-- MPD INTERATION

-- library

local socket = require 'socket'

--

local O = {

	hostname     = "localhost",

	password     = nil,

	port         = 6600,

}

local F = { }

-- separator allows split output into records, that are started by any of present in separator keys

-- returns table of field (lowercase) - value records

-- command status is returned in STATUS field

-- on unexpected errors returns just false, dropping any available data

function F.receive_message ( tcp, separator )

	local ret  = {}

	local line = tcp:receive ( '*l' )

	while line and not ( line:match ( '^OK' ) or line:match ( '^ACK' ) ) do

		local key, val = line:match ( '^(.-):%s*(.*)$' )

		if key then

			if separator then

				key = key:lower ()

				if separator[key] then

					table.insert ( ret, {} )

				end

				ret[#ret][key]   = val

			else

				ret[key:lower()] = val

			end

		end

		line = tcp:receive ( '*l' )

	end

	if not line then

		return false -- an error occured, ret, most likely, does not contains exact and complete info...

	else

		ret.STATUS = line:match ( '^%S+' )

		return ret

	end

end

-- use: mpd.call_command { 'status' }

--      mpd.call_command { 'lsinfo misc', list = { file = true, directory = true } }

--      mpd.call_command { 'next', noret = true } -- removed, early termination with password :/

--      mpd.call_command { 'status', 'currentsong' }

-- on one command returns just results of that command, on multi - array of results

-- on errors returns nil

-- noret can terminate socket too early, thus, do not use it with lists of commands

function F.call_command ( opts )

	local tcp = socket.tcp ()

	if not tcp then

		print ( 'mpd: cannot get master tcp object' )

		return nil

	end

	if not O.hostname then

		local server = os.getenv ( 'MPD_HOST' )

		if server then

			local password, host = server:match ( '(.+)@(.-)' )

			if password then

				F.server ( host, os.getenv ( 'MPD_PORT' ) or 6600, password )

			else

				F.server ( server, os.getenv ( 'MPD_PORT' ) or 6600, nil )

			end

		else

			F.server ( "localhost", 6600, nil )

		end

	end

	if not tcp:connect ( O.hostname, O.port ) then

		tcp:close ()

		print ( 'mpd: cannot connect to server' )

		return nil

	end

	local ret = {}

	ret = F.receive_message ( tcp )

	if not ret then

		tcp:close ()

		print ( 'mpd: error getting greeting from server' )

		return nil

	elseif ret.STATUS ~= 'OK' then

		print ( 'mpd: server ack\'s in greeting' )

	end

	if O.password then

		if not tcp:send ( "password " .. O.password .. "\n" ) then

			tcp:close ()

			print ( 'mpd: error sending password' )

			return nil

		end

		ret = mpd.receive_message ( tcp )

		if not ret then

			tcp:close ()

			print ( 'mpd: error getting response for password' )

			return nil

		elseif ret.STATUS ~= 'OK' then

			print ( 'mpd: server refuses password' )

		end

	end

	for num, command in ipairs ( opts ) do

		if not tcp:send ( command .. "\n" ) then

			tcp:close ()

			print ( 'mpd: error sending command ' .. command )

			return nil

		end

		ret[num] = F.receive_message ( tcp, opts.list )

		if not ret[num] then

			print ( 'mpd: error getting result' )

		end

		if ret[num]['STATUS'] ~= 'OK' then

			print ( 'mpd: server acks our command ' .. command )

		end

	end

	tcp:close ()

	if #ret > 1 then

		return ret

	else

		return ret[1]

	end

end

function F.server ( host, port, password )

	O.hostname = host

	O.port     = port

	O.password = password

end

return F

-- vim: se ts=4: --