mpv script that logs metadata from Icecast streams

icylogger.lua

-- mpv script that logs metadata from Icecast streams.
-- Also adds a key binding to add an explicit current playing item to a favorite file.
-- Other changes are the string format and date format written to the log files

local CONFIG_DIR = (os.getenv("APPDATA") or os.getenv("HOME").."/.config");
local HISTFILE = CONFIG_DIR.."/mpv/icyhistory.log";
local FAVFILE = CONFIG_DIR.."/mpv/icyfavorites.log";

local function append_to_file(file, val)
    local logfile;

    if val ~= nil and val["icy-title"] then
        logfile = io.open(file, "a+");
        logfile:write(("%s | %s | %s\n"):format(os.date("%Y-%m-%d | %H:%M:%S"), val["icy-title"], val["icy-name"]));
        logfile:close();
    end
end

mp.observe_property("metadata", "native", function(name, val)
    append_to_file(HISTFILE, val);
end)

mp.add_key_binding("h", "save_icy_title", function()
    local val;

    val = mp.get_property_native("metadata");
    append_to_file(FAVFILE, val);
    print(("saved '%s' to %s"):format(val["icy-title"], FAVFILE));
end)