Allow mission descriptions to refer to the effects of the mission.

doc/MISSIONS_JSON.md

@@ -7,6 +7,7 @@ NPCs can assign missions to the player.  There is a fairly regular structure for
     "id": "MISSION_GET_BLACK_BOX_TRANSCRIPT",
     "type": "mission_definition",
     "name": "Retrieve Black Box Transcript",
+    "description": "Decrypt the contents of the black box using a terminal from a nearby lab.",
     "goal": "MGOAL_FIND_ITEM",
     "difficulty": 2,
     "value": 150000,
@@ -36,11 +37,28 @@ Must always be there and must always be "mission_definition".
 
 ### id
 The mission id is required, but for new missions, it can be arbitrary.  Convention is to start
-it with "MISSION" and to use a fairly desriptive name.
+it with "MISSION" and to use a fairly descriptive name.
 
 ### name
-The name is also required, and the name is what is displayed in the 'm'issions menu, so please
-make it descriptive.
+The name is also required, and is displayed to the user in the 'm'issions menu.
+
+### description
+Not required, but it's strongly recommended that you summarize all relevant info for the mission.
+You may refer to mission end effects of the "u_buy_item" type, as long as they do not come at a 
+cost to the player. See the example below:
+```JSON
+    "id": "MISSION_EXAMPLE_TOKENS",
+    "type": "mission_definition",
+    "name": "Murder Money",
+    "description": "Whack the target in exchange for <reward_item:FMCNote> c-notes and <reward_item:cig> cigarettes.",
+    "goal": "MGOAL_ASSASSINATE",
+    "end": {
+      "effect": [
+        { "u_buy_item": "FMCNote", "count": 999 },
+        { "u_buy_item": "cig", "count": 666 } ]
+    }
+```
+This system may be expanded in the future to allow referring to other mission parameters and effects.
 
 ### goal
 Must be included, and must be one of these strings:

src/dialogue.h

@@ -86,6 +86,7 @@ struct talk_topic {
 struct talk_effect_fun_t {
     private:
         std::function<void( const dialogue &d )> function;
+        std::vector<std::pair<int, std::string>> likely_rewards;
 
     public:
         talk_effect_fun_t() = default;
@@ -121,6 +122,7 @@ struct talk_effect_fun_t {
         void set_bulk_trade_accept( bool is_trade, bool is_npc = false );
         void set_npc_gets_item( bool to_use );
         void set_add_mission( std::string mission_id );
+        const std::vector<std::pair<int, std::string>> &get_likely_rewards() const;
         void set_u_buy_monster( const std::string &monster_type_id, int cost, int count, bool pacified,
                                 const translation &name );
         void set_u_learn_recipe( const std::string &learned_recipe_id );

src/mission.cpp

@@ -595,6 +595,11 @@ character_id mission::get_npc_id() const
     return npc_id;
 }
 
+const std::vector<std::pair<int, std::string>> &mission::get_likely_rewards() const
+{
+    return type->likely_rewards;
+}
+
 bool mission::has_generic_rewards() const
 {
     return type->has_generic_rewards;

src/mission.h

@@ -215,6 +215,9 @@ struct mission_type {
         // If the mission has generic rewards, so that the completion dialogue knows whether to offer them.
         bool has_generic_rewards = true;
 
+        // A limited subset of the talk_effects on the mission
+        std::vector<std::pair<int, std::string>> likely_rewards;
+
         // Points of origin
         std::vector<mission_origin> origins;
         itype_id item_id = "null";
@@ -365,6 +368,7 @@ class mission
         int get_id() const;
         const std::string &get_item_id() const;
         character_id get_npc_id() const;
+        const std::vector<std::pair<int, std::string>> &get_likely_rewards() const;
         bool has_generic_rewards() const;
         /**
          * Whether the mission is assigned to a player character. If not, the mission is free and

src/mission_ui.cpp

@@ -123,10 +123,21 @@ void game::list_missions()
             y += fold_and_print( w_missions, point( 31, y ), getmaxx( w_missions ) - 33, col,
                                  miss->name() + for_npc );
 
+            auto format_tokenized_description = []( const std::string description,
+            const std::vector<std::pair<int, std::string>> rewards ) {
+                std::string formatted_description = description;
+                for( const auto &reward : rewards ) {
+                    std::string token = "<reward_count:" + reward.second + ">";
+                    formatted_description = string_replace( formatted_description, token, string_format( "%d",
+                                                            reward.first ) );
+                }
+                return formatted_description;
+            };
+
             y++;
             if( !miss->get_description().empty() ) {
                 y += fold_and_print( w_missions, point( 31, y ), getmaxx( w_missions ) - 33, c_white,
-                                     miss->get_description() );
+                                     format_tokenized_description( miss->get_description(), miss->get_likely_rewards() ) );
             }
             if( miss->has_deadline() ) {
                 const time_point deadline = miss->get_deadline();

src/mission_util.cpp

@@ -14,6 +14,7 @@
 #include "mapgen_functions.h"
 #include "messages.h"
 #include "npc.h"
+#include "npctalk.h"
 #include "overmap.h"
 #include "overmapbuffer.h"
 #include "rng.h"
@@ -527,5 +528,13 @@ bool mission_type::parse_funcs( JsonObject &jo, std::function<void( mission * )>
             mission_function( miss );
         }
     };
+
+    for( talk_effect_fun_t &effect : talk_effects.effects ) {
+        auto rewards = effect.get_likely_rewards();
+        if( !rewards.empty() ) {
+            likely_rewards.insert( likely_rewards.end(), rewards.begin(), rewards.end() );
+        }
+    }
+
     return true;
 }

src/npctalk.cpp

@@ -1809,6 +1809,11 @@ void talk_effect_fun_t::set_u_buy_item( const std::string &item_name, int cost,
             popup( _( "%1$s gives you a %2$s." ), p.name, container.tname() );
         }
     };
+
+    // Update structure used by mission descriptions.
+    if( cost <= 0 ) {
+        likely_rewards.push_back( std::pair<int, std::string>( count, item_name ) );
+    }
 }
 
 void talk_effect_fun_t::set_u_sell_item( const std::string &item_name, int cost, int count )
@@ -2099,6 +2104,11 @@ void talk_effect_fun_t::set_add_mission( const std::string mission_id )
     };
 }
 
+const std::vector<std::pair<int, std::string>> &talk_effect_fun_t::get_likely_rewards() const
+{
+    return likely_rewards;
+}
+
 void talk_effect_fun_t::set_u_buy_monster( const std::string &monster_type_id, int cost, int count,
         bool pacified, const translation &name )
 {