--
-- (C) 2013-15 - ntop.org
--

dirs = ntop.getDirs()
package.path = dirs.installdir .. "/scripts/lua/modules/?.lua;" .. package.path

require "persistence"

other_stats_id = "Other"

-- #################################################

function getTop(stats, sort_field_key, max_num_entries, lastdump_dir, lastdump_key, use_threshold)
   local _filtered_stats, filtered_stats, counter, total,
         threshold, low_threshold

   if (use_threshold == nil) then use_threshold = true end

   -- stats is a hash of hashes organized as follows:
   -- { "id1" : { "key1": "value1", "key2": "value2", ...}, "id2 : { ... } }
   -- filter out the needed values
   _filtered_stats = {}
   for id,content in pairs(stats) do
      _filtered_stats[id] = content[sort_field_key]
   end

  local file_key = sort_field_key
  if (lastdump_key ~= nil) then
    file_key = file_key.."_"..lastdump_key
  end

   -- Read the lastdump; the name of the lastdump file has the following
   -- format: <lastdump_dir>/.<sort_field_key>_lastdump
   lastdump = lastdump_dir .. "/."..file_key.."_lastdump"
   last = nil
   if(ntop.exists(lastdump)) then
      last = persistence.load(lastdump)
   end
   if(last == nil) then last = {} end

   persistence.store(lastdump, _filtered_stats);

   for key, value in pairs(_filtered_stats) do
      if(last[key] ~= nil) then
         v = _filtered_stats[key]-last[key]
         if(v < 0) then v = 0 end
         _filtered_stats[key] = v
      end
   end

   -- order the filtered stats by using the value (bytes sent/received during
   -- the last time interval) as key
   filtered_stats = {}
   for key, value in pairs(_filtered_stats) do
      filtered_stats[value] = key
   end

   -- Compute traffic
   total = 0
   for _value,_ in pairsByKeys(filtered_stats, rev) do
      total = total + _value
   end

   threshold = total / 10 -- 10 %
   low_threshold = total * 0.05  -- 5%

   -- build a new hashtable sorted by the required field
   top_stats = {}
   other_stats = 0
   counter = 0
   for _value,_id in pairsByKeys(filtered_stats, rev) do
      if (counter < max_num_entries) then
         if ((_value == 0) or (use_threshold == true and ((_value < low_threshold or
             _value < threshold) and (counter > max_num_entries / 2)))) then
            other_stats = other_stats + _value
            goto loop_more_top
         end
         top_stats[_value] = _id -- still keep it in order
         counter = counter + 1
      else
         other_stats = other_stats + _value
      end
   ::loop_more_top::
   end

   if (other_stats > 0) then
     top_stats[other_stats] = other_stats_id
   end

   return top_stats
end

function filterBy(stats, col, val)
  local filtered_by = {}

  if (col == "" or col == nil or val == nil) then
    return stats
  end

  for id,content in pairs(stats) do
    if (content[col] == val) then
      filtered_by[id] = content
    end
  end

  return filtered_by
end

-- #####################################################

function getCurrentTopTalkers(ifid, ifname, filter_col, filter_val, concat, mode, use_threshold, lastdump_key)
   local max_num_entries = 10
   local rsp = ""
   local num = 0

   interface.select(ifname)
   hosts_stats = interface.getHostsInfo()
   hosts_stats = filterBy(hosts_stats, filter_col, filter_val)

   talkers_dir = fixPath(dirs.workingdir .. "/" .. ifid .. "/top_talkers")
   if(not(ntop.exists(talkers_dir))) then
      ntop.mkdir(talkers_dir)
   end

   if(concat == false and mode == nil) then
      rsp = rsp.."{\n"
   end
   rsp = rsp..'\t"hosts": [\n'

   if(mode == nil) then
      rsp = rsp .. "{\n"
      rsp = rsp .. '\t"senders": ['
   end

   --print("Hello\n")
   if((mode == nil) or (mode == "senders")) then
      top_talkers = getTop(hosts_stats, "bytes.sent", max_num_entries, talkers_dir, lastdump_key, use_threshold)
      num = 0
      other_stats = 0
      for value,id in pairsByKeys(top_talkers, rev) do
         if (id == other_stats_id) then
            other_stats = value
         else
	    if(num > 0) then rsp = rsp .. " }," end
	    rsp = rsp .. '\n\t\t { "address": "'..id.. '", "label": "'
	       ..hosts_stats[id]["name"]..'", "url": "'
                  ..ntop.getHttpPrefix()..
	       '/lua/host_details.lua?host='..id..'", "value": '..value..
	       ', "local": "'..tostring(hosts_stats[id]["localhost"])..'"'
	    num = num + 1
         end
      end
      if (other_stats > 0) then
         rsp = rsp .. '},\n\t\t { "address": "'..other_stats_id.. '", "label": "'
            ..other_stats_id..'", "url": "", "value": '..other_stats..
            ', "local": "false"'
      end
   end

   if(mode == nil) then
      if(num > 0) then rsp = rsp .. " }" end
      rsp = rsp .. "\n\t],\n"
      rsp = rsp .. '\t"receivers": ['
   end

   if((mode == nil) or (mode == "receivers")) then
      top_listeners = getTop(hosts_stats, "bytes.rcvd", max_num_entries, talkers_dir, lastdump_key, use_threshold)
      num = 0
      other_stats = 0
      for value,id in pairsByKeys(top_listeners, rev) do
         if (id == other_stats_id) then
            other_stats = value
         else
	    if(num > 0) then rsp = rsp .. " }," end
	    rsp = rsp .. '\n\t\t { "address": "'..id.. '", "label": "'
                  ..hosts_stats[id]["name"]..'", "url": "'
                  ..ntop.getHttpPrefix()..
                  '/lua/host_details.lua?host='..id..'", "value": '..value..
                  ', "local": "'..tostring(hosts_stats[id]["localhost"])..'"'
	    num = num + 1
         end
      end
      if (other_stats > 0) then
         rsp = rsp .. '},\n\t\t { "address": "'..other_stats_id.. '", "label": "'
            ..other_stats_id..'", "url": "", "value": '..other_stats..
            ', "local": "false"'
      end    
   end

   if(mode == nil) then
      if(num > 0) then rsp = rsp .. " }" end
      rsp = rsp .. "\n\t]\n"
      rsp = rsp .. "\n}\n"
   else
      if(num > 0) then rsp = rsp .. " }\n" end
   end

   rsp = rsp.."]"
   if(concat == false and mode == nil) then
      rsp = rsp.."\n}"
   end

   --print(rsp.."\n")
   return(rsp)
end

-- #####################################################

function groupStatsByColumn(ifid, ifname, col)
   local _group = {}
   local total = 0
   -- Group hosts info by the required column
   for _key, value in pairs(hosts_stats) do
      key = hosts_stats[_key][col]

      if ((col == "country" and key == "") or
          (col == "local_network_id" and key == -1) or
          (col == "os" and key == "")) then goto continue end
      if (_group[key] == nil) then
         _group[key] = {}
         old = 0
      else
         assert(_group[key][col.."_bytes.sent"] ~= nil)
         assert(_group[key][col.."_bytes.rcvd"] ~= nil)
         assert(_group[key][col.."_bytes"] ~= nil)
         old = _group[key][col.."_bytes"]
      end

      if (col == "asn") then
         if(key == 0) then
            _group[key]["name"] = "0 [Local/Unknown]"
         else
            _group[key]["name"] = key .." ["..hosts_stats[_key]["asname"].."]"
         end
      elseif (col == "vlan") then
         if (key == 0) then
           _group[key]["name"] = "No VLAN"
         else
           _group[key]["name"] = "VLAN"..hosts_stats[_key]["vlan"]
         end
      elseif (col == "country") then
         if (key == "") then
           _group[key]["name"] = "Unknown"
         else
           _group[key]["name"] = key
         end
      elseif (col == "local_network_id") then
         if (key == -1) then
           _group[key]["name"] = "[Unknown]"
         else
           _group[key]["name"] = hosts_stats[_key]["local_network_name"]
         end
      elseif (col == "os") then
         if (key == "") then
           _group[key]["name"] = "[Unknown]"
         else
           _group[key]["name"] = hosts_stats[_key]["os"]
         end
      end
      val = hosts_stats[_key]["bytes.sent"] + hosts_stats[_key]["bytes.rcvd"]
      total = total + val
      _group[key][col.."_bytes"] = old + val
      _group[key][col.."_bytes"] = old + val
      _group[key][col.."_bytes.sent"] = ternary(_group[key][col.."_bytes.sent"] ~= nil,
                                                _group[key][col.."_bytes.sent"], 0)
                                        + hosts_stats[_key]["bytes.sent"]
      _group[key][col.."_bytes.rcvd"] = ternary(_group[key][col.."_bytes.rcvd"] ~= nil,
                                                _group[key][col.."_bytes.rcvd"], 0)
                                        + hosts_stats[_key]["bytes.rcvd"]
     ::continue::
   end
  return _group, total
end

function getCurrentTopGroupsSeparated(ifid, ifname, max_num_entries, use_threshold,
                                      use_delta, filter_col, filter_val, col, key, loc, concat, mode, lastdump_key)
   max_num_entries = 10  -- TODO: check if max_num_entries can be forcefully set to 10
   rsp = ""

   interface.select(ifname)
   hosts_stats = interface.getHostsInfo()
   hosts_stats = filterBy(hosts_stats, filter_col, filter_val)
   if (loc ~= nil) then
     hosts_stats = filterBy(hosts_stats, "localhost", loc)
   end

   talkers_dir = fixPath(dirs.workingdir .. "/" .. ifid .. "/top_talkers")
   if(not(ntop.exists(talkers_dir))) then
      ntop.mkdir(talkers_dir)
   end

   _group, total = groupStatsByColumn(ifid, ifname, col)

   if(concat == false and mode == nil) then
      rsp = rsp.."{\n"
   end
   rsp = rsp..'\t"'..key..'": [\n'

   if(mode == nil) then
      rsp = rsp .. "{\n"
      rsp = rsp .. '\t"senders": ['
   end

   if((mode == nil) or (mode == "senders")) then
      top_talkers = getTop(_group, col.."_bytes.sent", max_num_entries, talkers_dir, lastdump_key)
      num = 0
      other_stats = 0
      for value,id in pairsByKeys(top_talkers, rev) do
         if (id == other_stats_id) then
            other_stats = value
         else
	    if(num > 0) then rsp = rsp .. " }," end
	    rsp = rsp .. '\n\t\t { "label": "'.._group[id]["name"].. '", "url": "'
                  ..ntop.getHttpPrefix()..
                  '/lua/hosts_stats.lua?'..col..'='..id..'", "address": "'
                  ..id..'", "value": '..value
	    num = num + 1
         end
      end
      if (other_stats > 0) then
         rsp = rsp .. '},\n\t\t { "address": "'..other_stats_id.. '", "label": "'
            ..other_stats_id..'", "url": "", "value": '..other_stats..
            ', "local": "false"'
      end
   end

   if(mode == nil) then
      if(num > 0) then rsp = rsp .. " }" end
      rsp = rsp .. "\n\t],\n"
      rsp = rsp .. '\t"receivers": ['
   end

   if((mode == nil) or (mode == "receivers")) then
      top_listeners = getTop(_group, col.."_bytes.rcvd", max_num_entries, talkers_dir, lastdump_key)
      num = 0
      other_stats = 0
      for value,id in pairsByKeys(top_listeners, rev) do
         if (id == other_stats_id) then
            other_stats = value
         else
	    if(num > 0) then rsp = rsp .. " }," end
	    rsp = rsp .. '\n\t\t { "label": "'.._group[id]["name"].. '", "url": "'
                  ..ntop.getHttpPrefix()..
                  '/lua/hosts_stats.lua?'..col..'='..id..'", "address": "'
                  ..id..'", "value": '..value
	    num = num + 1
         end
      end
      if (other_stats > 0) then
         rsp = rsp .. '},\n\t\t { "address": "'..other_stats_id.. '", "label": "'
            ..other_stats_id..'", "url": "", "value": '..other_stats..
            ', "local": "false"'
      end
   end

   if(mode == nil) then
      if(num > 0) then rsp = rsp .. " }" end
      rsp = rsp .. "\n\t]\n"
      rsp = rsp .. "\n}\n"
   else
      if(num > 0) then rsp = rsp .. " }\n" end
   end

   rsp = rsp.."]"
   if(concat == false and mode == nil) then
      rsp = rsp.."\n}"
   end

   --print(rsp.."\n")
   return(rsp)
end

function getCurrentTopGroups(ifid, ifname, max_num_entries, use_threshold,
                             use_delta, filter_col, filter_val, col, key, concat, mode, lastdump_key)
   rsp = ""

   --if(ifname == nil) then ifname = "any" end

   interface.select(ifname)
   hosts_stats = interface.getHostsInfo()
   hosts_stats = filterBy(hosts_stats, filter_col, filter_val)

   talkers_dir = fixPath(dirs.workingdir .. "/" .. ifid .. "/top_talkers")
   if(not(ntop.exists(talkers_dir))) then
      ntop.mkdir(talkers_dir)
   end

   _group, total = groupStatsByColumn(ifid, ifname, col)

   if(concat == true) then
      rsp = rsp..'"'..key..'": '
   end

   rsp = rsp .. "[\n"

   -- Get top groups
   top_groups = getTop(_group, col.."_bytes", max_num_entries, talkers_dir, lastdump_key, use_threshold)

   num = 0
   other_stats = 0
   for _value,_key in pairsByKeys(top_groups, rev) do
      if (key == other_stats_id) then
         other_stats = value
      else
         if(num > 0) then rsp = rsp .. " }," end
         rsp = rsp .. '\n\t\t { "label": "'.._key..'", "url": "'
               ..ntop.getHttpPrefix()..
	    '/lua/hosts_stats.lua?'..col..'='.._key..'", "name": "'

	 if((_group[_key] ~= nil) and (_group[_key]["name"] ~= nil)) then rsp = rsp .. _group[_key]["name"] end
	 rsp = rsp ..'", "value": '.._value
         num = num + 1
      end
   end
   if (other_stats > 0) then
      rsp = rsp .. '},\n\t\t { "address": "'..other_stats_id.. '", "label": "'
         ..other_stats_id..'", "url": "", "value": '..other_stats..
         ', "local": "false"'
   end

   if (num > 0) then
      rsp = rsp .. " }\n"
   end
   rsp = rsp .. "\n]"

   return(rsp)
end