require "colorize"
require "yaml"

class Baguette::Context
	# By default, just print everything.
	class_property verbosity = 4
end

class Baguette::Configuration
	class_property project_directory : String? = nil

	class Base
		include YAML::Serializable

		# Check for $XDG_CONFIG_HOME/baguette/<project-name>/<class>.yml,
		# then /etc/baguette/<project-name>/<class>.yml.
		# (project name is not mandatory)
		def self.get(file : String? = nil)
			filename = "/" + (self.name.downcase.gsub /baguette::configuration::/, "") + ".yml"
			directory = "/baguette"

			if pdir = Baguette::Configuration.project_directory
				directory += "/" + pdir
			end

			suffix = "#{directory}#{filename}"
			user_configuration   = (ENV["XDG_CONFIG_HOME"]? || "#{ENV["HOME"]}/.config") + suffix
			system_configuration = "/etc#{suffix}"

			if ! file.nil? && ! File.exists? file.not_nil!
				Baguette::Log.warning "Provided configuration file does not exist: #{file}"
			end

			if ! file.nil? && File.exists? file.not_nil!
				Baguette::Log.info "Using configuration file: #{file}"
				self.from_yaml File.read(file.not_nil!)
			elsif File.exists? user_configuration
				Baguette::Log.info "Using user configuration: #{user_configuration}"
				self.from_yaml File.read(user_configuration)
			elsif File.exists? system_configuration
				Baguette::Log.info "Using system configuration: #{system_configuration}"
				self.from_yaml File.read(system_configuration)
			else
				Baguette::Log.warning "No configuration found"
				Baguette::Log.warning "Searched in: #{user_configuration}"
				Baguette::Log.warning "Searched in: #{system_configuration}"
				nil
			end
		end
	end

	class IPC < Base
		enum MESSAGE
			TIMER
			CONNECTION
			DISCONNECTION
			EXTERNAL  # extra socket
			RX
			TX
			SWITCH
			ERROR
			EXCEPTION
		end

		property ipc_timer                  : Int32 = 30_000 # 30 seconds.
		property ipc_messages_to_show       : Array(IPC::MESSAGE) = [MESSAGE::ERROR, MESSAGE::EXCEPTION]
		property verbosity                  : Int32 = 4

		def initialize
		end
	end

	# Read options from the CLI.
	# We currently want to know:
	# - the program verbosity
	# - the configuration directory to use (project name)
	# - if the configuration files should be ignored
	# - if this is just a simulation (used to print configuration then quit)
	def self.option_parser
		simulation = false
		no_configuration = false
		configuration_file = nil

		help = false

		OptionParser.parse do |parser|
			parser.banner = "usage: #{PROGRAM_NAME} [-ns][--project project-name]"

			parser.on "-s", "--simulation", "Print configuration then quit." do
				simulation = true
			end

			parser.on "-n", "--no-configuration", "No configuration file should be read." do
				no_configuration = true
			end

			parser.on "--configuration file", "Configuration file to use." do |f|
				configuration_file = f
			end

			parser.on "-v verbosity", "--verbosity level",
				"Verbosity level. From 0 to 4. Default: 4" do |v|
				Baguette::Context.verbosity = v.to_i
			end

			parser.on "--project project-name",
				"Project name. Will search in $XDG_CONFIG_HOME/baguette/<project-name>/<class>.yml then /etc/baguette/<project-name>/<class>.yml." do |dir|
				Baguette::Configuration.project_directory = dir
			end

			parser.invalid_option do |arg|
				# Do not print anything: we only check for configuration file stuff.
			end

			parser.on "-h", "--help", "Show this help" do
				puts parser
				help = true
			end
		end

		# Options are removed once read from the ARGV array, but we want to propagate
		# this particular option to print the second set of options.
		ARGV.push "-h" if help

		return simulation, no_configuration, configuration_file
	end
end

# `Baguette::Log` is a library to display information.
# A filename can be given to write logs in a file.
class Baguette::Log
	# FIXME: def log(), that puts stuff as-is in the logs.

	# Name of the file.
	class_property log_path : String? = nil

	enum LOGTYPE
		DEBUG   = 5
		INFO    = 4
		TITLE   = 3
		WARNING = 2
		ERROR   = 1
	end

	def self.now() : String
		Time.local.to_s("%Y-%m-%d_%H:%M:%S")
	end

	def self.write_log_fancy(io : IO, logtype : LOGTYPE, text)
		case logtype
		when .debug?
			io.<<(self.now).<<(" :: ".colorize(:cyan)).<<(text.colorize(:cyan)).<<("\n")
		when .info?
			io.<<(self.now).<<(" :: ".colorize(:blue)).<<(text.colorize(:white)).<<("\n")
		when .title?
			io.<<(self.now).<<(" |> ".colorize(:blue).bright).<<(text.colorize(:white).bright).<<("\n")
		when .warning?
			io.<<(self.now).<<(" :: ".colorize(:yellow).bright).<<(text.colorize(:yellow)).<<("\n")
		when .error?
			io.<<(self.now).<<(" !! ".colorize(:red).bright).<<(text.colorize(:red)).<<("\n")
		end
	end

	def self.write_log_plain(io : IO, logtype : LOGTYPE, text)
		case logtype
		when .debug?
			io.<<(self.now).<<(" (debug) ").<<(text).<<("\n")
		when .info?
			io.<<(self.now).<<(" (info) ").<<(text).<<("\n")
		when .title?
			io.<<(self.now).<<(" (title) ").<<(text).<<("\n")
		when .warning?
			io.<<(self.now).<<(" (warning) ").<<(text).<<("\n")
		when .error?
			io.<<(self.now).<<(" (error) ").<<(text).<<("\n")
		end
	end

	def self.write_log(logtype : LOGTYPE, text)
		if path = @@log_path
			File.open path, "a" do |io|
				self.write_log_plain io, logtype, text
			end

			# In case the thing we want to print is important, put it on the screen too.
			if logtype <= LOGTYPE::WARNING
				self.write_log_fancy STDERR, logtype, text
			end
		else
			if logtype <= LOGTYPE::WARNING
				self.write_log_fancy STDERR, logtype, text
			else
				self.write_log_fancy STDOUT, logtype, text
			end
		end
	end

	def self.debug(text)
		return unless Baguette::Context.verbosity > 3
		self.write_log LOGTYPE::DEBUG, text
	end
	def self.info(text)
		return unless Baguette::Context.verbosity > 2
		self.write_log LOGTYPE::INFO, text
	end
	def self.title(text)
		return unless Baguette::Context.verbosity > 2
		self.write_log LOGTYPE::TITLE, text
	end
	def self.warning(text)
		return unless Baguette::Context.verbosity > 1
		self.write_log LOGTYPE::WARNING, text
	end
	def self.error(text)
		return unless Baguette::Context.verbosity > 0
		self.write_log LOGTYPE::ERROR, text
	end
end