Create a new version of paste:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

using Engine;

namespace SuperAdventure
{
    public partial class SuperAdventure : Form
    {
        private Player _player;
        private Monster _currentMonster;
        private HealingPotion _healingPotion;
        
        public SuperAdventure()
        {
            InitializeComponent();

            _player = new Player(10, 10, 20, 0);
            MoveTo(World.LocationByID(World.LOCATION_ID_HOME));
          
            _player.Inventory.Add(new InventoryItem(World.ItemByID(World.ITEM_ID_RUSTY_SWORD), 1));
            _player.Inventory.Add(new InventoryItem(World.ItemByID(World.ITEM_ID_HEALING_POTION), 1));

            UpdateInventoryListInUI(); //shows weapon at the beginning, if any
            UpdatePotionListInUI(); //shows potion at the beginning, if any

            UpdatePlayerStats(); //shows current stats at the beginning
        }

        private void btnNorth_Click(object sender, EventArgs e)
        {
            MoveTo(_player.CurrentLocation.LocationToNorth);
        }

        private void btnEast_Click(object sender, EventArgs e)
        {
            MoveTo(_player.CurrentLocation.LocationToEast);
        }

        private void btnSouth_Click(object sender, EventArgs e)
        {
            MoveTo(_player.CurrentLocation.LocationToSouth);
        }

        private void btnWest_Click(object sender, EventArgs e)
        {
            MoveTo(_player.CurrentLocation.LocationToWest);
        }

        public void MoveTo(Location newLocation)
        {
            if (!_player.HasRequiredItemToEnterThisLocation(newLocation))
            {
                ScrollToBottomOfMessages();
                rtbMessages.Text += "You must have a/an " + newLocation.ItemRequiredToEnter.Name + " to enter this location." + Environment.NewLine;
                return;
                
            }

            //Update the player's current location
            _player.CurrentLocation = newLocation;

            //Show/hide available movement buttons
            btnNorth.Visible = (newLocation.LocationToNorth != null);
            btnEast.Visible = (newLocation.LocationToEast != null);
            btnSouth.Visible = (newLocation.LocationToSouth != null);
            btnWest.Visible = (newLocation.LocationToWest != null);

            //Display current location name and description
            rtbLocation.Text = newLocation.Name + Environment.NewLine;
            rtbLocation.Text += newLocation.Description + Environment.NewLine;

            //Does the location have a quest?
            if (newLocation.QuestAvailableHere != null)
            {
                //see if the player already has the quest, and if they've completed it
                bool playerAlreadyHasQuest = _player.HasThisQuest(newLocation.QuestAvailableHere);
                bool playerAlreadyHasCompletedQuest = _player.CompletedThisQuest(newLocation.QuestAvailableHere);

                //See if the player already has the quest
                if (playerAlreadyHasQuest)
                {
                    //if the player has not completed the quest yet
                    if (!playerAlreadyHasCompletedQuest)
                    {
                        //See if the player has all the items needed to complete the quest 
                        bool playerHasAllTheItemsToCompleteQuest = _player.HasAllQuestCompletionItems(newLocation.QuestAvailableHere);

                        if (playerHasAllTheItemsToCompleteQuest)
                        {
                            //display message
                            ScrollToBottomOfMessages();
                            rtbMessages.Text += Environment.NewLine;
                            ScrollToBottomOfMessages();
                            rtbMessages.Text += "You complete the " + "«" + newLocation.QuestAvailableHere.Name + "»" + " quest." + Environment.NewLine;
                            

                            //remove quest items from inventory
                            _player.RemoveQuestCompletionItems(newLocation.QuestAvailableHere);

                            //give quest rewards
                            ScrollToBottomOfMessages();
                            rtbMessages.Text += "You receive: " + Environment.NewLine;
                            rtbMessages.Text += newLocation.QuestAvailableHere.RewardExperiencePoints.ToString() + " experience points" + Environment.NewLine;
                            rtbMessages.Text += newLocation.QuestAvailableHere.RewardGold.ToString() + " gold" + Environment.NewLine;
                            rtbMessages.Text += newLocation.QuestAvailableHere.RewardItem.Name + Environment.NewLine;
                            rtbMessages.Text += Environment.NewLine;

                            _player.ExperiencePoints += newLocation.QuestAvailableHere.RewardExperiencePoints;
                            _player.Gold += newLocation.QuestAvailableHere.RewardGold;

                            
                            //Add reward item to the player's inventory
                            _player.AddItemToInventory(newLocation.QuestAvailableHere.RewardItem);

                            //mark the quest as completed
                            _player.MarkQuestCompleted(newLocation.QuestAvailableHere);

                            //Update UI text
                            UpdateInventoryListInUI();

                            UpdatePotionListInUI();

                            lblGold.Text = _player.Gold.ToString();
                            lblExperience.Text = _player.ExperiencePoints.ToString();

                        }
                    }
                }
                else
                {
                    //the player does not already have the quest

                    //display messages
                    ScrollToBottomOfMessages();
                    rtbMessages.Text += "You receive the " + "«" + newLocation.QuestAvailableHere.Name + "»" + " quest." + Environment.NewLine;
                    rtbMessages.Text += newLocation.QuestAvailableHere.Description + Environment.NewLine;
                    rtbMessages.Text += "To complete it, return with: " + Environment.NewLine;
                    foreach (QuestCompletionItem qci in newLocation.QuestAvailableHere.QuestCompletionItems)
                    {
                        if (qci.Quantity == 1)
                        {
                            ScrollToBottomOfMessages();
                            rtbMessages.Text += qci.Quantity.ToString() + " " + qci.Details.Name + Environment.NewLine;
                        }
                        else
                        {
                            ScrollToBottomOfMessages();
                            rtbMessages.Text += qci.Quantity.ToString() + " " + qci.Details.NamePlural + Environment.NewLine;
                        }
                    }
                    ScrollToBottomOfMessages();
                    rtbMessages.Text += Environment.NewLine;

                    //Add the quest to the player quest's list
                    _player.Quests.Add(new PlayerQuest(newLocation.QuestAvailableHere));
                }
            }

            //Does the location have a monster?
            if (newLocation.MonsterLivingHere != null)
            {
                ScrollToBottomOfMessages();
                rtbMessages.Text += "You see a " + newLocation.MonsterLivingHere.Name + "." + Environment.NewLine;

                //make a new monster, using the values from the standard monster in the World.Monster list
                Monster standardMonster = World.MonsterByID(newLocation.MonsterLivingHere.ID);

                _currentMonster = new Monster(standardMonster.ID, standardMonster.Name, standardMonster.MaximumDamage,
                    standardMonster.RewardExperiencePoints, standardMonster.RewardGold, standardMonster.CurrentHitPoints, standardMonster.MaximumHitPoints);

                foreach (LootItem lootItem in standardMonster.LootTable)
                {
                    _currentMonster.LootTable.Add(lootItem);
                }

                cboWeapons.Visible = true;
                btnUseWeapon.Visible = true;

            }
            else
            {
                _currentMonster = null;

                cboWeapons.Visible = false;
                btnUseWeapon.Visible = false;
            }

            //refresh player's inventory list
            UpdateInventoryListInUI();

            //refresh player's quest list
            UpdateQuestListInUI();

            //refresh player's weapons combobox
            UpdateWeaponsListInUI();

            //refresh player's potion combobox
            UpdatePotionListInUI();
        }

        private void UpdateInventoryListInUI()
        {
            dgvInventory.RowHeadersVisible = false;

            dgvInventory.ColumnCount = 2;
            dgvInventory.Columns[0].Name = "Name";
            dgvInventory.Columns[0].Width = 209;
            dgvInventory.Columns[1].Name = "Quantity";

            dgvInventory.Rows.Clear();

            foreach (InventoryItem inventoryItem in _player.Inventory)
            {
                if (inventoryItem.Quantity > 0)
                {
                    dgvInventory.Rows.Add(new[] { inventoryItem.Details.Name, inventoryItem.Quantity.ToString() });
                }
            }
        }

        private void UpdateQuestListInUI()
        {

            dgvQuests.RowHeadersVisible = false;

            dgvQuests.ColumnCount = 2;
            dgvQuests.Columns[0].Name = "Name";
            dgvQuests.Columns[0].Width = 209;
            dgvQuests.Columns[1].Name = "Cleared?";
            

            dgvQuests.Rows.Clear();

            foreach (PlayerQuest playerQuest in _player.Quests)
            {
                if (playerQuest.IsCompleted)
                {
                    dgvQuests.Rows.Add(new[] { playerQuest.Details.Name, "Yes" });
                }
                else
                {
                    dgvQuests.Rows.Add(new[] { playerQuest.Details.Name, "No" });
                }
            }
        }

        private void UpdateWeaponsListInUI()
        {

            List<Weapon> weapons = new List<Weapon>();

            foreach (InventoryItem inventoryItem in _player.Inventory)
            {
                if (inventoryItem.Details is Weapon)
                {
                    if (inventoryItem.Quantity > 0)
                    {
                        weapons.Add((Weapon)inventoryItem.Details);
                    }
                }
            }

            if (weapons.Count == 0)
            {
                //the player has no weapons, hide the combobox and "use" button
                cboWeapons.Visible = false;
                btnUseWeapon.Visible = false;
            }
            else
            {
                cboWeapons.DataSource = weapons;
                cboWeapons.DisplayMember = "Name";
                cboWeapons.ValueMember = "ID";

                cboWeapons.SelectedIndex = 0;
            }
        }

        private void UpdatePotionListInUI()
        {
            List<HealingPotion> healingPotions = new List<HealingPotion>();

            foreach (InventoryItem inventoryItem in _player.Inventory)
            {
                if (inventoryItem.Details is HealingPotion)
                {
                    if (inventoryItem.Quantity > 0)
                    {
                        healingPotions.Add((HealingPotion)inventoryItem.Details);
                    }
                }
            }

            if (healingPotions.Count == 0)
            {
                //the player does not have any potions, hide the combobox and "use button
                cboPotions.Visible = false;
                btnUsePotion.Visible = false;
            }
            else
            {
                cboPotions.Visible = true;
                btnUsePotion.Visible = true;

                cboPotions.DataSource = healingPotions;
                cboPotions.DisplayMember = "Name";
                cboPotions.ValueMember = "ID";

                cboPotions.SelectedIndex = 0;
            }
        }

        private void UpdatePlayerStats()
        {
            // Refresh player information and inventory controls
            lblHitPoints.Text = _player.CurrentHitPoints.ToString();
            lblGold.Text = _player.Gold.ToString();
            lblExperience.Text = _player.ExperiencePoints.ToString();
            lblLevel.Text = _player.Level.ToString();
        }

        private void btnUseWeapon_Click(object sender, EventArgs e)
        {
            //get the currently selected weapon from cboWeapons combobox
            Weapon currentWeapon = (Weapon)cboWeapons.SelectedItem;

            //Determine the amount of damage to do to the monster
            int damageToMonster = RandomNumberGenerator.NumberBetween(currentWeapon.MinimumDamage, currentWeapon.MaximumDamage);

            //apply damage to monster's currenthitpoints
            _currentMonster.CurrentHitPoints -= damageToMonster;

            //display message
            ScrollToBottomOfMessages();
            rtbMessages.Text += "You hit the " + _currentMonster.Name + " for " + damageToMonster.ToString() + " points." + Environment.NewLine;

            //check if the monster is dead
            if (_currentMonster.CurrentHitPoints <= 0)
            {
                //Monster is dead
                ScrollToBottomOfMessages();
                rtbMessages.Text += Environment.NewLine;
                rtbMessages.Text += "You defeated the " + _currentMonster.Name + "." + Environment.NewLine;


                btnUseWeapon.Visible = false;
                cboWeapons.Visible = false;

                //Give player experience for killing the monster
                _player.ExperiencePoints += _currentMonster.RewardExperiencePoints;
                ScrollToBottomOfMessages();
                rtbMessages.Text += "You receive " + _currentMonster.RewardExperiencePoints.ToString() + " experience points." + Environment.NewLine;

                //Give player gold for killing the monster
                _player.Gold += _currentMonster.RewardGold;
                if (_currentMonster.RewardGold == 1)
                {
                    ScrollToBottomOfMessages();
                    rtbMessages.Text += "You get " + _currentMonster.RewardGold.ToString() + " piece of gold." + Environment.NewLine;
                }
                else
                {
                    ScrollToBottomOfMessages();
                    rtbMessages.Text += "You get " + _currentMonster.RewardGold.ToString() + " pieces of gold." + Environment.NewLine;
                }

                //get random loot items from the monster
                List<InventoryItem> lootedItems = new List<InventoryItem>();

                //Add items to the lootedItems list, comparing a random number to the drop percentage
                foreach (LootItem lootItem in _currentMonster.LootTable)
                {
                    if (RandomNumberGenerator.NumberBetween(1, 100) <= lootItem.DropPercentage)
                    {
                        lootedItems.Add(new InventoryItem(lootItem.Details, 1));
                    }
                }

                //if no items were randomly selected, then add the default loot item(s)
                if (lootedItems.Count == 0)
                {
                    foreach (LootItem lootItem in _currentMonster.LootTable)
                    {
                        if (lootItem.IsDefaultItem)
                        {
                            lootedItems.Add(new InventoryItem(lootItem.Details, 1));
                        }
                    }
                }

                //add the looted items to the player's inventory
                foreach (InventoryItem inventoryItem in lootedItems)
                {
                    _player.AddItemToInventory(inventoryItem.Details);

                    if (inventoryItem.Quantity == 1)
                    {
                        ScrollToBottomOfMessages();
                        rtbMessages.Text += "You loot " + inventoryItem.Quantity.ToString() + " " + inventoryItem.Details.Name + Environment.NewLine;
                    }
                    else
                    {
                        ScrollToBottomOfMessages();
                        rtbMessages.Text += "You loot " + inventoryItem.Quantity.ToString() + inventoryItem.Details.NamePlural + Environment.NewLine;
                    }
                }


                //refresh player information and inventory controls
                UpdatePlayerStats();


                UpdateInventoryListInUI();
                UpdateWeaponsListInUI();
                UpdatePotionListInUI();

                _currentMonster = null;
            }
            else
            {
                //monster is still alive

                //determine the amount of damage the monster does to the player
                int damageToPlayer = RandomNumberGenerator.NumberBetween(1, _currentMonster.MaximumDamage);

                //display message
                ScrollToBottomOfMessages();
                rtbMessages.Text += "The " + _currentMonster.Name + " did " + damageToPlayer.ToString() + " points of damage." + Environment.NewLine;

                //subtract damage from player 
                _player.CurrentHitPoints -= damageToPlayer;

                //refresh player data in UI
                lblHitPoints.Text = _player.CurrentHitPoints.ToString();

                if (_player.CurrentHitPoints <= 0)
                {
                    ScrollToBottomOfMessages();
                    rtbMessages.Text += "The " + _currentMonster.Name + " killed you." + Environment.NewLine;

                    ResetByDeath();
                }
            }
        }

        private void btnUsePotion_Click(object sender, EventArgs e)
        {
            //get the currently selected potion from the combobox
            HealingPotion potion = (HealingPotion)cboPotions.SelectedItem;

            //Add healing amount to the player's current hit points
            _player.CurrentHitPoints += potion.AmountToHeal;

            //current hit points cannot exceed player's max hit points
            if (_player.CurrentHitPoints > _player.MaximumHitPoints)
            {
                _player.CurrentHitPoints = _player.MaximumHitPoints;
            }

            //remove the potion from the player's inventory
            foreach (InventoryItem ii in _player.Inventory)
            {
                if (ii.Details.ID == potion.ID)
                {
                    ii.Quantity--;
                    break;
                }
            }
            //display message
            ScrollToBottomOfMessages();
            rtbMessages.Text += "You drink a " + potion.Name + " that replenishes " + potion.AmountToHeal.ToString() + " hit points." + Environment.NewLine;

            if (_currentMonster != null)
            {
                //monster gets their turn to attack

                //determine the amount of damage the monster does to the player
                int damageToPlayer = RandomNumberGenerator.NumberBetween(0, _currentMonster.MaximumDamage);

                //display message
                ScrollToBottomOfMessages();
                rtbMessages.Text += "The " + _currentMonster.Name + " did " + damageToPlayer.ToString() + " points of damage." + Environment.NewLine;

                //subtract damage from player 
                _player.CurrentHitPoints -= damageToPlayer;

                if (_player.CurrentHitPoints <= 0)
                {
                    ScrollToBottomOfMessages();
                    rtbMessages.Text += "The " + _currentMonster.Name + " killed you." + Environment.NewLine;

                    ResetByDeath();

                }
            }

            //refresh player data in UI
            lblHitPoints.Text = _player.CurrentHitPoints.ToString();
            UpdateInventoryListInUI();
            UpdatePotionListInUI();
        }

        public void ResetByDeath()
            
        {
            List<PlayerQuest> previousQuests = _player.Quests;
            List<InventoryItem> previousInventory = _player.Inventory;
            List<InventoryItem> itemsToEnterPlaces = new List<InventoryItem>();
            
            foreach (InventoryItem ii in previousInventory)
            {
               foreach (Location location in World.Locations)
                { 
                   if(location.ItemRequiredToEnter != null)
                    {
                        if(ii.Details == location.ItemRequiredToEnter)
                        {
                            itemsToEnterPlaces.Add(ii); //stores items that are required to enter locations
                        }
                    }
                }
            }

            _player = new Player(_player.CurrentHitPoints, _player.MaximumHitPoints, 20, _player.ExperiencePoints);
            _player.CurrentHitPoints = _player.MaximumHitPoints;
            _player.Inventory.Add(new InventoryItem(World.ItemByID(World.ITEM_ID_RUSTY_SWORD), 1));
            _player.Inventory.Add(new InventoryItem(World.ItemByID(World.ITEM_ID_HEALING_POTION), 1));


            foreach(InventoryItem item in itemsToEnterPlaces)
            {
                _player.Inventory.Add(item); //keeps only items that are required to enter places
            }


            _player.Quests = previousQuests; //keeps quest list and quests done when you die

            UpdateInventoryListInUI();
            UpdatePotionListInUI();
            UpdateQuestListInUI();

            MoveTo(World.LocationByID(World.LOCATION_ID_HOME));

            UpdatePlayerStats();


            ScrollToBottomOfMessages();
            rtbMessages.Text += Environment.NewLine + Environment.NewLine + Environment.NewLine;
        }

        private void ScrollToBottomOfMessages()
        {
            rtbMessages.SelectionStart = rtbMessages.Text.Length;
            rtbMessages.ScrollToCaret();
        }
    }
}