mpd.lua

   1 #!/usr/bin/lua
   2
   3 require "uci"
   4 require("socket")
   5 json=require("json")
   6
   7 function url_decode(str)
   8   if not str then return nil end
   9   str = string.gsub (str, "+", " ")
  10   str = string.gsub (str, "%%(%x%x)", function(h) return
  11     string.char(tonumber(h,16)) end)
  12   str = string.gsub (str, "\r\n", "\n")
  13   return str
  14 end
  15
  16 function split(s, delimiter)
  17     local result = {};
  18     for match in (s..delimiter):gmatch("(.-)"..delimiter) do
  19         result[#result+1] = match;
  20     end
  21     return result;
  22 end
  23
  24 function string.starts(String,Start)
  25    return string.sub(String,1,string.len(Start))==Start
  26 end
  27
  28 function process_playlist(playlist)
  29   local res={}
  30   for _,record in pairs(playlist) do
  31     local splitted = split(record,": ")
  32     local name = splitted[2]
  33     local splitted = split(splitted[1],":")
  34     local id = splitted[1]
  35     local rectype = splitted[2]
  36     local rec = {}
  37     if not (id == "OK") then
  38       rec["id"] = id
  39       rec["type"] = rectype
  40       rec["name"] = name
  41       res[id] = rec
  42     end
  43   end
  44   return res
  45 end
  46
  47 function process_playlists(playlists)
  48   local res={}
  49   for _,record in pairs(playlists) do
  50     local splitted = split(record,": ")
  51     if splitted[1]=="playlist" then
  52       res[#res+1] = splitted[2]
  53     end
  54   end
  55   return res
  56 end
  57
  58 function process_directory(directory)
  59   local res={}
  60   for _,record in pairs(directory) do
  61     local splitted = split(record,": ")
  62     if splitted[1]=="directory" or splitted[1]=="file" then
  63       local rec={}
  64       rec["type"] = splitted[1]
  65       rec["name"] = splitted[2]
  66       res[#res+1] = rec
  67     end
  68   end
  69   return res
  70 end
  71
  72 function mpd_new(settings)
  73     local client = {}
  74     if settings == nil then settings = {} end
  75
  76     client.hostname = settings.hostname or "localhost"
  77     client.port     = settings.port or 6600
  78     client.desc     = settings.desc or client.hostname
  79     client.password = settings.password
  80     client.timeout  = settings.timeout or 1
  81     client.retry    = settings.retry or 60
  82
  83     return client
  84 end
  85
  86 function mpd_send(mpd,action,raw)
  87
  88     local command = string.format("%s\n", action)
  89     local values = {}
  90
  91     -- connect to MPD server if not already done.
  92     if not mpd.connected then
  93         local now = os.time();
  94         if not mpd.last_try or (now - mpd.last_try) > mpd.retry then
  95             mpd.socket = socket.tcp()
  96             mpd.socket:settimeout(mpd.timeout, 't')
  97             mpd.last_try = os.time()
  98             mpd.connected = mpd.socket:connect(mpd.hostname, mpd.port)
  99             if not mpd.connected then
 100                 return { errormsg = "could not connect" }
 101             end
 102             mpd.last_error = nil
 103
 104             -- Read the server's hello message
 105             local line = mpd.socket:receive("*l")
 106             if not line:match("^OK MPD") then -- Invalid hello message?
 107                 mpd.connected = false
 108                 return { errormsg = string.format("invalid hello message: %s", line) }
 109             else
 110                 _, _, mpd.version = string.find(line, "^OK MPD ([0-9.]+)")
 111             end
 112
 113             -- send the password if needed
 114             if mpd.password then
 115                 local rsp = mpd_send(mpd,string.format("password %s", mpd.password))
 116                 if rsp.errormsg then
 117                     return rsp
 118                 end
 119             end
 120         else
 121             local retry_sec = mpd.retry - (now - mpd.last_try)
 122             return { errormsg = string.format("%s (retrying in %d sec)", mpd.last_error, retry_sec) }
 123         end
 124     end
 125
 126     mpd.socket:send(command)
 127
 128     local line = ""; err=0
 129     while not line:match("^OK$") do
 130         line, err = mpd.socket:receive("*l")
 131         if not line then -- closed,timeout (mpd killed?)
 132             mpd.last_error = err
 133             mpd.connected = false
 134             mpd.socket:close()
 135             return mpd_send(mpd,action)
 136         end
 137
 138         if line:match("^ACK") then
 139             return { errormsg = line }
 140         end
 141
 142         if not raw then
 143
 144           local pattern = string.format("(%s)", ": ")
 145           local i = string.find (line, pattern, 0)
 146
 147           if i ~= nil then
 148               local key=string.sub(line,1,i-1)
 149               local value=string.sub(line,i+2,-1)
 150               values[string.lower(key)] = value
 151           end
 152
 153         else
 154
 155           values[#values+1]=line
 156
 157         end
 158     end
 159
 160     return values
 161 end
 162
 163 x = uci.cursor()
 164
 165 settings = {}
 166 settings['host'] = x.get("mpd","server","host") or "localhost"
 167 settings['port'] = x.get("mpd","server","port") or 6600
 168 settings['timeout'] = x.get("mpd","server","timeout") or 1
 169
 170 volstep = x.get("mpd","control","volume_step") or 3
 171
 172 password = x.get("mpd","server","password")
 173 if password then
 174   settings["password"] = password
 175 end
 176
 177 m = mpd_new(settings)
 178
 179 command = url_decode(os.getenv('QUERY_STRING'))
 180
 181 if not command or command=="" then
 182   command="idle"
 183 end
 184
 185 if command=="play" or command=="pause" or command=="stop" or command=="previous" or command=="next" then
 186
 187   res=mpd_send(m,command)
 188
 189 elseif command=="idle" then
 190
 191   m.timeout=30
 192   res=mpd_send(m,command)
 193
 194 elseif command=="vold" then
 195
 196   status=mpd_send(m,"status")
 197   volume=tonumber(status["volume"])
 198   res=mpd_send(m,"setvol "..(volume-volstep))
 199
 200 elseif command=="volu" then
 201
 202   status=mpd_send(m,"status")
 203   volume=tonumber(status["volume"])
 204   res=mpd_send(m,"setvol "..(volume+volstep))
 205
 206 elseif command=="status" then
 207
 208   res=mpd_send(m,"status")
 209   song=res["song"]
 210   playlist=mpd_send(m,"playlist",1)
 211   pl=process_playlist(playlist)
 212
 213   if song then
 214     res['current_playing']=pl[song]['name']
 215   else
 216     res['current_playing']="No songs selected"
 217   end
 218
 219 elseif command=="playlist" then
 220
 221   playlist=mpd_send(m,"playlist",1)
 222   res=process_playlist(playlist)
 223
 224 elseif command=="repeat" then
 225
 226   status=mpd_send(m,"status")
 227   rep=1-status["repeat"]
 228   res=mpd_send(m,"repeat "..rep)
 229
 230 elseif string.starts(command,"cpl") then
 231
 232   cmd=split(command,"|")
 233   id=cmd[3]
 234   command=cmd[2]
 235
 236   if command=="playitem" then
 237     command="play "..id
 238     res=mpd_send(m,command)
 239   end
 240
 241   if command=="clear" then
 242     res=mpd_send(m,"clear")
 243   end
 244
 245   if command=="remove" then
 246     command="delete "..id
 247     res=mpd_send(m,command)
 248   end
 249
 250   if command=="moveup" then
 251     command="swap "..id.." "..(id-1)
 252     res=mpd_send(m,command)
 253   end
 254
 255   if command=="movedown" then
 256     command="swap "..id.." "..(id+1)
 257     res=mpd_send(m,command)
 258   end
 259
 260 elseif string.starts(command,"lists") then
 261
 262   cmd=split(command,"|")
 263   command=cmd[2]
 264
 265   if command=="load" then
 266     if not cmd[3] then
 267       lists=mpd_send(m,"listplaylists",1)
 268       res=process_playlists(lists)
 269     else
 270       res=mpd_send(m,"load "..cmd[3],1)
 271     end
 272   end
 273
 274   if command=="save" and cmd[3] then
 275     res=mpd_send(m,"save "..cmd[3],1)
 276   end
 277
 278   if command=="delete" and cmd[3] then
 279     res=mpd_send(m,"rm "..cmd[3],1)
 280   end
 281
 282   if command=="edit" then
 283     if cmd[3] then
 284       dir=mpd_send(m,"lsinfo \""..cmd[3].."\"",1)
 285     else
 286       dir=mpd_send(m,"lsinfo",1)
 287     end
 288     res=process_directory(dir)
 289   end
 290
 291   if command=="add" then
 292     res={}
 293     if cmd[3] then
 294       res=mpd_send(m,"add \""..cmd[3].."\"")
 295     end
 296   end
 297
 298 end
 299
 300 if not res then
 301   print("Content-Type: text/plain\r\n")
 302   print("MPD server - unknown command "..command)
 303 elseif (res['error_msg']) then
 304   print("Content-Type: text/plain\r\n")
 305   print("MPD server connection error: "..res['error_msg'])
 306 else
 307   print "Content-Type: text/plain\r\n"
 308   print(json.encode(res))
 309 end