package bans

import (
  "encoding/json"
  "io/ioutil"
  "net/http"
  "strings"
  "regexp"
  "time"
  "fmt"
)

type BanSettings struct{
  ProxySites []string
  ProxyInterval int
  ProxyBanReason string
  OptimizationStarter int
}

// call this function on a timer
func optimizeBanTable(optimization_starter int, ban_reason string){
  var explored_ips []string // ["192.0.0.0/17","192.0.0.128/17"]
  //1 Fetch all bans
  var bans []string
  bans = getBanList()
  //2 take one ban
  for _, ban := range bans{
    // build subnet chunks and itterate over them
      // eg for 192.168.1.1
      // 192.0.0.0/9 , 192.128.0.0/9 , 192.168.0.0/17 , 192.168.128.0/17 , 192.168.1.0/25 , 192.168.1.128/25    6x
      // or for ipv6 , 2605:8d80:504:4fb1:1c6b:ea11:a067:e812 , a less chunked system
      //  2605:0:0:0:0:0:0:0/16 ,  2605:8d80:0:0:0:0:0:0/32 , 2605:8d80:504:0:0:0:0:0/48 , 2605:8d80:504:4fb1:0:0:0:0/64 , 2605:8d80:504:4fb1:1c6b:0:0:0/80 ,  2605:8d80:504:4fb1:1c6b:ea11:0:0/96    6x
    for i := 0 ; i < 6 ; i++ {
      is_ipv4 := strings.Contains(ban, ".")
      var search_ip string
      // A chunk is a number of FF blocks in an IP address(ff.0.0.0 or ff00:::::)
      if is_ipv4{
        search_ip = createOffsetChunk(i + 1)
      } else{
        search_ip = createOffsetChunk((i + 1) * 2)
      }
      is_explored := false
      for _, explored_ip := range explored_ips{
        // use explored_subnets for redundant checks(if a search equals an already explored search it's pointless)
        if checkBanContained(search_ip, explored_ip) == 0{
          is_explored = true
          break
        }
      }
      if is_explored{
        continue
      }
      // itterate over bans for main action
      chunk_weight := 0
      var counted_bans []string
      for _, existing_ban := range bans{
        containment_check := checkBanContained(search_ip, existing_ban)
        if containment_check == 1{
          // see if search already exists in a prexisting ban(redundancy check)
          break
        } else{
          // within each itterated chunk check the ban list for items falling within this
            // if  an item is found add it to the count
            // A subnet counts as a number based on the mask bit
              // a ban of ff.0.0.0/7 counts for 720*optimization_starter bans(2160)
              // a ban of ff.ff.0.0/17 counts for 24*optimization_starter bans(72)
              // a ban of ff.ff.ff.0/25 counts for 2*optimization_starter bans(6)
              // A single IP counts for 1
            // for IPv6 these values are weighted on the same ratios
          chunk_weight = chunk_weight + weightBanContainment(search_ip, existing_ban)
          counted_bans = append(counted_bans, existing_ban)
        }
      }
      // use a factorial system based on the mask value to evaluate weather the number of bans is enough to lock the current chunk with a ban
      chunk_threshold = optimization_starter
      for j := 6 ; j > i ; j--{
        // 6 x 5 x 4 x 3 x 2 x 1 x starter
          // a ban of ff.0.0.0/7 will take 720*optimization_starter bans(2160)
        // 4 x 3 x 2 x 1 x starter
          // a ban of ff.ff.0.0/17 will take 24*optimization_starter bans(72)
        // 2 x 1 x starter
          // a ban of ff.ff.ff.0/25 will take 2*optimization_starter bans(6)
        chunk_threshold = chunk_threshold*(j)
      }
      if chunk_weight > chunk_threshold{
        // if it's enough to warant a lock, add the bans used for counting to the explored_ips list.
        // remove these contained bans if they are given the autoban reason. This will lead to some inevitable inaccuracies in the algorithm through the overweighting of manual bans on a subnet over automatic ones.
          // this may be preferable but it is not tunable
        newBan(search_ip,  ban_reason + " (Automatic)")
        for _, ban_ip := range counted_bans{
          // remove only the targetted
          removeBan(ban_ip, []string{ban_reason, ban_reason + " (Automatic)"})
        }
      }
    }
  }
}

func getBansFromProxySites(sitelist []string, reason string){
  //https://www.regexpal.com/?fam=104038
  ipv4_or_6_reg_with_possible_mask := regexp.MustCompile("(?i)\\b((((([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])))|(((([0-9a-f]{1,4}:){7}([0-9a-f]{1,4}|:))|(([0-9a-f]{1,4}:){6}(:[0-9a-f]{1,4}|((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3})|:))|(([0-9a-f]{1,4}:){5}(((:[0-9a-f]{1,4}){1,2})|:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3})|:))|(([0-9a-f]{1,4}:){4}(((:[0-9a-f]{1,4}){1,3})|((:[0-9a-f]{1,4})?:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3}))|:))|(([0-9a-f]{1,4}:){3}(((:[0-9a-f]{1,4}){1,4})|((:[0-9a-f]{1,4}){0,2}:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3}))|:))|(([0-9a-f]{1,4}:){2}(((:[0-9a-f]{1,4}){1,5})|((:[0-9a-f]{1,4}){0,3}:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3}))|:))|(([0-9a-f]{1,4}:){1}(((:[0-9a-f]{1,4}){1,6})|((:[0-9a-f]{1,4}){0,4}:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3}))|:))|(:(((:[0-9a-f]{1,4}){1,7})|((:[0-9a-f]{1,4}){0,5}:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3}))|:)))))(/[0-9]+)?\\b")
  var ip_list [][][]byte
  for _,site := range sitelist{
    fmt.Println(site)
    response, err:=http.Get(site)
    if err != nil{
      fmt.Println("GET ERROR : " + site)
      continue
    }
    contents, err := ioutil.ReadAll(response.Body)
    if err != nil{
      panic(err)
    }
    response.Body.Close()
    var ip_matches [][]byte
    ip_matches = ipv4_or_6_reg_with_possible_mask.FindAll(contents, -1)
    ip_list = append(ip_list, ip_matches...)
  }
  // remove duplicates for less DB checks
  for _,ip_a := range ip_list{
    dup := false
    for _,ip_b := range ip_list{
      if Compare(ip_a, ip_b) == 0{
        dup = true
        break;
      }
    }
    if dup == false{
      newBan(ip_a, reason)
    }
  }
}

func CreateRecurentActionTicker(){
  fmt.Println("Setting up proxy actions...")
  ban_info,_ := ioutil.ReadFile("./.ban-actions.json")
  var settings BanSettings
  err := json.Unmarshal(ban_info, &settings)
  if err != nil{
    panic(err)
  }
  fmt.Printf("sites ... %v\n" , settings.ProxySites)
  fmt.Printf("time ... %d\n" ,  settings.ProxyInterval)
  ban_ticker := time.NewTicker(time.Duration(settings.ProxyInterval) * time.Second)
  go func() {
      for {
          <-ban_ticker.C
          fmt.Printf("Action\n")
          // JSON data may have changed since initializing
          ban_info,_ = ioutil.ReadFile("./.ban-actions.json")
          err := json.Unmarshal(ban_info, &settings)
          if err != nil{
            panic(err)
          }
          // Get bans from list
          getBansFromProxySites(settings.ProxySites, settings.ProxyBanReason)
          // Optimize table and make esitimations
          optimizeBanTable(settings.OptimizationStarter, settings.ProxyBanReason)
      }
  }()

  //getBansFromProxySites(settings.ProxySites, settings.ProxyBanReason)

}