Inventory System

local inventoryDB = db:Collection("inventories")

-- Create indexes (sync is fine for initialization)
inventoryDB:CreateIndex({ steamid = 1 }, true, "steamid_unique")

function InitInventory(steamid, callback)
    inventoryDB:InsertOneAsync({
        steamid = steamid,
        max_slots = 20,
        items = {},
        created_at = os.time()
    }, function(err, id)
        if err then
            ErrorNoHalt("Failed to create inventory: " .. err .. "\n")
            if callback then callback(false) end
            return
        end
        
        print("✓ Created inventory for " .. steamid)
        if callback then callback(true, id) end
    end)
end

function AddItem(steamid, itemId, quantity, callback)
    -- First check if item already exists
    inventoryDB:FindOneAsync({
        steamid = steamid,
        ["items.item_id"] = itemId
    }, function(err, has)
        if err then
            ErrorNoHalt("Failed to check inventory: " .. err .. "\n")
            if callback then callback(false, "Database error") end
            return
        end
        
        if has then
            -- Item exists - increment quantity
            inventoryDB:UpdateOneAsync(
                {
                    steamid = steamid,
                    ["items.item_id"] = itemId
                },
                {
                    ["$inc"] = { ["items.$.quantity"] = quantity }
                },
                false,
                function(err, count)
                    if err then
                        ErrorNoHalt("Failed to add item: " .. err .. "\n")
                        if callback then callback(false, "Update failed") end
                    elseif count > 0 then
                        print("✓ Added " .. quantity .. "x " .. itemId)
                        if callback then callback(true, "updated") end
                    end
                end
            )
        else
            -- New item - add to array
            inventoryDB:UpdateOneAsync(
                { steamid = steamid },
                {
                    ["$push"] = {
                        items = {
                            item_id = itemId,
                            quantity = quantity,
                            added_at = os.time()
                        }
                    }
                },
                false,
                function(err, count)
                    if err then
                        ErrorNoHalt("Failed to add item: " .. err .. "\n")
                        if callback then callback(false, "Insert failed") end
                    elseif count > 0 then
                        print("✓ Added new item " .. itemId .. " x" .. quantity)
                        if callback then callback(true, "added") end
                    end
                end
            )
        end
    end)
end

function RemoveItem(steamid, itemId, quantity, callback)
    -- First get the current inventory
    inventoryDB:FindOneAsync({ steamid = steamid }, function(err, inv)
        if err then
            ErrorNoHalt("Failed to get inventory: " .. err .. "\n")
            if callback then callback(false, "Database error") end
            return
        end
        
        if not inv then
            if callback then callback(false, "Inventory not found") end
            return
        end
        
        -- Find current quantity
        local currentQty = 0
        for _, item in ipairs(inv.items or {}) do
            if item.item_id == itemId then
                currentQty = item.quantity
                break
            end
        end
        
        if currentQty < quantity then
            if callback then callback(false, "Insufficient quantity") end
            return
        end
        
        if currentQty == quantity then
            -- Remove item completely
            inventoryDB:UpdateOneAsync(
                { steamid = steamid },
                { ["$pull"] = { items = { item_id = itemId } } },
                false,
                function(err, count)
                    if err then
                        ErrorNoHalt("Failed to remove item: " .. err .. "\n")
                        if callback then callback(false, "Remove failed") end
                    elseif count > 0 then
                        print("✓ Removed " .. itemId .. " from inventory")
                        if callback then callback(true, "removed") end
                    end
                end
            )
        else
            -- Decrease quantity
            inventoryDB:UpdateOneAsync(
                {
                    steamid = steamid,
                    ["items.item_id"] = itemId
                },
                { ["$inc"] = { ["items.$.quantity"] = -quantity } },
                false,
                function(err, count)
                    if err then
                        ErrorNoHalt("Failed to update quantity: " .. err .. "\n")
                        if callback then callback(false, "Update failed") end
                    elseif count > 0 then
                        print("✓ Removed " .. quantity .. "x " .. itemId)
                        if callback then callback(true, "decreased") end
                    end
                end
            )
        end
    end)
end

function GetInventory(steamid, callback)
    inventoryDB:FindOneAsync({ steamid = steamid }, function(err, inv)
        if err then
            ErrorNoHalt("Failed to get inventory: " .. err .. "\n")
            callback(nil, err)
            return
        end
        
        callback(inv)
    end)
end

function HasItem(steamid, itemId, minQuantity, callback)
    GetInventory(steamid, function(inv, err)
        if err or not inv then
            callback(false)
            return
        end
        
        for _, item in ipairs(inv.items or {}) do
            if item.item_id == itemId then
                callback(item.quantity >= minQuantity, item.quantity)
                return
            end
        end
        
        callback(false, 0)
    end)
end

-- Complete example with async operations
function PurchaseItem(ply, itemId, quantity, cost)
    local steamid = ply:SteamID()
    
    -- Step 1: Check if player has enough credits
    playersDB:FindOneAsync({ steamid = steamid }, function(err, playerData)
        if err or not playerData then
            ply:ChatPrint("Error loading player data!")
            return
        end
        
        local credits = playerData.credits or 0
        if credits < cost then
            ply:ChatPrint("Insufficient credits! Need " .. cost .. ", have " .. credits)
            return
        end
        
        -- Step 2: Deduct credits
        playersDB:UpdateOneAsync(
            { steamid = steamid },
            { ["$inc"] = { credits = -cost } },
            false,
            function(err, count)
                if err or count == 0 then
                    ply:ChatPrint("Failed to deduct credits!")
                    return
                end
                
                -- Step 3: Add item to inventory
                AddItem(steamid, itemId, quantity, function(success, msg)
                    if success then
                        ply:ChatPrint("Successfully purchased " .. quantity .. "x " .. itemId .. "!")
                        ply:SetNWInt("Credits", credits - cost)
                    else
                        -- Refund credits on failure
                        playersDB:UpdateOneAsync(
                            { steamid = steamid },
                            { ["$inc"] = { credits = cost } }
                        )
                        ply:ChatPrint("Purchase failed: " .. msg)
                    end
                end)
            end
        )
    end)
end

concommand.Add("inventory", function(ply)
    if not IsValid(ply) then return end
    
    GetInventory(ply:SteamID(), function(inv, err)
        if err then
            ply:ChatPrint("Error loading inventory!")
            return
        end
        
        if not inv or not inv.items or #inv.items == 0 then
            ply:ChatPrint("Your inventory is empty!")
            return
        end
        
        ply:ChatPrint("=== Your Inventory ===")
        ply:ChatPrint("Slots: " .. #inv.items .. "/" .. inv.max_slots)
        
        for i, item in ipairs(inv.items) do
            ply:ChatPrint(string.format("%d. %s x%d", i, item.item_id, item.quantity))
        end
    end)
end)