Load on Join

local Players = game:GetService("Players")
local ServerStorage = game:GetService("ServerStorage")
local RunService = game:GetService("RunService")
local DataStoreService = game:GetService("DataStoreService")
local Settings = require(game.ReplicatedStorage.Settings)

local remotes = game.ReplicatedStorage.Remotes
local piles = workspace.Piles
local petParts = workspace.PetParts
local saveStore = DataStoreService:GetDataStore("Pets")
local pileSpot = {} -- each pile -> the spot it stands on
local lastHit = {} -- each player -> when they last hit

print("A Meadow pile gives " .. Settings.PileValue .. " coins")

-- Settings.Pets by name
local petInfo = {}
for _, info in Settings.Pets do
	petInfo[info.Name] = info
end

-- A pet: a StringValue in the player's Pets folder holding its name, with
-- its rarity and power as attributes
local function givePet(player, name, equipped)
	local info = petInfo[name]
	local pet = Instance.new("StringValue")
	pet.Name = "Pet"
	pet.Value = name
	pet:SetAttribute("Rarity", info.Rarity)
	pet:SetAttribute("Power", info.Power)
	pet:SetAttribute("Equipped", equipped)
	pet.Parent = player.Pets
	return pet
end

-- how many pets a player has out
local function equippedCount(player)
	local count = 0
	for _, pet in player.Pets:GetChildren() do
		if pet:GetAttribute("Equipped") then
			count += 1
		end
	end
	return count
end

-- what a player's pets add to each hit
local function petPower(player)
	local power = 0
	for _, pet in player.Pets:GetChildren() do
		if pet:GetAttribute("Equipped") then
			power += pet:GetAttribute("Power")
		end
	end
	return power
end

-- Every player gets Coins on the leaderboard
Players.PlayerAdded:Connect(function(player)
	local leaderstats = Instance.new("Folder")
	leaderstats.Name = "leaderstats"
	leaderstats.Parent = player

	local coins = Instance.new("IntValue")
	coins.Name = "Coins"
	coins.Parent = leaderstats

	-- the pets they own
	local pets = Instance.new("Folder")
	pets.Name = "Pets"
	pets.Parent = player
	-- Lesson 20: Load on Join goes here
end)

-- A coin pile on a spot: a copy of ServerStorage.CoinPile with its health
-- and value as attributes
local function spawnPile(spot)
	local desert = spot.Parent.Parent.Name == "Desert"
	local health = desert and Settings.DesertHealth or Settings.PileHealth
	local pile = ServerStorage.CoinPile:Clone()
	pile.Position = spot.Position
	pile:SetAttribute("MaxHealth", health)
	pile:SetAttribute("Health", health)
	pile:SetAttribute("Value", desert and Settings.DesertValue or Settings.PileValue)
	pile:SetAttribute("Zone", spot.Parent.Parent.Name)
	pile.HealthGui.Label.Text = pile:GetAttribute("Health") .. "/" .. pile:GetAttribute("MaxHealth")
	pileSpot[pile] = spot
	pile.Parent = piles
	return pile
end

-- A hit takes 1, plus the power of the player's pets, off a pile's health;
-- at 0 the pile breaks and pays its value
local function hitPile(player, pile)
	local health = pile:GetAttribute("Health") - (1 + petPower(player))
	if health > 0 then
		pile:SetAttribute("Health", health)
		pile.HealthGui.Label.Text = health .. "/" .. pile:GetAttribute("MaxHealth")
		return
	end
	player.leaderstats.Coins.Value += pile:GetAttribute("Value")
	local spot = pileSpot[pile]
	pileSpot[pile] = nil
	pile:Destroy()
	-- a new pile on the same spot, a few seconds later
	task.delay(Settings.RespawnTime, spawnPile, spot)
end

-- A pile on every spot, in every zone
for _, zone in workspace.Zones:GetChildren() do
	for _, spot in zone.Spawns:GetChildren() do
		spawnPile(spot)
	end
end

-- The client asks to hit a pile. Never trust the client: anyone can fire
-- this remote with anything, from anywhere, as fast as they like.
remotes.Hit.OnServerEvent:Connect(function(player, pile)
	-- a real pile
	if typeof(pile) ~= "Instance" or pile.Parent ~= piles then
		return
	end
	-- in reach
	local character = player.Character
	local root = character and character:FindFirstChild("HumanoidRootPart")
	if not root or (root.Position - pile.Position).Magnitude > Settings.Reach then
		return
	end
	-- not too fast
	local now = time()
	if lastHit[player] and now - lastHit[player] < Settings.HitCooldown then
		return
	end
	lastHit[player] = now
	-- in a zone the player has opened
	if pile:GetAttribute("Zone") == "Desert" and not player:GetAttribute("Desert") then
		return
	end
	hitPile(player, pile)
end)

-- A weighted roll: each pet's Chance (out of 100) is its share of the line
local function rollPet()
	local roll = math.random() * 100
	for _, info in Settings.Pets do
		roll -= info.Chance
		if roll <= 0 then
			return info.Name
		end
	end
	return Settings.Pets[1].Name
end

-- Hatching: the egg's prompt, paid for in coins
workspace.Egg.ProximityPrompt.Triggered:Connect(function(player)
	local coins = player.leaderstats.Coins
	if coins.Value < Settings.EggPrice then
		return
	end
	coins.Value -= Settings.EggPrice
	local name = rollPet()
	-- out at once, if there is room
	local pet = givePet(player, name, equippedCount(player) < Settings.MaxEquipped)
	print(player.Name .. " hatched a " .. name)
	-- everyone hears about the rarest pets
	if pet:GetAttribute("Rarity") == "Legendary" then
		remotes.Announce:FireAllClients(player.Name, name)
	end
end)

-- Pets out follow their owner: each one has a part in the world, kept
-- in a row behind the player every frame
local petModels = {} -- each pet -> its part in the world
RunService.Heartbeat:Connect(function()
	for _, player in Players:GetPlayers() do
		local root = player.Character and player.Character:FindFirstChild("HumanoidRootPart")
		local pets = player:FindFirstChild("Pets")
		local slot = 0
		for _, pet in pets and pets:GetChildren() or {} do
			local model = petModels[pet]
			if pet:GetAttribute("Equipped") and root then
				slot += 1
				if not model then
					model = ServerStorage.PetModels[pet.Value]:Clone()
					model.Parent = petParts
					petModels[pet] = model
				end
				model.CFrame = root.CFrame * CFrame.new((slot - 2) * 3, -1.5, 4)
			elseif model then
				-- put away: its part goes
				model:Destroy()
				petModels[pet] = nil
			end
		end
	end
end)

-- The client asks to put a pet out or away. The server checks: the pet is
-- the player's own, and no more than MaxEquipped are out.
remotes.Equip.OnServerEvent:Connect(function(player, pet)
	if typeof(pet) ~= "Instance" or pet.Parent ~= player.Pets then
		return
	end
	if pet:GetAttribute("Equipped") then
		pet:SetAttribute("Equipped", false)
	elseif equippedCount(player) < Settings.MaxEquipped then
		pet:SetAttribute("Equipped", true)
	end
end)

-- The Desert gate: pay once and it opens, for that player only
workspace.Gate.ProximityPrompt.Triggered:Connect(function(player)
	local coins = player.leaderstats.Coins
	if player:GetAttribute("Desert") or coins.Value < Settings.GatePrice then
		return
	end
	coins.Value -= Settings.GatePrice
	player:SetAttribute("Desert", true)
end)

-- Saving: Coins, the Desert, and every pet
local function save(player)
	local pets = {}
	for _, pet in player.Pets:GetChildren() do
		table.insert(pets, { Name = pet.Value, Equipped = pet:GetAttribute("Equipped") == true })
	end
	local data = {
		Coins = player.leaderstats.Coins.Value,
		Desert = player:GetAttribute("Desert") == true,
		Pets = pets,
	}
	pcall(function()
		saveStore:SetAsync(player.UserId, data)
	end)
end

Players.PlayerRemoving:Connect(save)

game:BindToClose(function()
	for _, player in Players:GetPlayers() do
		save(player)
	end
end)