Add Druid logger

druid/system/druid_logger.lua

@@ -0,0 +1,39 @@
+local helper = require("druid.helper")
+
+---@class druid.logger
+---@field trace fun(_, msg: string, data: any)
+---@field debug fun(_, msg: string, data: any)
+---@field info fun(_, msg: string, data: any)
+---@field warn fun(_, msg: string, data: any)
+---@field error fun(_, msg: string, data: any)
+local M = {}
+
+local EMPTY_FUNCTION = function(_, message, context) end
+
+---@type druid.logger
+local empty_logger = {
+	trace = EMPTY_FUNCTION,
+	debug = EMPTY_FUNCTION,
+	info = EMPTY_FUNCTION,
+	warn = EMPTY_FUNCTION,
+	error = EMPTY_FUNCTION,
+}
+
+---@type druid.logger
+local default_logger = {
+	trace = function(_, msg, data) print("TRACE: " .. msg, helper.table_to_string(data)) end,
+	debug = function(_, msg, data) print("DEBUG: " .. msg, helper.table_to_string(data)) end,
+	info = function(_, msg, data) print("INFO: " .. msg, helper.table_to_string(data)) end,
+	warn = function(_, msg, data) print("WARN: " .. msg, helper.table_to_string(data)) end,
+	error = function(_, msg, data) print("ERROR: " .. msg, helper.table_to_string(data)) end
+}
+
+local METATABLE = { __index = default_logger }
+
+---@param logger druid.logger|table|nil
+function M.set_logger(logger)
+	METATABLE.__index = logger or empty_logger
+end
+
+
+return setmetatable(M, METATABLE)