package main

import (
	"bytes"
	"fmt"
	"io/ioutil"
	"log"
	"net"
	"net/http"
)

//Zexpressions is the set of regexp being used by zardoz
var Zexpressions = []string{
	`[[:alpha:]]{4,32}`,                              // alpha digit token
	`[ ]([A-Za-z0-9-_]{4,}\.)+\w+`,                   // domain name
	`[ ]/[A-Za-z0-9-_/.]{4,}[ ]`,                     // URI path (also partial)
	`[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}`, // IP address
	`[0-9a-fA-F]{8}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{12}`, // UUID
}

func passAndLearn(resp *http.Response) error {

	ProxyFlow.response = resp
	ProxyFlow.seniority++
	req := ProxyFlow.request

	switch {
	case isAuth(resp):
		log.Println("401: We don't want to store credentials")
	case isError(resp):
		buf := bytes.NewBufferString(BlockMessage)
		resp.Body = ioutil.NopCloser(buf)
		resp.Status = "403 Forbidden"
		resp.StatusCode = 403
		resp.Header["Content-Length"] = []string{fmt.Sprint(buf.Len())}
		resp.Header.Set("Content-Encoding", "none")
		resp.Header.Set("Cache-Control", "no-cache, no-store")
		log.Println("Filing inside bad class")
		feedRequest(req, "BAD")
		ControPlane.StatsTokens <- "DOWNGRADE"
	case isSuccess(resp):
		log.Println("Filing inside Good Class: ", resp.StatusCode)
		feedRequest(req, "GOOD")
	}

	return nil
}

func blockAndlearn(resp *http.Response) error {

	ProxyFlow.response = resp
	ProxyFlow.seniority++
	req := ProxyFlow.request

	buf := bytes.NewBufferString(BlockMessage)
	resp.Body = ioutil.NopCloser(buf)
	resp.Status = "403 Forbidden"
	resp.StatusCode = 403
	resp.Header["Content-Length"] = []string{fmt.Sprint(buf.Len())}
	resp.Header.Set("Content-Encoding", "none")
	resp.Header.Set("Cache-Control", "no-cache, no-store")

	switch {
	case isAuth(resp):
		log.Println("401: We don't want to store credentials")
	case isError(resp):
		log.Println("Filing inside bad class")
		feedRequest(req, "BAD")
	case isSuccess(resp):
		log.Println("Filing inside Good Class: ", resp.StatusCode)
		ControPlane.StatsTokens <- "UPGRADED"
		feedRequest(req, "GOOD")
	}

	return nil

}

func feedRequest(req *http.Request, class string) {

	feed := SourceIP(req)

	//	feed := formatRequest(req)

	if class == "BAD" {

		log.Println("Feeding BAD token: ", feed)

		ControPlane.BadTokens <- feed

	}

	if class == "GOOD" {

		log.Println("Feeding GOOD Token:", feed)

		ControPlane.GoodTokens <- feed

	}

}

//Unique returns unique elements in the string
func Unique(slice []string) []string {
	// create a map with all the values as key
	uniqMap := make(map[string]struct{})
	for _, v := range slice {
		uniqMap[v] = struct{}{}
	}

	// turn the map keys into a slice
	uniqSlice := make([]string, 0, len(uniqMap))
	for v := range uniqMap {
		uniqSlice = append(uniqSlice, v)
	}
	return uniqSlice
}

func isSuccess(resp *http.Response) bool {
	return resp.StatusCode <= 299
}

func isAuth(resp *http.Response) bool {
	return resp.StatusCode == 401
}

func isError(resp *http.Response) bool {
	return resp.StatusCode >= 400 && resp.StatusCode != 401
}

//SourceIP returns the source IP of a http call
func SourceIP(req *http.Request) string {

	var feed string

	if feed = req.Header.Get("X-Forwarded-For"); feed != "" {
		log.Println("Got X-Forwarded-For: " + feed)
	} else {

		feed, _, _ = net.SplitHostPort(req.RemoteAddr)

		log.Println("NO X-Forwarded-For, using: "+feed+" from ", req.RemoteAddr)
	}

	return feed

}