local serial = require("serialization")
local fs = require("filesystem")
local comp = require("component")

local image = {}

function image.load(path)
  local retIm = {}
  if fs.exists(path) then
    file = io.open(path, "r")
    retIm = serial.unserialize(file:read("*all"))
    file:close()
    local imData = compressImage(retIm)
    return imData
  end
  return false
end

function compressImage(data)
    local pTab = {}
    for i = 1, #data["layerData"] do
        pTab[i] = {}
        if data["layerData"][i]["hidden"] then
            pTab[i]["hidden"] = true
        else
            pTab[i]["hidden"] = false
        end
        for line = #data["layerData"][i], 1, -1 do
            local colCount = 0
            local curBg = data["layerData"][i][line][1]["bg"]
            local curFg = data["layerData"][i][line][1]["fg"]
            local curSt = data["layerData"][i][line][1]["char"]
            local stx = 1
            local sty = 1 + (line - 1)
            pTab[i][line] = {}
            for pix = 1, #data["layerData"][i][line] do
                curBg = data["layerData"][i][line][pix]["bg"]
                curFg = data["layerData"][i][line][pix]["fg"]
                curSt = data["layerData"][i][line][pix]["char"]
                if curBg == "trans" then
                    for x = i, 1, -1 do
                        if not data["layerData"][x]["hidden"] then
                            if data["layerData"][x][line][pix]["bg"] ~= "trans" then
                                curBg = data["layerData"][x][line][pix]["bg"]
                            end
                        elseif x == 1 then
                            curBg = data["layerData"][x][line][pix]["bg"]
                        end
                    end
                end
                if pix == 1 or curBg ~= pTab[i][line][colCount]["bg"] or curFg ~= pTab[i][line][colCount]["fg"] then
                    colCount = colCount + 1
                    pTab[i][line][colCount] = {
                        bg = curBg,
                        fg = curFg,
                        st = curSt,
                        yp = sty,
                        xp = stx,
                        }
                else
                    pTab[i][line][colCount]["st"] = pTab[i][line][colCount]["st"]..curSt
                end
                stx = stx + 1
            end
        end
    end
    return(pTab)
end

function image.draw(data, gpu, x, y)
  if data ~= nil then
    for layer = 1, #data do
      for line = 1, #data[layer] do
        if not data[layer]["hidden"] then
          for col = 1, #data[layer][line] do
            if data[layer][line][col]["bg"] ~= "trans" then
              local xPos = x + data[layer][line][col]["xp"] - 1
              local yPos = y + data[layer][line][col]["yp"] - 1
              gpu.setBackground(data[layer][line][col]["bg"])
              gpu.setForeground(data[layer][line][col]["fg"])
              gpu.set(xPos, yPos, data[layer][line][col]["st"])
            end
          end
        end
      end
    end
  end
  gpu.setBackground(0x000000)
  gpu.setForeground(0xFFFFFF)
end

return image