Bionics can require another bionic

data/json/bionics.json

@@ -1097,7 +1097,8 @@
     "flags": [ "BIONIC_TOGGLED", "BIONIC_NPC_USABLE" ],
     "act_cost": "10 kJ",
     "react_cost": "10 kJ",
-    "time": "1 s"
+    "time": "1 s",
+    "required_bionic": "bio_weight"
   },
   {
     "id": "bio_infrared",

src/bionics.cpp

@@ -364,6 +364,7 @@ void bionic_data::load( const JsonObject &jsobj, const std::string &src )
     optional( jsobj, was_loaded, "included_bionics", included_bionics );
     optional( jsobj, was_loaded, "included", included );
     optional( jsobj, was_loaded, "upgraded_bionic", upgraded_bionic );
+    optional( jsobj, was_loaded, "required_bionic", required_bionic );
     optional( jsobj, was_loaded, "fuel_options", fuel_opts );
     optional( jsobj, was_loaded, "activated_on_install", activated_on_install, false );
 
@@ -568,6 +569,14 @@ void bionic_data::check_bionic_consistency()
                           bio.id.c_str(), bio.upgraded_bionic.c_str() );
             }
         }
+        if( bio.required_bionic ) {
+            if( bio.required_bionic == bio.id ) {
+                debugmsg( "Bionic %s requires itself as a prerequisite for installation", bio.id.c_str() );
+            } else if( !bio.required_bionic.is_valid() ) {
+                debugmsg( "Bionic %s requires undefined bionic %s",
+                          bio.id.c_str(), bio.required_bionic.c_str() );
+            }
+        }
         if( !item::type_is_defined( bio.itype() ) && !bio.included ) {
             debugmsg( "Bionic %s has no defined item version", bio.id.c_str() );
         }
@@ -2113,6 +2122,14 @@ bool Character::can_uninstall_bionic( const bionic &bio, Character &installer, b
         return false;
     }
 
+    for( const bionic_id &bid : get_bionics() ) {
+        if( bid->required_bionic && bid->required_bionic == bio.id ) {
+            popup( _( "%s cannot be removed because installed bionic %s requires it." ), bio.id->name,
+                   bid->name );
+			return false;
+        }
+    }
+
     if( bio.id->cant_remove_reason.has_value() ) {
         popup( string_format( bio.id->cant_remove_reason.value(), disp_name( true ), disp_name() ) );
         return false;
@@ -2331,6 +2348,10 @@ ret_val<void> Character::is_installable( const item *it, const bool by_autodoc )
                !has_bionic( bid->upgraded_bionic ) &&
                it->is_upgrade() ) {
         return ret_val<void>::make_failure( _( "No base version installed." ) );
+    } else if( bid->required_bionic &&
+               !has_bionic( bid->required_bionic ) ) {
+        return ret_val<void>::make_failure( _( "CBM requires prior installation of %s." ),
+                                            bid->required_bionic.obj().name );
     } else if( std::any_of( bid->available_upgrades.begin(),
                             bid->available_upgrades.end(),
     [this]( const bionic_id & b ) {

src/bionics.h

@@ -167,7 +167,13 @@ struct bionic_data {
      */
     std::set<bionic_id> available_upgrades;
 
-    /**Requirement to bionic installation*/
+    /**
+     * Id of another bionic which this bionic needs to have installed to be installed.
+     * Also prevents that bionic from being removed while this bionic is installed.
+     */
+    bionic_id required_bionic;
+
+    /**Requirement to bionic installation - this is a crafting requirement such as soldering_standard or surface_heat*/
     requirement_id installation_requirement;
 
     cata::flat_set<json_character_flag> flags;

src/item.cpp

@@ -5112,6 +5112,12 @@ void item::bionic_info( std::vector<iteminfo> &info, const iteminfo_query *parts
 
     insert_separation_line( info );
 
+    if( bid->required_bionic ) {
+        info.emplace_back( "CBM", string_format( "* This CBM requires another CBM to also be installed: %s",
+                           bid->required_bionic->name ) );
+    }
+    insert_separation_line( info );
+
     // TODO refactor these almost identical blocks
     if( !bid->encumbrance.empty() ) {
         info.emplace_back( "DESCRIPTION", _( "<bold>Encumbrance</bold>:" ),