note
	description: "[
		Representation of a submarine in VITP.
		]"
	author: "Jimmy J. Johnson"

deferred class
	SUBMARINE

inherit

	ATTACK_UNIT
		redefine
			patrol_distance,
			raid_distance,
--			arrival_position,
			join_force,			-- inapplicable
			leave_force,		-- inapplicable
			internal_is_movable
		end

feature -- Access

	patrol_distance: INTEGER = 1000
			-- How may sea areas can Current move through as patroller?
			-- Just set to a very large number.

	raid_distance: INTEGER = 1000
			-- How may sea areas can Current move through as raider?
			-- Just set to a very large number.

--	arrival_position: like position
--			-- The location (latitude/longitude-like coordinates) where Current
--			-- will enter the game.  Redefine to make it enter at its own position.
--		do
--			if nationality = game.japanese then
--				Result := [200, 50]
--			else
--				Result := [750, 600]
--			end
--		end

	patrollable_sea_areas: LINKED_SET [SEA_AREA]
			-- A list containing each {SEA_AREA} which Current can patrol
			-- from its `home_port' at this point in the game
		do
			create Result.make
		end

	raidable_sea_areas: LINKED_SET [SEA_AREA]
			-- A list containing each {SEA_AREA} which Current can raid
			-- from its `home_port' at this point in the game
		do
			create Result.make
			from game.sea_areas.start
			until game.sea_areas.after
			loop
				Result.extend (game.sea_areas.item_for_iteration)
				game.sea_areas.forth
			end
		end

feature -- Status report

	is_sunk: BOOLEAN = False
			-- Submarines do not take fire

	is_patrollable: BOOLEAN = False
			-- Can this unit be a patroller for area control purposes?

	is_raidable: BOOLEAN = False
			-- Can this unit be a raider?

	is_patrolling: BOOLEAN = False
			-- Is this unit a patroller (as opposed to a raider)?
			-- Air units a `is_patrollable' but don't move as patrollers.

	is_raiding: BOOLEAN = False
			-- Is this unit a raider?

feature -- Basic operations

	return_to_port (a_port: PORT)
		require
--			is_return_allowed: is_at_sea and then a_port.controller = nationality and then
--				(location.adjoins (a_port) or else a_port.is_major)
		do
			location := a_port
		end

	repair
			-- Do repairs on the ship
		require
--			is_in_port: location.is_port
			port_has_repair_capability:
		do

		end

	join_force (a_other: ATTACK_UNIT)
			-- Join forces with `a_other' as a single `task_force'
		do
			check
				do_not_call: false then
					-- Because inapplicable to {AIR_UNIT}
			end
		end

	leave_force
			-- Remove Current from the `task_force' to which it belongs, but only
			-- if there are other ships in the force, and put it in its own.
		do
			check
				do_not_call: false then
					-- Because inapplicable to {AIR_UNIT}
			end
		end

feature -- Query

	is_incompatible_position (a_position: VITP_POSITION): BOOLEAN
			-- Is `a_position' located on a unit with which Current is NOT
			-- allowed to `join_force' (e.g. on a submarine or an enemy)?
		local
			u_list: VITP_TABLE [ATTACK_UNIT]
			au: ATTACK_UNIT
		do
			if not is_in_game then
				Result := false
			else
				u_list := game.all_attack_units
				from u_list.start
				until u_list.after or else Result
				loop
					au := u_list.item_for_iteration
					Result := au.contains_position (a_position)
					u_list.forth
				end
			end
				-- Temp for testing
			Result := false
		end

feature {NONE} -- Implementation

	internal_is_movable: BOOLEAN
			-- Can Current (not the `task_force') move at this time?
		local
			sop: VITP_SEQUENCE_OF_PLAY
		do
			sop := game.sequence_of_play
			Result := not is_sunk and
					(sop.is_moving_submarine_step)	-- or else
--					 sop.is_returning_submarine_to_port_step)
		end

end