module JosieHealth
  module Utils
    module Log
      @@debug_enabled : Bool = ENV.has_key?("DEBUG") || ENV["LOG_LEVEL"]? == "debug"
      @@prefix : String = ""

      def self.debug_enabled? : Bool
        @@debug_enabled
      end

      def self.enable_debug
        @@debug_enabled = true
      end

      def self.disable_debug
        @@debug_enabled = false
      end

      def self.prefix=(value : String)
        @@prefix = value
      end

      def self.prefix : String
        @@prefix
      end

      private def self.format(level : String, message : String) : String
        timestamp = Time.utc.to_s("%Y-%m-%d %H:%M:%S")
        if @@prefix.empty?
          "[#{timestamp}] [#{level}] #{message}"
        else
          "[#{timestamp}] [#{@@prefix}] [#{level}] #{message}"
        end
      end

      def self.debug(message : String)
        return unless @@debug_enabled
        STDERR.puts format("DEBUG", message)
      end

      def self.debug(context : String, message : String)
        return unless @@debug_enabled
        STDERR.puts format("DEBUG", "[#{context}] #{message}")
      end

      def self.info(message : String)
        STDERR.puts format("INFO", message)
      end

      def self.info(context : String, message : String)
        STDERR.puts format("INFO", "[#{context}] #{message}")
      end

      def self.warn(message : String)
        STDERR.puts format("WARN", message)
      end

      def self.warn(context : String, message : String)
        STDERR.puts format("WARN", "[#{context}] #{message}")
      end

      def self.error(message : String)
        STDERR.puts format("ERROR", message)
      end

      def self.error(context : String, message : String)
        STDERR.puts format("ERROR", "[#{context}] #{message}")
      end

      def self.error(message : String, ex : Exception)
        STDERR.puts format("ERROR", "#{message}: #{ex.message}")
        STDERR.puts ex.backtrace.join("\n") if @@debug_enabled && ex.backtrace?
      end
    end
  end
end