implement fix/wildlife ignore

docs/fix/wildlife.rst

@@ -31,12 +31,15 @@ stuck for 7 days.
 Unlike most bugfixes, this one is not enabled by default since some players
 like to keep wildlife around for creative purposes (e.g. for intentionally
 stalling wildlife waves or for controlled startling of friendly necromancers).
+These players can selectively ignore the wildlife they want to keep captive
+before they enable `fix/wildlife`.
 
 Usage
 -----
 ::
 
     fix/wildlife [<options>]
+    fix/wildlife ignore [unit ID]
 
 Examples
 --------
@@ -48,6 +51,10 @@ Examples
     Remove wildlife that has been stuck for at least a week. The command must
     be run periodically with this option so it can discover newly stuck
     wildlife and remove wildlife when timeouts expire.
+``fix/wildlife ignore``
+    Disconnect the selected unit from its wildlife population so it doesn't
+    block new wildlife from entering the map, but keep the unit on the map.
+    This unit will not be touched by future invocations of this tool.
 
 Options
 -------

fix/wildlife.lua

@@ -61,6 +61,13 @@ local function refund_population(entry)
     end
 end
 
+-- refund unit to population and ensure it doesn't get picked up by unstick_surface_wildlife in the future
+local function detach_unit(unit)
+    unit.flags2.roaming_wilderness_population_source = false
+    unit.flags2.roaming_wilderness_population_source_not_a_map_feature = false
+    refund_population{race=unit.race, pop=unit.animal.population, known=true, count=1}
+end
+
 local TICKS_PER_DAY = 1200
 local TICKS_PER_WEEK = TICKS_PER_DAY * 7
 local TICKS_PER_MONTH = 28 * TICKS_PER_DAY
@@ -88,16 +95,18 @@ local function to_key(pop)
         pop.region_x, pop.region_y, pop.feature_idx, pop.cave_id, pop.site_id, pop.population_idx)
 end
 
+local function is_active_wildlife(unit)
+    return not dfhack.units.isDead(unit) and
+        dfhack.units.isActive(unit) and
+        dfhack.units.isWildlife(unit) and
+        unit.flags2.roaming_wilderness_population_source
+end
+
 local function unstick_surface_wildlife(opts)
     local unstuck = {}
     local week_ago_ticks = math.max(0, df.global.cur_year_tick - TICKS_PER_WEEK)
     for _,unit in ipairs(df.global.world.units.active) do
-        if dfhack.units.isDead(unit) or
-            not dfhack.units.isActive(unit) or
-            not dfhack.units.isWildlife(unit) or
-            not unit.flags2.roaming_wilderness_population_source or
-            unit.animal.leave_countdown > 0
-        then
+        if not is_active_wildlife(unit) or unit.animal.leave_countdown > 0 then
             goto skip
         end
         if not check_timeout(opts, unit, week_ago_ticks) then
@@ -146,4 +155,24 @@ if positionals[1] == 'help' or opts.help then
     return
 end
 
-unstick_surface_wildlife(opts)
+if positionals[1] == 'ignore' then
+    local unit
+    local unit_id = positionals[2] and argparse.nonnegativeInt(positionals[2], 'unit_id')
+    if unit_id then
+        unit = df.unit.find(unit_id)
+    else
+        unit = dfhack.gui.getSelectedUnit(true)
+    end
+    if not unit then
+        qerror('please select a unit or pass a unit ID on the commandline')
+    end
+    if not is_active_wildlife(unit) then
+        qerror('selected unit is not blocking new waves of wildlife; nothing to do')
+    end
+    detach_unit(unit)
+    if not opts.quiet then
+        print(('%s will now be ignored by fix/wildlife'):format(dfhack.units.getReadableName(unit)))
+    end
+else
+    unstick_surface_wildlife(opts)
+end