View difference between Paste ID: WH1APpZ8 and qSiLE2Ae

 w = {}
 
 -- APIs
 
 -- properties
 local data = { }
 local data_name = nil
 local data_handlers = { }
 
 local device_handlers = {}
 
 local event_handlers = {}
 local event_timers = {}
 
 local monitors = {}
 local monitor_textScale = 0.5
 
 local page_handlers = {}
 local page_endText = ""
 local page_callbackDisplay
 local page_callbackKey
 
 local run_refreshPeriod_s = 3.0
 local status_period_s = 1.0
 
 local styles = {
   normal   = { front = colors.black    , back = colors.lightGray },
   good     = { front = colors.lime     , back = colors.lightGray },
   bad      = { front = colors.red      , back = colors.lightGray },
   disabled = { front = colors.gray     , back = colors.lightGray },
   help     = { front = colors.white    , back = colors.blue      },
   header   = { front = colors.orange   , back = colors.black     },
   control  = { front = colors.white    , back = colors.blue      },
   selected = { front = colors.black    , back = colors.lightBlue },
   warning  = { front = colors.white    , back = colors.red       },
   success  = { front = colors.white    , back = colors.lime      },
 }
 
 ----------- Terminal & monitor support
 
 local function setMonitorColorFrontBack(colorFront, colorBackground)
   term.setTextColor(colorFront)
   term.setBackgroundColor(colorBackground)
   if monitors ~= nil then
     for key, monitor in pairs(monitors) do
       monitor.setTextColor(colorFront)
       monitor.setBackgroundColor(colorBackground)
     end
   end
 end
 
 local function write(text)
   term.write(text)
   if monitors ~= nil then
     for key, monitor in pairs(monitors) do
       if key ~= data.radar_monitorIndex then
         monitor.write(text)
       end
     end
   end
 end
 
 local function getCursorPos()
   local x, y = term.getCursorPos()
   return x, y
 end
 
 local function setCursorPos(x, y)
   term.setCursorPos(x, y)
   if monitors ~= nil then
     for key, monitor in pairs(monitors) do
       if key ~= data.radar_monitorIndex then
         monitor.setCursorPos(x, y)
       end
     end
   end
 end
 
 local function getResolution()
   local sizeX, sizeY = term.getSize()
   return sizeX, sizeY
 end
 
 local function setColorNormal()
   w.setMonitorColorFrontBack(styles.normal.front, styles.normal.back)
 end
 
 local function setColorGood()
   w.setMonitorColorFrontBack(styles.good.front, styles.good.back)
 end
 
 local function setColorBad()
   w.setMonitorColorFrontBack(styles.bad.front, styles.bad.back)
 end
 
 local function setColorDisabled()
   w.setMonitorColorFrontBack(styles.disabled.front, styles.disabled.back)
 end
 
 local function setColorHelp()
   w.setMonitorColorFrontBack(styles.help.front, styles.help.back)
 end
 
 local function setColorHeader()
   w.setMonitorColorFrontBack(styles.header.front, styles.header.back)
 end
 
 local function setColorControl()
   w.setMonitorColorFrontBack(styles.control.front, styles.control.back)
 end
 
 local function setColorSelected()
   w.setMonitorColorFrontBack(styles.selected.front, styles.selected.back)
 end
 
 local function setColorWarning()
   w.setMonitorColorFrontBack(styles.warning.front, styles.warning.back)
 end
 
 local function setColorSuccess()
   w.setMonitorColorFrontBack(styles.success.front, styles.success.back)
 end
 
 local function clear(colorFront, colorBack)
   if colorFront == nil or colorBack == nil then
     w.setColorNormal()
   else
     w.setMonitorColorFrontBack(colorFront, colorBack)
   end
   term.clear()
   if monitors ~= nil then
     for key, monitor in pairs(monitors) do
       if key ~= data.radar_monitorIndex then
         monitor.clear()
       end
     end
   end
   w.setCursorPos(1, 1)
 end
 
 local function clearLine()
   term.clearLine()
   if monitors ~= nil then
     for key, monitor in pairs(monitors) do
       if key ~= data.radar_monitorIndex then
         monitor.clearLine()
       end
     end
   end
   local x, y = w.getCursorPos()
   w.setCursorPos(1, y)
 end
 
 local function writeLn(text)
   w.write(text)
   local x, y = w.getCursorPos()
   local xSize, ySize = w.getResolution()
   if y > ySize - 1 then
     y = 1
   end
   w.setCursorPos(1, y + 1)
 end
 
 local function writeMultiLine(text)
   local textToParse = text or ""
   for line in string.gmatch(textToParse, "[^\n]+") do
     if line ~= "" then
       w.writeLn(line)
     end
   end
 end
 
 local function writeCentered(y, text)
   local unused
   if text == nil then
     text = y
     unused, y = w.getCursorPos()
   end
 
   w.setCursorPos((51 - text:len()) / 2, y)
   term.write(text)
   if monitors ~= nil then
     for key, monitor in pairs(monitors) do
       if key ~= data.radar_monitorIndex then
         local xSize, ySize = monitor.getSize()
         if xSize ~= nil then
           monitor.setCursorPos((xSize - text:len()) / 2, y)
           monitor.write(text)
         end
       end
     end
   end
   w.setCursorPos(1, y + 1)
 end
 
 local function writeFullLine(text)
   w.write(text)
   local xSize, ySize = w.getResolution()
   local xCursor, yCursor = w.getCursorPos()
   for i = xCursor, xSize do
     w.write(" ")
   end
   w.setCursorPos(1, yCursor + 1)
 end
 
 ----------- Page support
 
 local function page_begin(text)
   w.clear()
   w.setCursorPos(1, 1)
   w.setColorHeader()
   w.clearLine()
   w.writeCentered(1, text)
   w.status_refresh()
   w.setCursorPos(1, 2)
   w.setColorNormal()
 end
 
 local function page_colors()
   w.clear(colors.white, colors.black)
   for key, value in pairs(colors) do
     local text = string.format("%12s", key)
     w.setMonitorColorFrontBack(colors.white, colors.black)
     w.write(text .. " ")
     w.setMonitorColorFrontBack(value, colors.black)
     w.write(" " .. text .. " ")
     w.setMonitorColorFrontBack(colors.black, value)
     w.write(" " .. text .. " ")
     w.setMonitorColorFrontBack(colors.white, value)
     w.write(" " .. text .. " ")
     w.setMonitorColorFrontBack(value, colors.white)
     w.write(" " .. text .. " ")
     w.writeLn("")
   end
   w.writeLn("")
   local index = 0
   for key, value in pairs(styles) do
     local text = string.format("%12s", key)
     if index % 2 == 0 then
       w.setMonitorColorFrontBack(colors.white, colors.black)
       w.write(text .. " ")
       w.setMonitorColorFrontBack(value.front, value.back)
       w.write(" " .. text .. " ")
     else
       w.setMonitorColorFrontBack(value.front, value.back)
       w.write(" " .. text .. " ")
       w.setMonitorColorFrontBack(colors.white, colors.black)
       w.write(text .. " ")
       w.writeLn("")
     end
     index = index + 1
   end
   w.setMonitorColorFrontBack(colors.white, colors.black)
 end
 
 local function page_end()
   w.setCursorPos(1, 18)
   w.setColorControl()
   w.writeFullLine(page_endText)
 end
 
 local function page_getCallbackDisplay()
   return page_callbackDisplay
 end
 
 local function page_register(index, callbackDisplay, callbackKey)
   page_handlers[index] = { display = callbackDisplay, key = callbackKey }
 end
 
 local function page_setEndText(text)
   page_endText = text
 end
 
 ----------- Status line support
 
 local status_clockTarget = -1 -- < 0 when stopped, < clock when elapsed, > clock when ticking
 local status_isWarning = false
 local status_line = 0
 local status_text = ""
 local function status_clear()
   if status_clockTarget > 0 then
     status_clockTarget = -1
     w.event_timer_stop("status")
     local xSize, ySize = w.getResolution()
     w.setCursorPos(1, ySize)
     w.setColorNormal()
     w.clearLine()
   end
 end
 local function status_isActive()
   return status_clockTarget > 0 and w.event_clock() < status_clockTarget
 end
 local function status_show(isWarning, text)
   if isWarning or not w.status_isActive() then
     status_line = 1
     status_isWarning = isWarning
     status_text = {}
     local textToParse = (text and text ~= "") and text or "???"
     for line in string.gmatch(textToParse, "[^\n]+") do
       if line ~= "" then
         table.insert(status_text, line)
       end
     end
     if isWarning then
       status_clockTarget = w.event_clock() + 1.0 * #status_text
     else
       status_clockTarget = w.event_clock() + 0.5 * #status_text
     end
     w.event_timer_start("status", status_period_s, "timer_status")
   end
   -- always refresh as a visual clue
   w.status_refresh()
 end
 local function status_refresh()
   if status_clockTarget > 0 then
     if w.event_clock() > status_clockTarget and status_line == 1 then
       w.status_clear()
     else
       local xSize, ySize = w.getResolution()
       w.setCursorPos(1, ySize)
       w.setColorNormal()
       w.clearLine()
 
       if status_isWarning then
         w.setColorWarning()
       else
         w.setColorSuccess()
       end
       local text = status_text[status_line]
       w.writeCentered(" " .. text .. " ")
       w.setColorNormal()
     end
   end
 end
 local function status_showWarning(text)
   w.status_show(true, text)
 end
 local function status_showSuccess(text)
   w.status_show(false, text)
 end
 local function status_tick()
   if status_clockTarget > -1 then
     local clockCurrent = w.event_clock()
     if clockCurrent > status_clockTarget then
       w.status_clear()
     else
       status_line = (status_line % #status_text) + 1
       w.status_refresh()
     end
   end
 end
 
 ----------- Formatting
 
 local function format_float(value, nbchar)
   local str = "?"
   if value ~= nil then
     if type(value) == "number" then
       str = string.format("%g", value)
     else
       str = type(value)
     end
   end
   if nbchar ~= nil then
     str = string.sub("               " .. str, -nbchar)
   end
   return str
 end
 
 local function format_integer(value, nbchar)
   local str = "?"
   if value ~= nil then
     if type(value) == "number" then
       str = string.format("%d", math.floor(value))
     else
       str = type(value)
     end
   end
   if nbchar ~= nil then
     str = string.sub("               " .. str, -nbchar)
   end
   return str
 end
 
 local function format_boolean(value, strTrue, strFalse)
   if value ~= nil then
     if type(value) == "boolean" then
       if value then
         return strTrue
       else
         return strFalse
       end
     else
       return type(value)
     end
   end
   return "?"
 end
 
 local function format_string(value, nbchar)
   local str = "?"
   if value ~= nil then
     str = "" .. value
   end
   if nbchar ~= nil then
     if #str > math.abs(nbchar) then
       str = string.sub(str, 1, math.abs(nbchar) - 1) .. "~"
     else
       str = string.sub(str .. "                                                  ", 1, nbchar)
     end
   end
   return str
 end
 
 local function format_address(value)
   local str = "?"
   if value ~= nil then
     str = "" .. value
   end
   str = string.sub(str, 10, 100)
   return str
 end
 
 local function format_charNumber(value)
   if  value ~= nil
   and type(value) == "number"
   and value <= 255
   and value >= 0 then
     return string.char(value)
   else
     return string.char(0)
   end
 end
 
 ----------- Input controls
 
 local function input_readInteger(currentValue)
   local inputAbort = false
   local input = w.format_integer(currentValue)
   if input == "0" then
     input = ""
   end
   local ignoreNextChar = false
   local x, y = w.getCursorPos()
 
   term.setCursorBlink(true)
   repeat
     w.setCursorPos(x, y)
     w.setColorNormal()
     w.write(input .. "            ")
     input = string.sub(input, -9)
     w.setCursorPos(x + #input, y)
 
     local params = { os.pullEventRaw() }
     local eventName = params[1]
     local firstParam = params[2]
     if firstParam == nil then firstParam = "none" end
     if eventName == "key" then
       local keycode = params[2]
 
       if keycode >= 2 and keycode <= 10 then -- 1 to 9
         input = input .. w.format_string(keycode - 1)
         ignoreNextChar = true
       elseif keycode == 11 or keycode == 82 then -- 0 & keypad 0
         input = input .. "0"
         ignoreNextChar = true
       elseif keycode >= 79 and keycode <= 81 then -- keypad 1 to 3
         input = input .. w.format_string(keycode - 78)
         ignoreNextChar = true
       elseif keycode >= 75 and keycode <= 77 then -- keypad 4 to 6
         input = input .. w.format_string(keycode - 71)
         ignoreNextChar = true
       elseif keycode >= 71 and keycode <= 73 then -- keypad 7 to 9
         input = input .. w.format_string(keycode - 64)
         ignoreNextChar = true
       elseif keycode == 14 then -- Backspace
         input = string.sub(input, 1, string.len(input) - 1)
         ignoreNextChar = true
       elseif keycode == 211 then -- Delete
         input = ""
         ignoreNextChar = true
       elseif keycode == 28 then -- Enter
         inputAbort = true
         ignoreNextChar = true
       elseif keycode == 74 or keycode == 12 or keycode == 49 then -- - on numeric keypad or - on US top or n letter
         if string.sub(input, 1, 1) == "-" then
           input = string.sub(input, 2)
         else
           input = "-" .. input
         end
         ignoreNextChar = true
       elseif keycode == 78 then -- +
         if string.sub(input, 1, 1) == "-" then
           input = string.sub(input, 2)
         end
         ignoreNextChar = true
       else
         ignoreNextChar = false
         -- w.status_showWarning("Key " .. keycode .. " is not supported here")
       end
 
     elseif eventName == "char" then
       local character = params[2]
       if ignoreNextChar then
         ignoreNextChar = false
         -- w.status_showWarning("Ignored char #" .. string.byte(character) .. " '" .. character .. "'")
       elseif character >= '0' and character <= '9' then -- 0 to 9
         input = input .. character
       elseif character == '-' or character == 'n' or character == 'N' then -- - or N
         if string.sub(input, 1, 1) == "-" then
           input = string.sub(input, 2)
         else
           input = "-" .. input
         end
       elseif character == '+' or character == 'p' or character == 'P' then -- + or P
         if string.sub(input, 1, 1) == "-" then
           input = string.sub(input, 2)
         end
       else
         w.status_showWarning("Key '" .. character .. "' is not supported here (" .. string.byte(character) .. ")")
       end
 
     elseif eventName == "terminate" then
       inputAbort = true
 
     else
       local isSupported, needRedraw = w.event_handler(eventName, firstParam)
       if not isSupported then
         w.status_showWarning("Event '" .. eventName .. "', " .. firstParam .. " is unsupported")
       end
     end
   until inputAbort
   term.setCursorBlink(false)
   w.setCursorPos(1, y + 1)
   if input == "" or input == "-" then
     return currentValue
   else
     return tonumber(input)
   end
 end
 
 local function input_readText(currentValue)
   local inputAbort = false
   local input = w.format_string(currentValue)
   local ignoreNextChar = false
   local x, y = w.getCursorPos()
 
   term.setCursorBlink(true)
   repeat
     -- update display clearing extra characters
     w.setCursorPos(x, y)
     w.setColorNormal()
     w.write(w.format_string(input, 37))
     -- truncate input and set caret position
     input = string.sub(input, -36)
     w.setCursorPos(x + #input, y)
 
     local params = { os.pullEventRaw() }
     local eventName = params[1]
     local firstParam = params[2]
     if firstParam == nil then firstParam = "none" end
     if eventName == "key" then
       local keycode = params[2]
 
       if keycode == 14 then -- Backspace
         input = string.sub(input, 1, string.len(input) - 1)
         ignoreNextChar = true
       elseif keycode == 211 then -- Delete
         input = ""
         ignoreNextChar = true
       elseif keycode == 28 then -- Enter
         inputAbort = true
         ignoreNextChar = true
       else
         ignoreNextChar = false
         -- w.status_showWarning("Key " .. keycode .. " is not supported here")
       end
 
     elseif eventName == "char" then
       local character = params[2]
       if ignoreNextChar then
         ignoreNextChar = false
         -- w.status_showWarning("Ignored char #" .. string.byte(character) .. " '" .. character .. "'")
       elseif character >= ' ' and character <= '~' then -- any ASCII table minus controls and DEL
         input = input .. character
       else
         w.status_showWarning("Key '" .. character .. "' is not supported here (" .. string.byte(character) .. ")")
       end
 
     elseif eventName == "terminate" then
       inputAbort = true
 
     else
       local isSupported, needRedraw = w.event_handler(eventName, firstParam)
       if not isSupported then
         w.status_showWarning("Event '" .. eventName .. "', " .. firstParam .. " is unsupported")
       end
     end
   until inputAbort
   term.setCursorBlink(false)
   w.setCursorPos(1, y + 1)
   if input == "" then
     return currentValue
   else
     return input
   end
 end
 
 local function input_readConfirmation(message)
   if message == nil then
     message = "Are you sure? (Y/n)"
   end
   w.status_showWarning(message)
   repeat
     local params = { os.pullEventRaw() }
     local eventName = params[1]
     local firstParam = params[2]
     if firstParam == nil then firstParam = "none" end
     if eventName == "key" then
       local keycode = params[2]
 
       if keycode == 28 then -- Return or Enter
         w.status_clear()
         return true
       end
 
     elseif eventName == "char" then
       local character = params[2]
       w.status_clear()
       if character == 'y' or character == 'Y' then -- Y
         return true
       else
         return false
       end
 
     elseif eventName == "terminate" then
       return false
 
     else
       local isSupported, needRedraw = w.event_handler(eventName, firstParam)
       if not isSupported then
         w.status_showWarning("Event '" .. eventName .. "', " .. firstParam .. " is unsupported")
       end
     end
     if not w.status_isActive() then
       w.status_showWarning(message)
     end
   until false
 end
 
 local function input_readEnum(currentValue, list, toValue, toDescription, noValue)
   local inputAbort = false
   local inputKey = nil
   local input = nil
   local inputDescription = nil
   local ignoreNextChar = false
   local x, y = w.getCursorPos()
 
   w.setCursorPos(1, 17)
   for key, entry in pairs(list) do
     if toValue(entry) == currentValue then
       inputKey = key
     end
   end
 
   term.setCursorBlink(true)
   repeat
     w.setCursorPos(x, y)
     w.setColorNormal()
     if #list == 0 then
       inputKey = nil
     end
     if inputKey == nil then
       if currentValue ~= nil then
         input = noValue
         inputDescription = "Press enter to return previous entry"
       else
         input = noValue
         inputDescription = "Press enter to close listing"
       end
     else
       if inputKey < 1 then
         inputKey = #list
       elseif inputKey > #list then
         inputKey = 1
       end
 
       input = toValue(list[inputKey])
       inputDescription = toDescription(list[inputKey])
     end
     w.setColorNormal()
     w.write(input .. "                                                  ")
     w.setCursorPos(1, y + 1)
     w.setColorDisabled()
     w.write(inputDescription .. "                                                  ")
 
     local params = { os.pullEventRaw() }
     local eventName = params[1]
     local firstParam = params[2]
     if firstParam == nil then firstParam = "none" end
     if eventName == "key" then
       local keycode = params[2]
 
       if keycode == 14 or keycode == 211 then -- Backspace or Delete
         inputKey = nil
         ignoreNextChar = true
       elseif keycode == 200 or keycode == 203 or keycode == 78 then -- Up or Left or +
         if inputKey == nil then
           inputKey = 1
         else
           inputKey = inputKey - 1
         end
         ignoreNextChar = true
       elseif keycode == 208 or keycode == 205 or keycode == 74 then -- Down or Right or -
         if inputKey == nil then
           inputKey = 1
         else
           inputKey = inputKey + 1
         end
         ignoreNextChar = true
       elseif keycode == 28 then -- Enter
         inputAbort = true
         ignoreNextChar = true
       else
         ignoreNextChar = false
         -- w.status_showWarning("Key " .. keycode .. " is not supported here")
       end
 
     elseif eventName == "char" then
       local character = params[2]
       if ignoreNextChar then
         ignoreNextChar = false
         -- w.status_showWarning("Ignored char #" .. string.byte(character) .. " '" .. character .. "'")
       elseif character == '+' then -- +
         if inputKey == nil then
           inputKey = 1
         else
           inputKey = inputKey - 1
         end
       elseif character == '-' then -- -
         if inputKey == nil then
           inputKey = 1
         else
           inputKey = inputKey + 1
         end
       else
         w.status_showWarning("Key '" .. character .. "' is not supported here (" .. string.byte(character) .. ")")
       end
 
     elseif eventName == "terminate" then
       inputAbort = true
 
     elseif not w.event_handler(eventName, firstParam) then
       w.status_showWarning("Event '" .. eventName .. "', " .. firstParam .. " is unsupported")
     end
   until inputAbort
   term.setCursorBlink(false)
   w.setCursorPos(1, y + 1)
   w.clearLine()
   if inputKey == nil then
     return nil
   else
     return toValue(list[inputKey])
   end
 end
 
 ----------- Event handlers
 
 local function reboot()
   os.reboot()
 end
 
 local function sleep(delay)
   os.sleep(delay)
 end
 
 -- return a global clock measured in second
 local function event_clock()
   return os.clock()
 end
 
 local function event_timer_start(name_, period_s_, eventId_)
   local name = name_ or "-nameless-"
   local eventId = eventId_ or "timer_" .. name
   -- check for an already active timer
   local countActives = 0
   for id, entry in pairs(event_timers) do
     if entry.name == name and entry.active then -- already one started
       countActives = countActives + 1
     end
   end
   if countActives > 0 then
     if name ~= "status" then -- don't report status timer overlaps to prevent a stack overflow
       w.status_showWarning("Timer already started for " .. name)
     end
     return
   end
   -- start a new timer
   local period_s = period_s_ or 1.0
   local id = os.startTimer(period_s)
   event_timers[id] = {
     active = true,
     eventId = eventId,
     name = name,
     period_s = period_s
   }
 end
 
 local function event_timer_stop(name_)
   local name = name_ or "-nameless-"
   for id, entry in pairs(event_timers) do
     if entry.name == name then
       if entry.active then -- kill any active one
         entry.active = false
         os.cancelTimer(id)
       else -- purge all legacy ones
         event_timers[id] = nil
       end
     end
   end
 end
 
 local function event_timer_stopAll()
   for id, entry in pairs(event_timers) do
     if entry.active then
       event_timers[id] = nil
       os.cancelTimer(id)
     end
   end
 end
 
 local function event_timer_tick(id)
   local entry = event_timers[id]
   local isUnknown = entry == nil
   if isUnknown then -- unknown id, report a warning
     w.status_showWarning("Timer #" .. id .. " is unknown")
     return
   end
   if not entry.active then -- dying timer, just ignore it
     return
   end
   -- resolve the timer
   os.queueEvent(entry.eventId, nil, nil, nil)
   -- CC timers are one shot, so we start a new one, if still needed
   if entry.active then
     entry.active = false
     w.event_timer_start(entry.name, entry.period_s)
   end
 end
 
 local function event_register(eventName, callback)
   event_handlers[eventName] = callback
 end
 
 -- returns isSupported, needRedraw
 local function event_handler(eventName, param)
   local needRedraw = false
   if event_handlers[eventName] ~= nil then
     needRedraw = event_handlers[eventName](eventName, param)
   elseif eventName == "redstone" then
     w.event_redstone(param)
   elseif eventName == "timer" then
     w.event_timer_tick(param)
   elseif eventName == "key_up" then
   elseif eventName == "mouse_click" then
     w.status_showSuccess("Use the keyboard, Luke!")
   elseif eventName == "mouse_up" then
   elseif eventName == "mouse_drag" then
   elseif eventName == "mouse_scroll" then
   elseif eventName == "monitor_touch" then
   elseif eventName == "monitor_resize" then
   elseif eventName == "disk" then
   elseif eventName == "disk_eject" then
   elseif eventName == "peripheral" then
   elseif eventName == "peripheral_detach" then
   -- not supported: task_complete, rednet_message, modem_message
   else
     return false, needRedraw
   end
   return true, needRedraw
 end
 
 ----------- Redstone support
 
 local tblRedstoneState = {-- Remember redstone state on each side
   ["top"] = rs.getInput("top"),
   ["front"] = rs.getInput("front"),
   ["left"] = rs.getInput("left"),
   ["right"] = rs.getInput("right"),
   ["back"] = rs.getInput("back"),
   ["bottom"] = rs.getInput("bottom"),
 }
 
 local function event_redstone()
   -- Event only returns nil so we need to check sides manually
   local message = ""
   for side, state in pairs(tblRedstoneState) do
     if rs.getInput(side) ~= state then
       -- print(side .. " is now " .. tostring(rs.getInput(side)))
       message = message .. side .. " "
       tblRedstoneState[side] = rs.getInput(side)
     end
   end
   if message ~= "" then
     message = "Redstone changed on " .. message
     w.status_showWarning(message)
   end
 end
 
 ----------- Configuration
 
 local function data_get()
   return data
 end
 
 local function data_inspect(key, value)
   local stringValue = type(value) .. ","
   if type(value) == "boolean" then
     if value then
       stringValue = "true,"
     else
       stringValue = "false,"
     end
   elseif type(value) == "number" then
     stringValue = value .. ","
   elseif type(value) == "string" then
     stringValue = "'" .. value .. "',"
   elseif type(value) == "table" then
     stringValue = "{"
   end
   print(" " .. key .. " = " .. stringValue)
   if type(value) == "table" then
     for subkey, subvalue in pairs(value) do
       w.data_inspect(subkey, subvalue)
     end
     print("}")
   end
 end
 
 local function data_read()
   w.data_shouldUpdateName()
 
   data = { }
   if fs.exists("shipdata.txt") then
     local size = fs.getSize("shipdata.txt")
     if size > 0 then
       local file = fs.open("shipdata.txt", "r")
       if file ~= nil then
         local rawData = file.readAll()
         if rawData ~= nil then
           data = textutils.unserialize(rawData)
         end
         file.close()
         if data == nil then
           data = {}
         end
       end
     end
   end
 
   for name, handlers in pairs(data_handlers) do
     handlers.read(data)
   end
 end
 
 local function data_save()
   for name, handlers in pairs(data_handlers) do
     handlers.save(data)
   end
 
   local file = fs.open("shipdata.txt", "w")
   if file ~= nil then
     file.writeLine(textutils.serialize(data))
     file.close()
   else
     w.status_showWarning("No file system")
     w.sleep(3.0)
   end
 end
 
 local function data_getName()
   if data_name ~= nil then
     return data_name
   else
     return "-noname-"
   end
 end
 
 local function data_setName()
   -- check if any named component is connected
   local componentName = "computer"
   for name, handlers in pairs(data_handlers) do
     if handlers.name ~= nil then
       componentName = name
     end
   end
 
   -- ask for a new name
   w.page_begin("<==== Set " .. componentName .. " name ====>")
   w.setCursorPos(1, 4)
   w.setColorHelp()
   w.writeFullLine(" Press enter to validate.")
   w.setCursorPos(1, 3)
   w.setColorNormal()
   w.write("Enter " .. componentName .. " name: ")
   data_name = w.input_readText(data_name)
 
   -- update computer name
   os.setComputerLabel(data_name)
 
   -- update connected components
   for name, handlers in pairs(data_handlers) do
     if handlers.name ~= nil then
       handlers.name(data_name)
     end
   end
 
   -- w.reboot() -- not needed
 end
 
 local function data_shouldUpdateName()
   local shouldUpdateName = false
 
   -- check computer name
   data_name = os.getComputerLabel()
   if data_name == nil then
     shouldUpdateName = true
     data_name = "" .. os.getComputerID()
   end
 
   -- check connected components names
   for name, handlers in pairs(data_handlers) do
     if handlers.name ~= nil then
       local componentName = handlers.name()
       if componentName == "" then
         shouldUpdateName = true
       elseif shouldUpdateName then
         data_name = componentName
       elseif data_name ~= componentName then
         shouldUpdateName = true
         data_name = componentName
       end
     end
   end
 
   return shouldUpdateName
 end
 
 local function data_splitString(source, sep_)
   local sep = sep_ or ":"
   local fields = {}
   local pattern = string.format("([^%s]+)", sep)
   source:gsub(pattern, function(c) fields[#fields + 1] = c end)
   return fields
 end
 
 local function data_register(name, callbackRead, callbackSave, callbackName)
   -- read/save callbacks are always defined
   if callbackRead == nil then
     callbackRead = function() end
   end
   if callbackSave == nil then
     callbackSave = function() end
   end
 
   -- name callback is nil when not defined
 
   data_handlers[name] = { read = callbackRead, save = callbackSave, name = callbackName }
 end
 
 ----------- Devices
 
 local function device_get(address)
   return peripheral.wrap(address)
 end
 
 local function device_getMonitors()
   return monitors
 end
 
 local function device_register(deviceType, callbackRegister, callbackUnregister)
   device_handlers[deviceType] = { register = callbackRegister, unregister = callbackUnregister }
 end
 
 ----------- Main loop
 
 
 local function boot()
   if not term.isColor() then
     print("Advanced computer required")
     error()
   end
   print("loading...")
 
   math.randomseed(os.time())
 
   -- read configuration
   w.data_read()
   w.clear()
   print("data_read...")
 
   -- initial scanning
   monitors = {}
   w.page_begin(data_name .. " - Connecting...")
   w.writeLn("")
 
   local sides = peripheral.getNames()
   for key, address in pairs(sides) do
     w.sleep(0)
     w.write("Checking " .. address .. " ")
     local deviceType = peripheral.getType(address)
     w.write(deviceType .. " ")
     if deviceType == "monitor" then
       w.write("wrapping!")
       local lmonitor = w.device_get(address)
       table.insert(monitors, lmonitor)
       lmonitor.setTextScale(monitor_textScale)
     else
       local handlers = device_handlers[deviceType]
       if handlers ~= nil then
         w.write("wrapping!")
         handlers.register(deviceType, address, w.device_get(address))
       end
     end
 
     w.writeLn("")
   end
 
   -- synchronize computer and connected components names
   local shouldUpdateName = w.data_shouldUpdateName()
   if shouldUpdateName then
     w.data_setName()
   end
 
   -- peripheral boot up
   if page_handlers['0'] == nil then
     w.status_showWarning("Missing handler for connection page '0'!")
     error()
   end
   page_handlers['0'].display(true)
 end
 
 local function run()
   local abort = false
   local refresh = true
   local ignoreNextChar = false
 
   local function selectPage(index)
     if page_handlers[index] ~= nil then
       page_callbackDisplay = page_handlers[index].display
       page_callbackKey = page_handlers[index].key
       refresh = true
       return true
     end
     return false
   end
 
   -- start refresh timer
   w.event_register("timer_refresh", function() return page_callbackDisplay ~= page_handlers['0'].display end )
   w.event_register("timer_status" , function() w.status_tick() return false end )
   w.event_timer_start("refresh", run_refreshPeriod_s, "timer_refresh")
 
   -- register common events
   w.event_register("enabled" , function(eventName, param) w.status_showWarning("Enabled '" .. w.format_string(param) .. "'") end )
   w.event_register("disabled", function(eventName, param) w.status_showWarning("Disabled '" .. w.format_string(param) .. "'") end )
 
   -- main loop
   selectPage('0')
   repeat
     if refresh then
       w.clear()
       page_callbackDisplay(false)
       w.page_end()
       refresh = false
     end
     local params = { os.pullEventRaw() }
     local eventName = params[1]
     local firstParam = params[2]
     if firstParam == nil then firstParam = "none" end
     -- w.writeLn("...")
     -- w.writeLn("Event '" .. eventName .. "', " .. firstParam .. " received")
     -- w.sleep(0.2)
 
     if eventName == "key" then
       local keycode = params[2]
 
       ignoreNextChar = false
       if keycode == 11 or keycode == 82 then -- 0
         if selectPage('0') then
           ignoreNextChar = true
         end
       elseif keycode == 2 or keycode == 79 then -- 1
         if selectPage('1') then
           ignoreNextChar = true
         end
       elseif keycode == 3 or keycode == 80 then -- 2
         if selectPage('2') then
           ignoreNextChar = true
         end
       elseif keycode == 4 or keycode == 81 then -- 3
         if selectPage('3') then
           ignoreNextChar = true
         end
       elseif keycode == 5 or keycode == 82 then -- 4
         if selectPage('4') then
           ignoreNextChar = true
         end
       elseif keycode == 6 or keycode == 83 then -- 5
         if selectPage('5') then
           ignoreNextChar = true
         end
       elseif page_callbackKey ~= nil and page_callbackKey("", keycode) then
         refresh = true
       else
         ignoreNextChar = false
         -- w.status_showWarning("Key " .. keycode .. " is not supported here")
       end
 
     elseif eventName == "char" then
       local character = params[2]
       if ignoreNextChar then
         ignoreNextChar = false
         -- w.status_showWarning("Ignored char #" .. string.byte(character) .. " '" .. character .. "'")
 --      elseif character == 'x' or character == 'X' then -- x for eXit
 --        -- os.pullEventRaw() -- remove key_up event
 --        abort = true
       elseif character == '0' then
         selectPage('0')
       elseif character == '1' then
         selectPage('1')
       elseif character == '2' then
         selectPage('2')
       elseif character == '3' then
         selectPage('3')
       elseif character == '4' then
         selectPage('4')
       elseif character == '5' then
         selectPage('5')
       elseif page_callbackKey ~= nil and page_callbackKey(character, -1) then
         refresh = true
       elseif string.byte(character) ~= 0 then -- not a control char
         w.status_showWarning("Key '" .. character .. "' is not supported here (" .. string.byte(character) .. ")")
       end
 
     elseif eventName == "terminate" then
       abort = true
 
     else
       local isSupported, needRedraw = w.event_handler(eventName, firstParam)
       if not isSupported then
         w.status_showWarning("Event '" .. eventName .. "', " .. firstParam .. " is unsupported")
       end
       refresh = needRedraw
     end
   until abort
 
   -- stop refresh timer
   w.event_timer_stop("refresh")
   w.event_timer_stopAll()
 end
 
 local function close()
   w.clear(colors.white, colors.black)
   for key, handlers in pairs(device_handlers) do
     w.writeLn("Closing " .. key)
     if handlers.unregister ~= nil then
       handlers.unregister(key)
     end
   end
 
   w.clear(colors.white, colors.black)
   w.setCursorPos(1, 1)
   w.writeLn("Program closed")
   w.writeLn("Type startup to return to home page")
 end
 
 -- we simulate LUA library behavior, so code is closer between CC and OC
 w = {
   setMonitorColorFrontBack = setMonitorColorFrontBack,
   write = write,
   getCursorPos = getCursorPos,
   setCursorPos = setCursorPos,
   getResolution = getResolution,
   setColorNormal = setColorNormal,
   setColorGood = setColorGood,
   setColorBad = setColorBad,
   setColorDisabled = setColorDisabled,
   setColorHelp = setColorHelp,
   setColorHeader = setColorHeader,
   setColorControl = setColorControl,
   setColorSelected = setColorSelected,
   setColorWarning = setColorWarning,
   setColorSuccess = setColorSuccess,
   clear = clear,
   clearLine = clearLine,
   writeLn = writeLn,
   writeMultiLine = writeMultiLine,
   writeCentered = writeCentered,
   writeFullLine = writeFullLine,
   page_begin = page_begin,
   page_colors = page_colors,
   page_end = page_end,
   page_getCallbackDisplay = page_getCallbackDisplay,
   page_register = page_register,
   page_setEndText = page_setEndText,
   status_clear = status_clear,
   status_isActive = status_isActive,
   status_show = status_show,
   status_refresh = status_refresh,
   status_showWarning = status_showWarning,
   status_showSuccess = status_showSuccess,
   status_tick = status_tick,
   format_float = format_float,
   format_integer = format_integer,
   format_boolean = format_boolean,
   format_string = format_string,
   format_address = format_address,
   format_charNumber = format_charNumber,
   input_readInteger = input_readInteger,
   input_readText = input_readText,
   input_readConfirmation = input_readConfirmation,
   input_readEnum = input_readEnum,
   reboot = reboot,
   sleep = sleep,
   event_clock = event_clock,
   event_timer_start = event_timer_start,
   event_timer_stop = event_timer_stop,
   event_timer_stopAll = event_timer_stopAll,
   event_timer_tick = event_timer_tick,
   event_register = event_register,
   event_handler = event_handler,
   event_redstone = event_redstone,
   data_get = data_get,
   data_inspect = data_inspect,
   data_read = data_read,
   data_save = data_save,
   data_getName = data_getName,
   data_setName = data_setName,
   data_shouldUpdateName = data_shouldUpdateName,
   data_splitString = data_splitString,
   data_register = data_register,
   device_get = device_get,
   device_getMonitors = device_getMonitors,
   device_register = device_register,
   boot = boot,
   run = run,
   close = close,
 }