require ("iuplua")

if (not loadstring) then
  loadstring = load
end

console = {}

console.prompt = iup.text{expand="Horizontal", dragdrop = "Yes"}
console.output = iup.text{expand="Yes", 
                  readonly="Yes", 
                  bgcolor="232 232 232", 
                  font = "Courier, 11",
                  appendnewline = "No",
                  multiline = "Yes"}

console.prompt.tip = "Enter - executes a Lua command\n"..
                     "Esc - clears the command\n"..
                     "Ctrl+Del - clears the output\n"..
                     "Ctrl+O - selects a file and execute it\n"..
                     "Ctrl+X - exits the console\n"..
                     "Up Arrow - shows the previous command in history\n"..
                     "Down Arrow - shows the next command in history\n"..
                     "Drop files here to execute them"
                  
console.orig_output = io.output
console.orig_write = io.write
console.orig_print = print

function io.output(filename)
  console.orig_output(filename)
  if (filename) then
    io.write = console.orig_write
  else
    io.write = console.new_write
  end
end

function console.new_write(...)
  -- Try to simulate the same behavior of the standard io.write
  local arg = {...}
  local str -- allow to print a nil value
  for i,v in ipairs(arg) do
    if (str) then
      str = str .. tostring(v) 
    else
      str = tostring(v)
    end
  end
  console.print2output(str, true)
end
io.write = console.new_write

function print(...)
  -- Try to simulate the same behavior of the standard print
  local arg = {...}
  local str -- allow to print a nil value
  for i,v in ipairs(arg) do
    if (i > 1) then
      str = str .. "\t"  -- only add Tab for more than 1 parameters
    end
    if (str) then
      str = str .. tostring(v) 
    else
      str = tostring(v)
    end
  end
  console.print2output(str)
end
                  
function console.print2output(s, no_newline)
  if (no_newline) then
    console.output.append = tostring(s)
    console.no_newline = no_newline
  else
    if (console.no_newline) then
      -- if io.write was called, then a print is called, must add a new line before
      console.output.append = "\n" .. tostring(s) .. "\n"
      console.no_newline = nil
    else  
      console.output.append = tostring(s) .. "\n"
    end
  end
end

function console.print_command(cmd)
  console.add_command(cmd)
  console.print2output("> " .. cmd)
end

function  console.add_command(cmd)
  console.cmd_index = nil
  if (not console.cmd_list) then
    console.cmd_list = {}
  end
  local n = #(console.cmd_list)
  console.cmd_list[n+1] = cmd
end

function  console.prev_command()
  if (not console.cmd_list) then
    return
  end
  if (not console.cmd_index) then
    console.cmd_index = #(console.cmd_list)
  else
    console.cmd_index = console.cmd_index - 1
    if (console.cmd_index == 0) then
      console.cmd_index = 1
    end
  end
  console.prompt.value = console.cmd_list[console.cmd_index]
end

function  console.next_command()
  if (not console.cmd_list) then
    return
  end
  if (not console.cmd_index) then
    return
  else
    console.cmd_index = console.cmd_index + 1
    local n = #(console.cmd_list)
    if (console.cmd_index == n+1) then
      console.cmd_index = n
    end
  end
  console.prompt.value = console.cmd_list[console.cmd_index]
end

function console.do_file(filename)
  local cmd = 'dofile(' .. string.format('%q', filename) .. ')'
  console.print_command(cmd)
  dofile(filename)
end

function console.do_string(cmd)
  console.print_command(cmd)
  assert(loadstring(cmd))()
end

function console.open_file()
  local fd=iup.filedlg{dialogtype="OPEN", title="Load File", 
                       nochangedir="NO", directory=console.last_directory,
                       filter="*.*", filterinfo="All Files", allownew="NO"}
  fd:popup(iup.CENTER, iup.CENTER)
  local status = fd.status
  local filename = fd.value
  console.last_directory = fd.directory -- save the previous directory
  fd:destroy()
  
  if (status == "-1") or (status == "1") then
    if (status == "1") then
      error ("Cannot load file: "..filename)
    end
  else
    console.do_file(filename)
  end
end

function console.prompt:dropfiles_cb(filename)
  -- will execute all dropped files, can drop more than one at once
  -- works in Windows and in Linux
  console.do_file(filename)
end

function console.prompt:k_any(key)
  if (key == iup.K_CR) then  -- Enter executes the string
    console.do_string(self.value)
    self.value = ""
  end
  if (key == iup.K_ESC) then  -- Esc clears console.prompt
    self.value = ""
  end
  if (key == iup.K_cO) then  -- Ctrl+O selects a file and execute it
    console.open_file()
  end
  if (key == iup.K_cX) then  -- Ctrl+X exits the console
    console.dialog:close_cb()
  end
  if (key == iup.K_cDEL) then  -- Ctrl+Del clears console.output
    console.output.value = ""
  end
  if (key == iup.K_UP) then  -- Up Arrow - shows the previous command in history
    console.prev_command()
  end
  if (key == iup.K_DOWN) then  -- Down Arrow - shows the next command in history
    console.next_command()
  end
end

console.dialog = iup.dialog
{
  iup.vbox
  {
    iup.frame
    {
      iup.hbox -- use it to inherit margins
      {
        console.prompt,
      },
      title = "Command:",
    },
    iup.frame
    {
      iup.hbox -- use it to inherit margins
      {
        console.output
      },
      title = "Output:",
    },
    margin = "5x5",
    gap = "5",
  },
  title="Lua Console", 
  size="250x180", -- initial size
  icon=0, -- use the Lua icon from the executable in Windows
}

function console.dialog:close_cb()
  print = console.orig_print  -- restore print and io.write
  io.write = console.orig_write
  iup.ExitLoop()  -- should be removed if used inside a bigger application
  console.dialog:destroy()
  return iup.IGNORE
end

function console.version_info()
  print(_VERSION, _COPYRIGHT) -- _COPYRIGHT does not exists by default, but it could...
  
  print("IUP " .. iup._VERSION .. "  " .. iup._COPYRIGHT)
  print("  System: " .. iup.GetGlobal("SYSTEM"))
  print("  System Version: " .. iup.GetGlobal("SYSTEMVERSION"))

  local mot = iup.GetGlobal("MOTIFVERSION")
  if (mot) then print("  Motif Version: ", mot) end
  
  local gtk = iup.GetGlobal("GTKVERSION")
  if (gtk) then print("  GTK Version: ", gtk) end
end

console.dialog:show()
console.dialog.size = nil -- reset initial size, allow resize to smaller values
iup.SetFocus(console.prompt)

console.version_info()

if (iup.MainLoopLevel() == 0) then
  iup.MainLoop()
end