local SGL = require ("SGL")

------------------------------

local ButtonLib = {}

------------------------------

function ButtonLib.NewButton (x, y, size_x, size_y, color, onClick, drag_react)

  drag_react = drag_react or false

  local button = {x = x, y = y, size_x = size_x, size_y = size_y, color = color, defEventProc = ButtonLib.DefaultEventProc, onClick = onClick, dragreact = dragreact}

  return button

end

------------------------------

function ButtonLib.AddButton (buttons, button)

  buttons[#buttons + 1] = button

end

------------------------------

function ButtonLib.OnMouseTest (button, mouse_x, mouse_y)

  return mouse_x >= button.x and mouse_x < button.x + button.size_x and mouse_y >= button.y and mouse_y < button.y + button.size_y

end

------------------------------

function ButtonLib.DrawButton (button)

  if button.onDraw then

    button.onDraw ()

  else

    SGL.Draw.Rect (button.x, button.y, button.size_x, button.size_y, button.color)

  end

end

------------------------------

function ButtonLib.OnTouch (button, event)

  local _, _, mouse_x, mouse_y = table.unpack (event)

  if ButtonLib.OnMouseTest (button, mouse_x, mouse_y) then return ButtonLib.OnAction (button) end

end

------------------------------

function ButtonLib.OnDrag (button, event)

  if not button.dragreact then return false end

  return ButtonLib.OnTouch (button, event)

end

------------------------------

function ButtonLib.OnAction (button)

  if button.onClick then return button.onClick (button) end

end

------------------------------

function ButtonLib.DefaultEventProc (button, event)

  local event_type = event[1]

  if     event_type == "touch" then if ButtonLib.OnTouch (button, event) then return true end
  elseif event_type == "drag"  then if ButtonLib.OnDrag  (button, event) then return true end

  end

end

------------------------------

function ButtonLib.ProcessButton (button, event)

  if button.onEvent then if button.onEvent (button, event) then return true end end

  if button.defEventProc (button, event) then

    return true

  end

  return false

end

------------------------------

function ButtonLib.DrawButtons (buttons)

  for index, button in pairs (buttons) do

    ButtonLib.DrawButton (button)

  end

end

------------------------------

function ButtonLib.ProcessButtons (buttons, event)

  if not event or not event[1] then return false end

  for index, button in pairs (buttons) do

    if ButtonLib.ProcessButton (button, event) then return true end

  end

  return false

end

------------------------------

return ButtonLib