--[[
Copyright (c) 2016, Vsevolod Stakhov <vsevolod@highsecure.ru>

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
]]--

local rspamd_logger = require 'rspamd_logger'
local rspamd_http = require "rspamd_http"

local E = {}

local rows = {}
local attachment_rows = {}
local urls_rows = {}
local specific_rows = {}
local asn_rows = {}
local nrows = 0

local settings = {
  limit = 1000,
  timeout = 5.0,
  bayes_spam_symbols = {'BAYES_SPAM'},
  bayes_ham_symbols = {'BAYES_HAM'},
  fann_symbols = {'FANN_SCORE'},
  fuzzy_symbols = {'FUZZY_DENIED'},
  whitelist_symbols = {'WHITELIST_DKIM', 'WHITELIST_SPF_DKIM', 'WHITELIST_DMARC'},
  dkim_allow_symbols = {'R_DKIM_ALLOW'},
  dkim_reject_symbols = {'R_DKIM_REJECT'},
  dmarc_allow_symbols = {'DMARC_POLICY_ALLOW'},
  dmarc_reject_symbols = {'DMARC_POLICY_REJECT', 'DMARC_POLICY_QUARANTINE'},
  table = 'rspamd',
  attachments_table = 'rspamd_attachments',
  urls_table = 'rspamd_urls',
  ipmask = 19,
  ipmask6 = 48,
  full_urls = false,
  from_tables = nil
}

--[[
Clickhouse schema:

CREATE TABLE rspamd
(
    Date Date,
    TS DateTime,
    From String,
    MimeFrom String,
    IP String,
    Score Float64,
    NRcpt UInt8,
    Size UInt32,
    IsWhitelist Enum8('blacklist' = 0, 'whitelist' = 1, 'unknown' = 2) DEFAULT CAST('unknown' AS Enum8('blacklist' = 0, 'whitelist' = 1, 'unknown' = 2)),
    IsBayes Enum8('ham' = 0, 'spam' = 1, 'unknown' = 2) DEFAULT CAST('unknown' AS Enum8('ham' = 0, 'spam' = 1, 'unknown' = 2)),
    IsFuzzy Enum8('whitelist' = 0, 'deny' = 1, 'unknown' = 2) DEFAULT CAST('unknown' AS Enum8('whitelist' = 0, 'deny' = 1, 'unknown' = 2)),
    IsFann Enum8('ham' = 0, 'spam' = 1, 'unknown' = 2) DEFAULT CAST('unknown' AS Enum8('ham' = 0, 'spam' = 1, 'unknown' = 2)),
    IsDkim Enum8('reject' = 0, 'allow' = 1, 'unknown' = 2) DEFAULT CAST('unknown' AS Enum8('reject' = 0, 'allow' = 1, 'unknown' = 2)),
    IsDmarc Enum8('reject' = 0, 'allow' = 1, 'unknown' = 2) DEFAULT CAST('unknown' AS Enum8('reject' = 0, 'allow' = 1, 'unknown' = 2)),
    NUrls Int32,
    Action Enum8('reject' = 0, 'rewrite subject' = 1, 'add header' = 2, 'greylist' = 3, 'no action' = 4) DEFAULT CAST('no action' AS Enum8('reject' = 0, 'rewrite subject' = 1, 'add header' = 2, 'greylist' = 3, 'no action' = 4)),
    FromUser String,
    MimeUser String,
    RcptUser String,
    RcptDomain String,
    ListId String,
    Digest FixedString(32)
) ENGINE = MergeTree(Date, (TS, From), 8192)

CREATE TABLE rspamd_attachments (
    Date Date,
    Digest FixedString(32),
    `Attachments.FileName` Array(String),
    `Attachments.ContentType` Array(String),
    `Attachments.Length` Array(UInt32),
    `Attachments.Digest` Array(FixedString(16))
) ENGINE = MergeTree(Date, Digest, 8192)

CREATE TABLE rspamd_urls (
    Date Date,
    Digest FixedString(32),
    `Urls.Tld` Array(String),
    `Urls.Url` Array(String)
) ENGINE = MergeTree(Date, Digest, 8192)

CREATE TABLE rspamd_asn (
    Date Date,
    Digest FixedString(32),
    ASN String,
    Country FixedString(2),
    IPNet String
) ENGINE = MergeTree(Date, Digest, 8192)
]]

local function clickhouse_main_row(tname)
  local fields = {
    'Date',
    'TS',
    'From',
    'MimeFrom',
    'IP',
    'Score',
    'NRcpt',
    'Size',
    'IsWhitelist',
    'IsBayes',
    'IsFuzzy',
    'IsFann',
    'IsDkim',
    'IsDmarc',
    'NUrls',
    'Action',
    'FromUser',
    'MimeUser',
    'RcptUser',
    'RcptDomain',
    'ListId',
    'Digest'
  }
  local elt = string.format('INSERT INTO %s (%s) VALUES ',
    tname, table.concat(fields, ','))

  return elt
end

local function clickhouse_attachments_row(tname)
  local attachement_fields = {
    'Date',
    'Digest',
    'Attachments.FileName',
    'Attachments.ContentType',
    'Attachments.Length',
    'Attachments.Digest',
  }
  local elt = string.format('INSERT INTO %s (%s) VALUES ',
    tname, table.concat(attachement_fields, ','))
  return elt
end

local function clickhouse_urls_row(tname)
  local urls_fields = {
    'Date',
    'Digest',
    'Urls.Tld',
    'Urls.Url',
  }
  local elt = string.format('INSERT INTO %s (%s) VALUES ',
    tname, table.concat(urls_fields, ','))
  return elt
end

local function clickhouse_asn_row(tname)
  local asn_fields = {
    'Date',
    'Digest',
    'ASN',
    'Country',
    'IPNet',
  }
  local elt = string.format('INSERT INTO %s (%s) VALUES ',
    tname, table.concat(asn_fields, ','))
  return elt
end

local function clickhouse_first_row()
  table.insert(rows, clickhouse_main_row(settings['table']))
  if settings['attachments_table'] then
    table.insert(attachment_rows,
      clickhouse_attachments_row(settings['attachments_table']))
  end
  if settings['urls_table'] then
    table.insert(urls_rows,
      clickhouse_urls_row(settings['urls_table']))
  end
  if settings['asn_table'] then
    table.insert(asn_rows,
      clickhouse_asn_row(settings['asn_table']))
  end
end

local function clickhouse_check_symbol(task, symbols, need_score)
  for _,s in ipairs(symbols) do
    if task:has_symbol(s) then
      if need_score then
        local sym = task:get_symbol(s)[1]
        return sym['score']
      else
        return true
      end
    end
  end

  return false
end

local function clickhouse_send_data(task)
  local function http_cb(err_message, code, _, _)
    if code ~= 200 or err_message then
      rspamd_logger.errx(task, "cannot send data to clickhouse server %s: %s:%s",
        settings['server'], code, err_message)
    else
      rspamd_logger.infox(task, "sent %s rows to clickhouse server %s",
        settings['limit'], settings['server'])
    end
  end

  local body = table.concat(rows, ' ')
  if not rspamd_http.request({
      task = task,
      url = 'http://' .. settings['server'],
      body = body,
      callback = http_cb,
      mime_type = 'text/plain',
      timeout = settings['timeout'],
    }) then
     rspamd_logger.errx(task, "cannot send data to clickhouse server %s: cannot make request",
        settings['server'])
  end

  if #attachment_rows > 1 then
    body = table.concat(attachment_rows, ' ')
    if not rspamd_http.request({
      task = task,
      url = 'http://' .. settings['server'],
      body = body,
      callback = http_cb,
      mime_type = 'text/plain',
      timeout = settings['timeout'],
    }) then
      rspamd_logger.errx(task, "cannot send attachments to clickhouse server %s: cannot make request",
        settings['server'])
    end
  end
  if #urls_rows > 1 then
    body = table.concat(urls_rows, ' ')
    if not rspamd_http.request({
      task = task,
      url = 'http://' .. settings['server'],
      body = body,
      callback = http_cb,
      mime_type = 'text/plain',
      timeout = settings['timeout'],
    }) then
      rspamd_logger.errx(task, "cannot send urls to clickhouse server %s: cannot make request",
        settings['server'])
    end
  end
  if #asn_rows > 1 then
    body = table.concat(asn_rows, ' ')
    if not rspamd_http.request({
      task = task,
      url = 'http://' .. settings['server'],
      body = body,
      callback = http_cb,
      mime_type = 'text/plain',
      timeout = settings['timeout'],
    }) then
      rspamd_logger.errx(task, "cannot send asn info to clickhouse server %s: cannot make request",
        settings['server'])
    end
  end

  for k,specific in pairs(specific_rows) do
    if #specific > 1 then
      body = table.concat(specific, ' ')
      if not rspamd_http.request({
        task = task,
        url = 'http://' .. settings['server'],
        body = body,
        callback = http_cb,
        mime_type = 'text/plain',
        timeout = settings['timeout'],
      }) then
        rspamd_logger.errx(task, "cannot send data for domain %s to clickhouse server %s: cannot make request",
          k, settings['server'])
      end
    end
  end
end

local function clickhouse_quote(str)
  if str then
    return str:gsub('[\'\\]', '\\%1'):lower()
  else
    return ''
  end
end

local function clickhouse_collect(task)
  local from_domain = ''
  local from_user = ''
  if task:has_from('smtp') then
    local from = task:get_from('smtp')[1]

    if from then
      from_domain = from['domain']
      from_user = from['user']
    end

    if from_domain == '' then
      if task:get_helo() then
        from_domain = task:get_helo()
      end
    end
  else
    if task:get_helo() then
      from_domain = task:get_helo()
    end
  end

  local mime_domain = ''
  local mime_user = ''
  if task:has_from('mime') then
    local from = task:get_from('mime')[1]
    if from then
      mime_domain = from['domain']
      mime_user = from['user']
    end
  end

  local ip_str = 'undefined'
  local ip = task:get_from_ip()
  if ip and ip:is_valid() then
    local ipnet
    if ip:get_version() == 4 then
      ipnet = ip:apply_mask(settings['ipmask'])
    else
      ipnet = ip:apply_mask(settings['ipmask6'])
    end
    ip_str = ipnet:to_string()
  end

  local rcpt_user = ''
  local rcpt_domain = ''
  if task:has_recipients('smtp') then
    local rcpt = task:get_recipients('smtp')[1]
    rcpt_user = rcpt['user']
    rcpt_domain = rcpt['domain']
  end

  local list_id = ''
  local lh = task:get_header('List-Id')
  if lh then
    list_id = lh
  end

  local score = task:get_metric_score('default')[1];
  local bayes = 'unknown';
  local fuzzy = 'unknown';
  local fann = 'unknown';
  local whitelist = 'unknown';
  local dkim = 'unknown';
  local dmarc = 'unknown';

  local ret

  ret = clickhouse_check_symbol(task, settings['bayes_spam_symbols'], false)
  if ret then
    bayes = 'spam'
  end

  ret = clickhouse_check_symbol(task, settings['bayes_ham_symbols'], false)
  if ret then
    bayes = 'ham'
  end

  ret = clickhouse_check_symbol(task, settings['fann_symbols'], true)
  if ret then
    if ret > 0 then
      fann = 'spam'
    else
      fann = 'ham'
    end
  end


  ret = clickhouse_check_symbol(task, settings['whitelist_symbols'], true)
  if ret then
    if ret < 0 then
      whitelist = 'whitelist'
    else
      whitelist = 'blacklist'
    end
  end

  ret = clickhouse_check_symbol(task, settings['fuzzy_symbols'], false)
  if ret then
    fuzzy = 'deny'
  end

  ret = clickhouse_check_symbol(task, settings['dkim_allow_symbols'], false)
  if ret then
    dkim = 'allow'
  end

  ret = clickhouse_check_symbol(task, settings['dkim_reject_symbols'], false)
  if ret then
    dkim = 'reject'
  end

  ret = clickhouse_check_symbol(task, settings['dmarc_allow_symbols'], false)
  if ret then
    dmarc = 'allow'
  end

  ret = clickhouse_check_symbol(task, settings['dmarc_reject_symbols'], false)
  if ret then
    dmarc = 'reject'
  end

  local nrcpts = 0
  if task:has_recipients('smtp') then
    nrcpts = #task:get_recipients('smtp')
  end

  local nurls = 0
  if task:has_urls(true) then
    nurls = #task:get_urls(true)
  end

  local timestamp = task:get_date({
    format = 'connect',
    gmt = false
  })

  local elt = string.format("(today(),%d,'%s','%s','%s',%.2f,%d,%d,'%s','%s','%s','%s','%s','%s',%d,'%s','%s','%s','%s','%s','%s','%s')",
        timestamp,
        clickhouse_quote(from_domain), clickhouse_quote(mime_domain), ip_str, score,
        nrcpts, task:get_size(), whitelist, bayes, fuzzy, fann,
        dkim, dmarc, nurls, task:get_metric_action('default'),
        clickhouse_quote(from_user), clickhouse_quote(mime_user),
        clickhouse_quote(rcpt_user), clickhouse_quote(rcpt_domain),
        clickhouse_quote(list_id), task:get_digest())
  table.insert(rows, elt)

  if settings['from_map'] and dkim == 'allow' then
    -- Use dkim
    local das = task:get_symbol(settings['dkim_allow_symbols'][1])
    if ((das or E)[1] or E).options then
      for _,dkim_domain in ipairs(das[1]['options']) do
        local specific = settings.from_map:get_key(dkim_domain)
        if specific then
          if not specific_rows[specific] then
            local first = clickhouse_main_row(specific)
            specific_rows[specific] = {first}
          end
          table.insert(specific_rows[specific], elt)
        end
      end
    end

  end

  -- Attachments step
  local attachments_fnames = {}
  local attachments_ctypes = {}
  local attachments_lengths = {}
  local attachments_digests = {}
  for _,part in ipairs(task:get_parts()) do
    local fname = part:get_filename()

    if fname then
      table.insert(attachments_fnames, string.format("'%s'", clickhouse_quote(fname)))
      local type, subtype = part:get_type()
      table.insert(attachments_ctypes, string.format("'%s/%s'",
        clickhouse_quote(type), clickhouse_quote(subtype)))
      table.insert(attachments_lengths, string.format("%s", tostring(part:get_length())))
      table.insert(attachments_digests, string.format("'%s'", string.sub(part:get_digest(), 1, 16)))
    end
  end

  if #attachments_fnames > 0 then
    elt = string.format("(today(),'%s',[%s],[%s],[%s],[%s])",
      task:get_digest(),
      table.concat(attachments_fnames, ','),
      table.concat(attachments_ctypes, ','),
      table.concat(attachments_lengths, ','),
      table.concat(attachments_digests, ','))
    table.insert(attachment_rows, elt)
  end

  -- Urls step
  local urls_tlds = {}
  local urls_urls = {}
  if task:has_urls(false) then
    for _,u in ipairs(task:get_urls()) do
      table.insert(urls_tlds, string.format("'%s'", clickhouse_quote(u:get_tld())))
      if settings['full_urls'] then
        table.insert(urls_urls, string.format("'%s'",
          clickhouse_quote(u:get_text())))
      else
        table.insert(urls_urls, string.format("'%s'",
          clickhouse_quote(u:get_host())))
      end
    end
  end

  if #urls_tlds > 0 then
    elt = string.format("(today(),'%s',[%s],[%s])",
      task:get_digest(),
      table.concat(urls_tlds, ','),
      table.concat(urls_urls, ','))
    table.insert(urls_rows, elt)
  end

  -- ASN information
  if settings['asn_table'] then
    local asn, country, ipnet = 'unknown', 'unknown', 'unknown'
    local pool = task:get_mempool()
    ret = pool:get_variable("asn")
    if ret then
      asn = ret
    end
    ret = pool:get_variable("country")
    if ret then
      country = ret
    end
    ret = pool:get_variable("ipnet")
    if ret then
      ipnet = ret
    end
    elt = string.format("(today(),'%s','%s','%s','%s')",
      task:get_digest(),
      clickhouse_quote(asn), clickhouse_quote(country), clickhouse_quote(ipnet))
    table.insert(asn_rows, elt)
  end

  nrows = nrows + 1

  if nrows > settings['limit'] then
    clickhouse_send_data(task)
    nrows = 0
    rows = {}
    attachment_rows = {}
    urls_rows = {}
    specific_rows = {}
    asn_rows = {}
    clickhouse_first_row()
  end
end

local opts = rspamd_config:get_all_opt('clickhouse')
if opts then
    for k,v in pairs(opts) do
      settings[k] = v
    end

    if not settings['server'] then
      rspamd_logger.infox(rspamd_config, 'no servers are specified, disabling module')
    else
      settings['from_map'] = rspamd_map_add('clickhouse', 'from_tables',
        'regexp', 'clickhouse specific domains')
      clickhouse_first_row()
      rspamd_config:register_symbol({
        name = 'CLICKHOUSE_COLLECT',
        type = 'postfilter',
        callback = clickhouse_collect,
        priority = 10
      })
      rspamd_config:register_finish_script(function(task)
        if nrows > 0 then
          clickhouse_send_data(task)
        end
      end)
    end
end
