local reindexFreq = 1 -- Per minute (0.5 to index every 2 minutes, ...)

local indexUpdated = false
local items
local outputSlots
local item  -- User choice
local count -- User choice

local chests = { peripheral.find("inventory") }
for i, chest in ipairs(chests) do
  if peripheral.getName(chest) == settings.get("ccVault.outputInventory") then
    table.remove(chests, i)
    break
  end
end

-- Functions
local getOutputSize
local indexChests
local loadIndex
local getItemNames
local userInput
local indexRefresh
local storageLoop
local transfer

function getOutputSize()
  if peripheral.getType(settings.get("ccVault.outputInventory")) == "create:depot" then
    outputSlots = 1
  else
    outputSlots = peripheral.call(settings.get("ccVault.outputInventory"), "size")
  end
end

-- Function to populate the index
function indexChests()
  while true do
    local itemIndex = {}
    for _, chest in ipairs(chests) do
      for slot, item in pairs(chest.list()) do
        if not itemIndex[item.name] then
          itemIndex[item.name] = {}
        end
        table.insert(itemIndex[item.name], { chest = peripheral.getName(chest), slot = slot })
      end
    end

    if fs.exists(settings.get("ccVault.file")) then
      local db = fs.open(settings.get("ccVault.file"), "r")
      if not db then
        printError("Couldn't open index databse!")
      else
        if textutils.unserializeJSON(db.readAll()) == itemIndex then
          db.close()
        else
          db.close()
          db = fs.open(settings.get("ccVault.file"), "w")
          if not db then
            printError("Couldn't write index databse!")
          else
            db.write(textutils.serializeJSON(itemIndex))
            db.close()
            indexUpdated = true
          end
        end
      end
    else
      local db = fs.open(settings.get("ccVault.file"), "w")
      db = fs.open(settings.get("ccVault.file"), "w")
      if not db then
        printError("Couldn't write index databse!")
      else
        db.write(textutils.serializeJSON(itemIndex))
        db.close()
        indexUpdated = true
      end
    end

    sleep(60 / reindexFreq)
  end
end

function loadIndex()
  local itemIndex
  local db = fs.open(settings.get("ccVault.file"), "r")
  if not db then
    -- printError("Couldn't open DB file!\n" .. settings.get("ccVault.file"))
    print("Index file not found. It probably wasn't created yet.")
    local iCount = 0
    write("Waiting until indexing is finished")
    while not db do
      if iCount >= 3 then
        term.setCursorPos(term.getCursorPos[1], 1)
        write("Waiting until indexing is finished.")
        iCount = 0
      else
        write(".")
        iCount = iCount + 1
      end
      db = fs.open(settings.get("ccVault.file"), "r")
      sleep(5)
    end
  end

  itemIndex = textutils.unserializeJSON(db.readAll())
  db.close()
  term.clear()
  term.setCursorPos(1, 1)
  return itemIndex
end

function indexRefresh()
  sleep(60 / reindexFreq)
end

function storageLoop()
  local itemIndex = loadIndex()
  while true do
    if indexUpdated then
      itemIndex = loadIndex()
      indexUpdated = false
    end
    items = getItemNames(itemIndex)
    parallel.waitForAny(userInput, indexRefresh)
    if item then
      if count == 0 or not count then count = 64 end
      transfer(item, count, itemIndex)
      item = nil
      count = nil
    end
    sleep(2)
    term.clear()
    term.setCursorPos(1, 1)
  end
end

---@param tItem string
---@param maxCount integer
---@param itemIndex table
function transfer(tItem, maxCount, itemIndex)
  local transfered = 0
  -- Stored item info
  local exists = itemIndex[tItem] ~= nil
  if exists then
    exists = itemIndex[tItem][1]
  end
  if not exists then
    print("Item not found.\nTry to wait for index update.")
    return
  end

  local sItemInfo = peripheral.call(itemIndex[tItem][1]["chest"], "getItemDetail", itemIndex[tItem][1]["slot"])
  if not sItemInfo then
    print("Index is out of date!\nWait for index update to resolve this error.")
    return
  elseif sItemInfo.count <= 0 then
    print("Index is out of date!\nWait for index update to resolve this error.")
    return
  elseif not sItemInfo.count then
    print("Index is out of date!\nWait for index update to resolve this error.")
    return
  end

  while transfered < count do
    if not itemIndex[tItem][1] then
      if transfered > 0 then
        print("Not enough of `" .. tItem .. "` was found.\nTransfered only " .. transfered .. ".")
      end
      break
    end

    ---@type ccTweaked.peripheral.item
    local lastSlot = peripheral.call(settings.get("ccVault.outputInventory"), "getItemDetail", outputSlots)
    if lastSlot then
      if lastSlot.count > 0 then
        print("Output inventory is full!")
        return
      end
    end

    if sItemInfo.name == tItem then
      local moved = peripheral.call(itemIndex[tItem][1]["chest"], "pushItems", settings.get("ccVault.outputInventory"),
        itemIndex[tItem][1]["slot"],
        maxCount)
      if moved == sItemInfo.count then
        transfered = transfered + moved
        table.remove(itemIndex[tItem], 1)
      elseif moved == 0 then
        if peripheral.call(settings.get("ccVault.outputInventory"), "size") == transfered then
          print("Output inventory is full!")
          break
        else
          table.remove(itemIndex[tItem], 1)
        end
      elseif not moved then
        print("Item not found!")
        break
      else
        transfered = transfered + moved
      end
    else
      table.remove(itemIndex[tItem], 1)
    end
  end
end

---@param itemIndex table -- Index table of all the items
---@return table names Table of strings
function getItemNames(itemIndex)
  local names = {}
  for name, _ in pairs(itemIndex) do
    table.insert(names, name)
  end
  return names
end

---@param items table Table of all item names as strings
function userInput()
  local completion = require "cc.completion"
  local input = read(nil, nil, function(text) return completion.choice(text, items) end)
  if not input then item, count = nil, nil end
  input = input .. " "
  local parsedInput = {}
  for w in input:gmatch("(.-) ") do table.insert(parsedInput, w) end
  -- item, count = string.match(input, "([^%s]+) (%d+)")
  item = parsedInput[1]
  count = tonumber(parsedInput[2])
end

getOutputSize()
parallel.waitForAny(indexChests, storageLoop)