/*
 * Copyright (c) 2022 Alibaba Group Holding Ltd.
 *
 * 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.
 */

package config

import (
	regexp "github.com/wasilibs/go-re2"
)

var DefaultBotRegex = []*regexp.Regexp{
	regexp.MustCompile(`(\/[A-Za-z0-9\.]+|) {0,5}([A-Za-z0-9 \-_\!\[\]:]{0,50}([Aa]rchiver|[Ii]ndexer|[Ss]craper|[Bb]ot|[Ss]pider|[Cc]rawl[a-z]{0,50}))[/ ](\d+)(\.(\d+)(\.(\d+)|)|)`),
	regexp.MustCompile(`((\/[A-Za-z0-9\.]+|) {0,5}([A-Za-z0-9 \-_\!\[\]:]{0,50}([Aa]rchiver|[Ii]ndexer|[Ss]craper|[Bb]ot|[Ss]pider|[Cc]rawl[a-z]{0,50})) (\d+)(\.(\d+)(\.(\d+)|)|))`),
	regexp.MustCompile(`((([A-z0-9]{1,50}|[A-z\-]{1,} ?|)( the |)(?:[Ss][Pp][Ii][Dd][Ee][Rr]|[Ss]crape|[Cc][Rr][Aa][Ww][Ll])[A-z0-9]{0,50})(([ /]| v)(\d+)(\.(\d+)|)(\.(\d+)|)|))`),
	regexp.MustCompile(`((Ant-)?Nutch|[A-z]+[Bb]ot|[A-z]+[Ss]pider|Axtaris|fetchurl|Isara|ShopSalad|Tailsweep)[ \-](\d+)(\.(\d+)(\.(\d+))?)?`),
	regexp.MustCompile(`\b(008|Altresium|Argus|BaiduMobaider|BoardReader|DNSGroup|DataparkSearch|EDI|Goodzer|Grub|INGRID|Infohelfer|LinkedInBot|LOOQ|Nutch|OgScrper|PathDefender|Peew|PostPost|Steeler|Twitterbot|VSE|WebCrunch|WebZIP|Y!J-BR[A-Z]|YahooSeeker|envolk|sproose|wminer)/(\d+)(?:\.(\d+)|)(?:\.(\d+)|)`),
	regexp.MustCompile(`((CSimpleSpider|Cityreview Robot|CrawlDaddy|CrawlFire|Finderbots|Index crawler|Job Roboter|KiwiStatus Spider|Lijit Crawler|QuerySeekerSpider|ScollSpider|Trends Crawler|USyd-NLP-Spider|SiteCat Webbot|BotName\/\$BotVersion|123metaspider-Bot|1470\.net crawler|50\.nu|8bo Crawler Bot|Aboundex|Accoona-[A-z]{1,30}-Agent|AdsBot-Google(?:-[a-z]{1,30}|)|altavista|AppEngine-Google|archive.{0,30}\.org_bot|archiver|Ask Jeeves|[Bb]ai[Dd]u[Ss]pider(?:-[A-Za-z]{1,30})(?:-[A-Za-z]{1,30}|)|bingbot|BingPreview|blitzbot|BlogBridge|Bloglovin|BoardReader Blog Indexer|BoardReader Favicon Fetcher|boitho.com-dc|BotSeer|BUbiNG|\b\w{0,30}favicon\w{0,30}\b|\bYeti(?:-[a-z]{1,30}|)|Catchpoint(?: bot|)|[Cc]harlotte|Checklinks|clumboot|Comodo HTTP\(S\) Crawler|Comodo-Webinspector-Crawler|ConveraCrawler|CRAWL-E|CrawlConvera|Daumoa(?:-feedfetcher|)|Feed Seeker Bot|Feedbin|findlinks|Flamingo_SearchEngine|FollowSite Bot|furlbot|Genieo|gigabot|GomezAgent|gonzo1|(?:[a-zA-Z]{1,30}-|)Googlebot(?:-[a-zA-Z]{1,30}|)|Google SketchUp|grub-client|gsa-crawler|heritrix|HiddenMarket|holmes|HooWWWer|htdig|ia_archiver|ICC-Crawler|Icarus6j|ichiro(?:/mobile|)|IconSurf|IlTrovatore(?:-Setaccio|)|InfuzApp|Innovazion Crawler|InternetArchive|IP2[a-z]{1,30}Bot|jbot\b|KaloogaBot|Kraken|Kurzor|larbin|LEIA|LesnikBot|Linguee Bot|LinkAider|LinkedInBot|Lite Bot|Llaut|lycos|Mail\.RU_Bot|masscan|masidani_bot|Mediapartners-Google|Microsoft .{0,30} Bot|mogimogi|mozDex|MJ12bot|msnbot(?:-media {0,2}|)|msrbot|Mtps Feed Aggregation System|netresearch|Netvibes|NewsGator[^/]{0,30}|^NING|Nutch[^/]{0,30}|Nymesis|ObjectsSearch|OgScrper|Orbiter|OOZBOT|PagePeeker|PagesInventory|PaxleFramework|Peeplo Screenshot Bot|PlantyNet_WebRobot|Pompos|Qwantify|Read%20Later|Reaper|RedCarpet|Retreiver|Riddler|Rival IQ|scooter|Scrapy|Scrubby|searchsight|seekbot|semanticdiscovery|SemrushBot|Simpy|SimplePie|SEOstats|SimpleRSS|SiteCon|Slackbot-LinkExpanding|Slack-ImgProxy|Slurp|snappy|Speedy Spider|Squrl Java|Stringer|TheUsefulbot|ThumbShotsBot|Thumbshots\.ru|Tiny Tiny RSS|Twitterbot|WhatsApp|URL2PNG|Vagabondo|VoilaBot|^vortex|Votay bot|^voyager|WASALive.Bot|Web-sniffer|WebThumb|WeSEE:[A-z]{1,30}|WhatWeb|WIRE|WordPress|Wotbox|www\.almaden\.ibm\.com|Xenu(?:.s|) Link Sleuth|Xerka [A-z]{1,30}Bot|yacy(?:bot|)|YahooSeeker|Yahoo! Slurp|Yandex\w{1,30}|YodaoBot(?:-[A-z]{1,30}|)|YottaaMonitor|Yowedo|^Zao|^Zao-Crawler|ZeBot_www\.ze\.bz|ZooShot|ZyBorg)(?:[ /]v?(\d+)(?:\.(\d+)(?:\.(\d+)|)|)|))`),
}

type BotDetectConfig struct {
	BlockedCode    uint32           `json:"blocked_code"`
	BlockedMessage string           `json:"blocked_message"`
	Allow          []*regexp.Regexp `json:"allow"`
	Deny           []*regexp.Regexp `json:"deny"`
}

func (bdc *BotDetectConfig) FillDefaultValue() {
	if bdc.BlockedCode == 0 {
		bdc.BlockedCode = 403
	}
	if bdc.BlockedMessage == "" {
		bdc.BlockedMessage = "Invalid User-Agent"
	}
}

func (bdc *BotDetectConfig) Process(ua string) (bool, string) {
	if ua == "" {
		return false, "can not be empty"
	}
	for _, allowRule := range bdc.Allow {
		if allowRule.MatchString(ua) {
			return true, ""
		}
	}
	for _, denyRule := range bdc.Deny {
		if denyRule.MatchString(ua) {
			return false, denyRule.String()
		}
	}
	for _, defaultRule := range DefaultBotRegex {
		if defaultRule.MatchString(ua) {
			return false, defaultRule.String()
		}
	}
	return true, ""
}