Script command "delitemidx" (#6247)

Added new command that allow delete items from inventory by index.

Co-authored-by: Lemongrass3110 <lemongrass@kstp.at>
Co-authored-by: Aleos <aleos89@users.noreply.github.com>
Co-authored-by: Daegaladh <Daegaladh@users.noreply.github.com>

doc/script_commands.txt

@@ -2903,6 +2903,7 @@ invoking character has in their inventory, including all the data needed to
 recreate these items perfectly if they are destroyed. Here's what you get:
 
 @inventorylist_id[]                - array of item ids.
+@inventorylist_idx[]               - array of item inventory index.
 @inventorylist_amount[]            - their corresponding item amounts.
 @inventorylist_equip[]             - on which position the item is equipped (see EQP_* constants)
                                      It will contain 0 if the item is not equipped.
@@ -4997,6 +4998,30 @@ See 'getitem2' for an explanation of the expanded parameters.
 
 ---------------------------------------
 
+*delitemidx <index>{,<amount>{,<char id>}}
+
+This command will remove an item at the given inventory index.
+
+If <amount> is not specified, this will remove all of the items at the specified index.
+
+The only way to get the inventory index is by using 'getinventorylist()'. After deleting
+an item at the given index, that index can remain empty until the player relogs, requiring
+'getinventorylist()' to be called again. If an item is deleted with an invalid index, the
+script will terminate with an error.
+
+This command returns true on success and false if the item at the given index could not be deleted or if
+not enough items were available at the given index.
+
+Example:
+
+	// This will remove all Red Potions from player's inventory
+	getinventorylist();
+	for (.@i = 0; .@i < @inventorylist_count; ++.@i)
+		if (@inventorylist_id[.@i] == 501)
+			delitemidx @inventorylist_idx[.@i];
+
+---------------------------------------
+
 *cartdelitem2 <item id>,<amount>,<identify>,<refine>,<attribute>,<card1>,<card2>,<card3>,<card4>{,<account ID>};
 *cartdelitem2 "<item name>",<amount>,<identify>,<refine>,<attribute>,<card1>,<card2>,<card3>,<card4>{,<account ID>};
 *storagedelitem2 <item id>,<amount>,<identify>,<refine>,<attribute>,<card1>,<card2>,<card3>,<card4>{,<account ID>};

src/map/script.cpp

@@ -8437,6 +8437,43 @@ BUILDIN_FUNC(delitem2)
 	return SCRIPT_CMD_FAILURE;
 }
 
+/// Deletes items from the target/attached player at given index.
+/// delitemidx <index>{,<amount>{,<char id>}};
+BUILDIN_FUNC(delitemidx) {
+	struct map_session_data* sd;
+
+	if (!script_charid2sd(4, sd)) {
+		script_pushint(st, false);
+		return SCRIPT_CMD_FAILURE;
+	}
+
+	int idx = script_getnum(st, 2);
+	if (idx < 0 || idx >= MAX_INVENTORY) {
+		ShowWarning("buildin_delitemidx: Index %d is out of the range 0-%d.\n", idx, MAX_INVENTORY - 1);
+		script_pushint(st, false);
+		return SCRIPT_CMD_FAILURE;
+	}
+
+	if (sd->inventory_data[idx] == nullptr) {
+		ShowWarning("buildin_delitemidx: No item can be deleted from index %d of player %s (AID: %u, CID: %u).\n", idx, sd->status.name, sd->status.account_id, sd->status.char_id);
+		script_pushint(st, false);
+		return SCRIPT_CMD_FAILURE;
+	}
+
+	int amount;
+	if (script_hasdata(st, 3))
+		amount = script_getnum(st, 3);
+	else
+		amount = sd->inventory.u.items_inventory[idx].amount;
+
+	if (amount > 0)
+		script_pushint(st, pc_delitem(sd, idx, amount, 0, 0, LOG_TYPE_SCRIPT) == 0);
+	else
+		script_pushint(st, false);
+
+	return SCRIPT_CMD_SUCCESS;
+}
+
 /*==========================================
  * Enables/Disables use of items while in an NPC [Skotlex]
  *------------------------------------------*/
@@ -14232,6 +14269,7 @@ BUILDIN_FUNC(getinventorylist)
 	for(i=0;i<MAX_INVENTORY;i++){
 		if(sd->inventory.u.items_inventory[i].nameid > 0 && sd->inventory.u.items_inventory[i].amount > 0){
 			pc_setreg(sd,reference_uid(add_str("@inventorylist_id"), j),sd->inventory.u.items_inventory[i].nameid);
+			pc_setreg(sd,reference_uid(add_str("@inventorylist_idx"), j),i);
 			pc_setreg(sd,reference_uid(add_str("@inventorylist_amount"), j),sd->inventory.u.items_inventory[i].amount);
 			pc_setreg(sd,reference_uid(add_str("@inventorylist_equip"), j),sd->inventory.u.items_inventory[i].equip);
 			pc_setreg(sd,reference_uid(add_str("@inventorylist_refine"), j),sd->inventory.u.items_inventory[i].refine);
@@ -25220,6 +25258,7 @@ struct script_function buildin_func[] = {
 	BUILDIN_DEF2(delitem2,"storagedelitem2","viiiiiiii?"),
 	BUILDIN_DEF2(delitem2,"guildstoragedelitem2","viiiiiiii?"),
 	BUILDIN_DEF2(delitem2,"cartdelitem2","viiiiiiii?"),
+	BUILDIN_DEF(delitemidx,"i??"),
 	BUILDIN_DEF2(enableitemuse,"enable_items",""),
 	BUILDIN_DEF2(disableitemuse,"disable_items",""),
 	BUILDIN_DEF(cutin,"si"),