zth_gui

local cmp = require("component")
local os = require("os")
local table = require("table")
local gpu = cmp.gpu
local term = require("term")
local event = require("event")
local uc = require("unicode")
local ret = {}
local widgets = {}

function ret.getWidgets()
  return widgets
end

function ret.drawProgressBar(x, y, width, current, max, color1, color2)
  term.setCursor(x, y)
  local prc = current * 100 / max
  local prc_w = prc * width / 100
  local inText = current.."/"..max

  ret.drawSpaces(x, y, color1, prc_w)
  ret.drawSpaces(x + prc_w, y, color2, width-prc_w-1)
end

function ret.addButton(x, y, title, color, color_active, isSwitch, callback)
  local lastID = #widgets+1
  table.insert(widgets, {})
  widgets[lastID]["x"] = x
  widgets[lastID]["y"] = y
  widgets[lastID]["title"] = title
  widgets[lastID]["color"] = color
  widgets[lastID]["color_active"] = color_active
  widgets[lastID]["callback"] = callback
  widgets[lastID]["isSwitch"] = isSwitch
  widgets[lastID]["state"] = "idle"
  widgets[lastID]["type"] = "button"
  return lastID
end

function ret.addLabel(x, y, width, colorFG, colorBG, title)
  local lastID = #widgets+1
  table.insert(widgets, {})
  widgets[lastID]["type"] = "label"
  widgets[lastID]["x"] = x
  widgets[lastID]["y"] = y
  widgets[lastID]["width"] = width
  widgets[lastID]["colorFG"] = colorFG
  widgets[lastID]["colorBG"] = colorBG
  widgets[lastID]["title"] = title
  return lastID
end

function ret.drawSpaces(x, y, color, num)
  local oldBG = gpu.setBackground(color)
  term.setCursor(x, y)
  for i = 1, num do term.write(" ") end
  gpu.setBackground(oldBG)
end

function ret.printAt(x, y, colorFG, colorBG, text)
  local oldBG = gpu.setBackground(colorBG)
  local oldFG = gpu.setForeground(colorFG)
  term.setCursor(x, y)
  term.write(text)
  gpu.setBackground(oldBG)
  gpu.setForeground(oldFG)
end

function drawButton(x, y, title, color)
  local oldBG = gpu.setBackground(color)
  ret.drawSpaces(x, y, color, uc.len(title)+4)
  term.setCursor(x, y+1)
  term.write("  "..title.."  ")
  ret.drawSpaces(x, y+2, color, uc.len(title)+4)
  gpu.setBackground(oldBG)
end

function drawLabel(key)
  local excess = key["width"] - uc.len(key["title"])
  ret.drawSpaces(key["x"]+uc.len(key["title"]), key["y"], key["colorBG"], excess)
  ret.printAt(key["x"], key["y"], key["colorFG"], key["colorBG"], key["title"])
end

function drawButtons(key)
  if key["type"] == "button" then
    if key["state"] == "idle" then
      drawButton(key["x"], key["y"], key["title"], key["color"])
    else
      drawButton(key["x"], key["y"], key["title"], key["color_active"])
    end
    if key["isSwitch"] == false then
      if key["state"] == "active" then
        key["state"] = "idle"
      end
    end
  end
end

function ret.drawUI()
  for elem, key in pairs(widgets) do
    if key["type"] == "button" then drawButtons(key) end
    if key["type"] == "label" then drawLabel(key) end
  end
end


function ret.callbackTouch(addr, x, y, btn, player)
  for elem, key in pairs(widgets) do
    if x >= key["x"] and x <= key["x"]+uc.len(key["title"])+4 then
      if y >= key["y"] and y <= key["y"]+2 then
        if key["isSwitch"] then
          if key["state"] == "idle" then
            widgets[elem]["state"] = "active"
          else
            widgets[elem]["state"] = "idle"
          end
        else
          widgets[elem]["state"] = "active"
        end
        pcall(key["callback"], widgets[elem]["state"])
      end
    end
  end

end

--event.listen("touch", callbackTouch)

return ret;