Come up with sillier names for the binaries

I'm not entirely sure, but it looks like some people might not like
jokes about the Holocaust.

On a more serious note, the project has become more serious over
the 7 or so years of its existence.

1 files changed, 178 insertions, 0 deletions

diff --git a/plugins/xC/last-fm.lua b/plugins/xC/last-fm.lua
new file mode 100644
index 0000000..3bdfed2
--- /dev/null
+++ b/plugins/xC/last-fm.lua
@@ -0,0 +1,178 @@
+--
+-- last-fm.lua: "now playing" feature using the last.fm API
+--
+-- Dependencies: lua-cjson (from luarocks e.g.)
+--
+-- I call this style closure-oriented programming
+--
+-- Copyright (c) 2016, Přemysl Eric Janouch <p@janouch.name>
+--
+-- Permission to use, copy, modify, and/or distribute this software for any
+-- purpose with or without fee is hereby granted.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+-- SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+-- OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+--
+
+local cjson = require "cjson"
+
+-- Setup configuration to load last.fm API credentials from
+local user, api_key
+xC.setup_config {
+	user    = {
+		type = "string",
+		comment = "last.fm username",
+		on_change = function (v) user    = v end
+	},
+	api_key = {
+		type = "string",
+		comment = "last.fm API key",
+		on_change = function (v) api_key = v end
+	},
+}
+
+-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+-- Generic error reporting
+local report_error = function (buffer, error)
+	buffer:log ("last-fm error: " .. error)
+end
+
+-- Process data return by the server and extract the now playing song
+local process = function (buffer, data, action)
+	-- There's no reasonable Lua package to parse HTTP that I could find
+	local s, e, v, status, message = string.find (data, "(%S+) (%S+) .+\r\n")
+	if not s then return "server returned unexpected data" end
+	if status ~= "200" then return status .. " " .. message end
+
+	local s, e = string.find (data, "\r\n\r\n")
+	if not s then return "server returned unexpected data" end
+
+	local parser = cjson.new ()
+	data = parser.decode (string.sub (data, e + 1))
+	if not data.recenttracks or not data.recenttracks.track then
+		return "invalid response" end
+
+	-- Need to make some sense of the XML automatically converted to JSON
+	local text_of = function (node)
+		if type (node) ~= "table" then return node end
+		return node["#text"] ~= "" and node["#text"] or nil
+	end
+
+	local name, artist, album
+	for i, track in ipairs (data.recenttracks.track) do
+		if track["@attr"] and track["@attr"].nowplaying then
+			if track.name   then name   = text_of (track.name)   end
+			if track.artist then artist = text_of (track.artist) end
+			if track.album  then album  = text_of (track.album)  end
+		end
+	end
+
+	if not name then
+		action (false)
+	else
+		local np = "\"" .. name .. "\""
+		if artist then np = np .. " by "   .. artist end
+		if album  then np = np .. " from " .. album  end
+		action (np)
+	end
+end
+
+-- Set up the connection and make the request
+local on_connected = function (buffer, c, host, action)
+	-- Buffer data in the connection object
+	c.data = ""
+	c.on_data = function (data)
+		c.data = c.data .. data
+	end
+
+	-- And process it after we receive everything
+	c.on_eof = function ()
+		error = process (buffer, c.data, action)
+		if error then report_error (buffer, error) end
+		c:close ()
+	end
+	c.on_error = function (e)
+		report_error (buffer, e)
+	end
+
+	-- Make the unencrypted HTTP request
+	local url = "/2.0/?method=user.getrecenttracks&user=" .. user ..
+		"&limit=1&api_key=" .. api_key .. "&format=json"
+	c:send ("GET " .. url .. " HTTP/1.1\r\n")
+	c:send ("User-agent: last-fm.lua\r\n")
+	c:send ("Host: " .. host .. "\r\n")
+	c:send ("Connection: close\r\n")
+	c:send ("\r\n")
+end
+
+-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+-- Avoid establishing more than one connection at a time
+local running
+
+-- Initiate a connection to last.fm servers
+async, await = xC.async, coroutine.yield
+local make_request = function (buffer, action)
+	if not user or not api_key then
+		report_error (buffer, "configuration is incomplete")
+		return
+	end
+
+	if running then running:cancel () end
+	running = async.go (function ()
+		local c, host, e = await (async.dial ("ws.audioscrobbler.com", 80))
+		if e then
+			report_error (buffer, e)
+		else
+			on_connected (buffer, c, host, action)
+		end
+		running = nil
+	end)
+end
+
+-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+local now_playing
+
+local tell_song = function (buffer)
+	if now_playing == nil then
+		buffer:log ("last-fm: I don't know what you're listening to")
+	elseif not now_playing then
+		buffer:log ("last-fm: not playing anything right now")
+	else
+		buffer:log ("last-fm: now playing: " .. now_playing)
+	end
+end
+
+local send_song = function (buffer)
+	if not now_playing then
+		tell_song (buffer)
+	else
+		buffer:execute ("/me is listening to " .. now_playing)
+	end
+end
+
+-- Hook input to simulate new commands
+xC.hook_input (function (hook, buffer, input)
+	if input == "/np" then
+		make_request (buffer, function (np)
+			now_playing = np
+			send_song (buffer)
+		end)
+	elseif input == "/np?" then
+		make_request (buffer, function (np)
+			now_playing = np
+			tell_song (buffer)
+		end)
+	elseif input == "/np!" then
+		send_song (buffer)
+	else
+		return input
+	end
+end)