module DFHack
    class << self
        # return an Unit
        # with no arg, return currently selected unit in df UI ('v' or 'k' menu)
        # with numeric arg, search unit by unit.id
        # with an argument that respond to x/y/z (eg cursor), find first unit at this position
        def unit_find(what=:selected, y=nil, z=nil)
            if what == :selected
                if curview._rtti_classname == :viewscreen_itemst
                    ref = curview.entry_ref[curview.cursor_pos]
                    ref.unit_tg if ref.kind_of?(GeneralRefUnit)
                else
                    case ui.main.mode
                    when :ViewUnits
                        # nobody selected => idx == 0
                        v = world.units.active[ui_selected_unit]
                        v if v and v.pos.z == cursor.z
                    when :LookAround
                        k = ui_look_list.items[ui_look_cursor]
                        k.unit if k.type == :Unit
                    end
                end
            elsif what.kind_of?(Integer)
                # search by id
                return world.units.all.binsearch(what) if not z
                # search by coords
                x = what
                world.units.all.find { |u| u.pos.x == x and u.pos.y == y and u.pos.z == z }
            elsif what.respond_to?(:x) or what.respond_to?(:pos)
                world.units.all.find { |u| same_pos?(what, u) }
            else
                raise "what what?"
            end
        end

        # returns an Array of all units that are current fort citizen (dwarves, on map, not hostile)
        def unit_citizens
            race = ui.race_id
            civ = ui.civ_id
            world.units.active.find_all { |u| 
                u.race == race and u.civ_id == civ and !u.flags1.dead and !u.flags1.merchant and
                !u.flags1.diplomat and !u.flags2.resident and !u.flags3.ghostly and
                !u.curse.add_tags1.OPPOSED_TO_LIFE and !u.curse.add_tags1.CRAZED and
                u.mood != :Berserk
                # TODO check curse ; currently this should keep vampires, but may include werebeasts
            }
        end

        # list workers (citizen, not crazy / child / inmood / noble)
        def unit_workers
            unit_citizens.find_all { |u|
                u.mood == :None and
                u.profession != :CHILD and
                u.profession != :BABY and
                # TODO MENIAL_WORK_EXEMPTION_SPOUSE
                !unit_entitypositions(u).find { |pos| pos.flags[:MENIAL_WORK_EXEMPTION] }
            }
        end

        # list currently idle workers
        def unit_idlers
            unit_workers.find_all { |u|
                # current_job includes eat/drink/sleep/pickupequip
                !u.job.current_job and 
                # filter 'attend meeting'
                u.meetings.length == 0 and
                # filter soldiers (TODO check schedule)
                u.military.squad_index == -1 and
                # filter 'on break'
                !u.status.misc_traits.find { |t| id == :OnBreak }
            }
        end

        def unit_entitypositions(unit)
            list = []
            return list if not hf = world.history.figures.binsearch(unit.hist_figure_id)
            hf.entity_links.each { |el|
                next if el._rtti_classname != :histfig_entity_link_positionst
                next if not ent = world.entities.all.binsearch(el.entity_id)
                next if not pa = ent.positions.assignments.binsearch(el.assignment_id)
                next if not pos = ent.positions.own.binsearch(pa.position_id)
                list << pos
            }
            list
        end
    end

    class LanguageName
        def to_s(english=true)
            df.translate_name(self, english)
        end
    end
end