Add artifact and invasion tracking to chronicle

chronicle.lua

@@ -1,4 +1,4 @@
--- Chronicles fortress events (currently only unit deaths)
+-- Chronicles fortress events: unit deaths, artifact creation, and invasions
 --@module = true
 --@enable = true
 
@@ -40,48 +40,47 @@ local function on_unit_death(unit_id)
     local date = format_date(df.global.cur_year, df.global.cur_year_tick)
     add_entry(string.format('Death of %s on %s', name, date))
 end
-local function check_artifacts()
-    local last_id = state.last_artifact_id
-    for _, rec in ipairs(df.global.world.artifacts.all) do
-        if rec.id > last_id then
-            local name = dfhack.translation.translateName(rec.name)
-            -- artifact_record stores the creation tick in `season_tick`
-            local date = format_date(rec.year, rec.season_tick or 0)
-            add_entry(string.format('Artifact "%s" created on %s', name, date))
-            last_id = rec.id
-        end
-    end
-    state.last_artifact_id = last_id
-end
 
-local function check_invasions()
-    for _, inv in ipairs(df.global.plotinfo.invasions.list) do
-        if inv.flags.active and not state.known_invasions[inv.id] then
-            state.known_invasions[inv.id] = true
-            local date = format_date(df.global.cur_year, df.global.cur_year_tick)
-            add_entry(string.format('Invasion started on %s', date))
-        end
+local function on_item_created(item_id)
+    local item = df.item.find(item_id)
+    if not item or not item.flags.artifact then return end
+
+    local gref = dfhack.items.getGeneralRef(item, df.general_ref_type.IS_ARTIFACT)
+    local rec = gref and df.artifact_record.find(gref.artifact_id) or nil
+    if not rec then return end
+
+    local name = dfhack.translation.translateName(rec.name)
+    local date = format_date(rec.year, rec.season_tick or 0)
+    if rec.id > state.last_artifact_id then
+        state.last_artifact_id = rec.id
     end
+    add_entry(string.format('Artifact "%s" created on %s', name, date))
 end
 
--- main loop; artifact and invasion tracking disabled to avoid scanning large
--- data structures, which was causing hangs on some forts
-local function event_loop()
-    if not state.enabled then return end
-    dfhack.timeout(1200, 'ticks', event_loop)
+local function on_invasion(invasion_id)
+    if state.known_invasions[invasion_id] then return end
+    state.known_invasions[invasion_id] = true
+    local date = format_date(df.global.cur_year, df.global.cur_year_tick)
+    add_entry(string.format('Invasion started on %s', date))
 end
+-- legacy scanning functions for artifacts and invasions have been removed in
+-- favor of event-based tracking. the main loop is no longer needed.
 
 local function do_enable()
     state.enabled = true
+    eventful.enableEvent(eventful.eventType.ITEM_CREATED, 1)
+    eventful.enableEvent(eventful.eventType.INVASION, 1)
     eventful.onUnitDeath[GLOBAL_KEY] = on_unit_death
+    eventful.onItemCreated[GLOBAL_KEY] = on_item_created
+    eventful.onInvasion[GLOBAL_KEY] = on_invasion
     persist_state()
-
-    event_loop()
 end
 
 local function do_disable()
     state.enabled = false
     eventful.onUnitDeath[GLOBAL_KEY] = nil
+    eventful.onItemCreated[GLOBAL_KEY] = nil
+    eventful.onInvasion[GLOBAL_KEY] = nil
     persist_state()
 end
 
@@ -95,6 +94,8 @@ end
 dfhack.onStateChange[GLOBAL_KEY] = function(sc)
     if sc == SC_MAP_UNLOADED then
         eventful.onUnitDeath[GLOBAL_KEY] = nil
+        eventful.onItemCreated[GLOBAL_KEY] = nil
+        eventful.onInvasion[GLOBAL_KEY] = nil
         state.enabled = false
         return
     end

docs/chronicle.rst

@@ -2,12 +2,11 @@ chronicle
 =========
 
 .. dfhack-tool::
-    :summary: Record fortress events like deaths. Artifact and invasion tracking disabled.
+    :summary: Record fortress events like deaths, artifacts, and invasions.
     :tags: fort gameplay
 
 This tool automatically records notable events in a chronicle that is stored
-with your save. Currently only unit deaths are recorded since artifact and
-invasion tracking has been disabled due to performance issues.
+with your save. Unit deaths, artifact creation, and invasions are recorded.
 
 Usage
 -----