PIM Shop

local fName = "trades"
local nameLength = 12
local chestSide = "down"
local expireDays = math.huge

local mon = peripheral.find("monitor")
mon.setBackgroundColor(colors.black)
mon.clear()
local pim = peripheral.find("pim")

local chestInv = {}
local deals = {}
local saveData = {deals=deals,chestInv=chestInv}
local buttons = {}
local players = {}
local curPl

-- offer=Item,price=Item,owner=uuid,startDay=number,
-- Item has display_name, dmg, max_dmg,qty, max_size, id
if fs.exists(fName) then
  local f = fs.open(fName,"r")
  saveData = textutils.unserialize(f.readAll())
  deals = saveData.deals
  chestInv = saveData.chestInv
  f.close()
end

local function save()
  local f = fs.open(fName,"w")
  f.write(textutils.serialize(saveData))
  f.close()
end


local pInv = {}
local invSlots
local function loadInventory()
  pInv = {}
  invSlots = pim.getAllStacks()
  for i,k in pairs(invSlots) do
    local j=k.basic()
    if pInv[j.id] and pInv[j.id][j.dmg] then
      local t = pInv[j.id][j.dmg]
      table.insert(t.slots,i)
      t.qty = t.qty + j.qty
    else
      pInv[j.id] = pInv[j.id] or {}
      pInv[j.id][j.dmg] = j
      j.slots = {i}
    end
  end
end

local function writeItem(I,x,y)
  mon.setCursorPos(x,y)
  mon.write(string.format("%2d %s",math.floor(I.qty),(I.display_name..(" "):rep(nameLength)):sub(1,nameLength)))
  mon.setCursorPos(x,y+1)
  mon.write(string.format("%s%3d",string.rep(" ",nameLength),I.stored))
end

local function addButton(d,x,y,revs,name)
  mon.setCursorPos(x,y)
  mon.write(name)
  table.insert(buttons,{xmin=x,xmax=x+#name,y=y,deal=d,reversed=revs,name=name})
end

local function addButtons(d,x,y,revs)
  addButton(d,x,y,revs,"1")
  addButton(d,x+2,y,revs,"1/2")
  addButton(d,x+6,y,revs,"all")
end

local function hasItem(i,n)
  return pInv[i.id] and pInv[i.id][i.dmg] and pInv[i.id][i.dmg].qty >= n
end

local function amount(i)
  return pInv[i.id] and pInv[i.id][i.dmg] and pInv[i.id][i.dmg].qty or 0
end

local function drawDeal(d,x,y)
  local bc = colors.gray
  if d.owner == curPl.uuid then
    if d.offer.stored < d.offer.qty then
      bc = colors.red
    else
      bc = colors.blue
    end
  elseif hasItem(d.price,d.price.qty) then
    bc = colors.green
  end
  mon.setBackgroundColor(bc)
  writeItem(d.offer,x,y)
  mon.setCursorPos(x+nameLength+3,y)
  mon.write(" for ")
  mon.setCursorPos(x+nameLength+3,y+1)
  mon.write("     ")
  writeItem(d.price,x+nameLength+8,y)
  mon.setBackgroundColor(colors.orange)
  if d.owner == curPl.uuid then
    addButton(d,x,y+1,nil,"refill")
    addButton(d,x+7,y+1,nil,"delete")
    if d.price.stored > 0 then
      addButton(d,x+14,y+1,nil,"take")
    end
  else
    addButtons(d,x,y+1,false)
    if d.reversable then
      addButtons(d,x+nameLength+8,y+1,true)
    end
  end
end

local function updateMonitor()
  mon.setCursorPos(1,1)
  mon.setBackgroundColor(colors.black)
  mon.write("Player: "..curPl.name..string.rep(" ",nameLength))
  buttons = {}
  local dNum = 1
  local mx,my = mon.getSize()
  for j=3,my,3 do
    for i=1,mx - 2*nameLength-11 ,2*nameLength+12 do
      if deals[dNum] then
        drawDeal(deals[dNum],i,j)
        dNum = dNum + 1
      else
        mon.setBackgroundColor(colors.orange)
        addButton(nil,i,j,nil,"New Trade")
        return
      end
    end
  end
end

local function updatePlayer()
  if #players == 1 then
    curPl = players[1]
    loadInventory()
  else
    curPl = {name=""}
    pInv = {}
  end
  updateMonitor()
end
updatePlayer()

local function copy(t)
  local r = {}
  for i,j in pairs(t) do
    if type(j) == "table" then
      r[i] = copy(j)
    else
      r[i] = j
    end
  end
  return r
end

local function store(I,n)
  local rem = n
  if hasItem(I,n) then
    local s = pInv[I.id][I.dmg].slots
    local si = #s
    local sc = 1
    while rem > 0 do
      local qty = invSlots[s[si]].basic().qty
      local k = chestInv[sc]
      while k and (k.id ~= I.id or k.dmg ~= I.dmg or k.max_size <= k.qty) do
        sc = sc + 1
        k = chestInv[sc]
      end
      local restSpace = k and k.max_size-k.qty or math.huge
      local put = pim.pushItem(chestSide,s[si],math.min(rem,qty,restSpace),sc)
      qty = qty - put
      rem = rem - put
      if k then
        k.qty = k.qty + put
      else
        chestInv[sc] = copy(I)
      end
      if qty == 0 then
        si = si - 1
        if si == 0 and rem > 0 then
          I.stored = I.stored+(n-rem)
          return false, n-rem
        end
      end
    end
    I.stored = I.stored+n
    return true,n
  end
  return false,0
end

local function giveOut(I,n)
  local rem = n
  local sc = #chestInv
  while rem > 0 do
    local k = chestInv[sc]
    while not k or k.id ~= I.id or k.dmg ~= I.dmg do
      sc = sc - 1
      if sc <= 0 then
        I.stored = I.stored-(n-rem)
        return false,n-rem
      end
      k = chestInv[sc]
    end
    local put = pim.pullItem(chestSide,sc,math.min(rem,chestInv[sc].qty))
    rem = rem - put
    if k then
      k.qty = k.qty - put
      if k.qty == 0 then
        chestInv[sc] = nil
      end
    end
  end
  I.stored = I.stored-n
  return true,n
end

while true do
  local e = {os.pullEvent()}
  if e[1] == "player_on" then
    table.insert(players,{name=e[2],uuid=e[3]})
    updatePlayer()
  elseif e[1] == "player_off" then
    for i,j in ipairs(players) do
      if j.uuid == e[3] then
        table.remove(players,i)
        break
      end
    end
    updatePlayer()
  elseif e[1] == "monitor_touch" then
    for i,j in ipairs(buttons) do
      if e[3] >= j.xmin and e[3] <= j.xmax and e[4] == j.y then
        if j.name == "New Trade" then
          local slots = pim.getAllStacks()
          if slots[4] and slots[6] then
            local ofr = slots[4].basic()
            local pri = slots[6].basic()
            ofr.stored = 0
            pri.stored = 0
            table.insert(deals,{offer=ofr,price=pri,owner=curPl.uuid,reversable=slots[5] and true or false,startDay=os.day()})
            save()
            updateMonitor()
          end
        elseif j.name == "delete" then
          for k,l in ipairs(deals) do
            if l == j.deal then
              giveOut(l.price,l.price.stored)
              giveOut(l.offer,l.offer.stored)
              table.remove(deals,k)
              save()
              mon.setBackgroundColor(colors.black)
              mon.clear()
              updateMonitor()
              break
            end
          end
        elseif j.name == "refill" then
          loadInventory()
          local item = j.deal.offer
          store(item,amount(item))
          save()
          updateMonitor()
        elseif j.name == "take" then
          loadInventory()
          local item = j.deal.price
          if item.stored > 0 then
            giveOut(item,item.stored)
          end
          save()
          updateMonitor()
        elseif j.name == "1" or j.name == "1/2" or j.name == "all" then
          loadInventory()
          local pri = j.deal.price
          local ofr = j.deal.offer
          if j.reversed then
            pri,ofr = ofr,pri
          end
          local times = 1
          if  j.name == "1/2" then
            times = math.floor(amount(pri) / pri.qty / 2)
          elseif j.name == "all" then
            times = math.floor(amount(pri) / pri.qty)
          end
          local s,taken = store(pri,times * pri.qty)
          if s then
            local s2,given = giveOut(ofr,times * ofr.qty)
            if not s2 then --panic a little bit and try to undo
              loadInventory()
              store(ofr,times * ofr.qty)
              giveOut(pri,times * pri.qty)
              print("Failed to give "..ofr.display_name.. " to "..pim.getInventoryName())
            end
          else
            giveOut(pri,taken)
          end
          save()
          updateMonitor()
        else
          error("Invalid Button press")
        end
      end
    end
  end
end