// within playlists.
+func (q *SongQueue) Traverse(visit func(i int, item QueueItem)) {
+	for iQueue, queueItem := range q.queue {
+		if queueItem.ItemType() == "playlist" {
+			for iPlaylist, playlistItem := range q.queue[iQueue].(*Playlist).songs.queue {
+				visit(iPlaylist, playlistItem)
+			}
+		} else {
+			visit(iQueue, queueItem)
+		}
+	}
+}
+
 // OnItemFinished event. Deletes item that just finished playing, then queues the next item.
 func (q *SongQueue) OnItemFinished() {
 	if q.Len() != 0 {
diff --git a/strings.go b/strings.go
index 8cfe78d..ef9b947 100644
--- a/strings.go
+++ b/strings.go
@@ -106,3 +106,8 @@ const VOLUME_SUCCESS_HTML = `
 const QUEUE_RESET_HTML = `
 	<b>%s</b> has cleared the song queue.
 `
+
+// Message shown to users when a user asks how many songs are in the queue.
+const NUM_SONGS_HTML = `
+	There are currently <b>%d</b> song(s) in the queue.
+`