sethmc atm turtle

-- Turtle ATM Script (turtle_atm.lua) with Gold Standard Validation
-- Secure Transaction Logic: Acquire -> Verify -> Server -> Commit/Revert

local modem = peripheral.find("modem")
if not modem then error("No modem found") end
modem.open(1)  -- Open channel 1 for communication with server
modem.open(2)  -- Open channel 2 for communication with ATM terminal

local function debug(message)
    print(os.date("%H:%M:%S") .. ": " .. message)
end

local function sendToServer(message)
    modem.transmit(1, 1, message)
    local timer = os.startTimer(5)
    while true do
        local event, id, channel, replyChannel, response = os.pullEvent()
        if event == "modem_message" and channel == 1 then
            return response
        elseif event == "timer" and id == timer then
            return nil
        end
    end
end

local function sendToATM(message)
    modem.transmit(2, 2, message)
end

local function findBlock(blockType)
    for i = 1, 4 do
        local success, data = turtle.inspect()
        if success and data.name:find(blockType) then
            return true
        end
        turtle.turnRight()
    end
    return false
end

local function isGold(item)
    return item and item.name == "minecraft:gold_ingot"
end

-- Helper to dump specific item type to front
local function dumpItems(itemCheckFn)
    for i = 1, 16 do
        local item = turtle.getItemDetail(i)
        if item and itemCheckFn(item) then
            turtle.select(i)
            turtle.drop()
        end
    end
    turtle.select(1)
end

-- Securely acquire X gold from front inventory (Barrel or Chest)
-- Keeps gold in turtle inventory. Returns success, message.
-- If targetAmount is "max", grabs everything valid.
local function acquireGold(targetAmount)
    local acquired = 0
    local isMax = (targetAmount == "max")

    while true do
        local needed = 64
        if not isMax then
            needed = targetAmount - acquired
            if needed > 64 then needed = 64 end
            if needed <= 0 then break end
        end

        -- Try to suck needed amount
        if turtle.suck(needed) then
            -- Verify what we just sucked
            local foundInvalid = false
            for i = 1, 16 do
                local item = turtle.getItemDetail(i)
                if item and not isGold(item) then
                    -- Junk item, spit it back
                    turtle.select(i)
                    turtle.drop()
                    turtle.select(1)
                    foundInvalid = true
                end
            end

            if foundInvalid and not isMax then
                 -- If we found invalid items during a specific request, we might want to fail or just retry?
                 -- simple retry logic: just continue loop, we counted valid ones below
            end

            -- Recount total gold in inventory to update progress
            local currentTotal = 0
            for i = 1, 16 do
                local item = turtle.getItemDetail(i)
                if item and isGold(item) then
                    currentTotal = currentTotal + item.count
                end
            end

            -- If we haven't increased, break (empty source)
            if currentTotal <= acquired then
                 break
            end
            acquired = currentTotal
        else
            break -- Sucking failed (empty)
        end
    end

    if isMax then
        if acquired > 0 then
            return true, acquired
        else
            return false, "No Gold Found"
        end
    else
        if acquired >= targetAmount then
             return true, acquired
        else
             return false, "Insufficient Gold: Found " .. acquired .. " of " .. targetAmount
        end
    end
end

-- Dumps ALL gold in inventory to front
local function commitGold()
    dumpItems(isGold)
end

local function handleDeposit(studentId, password, amount)
    local isMax = (amount == "max")
    local targetGold = 0
    if not isMax then
        targetGold = amount * 16
    end

    if isMax then
        debug("Deposit: MAX Eddies")
    else
        debug("Deposit: " .. amount .. " Eddies (" .. targetGold .. " Gold)")
    end

    if not findBlock("barrel") then
        sendToATM({action="complete", success=false, error="Barrel not found"})
        return
    end

    -- 1. Acquire from Barrel
    local success, result = acquireGold(isMax and "max" or targetGold)
    if not success then
        sendToATM({action="complete", success=false, error=result or "Failed to collect gold"})
        -- Refund what we grabbed back to Barrel
        commitGold()
        return
    end

    local totalGold = result
    local eddies = math.floor(totalGold / 16)
    local remainder = totalGold % 16

    if eddies <= 0 then
         sendToATM({action="complete", success=false, error="Not enough gold for 1 Eddie (Need 16)"})
         commitGold()
         return
    end

    -- 2. Server Update
    local response = sendToServer({type="update_balance", studentId=studentId, password=password, action="deposit", amount=eddies})

    if response and response.type == "balance_update_response" and response.success then
        -- 3. Success: Move processed gold to Chest, remainder to Barrel

        -- We need to separate the gold.
        -- Drop 'remainder' to Barrel first
        if remainder > 0 then
            -- We need to drop exactly 'remainder' amount.
            -- This is tricky because we have stacks.
            -- Logic: Select stacks, drop until remainder is gone.
            local dropped = 0
            for i = 1, 16 do
                local item = turtle.getItemDetail(i)
                if item and isGold(item) then
                    local toDrop = math.min(remainder - dropped, item.count)
                    if toDrop > 0 then
                        turtle.select(i)
                        turtle.drop(toDrop)
                        dropped = dropped + toDrop
                    end
                    if dropped >= remainder then break end
                end
            end
            turtle.select(1)
        end

        -- Now find chest and dump the rest (which should be exactly eddies * 16)
        if findBlock("chest") then
            commitGold() -- Dump valid gold to chest
            sendToATM({action="complete", success=true, newBalance=response.result, amountDeposited=eddies, remainder=remainder})
        else
            -- Critical Error: Chest missing after transaction!
            debug("CRITICAL: Chest missing during deposit commit!")
             -- Attempt to return to barrel to be safe
            if findBlock("barrel") then
                 commitGold()
                 sendToATM({action="complete", success=true, newBalance=response.result, warning="System Error: Chest full/missing. Gold returned to barrel but balance updated. Contact Admin.", amountDeposited=eddies, remainder=remainder})
            else
                 sendToATM({action="complete", success=true, newBalance=response.result, warning="System Error: Gold stuck in Turtle.", amountDeposited=eddies, remainder=remainder})
            end
        end
    else
        -- 4. Fail: Refund to Barrel
        debug("Server deposit failed: " .. (response and response.message or "Timeout"))
        if findBlock("barrel") then
            commitGold() -- Dump back to barrel
        end
        sendToATM({action="complete", success=false, error="Server rejected deposit"})
    end
end

local function handleWithdraw(studentId, password, amount)
    local goldAmount = amount * 16
    debug("Withdraw: " .. amount .. " Eddies (" .. goldAmount .. " Gold)")

    -- 0. Check Balance First (Quick fail)
    local balanceResponse = sendToServer({type="get_balance", studentId=studentId, password=password})
    if not (balanceResponse and balanceResponse.type == "balance_response") then
        sendToATM({action="complete", success=false, error="Failed to retrieve balance"})
        return
    end
    if tonumber(balanceResponse.balance) < amount then
        sendToATM({action="complete", success=false, error="Insufficient balance"})
        return
    end

    if not findBlock("chest") then
        sendToATM({action="complete", success=false, error="Chest not found"})
        return
    end

    -- 1. Acquire from Chest
    local success, msg = acquireGold(goldAmount)
    if not success then
        sendToATM({action="complete", success=false, error=msg or "ATM empty/low funds"})
        -- Revert to Chest
        commitGold()
        return
    end

    -- 2. Server Update
    local response = sendToServer({type="update_balance", studentId=studentId, password=password, action="withdraw", amount=amount})

    if response and response.type == "balance_update_response" and response.success then
        -- 3. Success: Move to Barrel
        if findBlock("barrel") then
            commitGold() -- Dump to barrel
            sendToATM({action="complete", success=true, newBalance=response.result})
        else
            debug("CRITICAL: Barrel missing during withdraw commit!")
            -- Refund to Chest? But user already paid on server.
            -- This is a 'money lost' scenario for user if we refund.
            -- Better to keep trying or dump?
            -- In production, we'd log this. Here, we return to Chest to save the gold and error out.
            -- User loses balance but ATM keeps gold. Admin intervention needed.
            commitGold()
            sendToATM({action="complete", success=false, error="Hardware error: Barrel missing. Gold retained in ATM. Contact Admin."})
        end
    else
        -- 4. Fail: Revert to Chest
        commitGold()
        sendToATM({action="complete", success=false, error="Server rejected withdraw"})
    end
end

while true do
    local event, side, channel, replyChannel, message = os.pullEvent("modem_message")
    if channel == 2 then
        if message.action == "deposit" then
            handleDeposit(message.studentId, message.password, message.amount)
        elseif message.action == "withdraw" then
            handleWithdraw(message.studentId, message.password, message.amount)
        end
    end
end