Add getrandmobid script command (#7309)

* Used to generate random monster ID in NPC scripts.

doc/script_commands.txt

@@ -3583,6 +3583,32 @@ This command does not count skills which are set as flag 4 (permament granted) (
 
 ---------------------------------------
 
+*getrandmobid(<type>{,<flag>{,<level>}})
+
+This command returns a random monster ID from the random monster group.
+With <flag> you can apply certain restrictions which monsters of the group can be returned.
+Returns 0 if one of the parameters is invalid or no monster could be found with the given parameters.
+
+Valid <type> are:
+	MOBG_BRANCH_OF_DEAD_TREE
+	MOBG_PORING_BOX
+	MOBG_BLOODY_DEAD_BRANCH
+	MOBG_RED_POUCH_OF_SURPRISE
+	MOBG_CLASSCHANGE
+	MOBG_TAEKWON_MISSION
+	
+Valid <flag> are:
+	RMF_NONE            = 0x00 - Apply no flags
+	RMF_DB_RATE         = 0x01 - Apply the summon success chance found in the list (otherwise get any monster from the db)
+	RMF_CHECK_MOB_LV    = 0x02 - Apply a monster level check
+	RMF_MOB_NOT_BOSS    = 0x04 - Selected monster should not be a Boss type (default)
+	                           - (except those from MOBG_BLOODY_DEAD_BRANCH)
+	RMF_MOB_NOT_SPAWN   = 0x08 - Selected monster must have normal spawn
+	RMF_MOB_NOT_PLANT   = 0x10 - Selected monster should not be a Plant type
+	RMF_ALL             = 0xFF - Apply all flags
+	
+---------------------------------------
+
 *getmonsterinfo(<mob ID>,<type>)
 *getmonsterinfo(<mob name>,<type>)
 

src/map/script.cpp

@@ -18226,6 +18226,52 @@ BUILDIN_FUNC(delmonsterdrop)
 }
 
 
+
+/*==========================================
+ * Returns a random mob_id
+ * type: Where to fetch from (see enum e_random_monster)
+ * flag: Type of checks to apply (see enum e_random_monster_flags)
+ * lv: Mob level to check against
+ *------------------------------------------*/
+BUILDIN_FUNC(getrandmobid)
+{
+	int type = script_getnum(st, 2);
+
+	if (type < MOBG_BRANCH_OF_DEAD_TREE || type >= MOBG_MAX) {
+		ShowWarning("buildin_getrandmobid: Invalid type %d.\n", type);
+		script_pushint(st, 0);
+		return SCRIPT_CMD_FAILURE;
+	}
+
+	int flag = script_hasdata(st, 3) ? script_getnum(st, 3) : RMF_MOB_NOT_BOSS;
+	if (flag < RMF_NONE || flag > RMF_ALL) {
+		ShowWarning("buildin_getrandmobid: Invalid flag %d.\n", flag);
+		script_pushint(st, 0);
+		return SCRIPT_CMD_FAILURE;
+	}
+
+	int lv;
+	if ( script_hasdata(st, 4) ) {
+		lv = script_getnum(st, 4);
+		
+		if (lv <= 0) {
+			ShowWarning("buildin_getrandmobid: Invalid level %d.\n", lv);
+			script_pushint(st, 0);
+			return SCRIPT_CMD_FAILURE;
+		}
+		
+		// If a level is provided, make sure it is respected
+		flag |= RMF_CHECK_MOB_LV;
+	} else {
+		lv = MAX_LEVEL;
+	}
+
+	script_pushint(st, mob_get_random_id(type, (enum e_random_monster_flags)flag, lv));
+
+	return SCRIPT_CMD_SUCCESS;
+}
+
+
 /*==========================================
  * Returns some values of a monster [Lupus]
  * Name, Level, race, size, etc...
@@ -27093,6 +27139,7 @@ struct script_function buildin_func[] = {
 	BUILDIN_DEF(setitemscript,"is?"), //Set NEW item bonus script. Lupus
 	BUILDIN_DEF(disguise,"i?"), //disguise player. Lupus
 	BUILDIN_DEF(undisguise,"?"), //undisguise player. Lupus
+	BUILDIN_DEF(getrandmobid, "i??"),
 	BUILDIN_DEF(getmonsterinfo,"vi"), //Lupus
 	BUILDIN_DEF(addmonsterdrop,"vii??"), //Akinari [Lupus]
 	BUILDIN_DEF(delmonsterdrop,"vi"), //Akinari [Lupus]

src/map/script_constants.hpp

@@ -4944,6 +4944,15 @@
 	export_constant(MOBG_CLASSCHANGE);
 	export_constant(MOBG_TAEKWON_MISSION);
 
+	/* mob random groups flags */
+	export_constant(RMF_NONE);
+	export_constant(RMF_DB_RATE);
+	export_constant(RMF_CHECK_MOB_LV);
+	export_constant(RMF_MOB_NOT_BOSS);
+	export_constant(RMF_MOB_NOT_SPAWN);
+	export_constant(RMF_MOB_NOT_PLANT);
+	export_constant(RMF_ALL);
+
 	/* random option attributes */
 	export_constant(ROA_ID);
 	export_constant(ROA_VALUE);