GoLua

--GoLua
--By Robert Miles (MineRobber___T)

local resolution = {term.getSize()}

local mainTerm = term.current()
local executionWindow = window.create(mainTerm,1,7,resolution[1],resolution[2]-5)
term.setCursorPos(1,6)
term.setBackgroundColor(colors.white)
term.clearLine()
executionWindow.setBackgroundColor(colors.white)
executionWindow.setTextColor(colors.black)
executionWindow.clear()

--Internal functions
local function drawHeader(message,backtarget)
  backtarget = backtarget and backtarget or executionWindow
  --if no printer attached, make sure people know
  if not message and not peripheral.find("printer") then message = "Attach a printer to use history print feature." end
  term.redirect(mainTerm)
  if term.isColor() then
    paintutils.drawFilledBox(1,1,resolution[1],5,colors.green)
  else
    paintutils.drawFilledBox(1,1,resolution[1],5,colors.white)
    term.setTextColor(colors.black)
  end
  term.setCursorPos(1,2)
  print("GoLua v0.1")
  print("Use exit() to exit.")
  print((message and message or "Use printHistory() to print usage history."))
  term.redirect(executionWindow)
end

function printHistory()
  local function displayError(t,pt)
    drawHeader(t,pt)
    sleep(3)
    drawHeader(nil,pt)
  end
  local printer = peripheral.find("printer")
  if not printer then
    displayError("Error finding printer.")
  else
    if printer.getInkLevel()<1 then displayError("Out of ink.") return end
    if printer.getPaperLevel()<1 then displayError("Out of paper.") return end
    local printerterm = {}
    local function defineValues(o)
      for k,v in pairs(o) do printerterm[k] = v end
    end
    defineValues(term)
    defineValues(printer)
    printerterm.scroll = function()
      while not printer.newPage() do
        if printer.getInkLevel()<1 then displayError("Out of ink, please refill",printerterm) end
        if printer.getPaperLevel()<1 then displayError("Out of paper, please refill",printerterm) end
      end
      printer.setPageTitle("GoLua Printout")
    end
    term.redirect(printerterm)
    local ok,err = pcall(function()
      term.scroll()
      for i=1,#tPrintableHistory do
        if i==#tPrintableHistory then
          write(line) --prevent unnessecary line
                      --break on last line
        else
          print(line)
        end
      end
    end)
    if not ok then displayError(err) return end
    local cp = {term.getCursorPos()}
    local pw,ph = printer.getPageSize()
    if cp[1]>1 and cp[2]<ph then
      cp[2] = cp[2]+1
      term.setCursorPos(1,cp[2])
      print(string.rep("-",pw))
      print("GoLua by MineRobber___T")
    end
    term.redirect(executionWindow)
    while not printer.endPage() do displayError("Output tray full please empty") end
    return "Printed output history."
  end
end

local nLine = 1
local function addToHistory(sIn,bInfo,bInOut,bErr)
    if bInfo then
        table.insert(tPrintableHistory,sIn)
    else
        sLog = bInOut and "In [" or "Out ["
        sLog = sLog..nLine.."]: "
        if bErr then sLog = sLog.."Error: " end
        sLog = sLog..sIn
        addToHistory(sLog,true) --recursiveness ftw
    end
end

local bRunning = true

local tEnv = {
  ["exit"] = function() bRunning = false end,
  ["_echo"] = function(...) return ... end,
  ["log"] = function(...)
    local sIn = table.concat({...}," ")
    --addToHistory(sIn,true)
  end
}

setmetatable( tEnv, { __index = _ENV } )

local tCommandHistory = {}

--functionality
drawHeader()
while bRunning do
    write( "lua> " )

    local s = read( nil, tCommandHistory, function( sLine )
        if settings.get( "lua.autocomplete" ) then
            local nStartPos = string.find( sLine, "[a-zA-Z0-9_%.:]+$" )
            if nStartPos then
                sLine = string.sub( sLine, nStartPos )
            end
            if #sLine > 0 then
                return textutils.complete( sLine, tEnv )
            end
        end
        return nil
    end )
    if s:match("%S") and tCommandHistory[#tCommandHistory] ~= s then
        table.insert( tCommandHistory, s )
        --addToHistory(s,false,true)
    end

    local nForcePrint = 0
    local func, e = load( s, "lua", "t", tEnv )
    local func2, e2 = load( "return _echo("..s..");", "lua", "t", tEnv )
    if not func then
        if func2 then
            func = func2
            e = nil
            nForcePrint = 1
        end
    else
        if func2 then
            func = func2
        end
    end

    if func then
        local tResults = table.pack( pcall( func ) )
        if tResults[1] then
            local function display(...)
                print(...)
                --addToHistory(table.concat({...}," "),false,false)
            end
            local n = 1
            while n < tResults.n or (n <= nForcePrint) do
                local value = tResults[ n + 1 ]
                if type( value ) == "table" then
                    local metatable = getmetatable( value )
                    if type(metatable) == "table" and type(metatable.__tostring) == "function" then
                        display( tostring( value ) )
                    else
                        local ok, serialised = pcall( textutils.serialise, value )
                        if ok then
                            display( serialised )
                        else
                            display( tostring( value ) )
                        end
                    end
                else
                    display( tostring( value ) )
                end
                n = n + 1
            end
        else
            printError( tResults[2] )
            --addToHistory(tResults[2],false,false,true)
        end
    else
        printError( e )
        --addToHistory(e,false,false,true)
    end
    --nLine = nLine + 1
    if s:find("printHistory()") then tPrintableHistory = {} end
end
term.redirect(mainTerm)
executionWindow.setVisible(false)
term.setBackgroundColor(colors.black)
term.setTextColor(colors.white)
term.clear()
term.setCursorPos(1,1)
print("Thanks for using GoLua!")