--[[
Copyright (c) 2011-2015, Vsevolod Stakhov <vsevolod@highsecure.ru>
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

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]]--

-- This is main lua config file for rspamd

local util = require "rspamd_util"
local rspamd_regexp = require "rspamd_regexp"
local rspamd_logger = require "rspamd_logger"

local reconf = config['regexp']

-- Uncategorized rules
local subject_re = rspamd_regexp.create('/^(?:(?:Re|Fwd|Fw|Aw|Antwort|Sv):\\s*)+(.+)$/i')

-- Local rules
local r_bgcolor = '/BGCOLOR=/iP'
local r_font_color = '/font color=[\\"\']?\\#FFFFFF[\\"\']?/iP'
reconf['R_WHITE_ON_WHITE'] = string.format('(!(%s) & (%s))', r_bgcolor, r_font_color)
reconf['R_FLASH_REDIR_IMGSHACK'] = '/^(?:http:\\/\\/)?img\\d{1,5}\\.imageshack\\.us\\/\\S+\\.swf/U'

-- Different text parts
rspamd_config.R_PARTS_DIFFER = function(task)
  local distance = task:get_mempool():get_variable('parts_distance', 'int')

  if distance then
    local nd = tonumber(distance)

    if nd < 50 then
      local score = 1 - util.tanh(nd / 100.0)

      task:insert_result('R_PARTS_DIFFER', score, tostring(nd) .. '%')
    end
  end

  return false
end

-- Date issues
rspamd_config.MISSING_DATE = function(task)
	if rspamd_config:get_api_version() >= 5 then
		if not task:get_header_raw('Date') then
			return true
		end
	end

	return false
end
rspamd_config.DATE_IN_FUTURE = function(task)
	if rspamd_config:get_api_version() >= 5 then
		local dm = task:get_date{format = 'message'}
		local dt = task:get_date{format = 'connect'}
		-- An 2 hour
		if dm > 0 and dm - dt > 7200 then
			return true
		end
	end

	return false
end
rspamd_config.DATE_IN_PAST = function(task)
	if rspamd_config:get_api_version() >= 5 then
    local dm = task:get_date{format = 'message', gmt = true}
    local dt = task:get_date{format = 'connect', gmt = true}
		-- A day
		if dm > 0 and dt - dm > 86400 then
			return true
		end
	end

	return false
end

rspamd_config.R_SUSPICIOUS_URL = {
  callback = function(task)
    local urls = task:get_urls()

    if urls then
      for i,u in ipairs(urls) do
        if u:is_obscured() then
          return true
        end
      end
    end
    return false
  end,
  score = 6.0,
  group = 'url',
  one_shot = true,
  description = 'Obfusicated or suspicious URL has been found in a message'
}

rspamd_config.SUBJ_ALL_CAPS = {
  callback = function(task)
    local sbj = task:get_header('Subject')

    if sbj then
      local stripped_subject = subject_re:search(sbj, false, true)
      if stripped_subject and stripped_subject[1] and stripped_subject[1][2] then
        sbj = stripped_subject[1][2]
      end

      if util.is_uppercase(sbj) then
        return true
      end
    end

    return false
  end,
  score = 3.0,
  group = 'headers',
  description = 'All capital letters in subject'
}