--[[
///////////////////////////////////////////////////////////////////////////////////////////
 'XMLDocument'
 
 Uses LuaXML-0.0.0, From Paul Chakravarti. Available at http://lua-users.org/wiki/LuaXml .
 I've made some modifications to LuaXML so that it's more flexible. Primarily, I added the
 ability to parse self-closing tags such as <br/> .

 Copyright(c) 2005, FreePlay. To use this, please contact me at FreePlayPSP@gmail.com.
///////////////////////////////////////////////////////////////////////////////////////////
]]--

function parseXML(XMLfile)
   local XMLHandle = assert(io.open(XMLfile, "r"))
   local XMLData = XMLHandle:read("*all")
   io.close(XMLHandle)
   return collect(XMLData)
end

function parseargs (s)
  local arg = {}
  gsub(s, "([%w:]+)=([\"'])(.-)%2", function (w, _, a)
    arg[w] = a
  end)
  return arg
end

function collect (s)
  string.gsub(s, "<br />","\n")
  --local logfile = assert(io.open("parse.log", "w"))
  local stack = {n=0}
  local top = {n=0}
  tinsert(stack, top)
  local ni,c,label,args, empty
  local i, j = 1, 1
  while 1 do
    ni,j,c,label,args, empty = strfind(s, "<(%/?)([%w:]+)(.-)(%/?)>", j)
    if label ~= nil then label = strlower(label) end
    --logfile:write("c  \""..valOrNil(c).."\"  label  \""..valOrNil(label).."\"  empty  \""..valOrNil(empty).."\"\n")
    if not ni then break end
    local text = strsub(s, i, ni-1)
    if not strfind(text, "^%s*$") then
      tinsert(top, text)
    end
    sct = false
    if c == "" and empty == "/" and label == "" then -- empty element tag
      tinsert(top, {n=0, label=label, args=parseargs(args), empty=1})
    elseif c == "" then   -- start tag
      top = {n=0, label=label, args=parseargs(args)}
      tinsert(stack, top)   -- new level
      if empty == "/" then
         --logfile:write("...\n")
         local toclose = tremove(stack)  -- remove top
         top = stack[stack.n]
         tinsert(top, toclose)
      end
    else  -- end tag
      local toclose = tremove(stack)  -- remove top
      top = stack[stack.n]
      if stack.n < 1 then
        --io.close(logfile)
        error("nothing to close with "..label)
      end
      if strlower(toclose.label) ~= strlower(label) then
        --logfile:write("!!!\n")
        --io.close(logfile)
        error("trying to close "..toclose.label.." with "..label)
      end
      tinsert(top, toclose)
    end 
    i = j + 1
  end
  local text = strsub(s, i)
  --logfile:write("text  "..valOrNil(text).."\n")
  if not strfind(text, "^%s*$") then
    tinsert(stack[stack.n], text)
  end
  if stack.n > 1 then
    --io.close(logfile)
    error("unclosed "..stack[stack.n].label)
  end
  --logfile:write("done\n")
  --logfile:close()
  return stack[1]
end