local ProfileService = require(game.ServerScriptService.ProfileService)

-----------------------------------------------------------
-- DataStore Configuration
-----------------------------------------------------------
local DataStoreName = "PlayerData_1" -- Change this name to reset all data

-- Default data template for new players.
-- If a player joins for the first time, their data will be initialized using these values.
local DataTemplate = {
    Coins = 0,                   -- Integer: Total coins the player has
    Loot = {},                   -- Dictionary: key = loot name, value = quantity
    Weapons = {"Bow"},           -- Array: List of weapon names the player owns (default: "Bow")
    Kills = 0,                   -- Integer: Total number of kills
    Equipped_Weapon = "Bow"      -- String: The weapon currently equipped (default: "Bow")
}

-----------------------------------------------------------
-- Global Variables
-----------------------------------------------------------
local Profiles = {} -- Table to store each player's loaded profile during gameplay

-- Create the ProfileStore using ProfileService.
-- This connects to the DataStore using the DataTemplate.
local ProfileStore = ProfileService.GetProfileStore(DataStoreName, DataTemplate)

-----------------------------------------------------------
-- Remote Setup for Live Data Updates
-----------------------------------------------------------
local ReplicatedStorage = game:GetService("ReplicatedStorage")
-- Get (or create) the Remotes folder in ReplicatedStorage.
local Remotes = ReplicatedStorage:FindFirstChild("Remotes") or Instance.new("Folder")
Remotes.Name = "Remotes"
Remotes.Parent = ReplicatedStorage

-- RemoteEvent to push live data updates to the client.
local UpdateEvent = Remotes:FindFirstChild("UpdatePlayerData") or Instance.new("RemoteEvent")
UpdateEvent.Name = "UpdatePlayerData"
UpdateEvent.Parent = Remotes

-- RemoteFunction to allow clients to fetch their data on startup.
local GetDataFunction = Remotes:FindFirstChild("GetPlayerData") or Instance.new("RemoteFunction")
GetDataFunction.Name = "GetPlayerData"
GetDataFunction.Parent = Remotes

-----------------------------------------------------------
-- DataManager Table
-----------------------------------------------------------
local DataManager = {}

-----------------------------------------------------------
-- Function: DataManager.SendUpdate
-- Description: Sends the current profile data to the specified player's client.
-- Parameters: player (Player) – the player whose data to update.
-----------------------------------------------------------
function DataManager.SendUpdate(player)
    local profile = Profiles[player]
    if profile then
        -- Fire the remote event with the player's current data table.
        UpdateEvent:FireClient(player, profile.Data)
    end
end

-----------------------------------------------------------
-- Function: DataManager.LoadData
-- Description: Loads a player's data using ProfileService when they join.
-- If the player has no previous data, it initializes with DataTemplate.
-- It also sets up a listener to kick the player if the profile is released.
-- Finally, if the player is still in-game, it stores their profile and sends an initial update.
-----------------------------------------------------------
function DataManager.LoadData(player)
    -- Attempt to load the player's profile from the DataStore using their UserId.
    local profile = ProfileStore:LoadProfileAsync("Player_" .. player.UserId)

    if profile then
        -- Link the profile to the player's UserId.
        profile:AddUserId(player.UserId)
        -- Reconcile the profile so any missing fields are filled using DataTemplate.
        profile:Reconcile()
        -- Listen for profile release (e.g. data error) and kick the player if it happens.
        profile:ListenToRelease(function()
            Profiles[player] = nil
            player:Kick("Data Error: Please rejoin!")
        end)

        -- Ensure every field defined in DataTemplate exists in profile.Data.
        for key, defaultValue in pairs(DataTemplate) do
            if profile.Data[key] == nil then
                profile.Data[key] = defaultValue
            end
        end

        --print("Data loaded for", player.Name, profile.Data)

        -- Only store the profile if the player is still in the game.
        if player:IsDescendantOf(game.Players) then
            Profiles[player] = profile
            -- Send the initial data update to the player's client.
            DataManager.SendUpdate(player)

            -- Immediately equip the weapon if the player's character already exists.
            if player.Character then
                -- Wait a short moment to ensure the Backpack is ready.
                local backpack = player:FindFirstChild("Backpack") or player:WaitForChild("Backpack")
                task.wait(0.5)
                DataManager.EquipWeapon(player, profile.Data.Equipped_Weapon)
            end

            -- Also listen for CharacterAdded to equip weapon on respawn.
            player.CharacterAdded:Connect(function(character)
                local backpack = player:FindFirstChild("Backpack") or player:WaitForChild("Backpack")
                task.wait(0.5) -- Small delay for smooth loading
                DataManager.EquipWeapon(player, profile.Data.Equipped_Weapon)
            end)
        else
            profile:Release()
        end
    else
        -- If profile fails to load, kick the player.
        player:Kick("Data failed to load. Try rejoining.")
    end
end

-----------------------------------------------------------
-- Function: DataManager.EquipWeapon
-- Description: Equips a weapon for the player by cloning the weapon tool from ReplicatedStorage.
-- It removes any existing weapon from the player's Backpack, then equips the new weapon.
-- Also updates the player's profile with the newly equipped weapon and sends a UI update.
-- Parameters:
--   player (Player): The player to equip the weapon.
--   weaponName (string): The name of the weapon to equip.
-----------------------------------------------------------
function DataManager.EquipWeapon(player, weaponName)
    -- Get the Weapons folder from ReplicatedStorage.
    local Weapons = ReplicatedStorage:FindFirstChild("Weapons")
    local profile = Profiles[player]
    if not Weapons then
        warn("Weapons folder missing in ReplicatedStorage!")
        return
    end

    -- Find the weapon tool by name.
    local clonedWeapon = Weapons:FindFirstChild(weaponName)
    -- Wait for the player's Backpack.
    local Backpack = player:WaitForChild("Backpack")
    local StarterGear = player:WaitForChild("StarterGear")
    if clonedWeapon and Backpack then
        -- Remove any existing weapon tools from the Backpack.
        for _, tool in ipairs(Backpack:GetChildren()) do
            if tool:IsA("Tool") then
                tool:Destroy()
            end
        end

        -- Also clear StarterGear to ensure consistency.
        for _, tool in ipairs(StarterGear:GetChildren()) do
            if tool:IsA("Tool") then
                tool:Destroy()
            end
        end

        -- Clone the weapon tool and parent it to the Backpack.
        local newWeapon = clonedWeapon:Clone()
        newWeapon.Parent = Backpack

        -- Clone for StarterGear as well.
        local starterGearWeapon = clonedWeapon:Clone()
        starterGearWeapon.Parent = StarterGear

        -- Update the player's profile with the newly equipped weapon.
        profile.Data.Equipped_Weapon = weaponName

        -- Send a live update to the client.
        DataManager.SendUpdate(player)
        -- Debug (optional): print("Equipped", weaponName, "to", player.Name)
    else
        warn("Could not equip weapon for", player.Name)
    end
end

-----------------------------------------------------------
-- RemoteFunction: GetDataFunction.OnServerInvoke
-- Description: When the client requests their data, this function waits until the player's profile is loaded
-- (with a maximum wait time) and then returns the stored data. If data isn’t available, it returns the default template.
-----------------------------------------------------------
function GetDataFunction.OnServerInvoke(player)
    local totalWait = 0
    while not Profiles[player] and totalWait < 5 do
        task.wait(0.2)
        totalWait = totalWait + 0.2
    end
    if not Profiles[player] then
        return DataTemplate
    end
    return Profiles[player].Data
end

-----------------------------------------------------------
-- Function: DataManager.SaveData
-- Description: Called when a player leaves. It releases their profile, which saves the data.
-----------------------------------------------------------
function DataManager.SaveData(player)
    local profile = Profiles[player]
    if profile then
        profile:Release()
    end
end

-----------------------------------------------------------
-- Update Methods for Player Data
-----------------------------------------------------------

-- Function: DataManager.UpdateStat
-- Updates a specific stat in the player's data, then sends a live update.
function DataManager.UpdateStat(player, stat, value)
    local profile = Profiles[player]
    if profile and profile.Data[stat] ~= nil then
        profile.Data[stat] = value
        DataManager.SendUpdate(player)
    end
end

-- Function: DataManager.AddLoot
-- Adds a specified amount of loot to the player's data if it is obtainable,
-- updates the player's profile, sends a live update, and triggers a GUI popup.
function DataManager.AddLoot(player, lootName, amount)
    local obtainableLoot = require(game.ServerScriptService.LootManager).GetObtainableLoot()
    local profile = Profiles[player]
    -- Only add loot if it's marked as obtainable.
    if profile and obtainableLoot[lootName] then
        profile.Data.Loot[lootName] = (profile.Data.Loot[lootName] or 0) + amount
        DataManager.SendUpdate(player)

        -- Trigger the loot popup GUI on the client.
        local ReplicatedStorage = game:GetService("ReplicatedStorage")
        local Remotes = ReplicatedStorage:WaitForChild("Remotes")
        local LootPopupEvent = Remotes:FindFirstChild("LootPopupEvent")
        if LootPopupEvent then
            LootPopupEvent:FireClient(player, lootName, amount)
        end
    end
end

-- Function: DataManager.RemoveLoot
-- Removes a specified amount of loot from the player's data if they have enough.
-- Returns true if successful; false otherwise.
function DataManager.RemoveLoot(player, lootName, amount)
    local profile = Profiles[player]
    if profile and profile.Data.Loot[lootName] and profile.Data.Loot[lootName] >= amount then
        profile.Data.Loot[lootName] = profile.Data.Loot[lootName] - amount
        if profile.Data.Loot[lootName] <= 0 then
            profile.Data.Loot[lootName] = nil
        end
        DataManager.SendUpdate(player)
        return true
    end
    return false
end

-- Function: DataManager.AddWeapon
-- Adds a weapon to the player's owned list (if they don't already own it) and sends an update.
function DataManager.AddWeapon(player, weaponName)
    local profile = Profiles[player]
    if profile and not table.find(profile.Data.Weapons, weaponName) then
        table.insert(profile.Data.Weapons, weaponName)
        DataManager.SendUpdate(player)
    end
end

-- Function: DataManager.AddCoins
-- Increments the player's coins by the given amount and sends an update.
function DataManager.AddCoins(player, amount)
    local profile = Profiles[player]
    if profile then
        profile.Data.Coins = profile.Data.Coins + amount
        DataManager.SendUpdate(player)
    end
end

-- Function: DataManager.RemoveCoins
-- Deducts coins from the player's data if they have enough.
-- Returns true if successful; false otherwise.
function DataManager.RemoveCoins(player, amount)
    local profile = Profiles[player]
    if profile and profile.Data.Coins >= amount then
        profile.Data.Coins = profile.Data.Coins - amount
        DataManager.SendUpdate(player)
        return true
    end
    return false
end

-- Function: DataManager.AddKill
-- Increments the player's kill count by one and sends an update.
function DataManager.AddKill(player)
    local profile = Profiles[player]
    if profile then
        profile.Data.Kills = profile.Data.Kills + 1
        DataManager.SendUpdate(player)
    end
end

-----------------------------------------------------------
-- Connect Player Events
-----------------------------------------------------------
game.Players.PlayerAdded:Connect(DataManager.LoadData)      -- Load data when a player joins
game.Players.PlayerRemoving:Connect(DataManager.SaveData)   -- Save data when a player leaves

-----------------------------------------------------------
-- Return the DataManager module
-----------------------------------------------------------
return DataManager