#!/usr/bin/lua

local host = os.getenv("HTTP_HOST")
local proto = os.getenv("SERVER_PROTOCOL")
local query = os.getenv("QUERY_STRING")
local method = os.getenv("REQUEST_METHOD")
local clength = os.getenv("CONTENT_LENGTH")
local ctype = os.getenv("CONTENT_TYPE")

function http_print(s)
  if s then
    io.stdout:write(tostring(s).."\r\n")
  else
    io.stdout:write("\r\n")
  end
end

function SendError(err,desc)
  http_print(proto.." "..err)
  http_print("Content-Type: text/html")
  http_print()
  local file = io.open("e404.html")
  if file then
    local tmp = file:read("*a")
    tmp = string.gsub(tmp,"404 Not Found",err .. " " .. desc)
    http_print(tmp)
    file:close()
  end
end

if not query then query = "" end
if not proto then proto = "HTTP/1.0" end
local DoUpdate = false
local DoCheck = false

if arg[1] then
  if arg[1] == "doupdate" then
    DoUpdate = true
    DoCheck = true
  else
    query = arg[1]
  end
end

if query == "check" then
  DoCheck = true
end

local userver = "download.digital-devices.de/download/linux"
local NewImage = "octonet.0000000000.img"
local CurImage = "octonet.0000000000.img"

if DoCheck then

  local tmp = io.open("/config/updateserver")
  if tmp then
    userver = tmp:read()
    tmp:close()
  end

  local tmp = io.popen(string.format("wget http://%s/octonet/ -q -O -",userver),"r")
  local serverdir = tmp:read("*a")
  tmp:close()

  local tmp = io.popen("ls /config/octonet.*.img","r")
  local configdir = tmp:read("*a")
  tmp:close()

  for v in string.gmatch(serverdir,"[\"/](octonet%.%d+%.img)\"") do
    if v > NewImage then
      NewImage = v
    end
  end

  for v in string.gmatch(configdir,"(octonet%.%d+%.img)") do
    if v > CurImage then
      CurImage = v
    end
  end
end

if DoUpdate then
  if NewImage > CurImage then
    os.execute("echo CheckDone >/tmp/updatestatus")
    os.remove("/config/tmpimage")
    local wgetstatus = os.execute(string.format("wget -q -P /config http://%s/octonet/%s -O /config/tmpimage >/dev/null 2>/dev/null",userver,NewImage))
    if wgetstatus == 0 then
      local ShaFile = string.gsub(NewImage,".img",".sha")
      wgetstatus = os.execute(string.format("wget -q -P /config http://%s/octonet/%s -O /config/%s >/dev/null 2>/dev/null",userver,ShaFile,ShaFile))
      os.execute("echo DownloadDone >/tmp/updatestatus")
      if wgetstatus == 0 then
        local tmp = io.popen(string.format("sha256sum /config/tmpimage","r"))
        local csum1 = tmp:read()
        tmp:close()
        local csum2 = io.open(string.format("/config/%s",ShaFile)):read()
        csum1 = string.match(csum1,"(%x+)")
        csum2 = string.match(csum2,"(%x+)")
        if csum1 == csum2 then
          os.execute("lua /etc/switch/swsetup.lua gb yb");
          os.rename("/config/tmpimage",string.format("/config/%s",NewImage))
          os.remove(string.format("/config/%s",CurImage))
          os.remove(string.format("/config/%s",string.gsub(CurImage,".img",".sha")))
          os.remove("/boot/uImage")
          os.execute("echo VerifyDone >/tmp/updatestatus")
        else
          print("Error")
          os.remove("/config/tmpimage")
          os.remove(string.format("/config/%s",ShaFile))
          os.execute("echo VerifyError >/tmp/updatestatus")
          return
        end
      else
        os.remove("/config/tmpimage")
        os.remove(string.format("/config/%s",ShaFile))
        os.execute("echo DownloadError >/tmp/updatestatus")
      end
    else
      os.remove("/config/tmpimage")
      os.execute("echo DownloadError >/tmp/updatestatus")
    end
  else
    os.execute("echo CheckError >/tmp/updatestatus")
  end
  return
end

JSONData = ""
if query == "check" then

   JSONData = "{ \"Info\":\""
   if NewImage > CurImage then
      JSONData = JSONData .. string.match(NewImage,"octonet%.(%d+)")
   end
   JSONData = JSONData .. "\"}"
  
elseif query == "update" then

   os.remove("/tmp/updatestatus")
   JSONData = "{ \"Status\":\"Started\", \"Error\":false }"
   os.execute("lua update.lua doupdate >/dev/null 2>/dev/null &")
   
elseif query == "updatestatus" then

   local tmp = io.open("/tmp/updatestatus")
   local updatestatus = ""
   if tmp then
      updatestatus = tmp:read()
      tmp:close()
   end
   UpdateError = "false"
      if string.match(updatestatus,"(Error)") then
   UpdateError = "true"
   end
   JSONData = "{ \"Status\":\""..updatestatus.."\", \"Error\":"..UpdateError.." }"
  
else
   JSONData = "{ \"Status\":\""..query.."\", \"Error\":true }"
end

http_print(proto.." 200" )
http_print("Pragma: no-cache")
http_print("Cache-Control: no-cache")
http_print("Content-Type: application/json; charset=UTF-8")
http_print(string.format("Content-Length: %d",#JSONData))
http_print()
http_print(JSONData)