class NotSetup
	def to_s(io : IO)
		io << "not setup"
	end
end

class Autoconfiguration
	def to_s(io : IO)
		io << "autoconfiguration"
	end
end

class DHCP
	def to_s(io : IO)
		io << "dhcp"
	end
end


class WirelessAPSetup
	property ssid : String

	# This is a list of parameters that should be unique to each AP
	property up : Bool
	property description : String?
	property mtu : Int32?
	property main_ip_v4 : IPAddress | DHCP | NotSetup
	property main_ip_v6 : IPAddress | DHCP | Autoconfiguration | NotSetup
	property aliasses_v4 : Array(IPAddress)
	property aliasses_v6 : Array(IPAddress)
	property dns : NetworkCommands::DNS

	# we currently only support WPA2-PSK wireless security mechanism
	property security : WPA

	class WPA
		property key : String
		def initialize(@key)
		end

		def to_s(io : IO)
			io << "WPA access point, key #{key}"
		end
	end

	def initialize(@ssid, @security)
		@main_ip_v4 = NotSetup.new
		@main_ip_v6 = NotSetup.new
		@aliasses_v4 = Array(IPAddress).new
		@aliasses_v6 = Array(IPAddress).new
		@up = true
		@dns = NetworkCommands::DNS.new
	end


	def to_s(io : IO)
		io << indent(1, to_string)
	end

	def to_string
		String.build do |str|
			str << "#{CBLUE}#{ssid}#{CRESET}\n"

			str << "\t#description #{description.not_nil!}\n" unless description.nil?
			str << "\t#{@up? "up" : "down"}\n"
			str << "\tmtu #{mtu}\n" unless mtu.nil?

			# ipv4
			unless main_ip_v4.is_a?(NotSetup)
				str << "\tinet #{main_ip_v4}\n"

				aliasses_v4.each do |a|
					str << "\talias #{a}\n"
				end
			end

			# ipv6
			unless main_ip_v6.is_a?(NotSetup)
				str << "\tinet6 #{main_ip_v6}\n"

				@aliasses_v6.each do |a|
					str << "\talias6 #{a}\n"
				end
			end

			str << indent(1, dns.to_s) unless dns.addresses.empty?
		end
	end

	def store_access_point_keys
		puts "TODO: store_access_point_keys"
		puts "security for #{ssid} = #{security}"
	end

	def execute
		puts "TODO: wireless configuration"

		# DNS configuration
		dns.execute
	end
end


#
# interface configuration
#

class InterfaceConfiguration

	property name : String
	property up : Bool
	property description : String?
	property mtu : Int32?
	property wireless : Bool
	property main_ip_v4 : IPAddress | DHCP | NotSetup
	property main_ip_v6 : IPAddress | Autoconfiguration | DHCP | NotSetup
	property aliasses_v4 : Array(IPAddress)
	property aliasses_v6 : Array(IPAddress)
	property wireless_networks : Hash(String, WirelessAPSetup)
	property dns : NetworkCommands::DNS

	def initialize (@name, @up,
					@description,
					@mtu,
					@main_ip_v4, @main_ip_v6, aliasses,
					@wireless, @wireless_networks,
					@dns
				   )

		@aliasses_v4 = Array(IPAddress).new
		@aliasses_v6 = Array(IPAddress).new

		aliasses.each do |ip|
			if ip.ipv4?
				aliasses_v4 << ip
			else
				aliasses_v6 << ip
			end
		end
	end

	def to_s(io : IO)
		io << to_string
	end

	def to_string
		String.build do |str|
			if NetworkCommands.interface_exists(@name)
				str << "#{CGREEN}#{@name}#{CRESET}\n"
			else
				str << "#{CRED}#{@name}#{CRESET}\n"
			end

			str << "\tdescription: '#{description.not_nil!}'\n" unless description.nil?

			str << "\t#{@up? "up" : "down"}\n"

			unless mtu.nil?
				str << "\tmtu #{mtu}\n"
			end

			# ipv4
			unless main_ip_v4.is_a?(NotSetup)
				str << "\tinet #{main_ip_v4}\n"

				aliasses_v4.each do |a|
					str << "\talias #{a}\n"
				end
			end

			# warning: alias but no main ip address
			if main_ip_v4.is_a?(NotSetup) && ! aliasses_v4.empty?
				str << "\t#{CRED}alias configured but no main ipv4 configuration.#{CRESET}\n"
				str << "\t#{CRED}Should main ipv4 be obtained from DHCP? Static configuration?#{CRESET}\n"
			end

			# ipv6
			unless main_ip_v6.is_a?(NotSetup)
				str << "\tinet6 #{main_ip_v6}\n"

				aliasses_v6.each do |a|
					str << "\talias6 #{a}\n"
				end
			end

			# warning: alias but no main ip address
			if main_ip_v6.is_a?(NotSetup) && ! aliasses_v6.empty?
				str << "\t#{CRED}alias6 configured but no main ipv6 configuration.#{CRESET}\n"
				str << "\t#{CRED}Should main ipv6 be obtained from autoconfiguration? DHCP? Static configuration?#{CRESET}\n"
			end

			str << indent(1, dns.to_s) unless dns.addresses.empty?

			unless wireless_networks.empty?
				wireless_networks.each do |k,v|
					str << v
				end
			end
		end
	end

	def access_point_connection
		ssid_list = NetworkCommands.scan name

		if ssid_list.nil?
			raise "no ssid scanned"
		end

		if wireless_networks.empty?
			raise "no configured access point for interface #{name}, cannot connect"
		end

		wireless_networks.each do |k,v|
			ssid_list.each do |ssid|
				if k == ssid
					puts "#{CGREEN}#{k} == #{ssid}#{CRESET}"
					v.execute
				end
			end
		end

		# TODO: sleep for a second before testing the gateway?
		# TODO: configuring the interface

		puts "TODO: connectivity check with the gateway"
	end

	def store_access_point_keys
		if wireless_networks.empty?
			raise "no configured access point for interface #{name}"
		end

		wireless_networks.each do |ssid, wireless_configuration|
			# k = ssid
			puts "#{CGREEN}configuring #{ssid}#{CRESET}"
			wireless_configuration.store_access_point_keys
		end
	end

	# configure the interface
	def execute
		unless NetworkCommands.interface_exists(@name)
			raise "The interface #{@name} doesn't exists, yet."
		end

		if up
			NetworkCommands.up name
		else
			puts "not marked as 'up' -- ending here"
			return
		end

		unless mtu.nil?
			NetworkCommands.mtu name, mtu
		end

		unless description.nil?
			NetworkCommands.description name, description.not_nil!
		end

		# TODO: treat differently wireless and non-wireless interfaces
		if @wireless
			puts "interface #{name} is wireless: connection to the access point"
			store_access_point_keys
			access_point_connection
		else
			puts "interface #{name} is not wireless"
		end

		# ipv4 configuration
		main_ip_v4.tap do |ip|
			case ip
			when IPAddress
				NetworkCommands.set_ip name, ip
			when DHCP
				NetworkCommands.dhcp name
			when NotSetup
				# do nothing
			else
				raise "ipv4 configuration: neither static nor dynamic"
			end

			# We wont setup aliasses unless there is an actual IP address
			if ip != NotSetup
				aliasses_v4.each do |ip_alias|
					NetworkCommands.set_alias name, ip_alias
				end
			end
		end

		# ipv6 configuration
		main_ip_v6.tap do |ip|
			case ip
			when IPAddress
				NetworkCommands.set_ip name, ip
			when Autoconfiguration
				NetworkCommands.autoconfiguration name
			when DHCP
				NetworkCommands.dhcp6 name
			when NotSetup
				# do nothing
			else
				raise "ipv6 configuration: neither static nor dynamic"
			end

			# We wont setup aliasses unless there is an actual IP address
			if ip != NotSetup
				aliasses_v6.each do |ip_alias|
					NetworkCommands.set_alias name, ip_alias
				end
			end
		end

		# DNS configuration
		dns.execute
	end

	def down
		unless NetworkCommands.interface_exists(@name)
			raise "The interface #{@name} doesn't exists or is already down."
		end

		NetworkCommands.flush name
		NetworkCommands.down name
	end

	def scan
		unless NetworkCommands.interface_exists(@name)
			raise "The interface #{@name} doesn't exists or is already down."
		end

		ssid_list = NetworkCommands.scan name
		pp! ssid_list
	end
end