<?php

namespace App\Services;

use App\Contracts\Service;
use App\Models\Acars;
use App\Models\Enums\AcarsType;
use App\Models\Pirep;
use App\Models\SimBrief;
use App\Models\SimBriefXML;
use Carbon\Carbon;
use GuzzleHttp\Client as GuzzleClient;
use GuzzleHttp\Exception\GuzzleException;
use Illuminate\Support\Facades\Log;

class SimBriefService extends Service
{
    private $httpClient;

    public function __construct(GuzzleClient $httpClient)
    {
        $this->httpClient = $httpClient;
    }

    /**
     * Check to see if the OFP exists server-side. If it does, download it and
     * cache it immediately
     *
     * @param string $user_id      User who generated this
     * @param string $ofp_id       The SimBrief OFP ID
     * @param string $flight_id    The flight ID
     * @param string $ac_id        The aircraft ID
     * @param array  $fares        Full list of fares for the flight
     * @param string $sb_userid    User's Simbrief ID (Used for Update)
     * @param string $sb_static_id Static ID for the generated OFP (Used for Update)
     *
     * @return SimBrief|null
     */
    public function downloadOfp(
        string $user_id,
        string $ofp_id,
        string $flight_id,
        string $ac_id,
        array $fares = [],
        string $sb_user_id = null,
        string $sb_static_id = null
    ) {
        $uri = str_replace('{id}', $ofp_id, config('phpvms.simbrief_url'));

        if ($sb_user_id && $sb_static_id) {
            // $uri = str_replace('{sb_user_id}', $sb_user_id, config('phpvms.simbrief_update_url'));
            // $uri = str_replace('{sb_static_id}', $sb_static_id, $uri);
            $uri = 'https://www.simbrief.com/api/xml.fetcher.php?userid='.$sb_user_id.'&static_id='.$sb_static_id;
        }

        $opts = [
            'connect_timeout' => 2, // wait two seconds by default
            'allow_redirects' => false,
        ];

        try {
            $response = $this->httpClient->request('GET', $uri, $opts);
            if ($response->getStatusCode() !== 200) {
                return null;
            }
        } catch (GuzzleException $e) {
            Log::error('Simbrief HTTP Error: '.$e->getMessage());
            return null;
        }

        $body = $response->getBody()->getContents();

        /** @var SimBriefXML $ofp */
        $ofp = simplexml_load_string($body, SimBriefXML::class);

        $attrs = [
            'user_id'     => $user_id,
            'flight_id'   => $flight_id,
            'aircraft_id' => $ac_id,
            'ofp_xml'     => $ofp->asXML(),
        ];

        // encode the fares data to JSONß
        if (!empty($fares)) {
            $attrs['fare_data'] = json_encode($fares);
        }

        // Try to download the XML file for ACARS. If it doesn't work, try to modify the main OFP
        $acars_xml = $this->getAcarsOFP($ofp);
        if (empty($acars_xml)) {
            $new_doctype = '<VMSAcars Type="FlightPlan" version="1.0" generated="'.time().'">';
            $acars_xml = str_replace('<OFP>', $new_doctype, $body);
            $acars_xml = str_replace('</OFP>', '</VMSAcars>', $acars_xml);
            $acars_xml = str_replace("\n", '', $acars_xml);

            $attrs['acars_xml'] = simplexml_load_string($acars_xml)->asXML();
        } else {
            $attrs['acars_xml'] = $acars_xml->asXML();
        }

        // Save this into the Simbrief table, if it doesn't already exist
        return SimBrief::updateOrCreate(
            ['id' => $ofp_id],
            $attrs
        );
    }

    /**
     * @param \App\Models\SimBriefXML $ofp
     *
     * @return \SimpleXMLElement|null
     */
    public function getAcarsOFP(SimBriefXML $ofp)
    {
        $url = $ofp->getAcarsXmlUrl();
        if (empty($url)) {
            return null;
        }

        $opts = [
            'connect_timeout' => 2, // wait two seconds by default
            'allow_redirects' => true,
        ];

        try {
            $response = $this->httpClient->request('GET', $url, $opts);
            if ($response->getStatusCode() !== 200) {
                return null;
            }
        } catch (GuzzleException $e) {
            Log::error('Simbrief HTTP Error: '.$e->getMessage());
            dd($e);
            return null;
        }

        $body = $response->getBody()->getContents();
        return simplexml_load_string($body);
    }

    /**
     * Create a prefiled PIREP from a given brief.
     *
     * 1. Read from the XML the basic PIREP info (dep, arr), and then associate the PIREP
     *    to the flight ID
     * 2. Remove the flight ID from the SimBrief model and assign the pirep ID to the row
     *    at the end of the flight. Keep flight ID until the flight ends (pirep file).
     * 3. Update the planned flight route in the acars table
     * 4. Add additional flight fields (ones which match ACARS)
     *
     * @param          $pirep
     * @param SimBrief $simBrief    The briefing to create the PIREP from
     * @param bool     $keep_flight True keeps the flight_id, default is false
     *
     * @return \App\Models\Pirep
     */
    public function attachSimbriefToPirep($pirep, SimBrief $simBrief, $keep_flight = false): Pirep
    {
        $this->addRouteToPirep($pirep, $simBrief);

        $simBrief->pirep_id = $pirep->id;
        $simBrief->flight_id = !empty($keep_flight) ? $pirep->flight_id : null;
        $simBrief->save();

        return $pirep;
    }

    /**
     * Add the route from a SimBrief flight plan to a PIREP
     *
     * @param Pirep    $pirep
     * @param SimBrief $simBrief
     *
     * @return Pirep
     */
    protected function addRouteToPirep($pirep, SimBrief $simBrief): Pirep
    {
        // Clear previous entries
        Acars::where(['pirep_id' => $pirep->id, 'type' => AcarsType::ROUTE])->delete();

        // Create the flight route
        $order = 1;
        foreach ($simBrief->xml->getRoute() as $fix) {
            $position = [
                'name'     => $fix->ident,
                'pirep_id' => $pirep->id,
                'type'     => AcarsType::ROUTE,
                'order'    => $order++,
                'lat'      => $fix->pos_lat,
                'lon'      => $fix->pos_long,
            ];

            $acars = new Acars($position);
            $acars->save();
        }

        return $pirep;
    }

    /**
     * Remove any expired entries from the SimBrief table.
     * Expired means there's a flight_id attached to it, but no pirep_id
     * (meaning it was never used for an actual flight)
     */
    public function removeExpiredEntries(): void
    {
        $expire_hours = setting('simbrief.expire_hours', 6);
        $expire_time = Carbon::now('UTC')->subHours($expire_hours);

        $briefs = SimBrief::where([
            ['pirep_id', null],
            ['created_at', '<=', $expire_time],
        ])->get();

        foreach ($briefs as $brief) {
            $brief->delete();

            // TODO: Delete any assets (Which assets ?)
        }
    }
}