-- Refined Storage autocraft
--
-- Run the program with the pathname of the crafts' listing file
-- Crafts file (a craft per line): [item_name] [count]
-- File example: https://pastebin.com/zDrXzfSM
--
-- Created by Nyhillius

local event = require("event")
local io = require("io")
local sides = require("sides")
local term = require("term")
local component = require("component")
local rs = component.block_refinedstorage_interface

local args = { ... }
local paths = {}

-- Print contents of `tbl`, with indentation.
-- `indent` sets the initial level of indentation.
function tprint (tbl, indent)
  if not indent then indent = 0 end
  for k, v in pairs(tbl) do
    formatting = string.rep("  ", indent) .. k .. ": "
    if type(v) == "table" then
      print(formatting)
      tprint(v, indent+1)
    elseif type(v) == 'boolean' then
      print(formatting .. tostring(v))
    else
      print(formatting .. v)
    end
  end
end

-- Check if the file exist
local function file_exist(path)
  local file = io.open(path)

  if (not file) then
    print("[ERROR]: No such file: " .. path .. ".")
    return false
  end
  io.close(file)
  return true
end

-- Load and parse the file, return a table with all the item to craft.
local function load_file(path)
  local crafts = {}

  for line in io.lines(path) do
    local n, c, m = line:match "(%S+)%s+(%d+)%s*(%d*)"
    local l = n:match "(%u%S+)"
    local f = n:match("(%l+:%l+)")
    if m == "" then
        m = nil
    end

    table.insert(crafts, { name = f, label = l, count = c, fullName = n, damage = m })
  end
  return crafts
end

-- Check if a task have missing items.
local function is_missing_items(task)
  if (task.missing.n > 0) then
    return true
  end
  return false
end

-- Check if craft is already on the tasks' queue.
local function craft_is_on_tasks(craft, tasks)
  for i, task in ipairs(tasks) do
    if craft.name == task.stack.name then
      local missing_items = rs.getMissingItems(task.stack, task.quantity)
      for j, item in ipairs(missing_items) do
        print("[WARNING]: Missing " .. item.size .. " " .. item.name)
      end
      return true
    end
  end
  return false
end

-- Craft an item
function craft_item(craft, tasks)
  local toCraft = tonumber(craft.count)

  if (rs.hasPattern(craft)) then
    if (not craft_is_on_tasks(craft, tasks)) then
      local rsStack = rs.getItem(craft)

      if (rsStack) then
        toCraft = toCraft - rsStack.size
      end
      if (toCraft > 0) then
        rs.scheduleTask(craft, toCraft)
        print("Crafting " .. toCraft .. "x of " .. craft.name)
      end
    end
  else
    print("[WARNING]: Missing pattern for: " .. craft.fullName .. ".")
  end
end

-- Destroy item
function destroy_item(item)
  local rs_item = rs.getItem(item)
  local limit = tonumber(item.count)

  if (not rs_item) then
    return
  end
  while (rs_item.size > limit) do
    local dropped = rs.extractItem(rs_item, rs_item.size - limit, sides.down)

    rs_item.size = rs_item.size - dropped
    if (dropped < 1) then
      break
    end
  end
end

-- Check the args
if (#args > 0) then
  paths[1] = os.getenv("PWD") .. "/" .. args[1]
  if not file_exist(paths[1]) then
    return
  end
else
  print("[ERROR]: Filename is needed.")
  return
end
if (#args > 1) then
  paths[2] = os.getenv("PWD") .. "/" .. args[2]
  file_exist(paths[2])
end

-- The main loop ("Ctrl + C" to interrup the program)
term.clear()
while (true) do
  local crafts = load_file(paths[1])
  local tasks = rs.getTasks()
  local bin = nil

  -- Craft needed items
  for i, craft in ipairs(crafts) do
    craft_item(craft, tasks)
  end

  -- Destroy items
  if (paths[2]) then
    bin = load_file(paths[2])
    for i, item in ipairs(bin) do
      destroy_item(item)
    end
  end

  -- Event handler
  local id = event.pull(5, "interrupted")
  if (id == "interrupted") then
    print("Program stopped.")
    break
  end
end