<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use LaravelLocalization;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Redis;

/**
 * Before we redirect users to the affiliate shops we will track the clicks ourself.
 * Reason is that many Affiliate shops redirect to invalid URLs (404, 500, ... Errors) which leads to bad user experience.
 * We will store the clicked Affiliate Link together with the final URL the user should land on.
 * No userdata or other metadata will be stored together with that information.
 * 
 * That way we can do manual validation of affiliate links and exclude bad partnershop links to be shown in the future. Since this will be
 * a lot of links we count the clicks so we can validate the most used ones first.
 */

class AdgoalController extends Controller
{
    # Data will be stored for 24 hours
    const STORAGE_DURATION_HOURS = 24;
    const REDIS_STORAGE_KEY = "affiliate_click";

    /**
     * This function is called when a user clicks on a affiliate link. It will first validate that the URL
     * was generated by us to prevent random redirect links to be manually created for our domains.
     * After that we will store the necessary information (link and affiliate link) into our database.
     * After that we will redirect the user to the affiliate shop
     */
    public function forward(Request $request){
        // $link = "https://metager.de";
        // $affillink = "https://test.de";
        // $password = self::generatePassword($affillink, $link);
        // dd(route('adgoal-redirect', ["link" => $link, "affillink" => $affillink, "password" => $password]));
        /**
         * Get Parameters (Result informations)
         * 1. affillink (With Affiliate Redirect)
         * 2. link
         * 5. Password (hmac with adgoal private key and the two parameters)
         */
        $request->validate([
            'affillink' => ['required', 'url', 'active_url'],
            'link' => ['required', 'url', 'active_url'],
            # Validation of redirect request so that one cannot generate random redirect URLs pointing to our domains
            'password' => function($attribute, $value, $fail) use($request) {
                // Check if hmac matches
                $correctPassword = self::generatePassword($request->input('affillink'), $request->input('link'));
                if(!hash_equals($correctPassword, $value)){
                    $fail('The given password is incorrect!');
                }
            }
        ]);

        $this->storePartnerCallFast($request->input('affillink'), $request->input('link'));

        return redirect($request->input('affillink'));
    }

    /**
     * Stores Click information into Redis Cache for fast execution since this is synchronous call
     * at search time.
     * A Cronjob will pick the data up and store it into Mariadb later (see self::storePartnerCall)
     */
    private function storePartnerCallFast($affillink, $link) {
        # Generate Data to store
        $host = parse_url($link, PHP_URL_HOST);
        if(empty($host)){
            return;
        }
        $storeObject = [
            "host" => $host,
            "affillink" => $affillink,
            "link" => $link,
        ];


        # Store Data in Redis
        $redis = Redis::connection(config('cache.stores.redis.connection'));
        $redis->rpush($this::REDIS_STORAGE_KEY, json_encode($storeObject));
    }

    public static function storePartnerCalls() {
        $redis = Redis::connection(config('cache.stores.redis.connection'));
        DB::transaction(function() use($redis){
            while(!empty($data = $redis->lpop(self::REDIS_STORAGE_KEY))){
                $data = json_decode($data, true);
                # Insert data into mariadb table
                DB::insert('insert into affiliate_clicks (hostname, affillink, link) values (?, ?, ?)', 
                    [$data["host"], $data["affillink"], $data["link"]]);
            }
        });
    }

    /**
     * Generates a Redirect URL for our partnershops
     */
    public static function generateRedirectUrl($affillink, $link){
        $password = self::generatePassword($affillink, $link);
        return LaravelLocalization::getLocalizedURL(
            LaravelLocalization::getCurrentLocale(), 
            route('adgoal-redirect', ["link" => $link, "affillink" => $affillink, "password" => $password])
        );
    }

    /**
     * Generates hmac password to validate redirect URLs
     */
    public static function generatePassword($affillink, $link){
        return hash_hmac("sha256", $affillink . $link, config('metager.metager.adgoal.private_key'));
    }


    /**
     * Routes for the Admin Interface
     */
    public function adminIndex(Request $request){
        return view('admin.affiliates.index')
            ->with('title', "Affilliates Overview - MetaGer")
            ->with('css', [
                mix('/css/admin/affilliates/index.css')
            ])
            ->with('darkcss', [
                mix('/css/admin/affilliates/index-dark.css')
            ])
            ->with('js', [
                mix('/js/admin/affilliates.js')
            ]);
    }

    public function blacklistJson(Request $request){
        $request->validate([
            "blacklist" => 'boolean'
        ]);

        $count = 5; # How Many results to return
        $skip = 0; # How many results to skip
        $blacklist = $request->input('blacklist', true);

        $total = DB::select("select count(*) as total_rows from affiliate_blacklist");
        $total = intval($total[0]->{"total_rows"});
        $blacklistItems = DB::select('select * from affiliate_blacklist where blacklist = ? order by created_at desc limit ? offset ?', [$blacklist, $count, $skip]);
        
        $result = [
            "count" => $count,
            "skip" => $skip,
            "total" => $total,
            "results" => $blacklistItems
        ];

        return response()->json($result);
    }

    public function whitelistJson(Request $request){
        $input = $request->all();
        $input["blacklist"] = true;
        $request->replace($input);
        return $this->blacklistJson($request);
    }

}