-- USAGE:
--   -- set arbitrary log levels to be printed immediately
--   log{ info = true, warning = true, ducksauce = true, }
--   -- disable storage of messages depending on log level
--   log{ error = false, verbose = false, }
--   -- send anything (except nil) to a log level
--   log("bacom", true, "text", 5, function() end, {})
--   -- print all messages saved at a particular log level
--   log("error")
--   -- toggle ALL logging on and off with a boolean
--   log(false) -- this deletes all stored messages
--   -- set a maximum number of stored messages per log level
--   log(50) -- warning: reaching large limits makes logging expensive
--   -- do anything to the stored messages (this example deletes them all)
--  log(function(messages) return {} end)
--  -- check if a log level is being displayed
--  if log.arbitrary_exit then log("arbitrary_exit") os.exit(1) end

local microlog = {} -- display_levels are stored directly here
local stored_messages = {}
local enable_logging = true
local message_limit = math.huge

return setmetatable(microlog, {
  __call = function(self, options, ...)
    local options_type = type(options)

    if (options_type == "string") and enable_logging then
      if microlog[options] == false then return end
      if not stored_messages[options] then stored_messages[options] = {} end
      local message_table = stored_messages[options]

      -- turn log message into text
      local tab = {...}
      for i = 1, #tab do
        tab[i] = tostring(tab[i])
      end
      local current_message = table.concat(tab, "\t")

      if #current_message == 0 then
        -- print all stored_messages of specified level
        for i = 1, #message_table do
          print(message_table[i])
        end

      else
        -- store message (and print if in display_levels)
        message_table[#message_table + 1] = current_message
        if #message_table > message_limit then table.remove(message_table, 1) end
        if microlog[options] then print(current_message) end
      end

    -- set display_levels
    elseif options_type == "table" then
      for k,v in pairs(options) do
        microlog[k] = v
      end

    elseif options_type == "number" then
      message_limit = options
      for k,v in pairs(stored_messages) do
        while #v > message_limit do
          table.remove(v, 1)
        end
      end

    -- turn all logging off and delete stored messages; or turn it on
    elseif options_type == "boolean" then
      if options then
        enable_logging = true
      else
        enable_logging = false
        stored_messages = {}
      end

    -- arbitrary access :D
    elseif options_type == "function" then
      local result = options(stored_messages)
      if type(result) == "table" then stored_messages = result end
    end
  end
})