<?php namespace MapGuesser\Controller;

use MapGuesser\Interfaces\Request\IRequest;
use MapGuesser\Util\Geo\Position;
use MapGuesser\Response\JsonContent;
use MapGuesser\Interfaces\Response\IContent;
use MapGuesser\Repository\PlaceRepository;

class GameFlowController
{
    const NUMBER_OF_ROUNDS = 5;
    const MAX_SCORE = 1000;

    private IRequest $request;

    private PlaceRepository $placeRepository;

    public function __construct(IRequest $request)
    {
        $this->request = $request;
        $this->placeRepository = new PlaceRepository();
    }

    public function getInitialData(): IContent
    {
        $mapId = (int) $this->request->query('mapId');
        $session = $this->request->session();

        if (!($state = $session->get('state')) || $state['mapId'] !== $mapId) {
            return new JsonContent(['error' => 'no_session_found']);
        }

        if (!isset($state['currentRound']) || $state['currentRound'] == -1 || $state['currentRound'] >= static::NUMBER_OF_ROUNDS) {
            $this->startNewGame($state, $mapId);
        }

        $response = [];

        $last = $state['rounds'][$state['currentRound']];
        $response['place'] = [
            'panoId' => $last['panoId'],
            'pov' => $last['pov']->toArray()
        ];

        $response['history'] = [];
        for ($i = 0; $i < $state['currentRound']; ++$i) {
            $round = $state['rounds'][$i];
            $response['history'][] = [
                'position' => $round['position']->toArray(),
                'guessPosition' => $round['guessPosition']->toArray(),
                'distance' => $round['distance'],
                'score' => $round['score']
            ];
        }

        return new JsonContent($response);
    }

    public function evaluateGuess(): IContent
    {
        $mapId = (int) $this->request->query('mapId');
        $session = $this->request->session();

        if (!($state = $session->get('state')) || $state['mapId'] !== $mapId) {
            return new JsonContent(['error' => 'no_session_found']);
        }

        $last = $state['rounds'][$state['currentRound']];

        $position = $last['position'];
        $guessPosition = new Position((float) $this->request->post('lat'), (float) $this->request->post('lng'));

        $distance = $this->calculateDistance($position, $guessPosition);
        $score = $this->calculateScore($distance, $state['area']);

        $last['guessPosition'] = $guessPosition;
        $last['distance'] = $distance;
        $last['score'] = $score;

        $state['rounds'][$state['currentRound']] = $last;
        $state['currentRound'] += 1;

        $response = [
            'result' => [
                'position' => $position->toArray(),
                'distance' => $distance,
                'score' => $score
            ]
        ];

        if ($state['currentRound'] < static::NUMBER_OF_ROUNDS) {
            $next = $state['rounds'][$state['currentRound']];

            $response['place'] = [
                'panoId' => $next['panoId'],
                'pov' => $next['pov']->toArray()
            ];
        }

        $session->set('state', $state);

        return new JsonContent($response);
    }

    private function startNewGame(array &$state, int $mapId)
    {
        $places = $this->placeRepository->getRandomNForMapWithValidPano($mapId, static::NUMBER_OF_ROUNDS);

        $state['rounds'] = [];
        $state['currentRound'] = 0;

        foreach ($places as $place) {
            $state['rounds'][] = [
                'placeId' => $place->getId(),
                'position' => $place->getPosition(),
                'panoId' => $place->getPanoIdCached(),
                'pov' => $place->getPov()
            ];
        }

        $this->request->session()->set('state', $state);
    }

    private function calculateDistance(Position $realPosition, Position $guessPosition): float
    {
        return $realPosition->calculateDistanceTo($guessPosition);
    }

    private function calculateScore(float $distance, float $area): int
    {
        $goodness = 1.0 - ($distance / (sqrt($area) * 1000));

        return (int) round(pow(static::MAX_SCORE, $goodness));
    }
}