local Element = require("element")
local List = Element:new{
  children = {},
  vertical = false
}

local function adjustPositions(elements, vertical, from)
    local newDims = 0
    local getDim = vertical and function(e) return e:getHeight() end or function(e) return e:getWidth() end
    for i=1,from-1 do
      newDims = newDims + getDim(elements[i])
    end
    
    local setDim = vertical and function(e, dim) e:setPos(0, dim) end or function(e, dim) e:setPos(dim, 0) end
    for i=from,#elements do
      setDim(elements[i])
      newDims = newDims + getDim(elements[i])
    end
end

function List:insertChild(child, atIndex)
  local index = math.min(math.max(1, atIndex or #self.children), #self.children)
  table.insert(self.children, index, child)
  adjustPositions(self.children, self:isVertical(), index)
end

function List:removeChild(child)
  local index
  local searchType = type(child)
  if searchType == "string" then
    for i,v in ipairs(self.children) do
        if v:getId() == child then
            index = i
            break
        end
    end
    return false, nil
  elseif searchType == "table" then
    for i,v in ipairs(self.children) do
        if v == child then
            index = i
        end
    end
    return false, nil
  else
    index = child
  end

  if index <= 0 or index > #self.children then
    return false, nil
  end

  local removed = table.remove(self.children, index)
  if index <= #self.children then
    adjustPositions(self.children, self:isVertical(), index)
  end

  return true, removed
end

function List:isVertical()
  return self.vertical
end

function List:isHorizontal()
  return not self:isVertical()
end

function List:draw()
  Element.draw(self)
  self:_getWindow().clear()
  for _,v in ipairs(self.children) do
    v:draw()
  end
end

function List:getHeight()
  local h = 0
  for _,v in ipairs(self.children) do
    h = h + v:getHeight()
  end
  return h
end

function List:getWidth()
  local h = 0
  for _,v in ipairs(self.children) do
    h = h + v:getHeight()
  end
  return h
end

function List:findById(id)
  local find = Element.findById(self, id)
  if find then
    return find
  end

  for _,v in ipairs(self.children) do
    local result = v:findById(id)
    if result then
        return result
    end
  end
  return nil
end

return List