ability to clear out specific dimensions (attempt 2) (#82999)

* typo

* add `clear_dimension` EOC function

* update doc

Author: Blueflowerss

data/json/effects_on_condition/example_eocs.json

@@ -544,5 +544,24 @@
       { "u_message": { "u_val": "destination_dimension" } },
       { "if": { "current_dimension": "" }, "then": { "u_message": "home sweet home" } }
     ]
+  },
+  {
+    "type": "effect_on_condition",
+    "id": "EOC_dimension_clear_test",
+    "//": "clears out a dimension in '/dimensions' folder",
+    "global": true,
+    "effect": [
+      {
+        "set_string_var": "",
+        "string_input": {
+          "title": { "str": "clear the dimension named:" },
+          "description": { "str": "the main dimension can't be cleared." },
+          "width": 30
+        },
+        "target_var": { "u_val": "target_dimension" }
+      },
+      { "clear_dimension": { "u_val": "target_dimension" } },
+      { "u_message": "if dimension with ID <u_val:target_dimension> existed, it doesn't anymore." }
+    ]
   }
 ]

doc/JSON/EFFECT_ON_CONDITION.md

@@ -1339,6 +1339,35 @@ Will give a message if you're in the dimension with the ID of "test".
   "then": { "u_message": "Currently loaded dimension is the one with ID of 'test'." } }
 ```
 
+### `clear_dimension`
+- type: string or [variable object](#variable-object)
+- deletes the dimension folder with the given string ID.
+
+#### Valid talkers:
+
+| Avatar | NPC | Monster | Furniture | Item | Vehicle |
+| ------  --------- | ---- | ------- | --- | ---- |
+| ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
+
+#### Examples
+Deletes (if present) the dimension with ID of 'test'.
+```jsonc
+{ { "clear_dimension": "test" } }
+```
+Asks for text input, will delete the dimension that matches the string ID.
+```jsonc
+{
+    "set_string_var": "",
+    "string_input": {
+      "title": { "str": "clear the dimension named:" },
+      "description": { "str": "the main dimension can't be cleared." },
+      "width": 30
+    },
+    "target_var": { "u_val": "target_dimension" }
+},
+{ "clear_dimension": { "u_val": "target_dimension" } }
+```
+
 ### `player_see_u`, `player_see_npc`
 - type: simple string
 - return true if player can see alpha or beta talker

src/game.cpp

@@ -13776,15 +13776,21 @@ cata_path PATH_INFO::world_base_save_path()
     return world_generator->active_world->folder_path();
 }
 
+cata_path PATH_INFO::dimensions_save_path()
+{
+    return PATH_INFO::world_base_save_path() / "dimensions";
+}
+
 cata_path PATH_INFO::current_dimension_save_path()
 {
     std::string dimension_prefix = g->get_dimension_prefix();
     if( !dimension_prefix.empty() ) {
-        return PATH_INFO::world_base_save_path() / "dimensions" / dimension_prefix;
+        return PATH_INFO::dimensions_save_path() / dimension_prefix;
     }
     return PATH_INFO::world_base_save_path();
 }
 
+
 cata_path PATH_INFO::current_dimension_player_save_path()
 {
     return PATH_INFO::current_dimension_save_path() / base64_encode( get_avatar().get_save_id() );

src/game.h

@@ -1373,7 +1373,7 @@ class game
         //currently used as a hacky workaround for dimension swapping
         bool swapping_dimensions = false; // NOLINT (cata-serialize)
     private:
-        // Stores the currently occupoed dimension.
+        // Stores the currently occupied dimension.
         // TODO: should be an id instead of a string.
         std::string dimension_prefix;
 };

src/npctalk.cpp

@@ -5,6 +5,7 @@
 #include <cmath>
 #include <cstddef>
 #include <exception>
+#include <filesystem>
 #include <iterator>
 #include <list>
 #include <map>
@@ -29,6 +30,7 @@
 #include "bodypart.h"
 #include "calendar.h"
 #include "cata_lazy.h"
+#include "cata_path.h"
 #include "cata_utility.h"
 #include "catacharset.h"
 #include "character.h"
@@ -58,6 +60,7 @@
 #include "faction.h"
 #include "faction_camp.h"
 #include "field.h"
+#include "filesystem.h"
 #include "flag.h"
 #include "flat_set.h"
 #include "flexbuffer_json.h"
@@ -107,6 +110,7 @@
 #include "output.h"
 #include "overmap_ui.h"
 #include "overmapbuffer.h"
+#include "path_info.h"
 #include "pickup.h"
 #include "pimpl.h"
 #include "player_activity.h"
@@ -4764,6 +4768,23 @@ talk_effect_fun_t::func f_place_override( const JsonObject &jo, std::string_view
     };
 }
 
+talk_effect_fun_t::func f_clear_dimension( const JsonObject &jo, std::string_view member,
+        std::string_view )
+{
+    str_or_var target_dimension = get_str_or_var( jo.get_member( member ), member, true );
+
+    return [target_dimension]( dialogue const & d ) {
+        const std::string target_dimension_id = target_dimension.evaluate(
+                d );
+        const std::vector<cata_path> dimensions_query = get_directories_with( target_dimension_id,
+                PATH_INFO::dimensions_save_path() );
+        if( dimensions_query.size() == 1 ) {
+            std::filesystem::remove_all( ( PATH_INFO::dimensions_save_path() /
+                                           target_dimension_id ).get_unrelative_path() );
+        }
+    };
+}
+
 talk_effect_fun_t::func f_mapgen_update( const JsonObject &jo, std::string_view member,
         std::string_view )
 {
@@ -7890,6 +7911,7 @@ parsers = {
     { "set_npc_cbm_reserve_rule", jarg::member, &talk_effect_fun::f_npc_cbm_reserve_rule },
     { "set_npc_cbm_recharge_rule", jarg::member, &talk_effect_fun::f_npc_cbm_recharge_rule },
     { "map_spawn_item", jarg::member, &talk_effect_fun::f_spawn_item },
+    { "clear_dimension", jarg::member, &talk_effect_fun::f_clear_dimension },
     { "mapgen_update", jarg::member, &talk_effect_fun::f_mapgen_update },
     { "alter_timed_events", jarg::member, &talk_effect_fun::f_alter_timed_events },
     { "revert_location", jarg::member, &talk_effect_fun::f_revert_location },

src/path_info.h

@@ -93,6 +93,7 @@ cata_path user_keybindings();
 cata_path user_moddir_path();
 cata_path user_sound();
 cata_path world_base_save_path();
+cata_path dimensions_save_path();
 cata_path current_dimension_save_path();
 cata_path current_dimension_player_save_path();