Add emigration script

scripts/emigration.lua

@@ -0,0 +1,130 @@
+--Allow stressed dwarves to emigrate from the fortress
+-- For 34.11 by IndigoFenix; update and cleanup by PeridexisErrant
+-- old version:  http://dffd.bay12games.com/file.php?id=8404
+--[[=begin
+
+emigration
+==========
+Allows dwarves to emigrate from the fortress when stressed,
+in proportion to how badly stressed they are and adjusted
+for who they would have to leave with - a dwarven merchant
+being more attractive than leaving alone (or with an elf).
+The check is made monthly.
+
+A happy dwarf (ie with negative stress) will never emigrate.
+
+Usage:  ``emigration enable|disable``
+
+=end]]
+
+local args = {...}
+if args[1] == "enable" then
+    enabled = true
+elseif args[1] == "disable" then
+    enabled = false
+end
+
+function desireToStay(unit,method,civ_id)
+    -- on a percentage scale
+    value = 100 - unit.status.current_soul.personality.stress_level / 5000
+    if method == 'merchant' or method == 'diplomat' then
+        if civ_id ~= unit.civ_id then value = value*2 end end
+    if method == 'wild' then
+        value = value*5 end
+    return value
+end
+
+function desert(u,method,civ)
+    u.relations.following = nil
+    local line = dfhack.TranslateName(dfhack.units.getVisibleName(u)) .. " has "
+    if method == 'merchant' then
+        line = line.."joined the merchants"
+        u.flags1.merchant = true
+        u.civ_id = civ
+    elseif method == 'diplomat' then
+        line = line.."followed the diplomat"
+        u.flags1.diplomat = true
+        u.civ_id = civ
+    else
+        line = line.."abandoned the settlement in search of a better life."
+        u.civ_id = -1
+        u.flags1.forest = true
+        u.animal.leave_countdown = 2
+    end
+    print(line)
+    dfhack.gui.showAnnouncement(line, COLOR_WHITE)
+end
+
+function canLeave(unit)
+    for _, skill in pairs(unit.status.current_soul.skills) do
+        if skill.rating > 14 then return false end
+    end
+    if unit.flags1.caged
+        or u.race ~= df.global.ui.race_id
+        or u.civ_id ~= df.global.ui.civ_id
+        or dfhack.units.isDead(u)
+        or dfhack.units.isOpposedToLife(u)
+        or u.flags1.merchant
+        or u.flags1.diplomat
+        or unit.flags1.chained
+        or dfhack.units.getNoblePositions(unit) ~= nil
+        or unit.military.squad_id ~= -1
+        or dfhack.units.isCitizen(unit)
+        or dfhack.units.isSane(unit)
+        or unit.profession ~= 103
+        or not dfhack.units.isDead(unit)
+            then return false end
+    return true
+end
+
+function checkForDeserters(method,civ_id)
+    local allUnits = df.global.world.units.active
+    for i=#allUnits-1,0,-1 do   -- search list in reverse
+        local u = allUnits[i]
+        if canLeave(u) and math.random(100) < desireToStay(u,method,civ_id) then
+            desert(u,method,civ_id)
+        end
+    end
+end
+
+function checkmigrationnow()
+    local merchant_civ_ids = {}
+    local diplomat_civ_ids = {}
+    local allUnits = df.global.world.units.active
+    for i=0, #allUnits-1 do
+        local unit = allUnits[i]
+        if dfhack.units.isSane(unit)
+        and not dfhack.units.isDead(unit)
+        and not dfhack.units.isOpposedToLife(unit)
+        and not unit.flags1.tame
+        then
+            if unit.flags1.merchant then table.insert(merchant_civ_ids, unit.civ_id) end
+            if unit.flags1.diplomat then table.insert(diplomat_civ_ids, unit.civ_id) end
+        end
+    end
+
+    for _, civ_id in pairs(merchant_civ_ids) do checkForDeserters('merchant', civ_id) end
+    for _, civ_id in pairs(diplomat_civ_ids) do checkForDeserters('diplomat', civ_id) end
+    checkForDeserters('wild', -1)
+end
+
+local function event_loop()
+    checkmigrationnow()
+    dfhack.timeout(1, 'months', event_loop)
+end
+
+dfhack.onStateChange.loadEmigration = function(code)
+    if code==SC_MAP_LOADED then
+        if enabled then
+            print("Emigration enabled.")
+            event_loop()
+        else
+            print("Emigration disabled.")
+        end
+    end
+end
+
+if dfhack.isMapLoaded() then
+    dfhack.onStateChange.loadEmigration(SC_MAP_LOADED)
+end
+