Implement currency, shops, and enhanced NPC interaction system

src/world.rs

@@ -79,10 +79,22 @@ pub struct RoomFile {
     pub exits: HashMap<String, String>,
 }
 
-#[derive(Deserialize)]
+#[derive(Deserialize, Clone)]
+pub struct ShopFile {
+    pub buys: Vec<String>, // List of item kinds or IDs the shop buys
+    pub sells: Vec<String>, // List of item IDs the shop sells
+    #[serde(default)]
+    pub markup: f32, // Multiplier for sell price (default 1.0)
+    #[serde(default)]
+    pub markdown: f32, // Multiplier for buy price (default 0.5)
+}
+
+#[derive(Deserialize, Clone)]
 pub struct NpcDialogue {
     #[serde(default)]
     pub greeting: Option<String>,
+    #[serde(default)]
+    pub keywords: HashMap<String, String>, // keyword -> response
 }
 
 #[derive(Deserialize)]
@@ -113,6 +125,14 @@ pub struct NpcFile {
     pub dialogue: Option<NpcDialogue>,
     #[serde(default)]
     pub combat: Option<NpcCombatFile>,
+    #[serde(default)]
+    pub shop: Option<ShopFile>,
+    #[serde(default)]
+    pub gold: i32,
+    #[serde(default)]
+    pub silver: i32,
+    #[serde(default)]
+    pub copper: i32,
 }
 
 fn default_attitude() -> Attitude {
@@ -143,6 +163,12 @@ pub struct ObjectFile {
     pub takeable: bool,
     #[serde(default)]
     pub stats: Option<ObjectStatsFile>,
+    #[serde(default)]
+    pub value_gold: i32,
+    #[serde(default)]
+    pub value_silver: i32,
+    #[serde(default)]
+    pub value_copper: i32,
 }
 
 // --- Race TOML schema ---
@@ -409,7 +435,12 @@ pub struct Npc {
     pub fixed_class: Option<String>,
     pub respawn_secs: Option<u64>,
     pub greeting: Option<String>,
+    pub keywords: HashMap<String, String>,
     pub combat: Option<NpcCombatStats>,
+    pub shop: Option<ShopFile>,
+    pub gold: i32,
+    pub silver: i32,
+    pub copper: i32,
 }
 
 #[derive(Clone, Serialize, Deserialize)]
@@ -429,6 +460,9 @@ pub struct Object {
     pub slot: Option<String>,
     pub takeable: bool,
     pub stats: ObjectStats,
+    pub value_gold: i32,
+    pub value_silver: i32,
+    pub value_copper: i32,
 }
 
 pub const DEFAULT_HUMANOID_SLOTS: &[&str] = &[
@@ -637,14 +671,18 @@ impl World {
 
             load_entities_from_dir(&region_path.join("npcs"), &region_name, &mut |id, content| {
                 let nf: NpcFile = toml::from_str(content).map_err(|e| format!("Bad npc {id}: {e}"))?;
+                let (greeting, keywords) = match nf.dialogue {
+                    Some(d) => (d.greeting, d.keywords),
+                    None => (None, HashMap::new()),
+                };
                 let combat = Some(nf.combat.map(|c| NpcCombatStats { max_hp: c.max_hp, attack: c.attack, defense: c.defense, xp_reward: c.xp_reward })
                     .unwrap_or(NpcCombatStats { max_hp: 20, attack: 4, defense: 2, xp_reward: 5 }));
-                let greeting = nf.dialogue.and_then(|d| d.greeting);
                 npcs.insert(id.clone(), Npc {
                     id: id.clone(), name: nf.name, description: nf.description, room: nf.room,
                     base_attitude: nf.base_attitude, faction: nf.faction,
                     fixed_race: nf.race, fixed_class: nf.class,
-                    respawn_secs: nf.respawn_secs, greeting, combat,
+                    respawn_secs: nf.respawn_secs, greeting, keywords, combat,
+                    shop: nf.shop, gold: nf.gold, silver: nf.silver, copper: nf.copper,
                 });
                 Ok(())
             })?;
@@ -656,6 +694,7 @@ impl World {
                     id: id.clone(), name: of.name, description: of.description, room: of.room,
                     kind: of.kind, slot: of.slot, takeable: of.takeable,
                     stats: ObjectStats { damage: stats.damage, armor: stats.armor, heal_amount: stats.heal_amount },
+                    value_gold: of.value_gold, value_silver: of.value_silver, value_copper: of.value_copper,
                 });
                 Ok(())
             })?;