<?php

// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the GNU Affero General Public License v3.0.
// See the LICENCE file in the repository root for full licence text.

namespace App\Models\Forum;

use App\Traits\Validatable;
use Carbon\Carbon;
use DB;

class TopicPoll
{
    use Validatable;

    private $topic;
    private $validated = false;
    private $params = [
        'hide_results' => false,
        'length_days' => 0,
        'max_options' => 1,
        'options' => [],
        'title' => null,
        'vote_change' => false,
    ];
    private $votedBy = [];

    public function __get(string $field)
    {
        return $this->params[$field];
    }

    public function canEdit()
    {
        return $this->topic->topic_time > Carbon::now()->subHours($GLOBALS['cfg']['osu']['forum']['poll_edit_hours']);
    }

    public function exists()
    {
        return present($this->topic->poll_title);
    }

    public function fill($params)
    {
        $this->params = [
            ...$this->params,
            ...$params,
        ];
        $this->validated = false;

        return $this;
    }

    public function isOpen()
    {
        if ($this->topic === null) {
            return false;
        }

        return $this->topic->pollEnd() === null || $this->topic->pollEnd()->isFuture();
    }

    public function isValid($revalidate = false)
    {
        if (!$this->validated || $revalidate) {
            $this->validated = true;
            $this->validationErrors()->reset();

            if (!present($this->params['title'])) {
                $this->validationErrors()->add('title', 'required');
            }

            $this->validateFieldLength(255, 'title');

            if (count($this->params['options']) > count(array_unique($this->params['options']))) {
                $this->validationErrors()->add('options', '.duplicate_options');
            }

            if (count($this->params['options']) < 2) {
                $this->validationErrors()->add('options', '.minimum_two_options');
            }

            if (count($this->params['options']) > 10) {
                $this->validationErrors()->add('options', '.too_many_options');
            }

            if ($this->params['max_options'] < 1) {
                $this->validationErrors()->add('max_options', '.minimum_one_selection');
            }

            if ($this->params['max_options'] > count($this->params['options'])) {
                $this->validationErrors()->add('max_options', '.invalid_max_options');
            }

            if ($this->params['hide_results'] && $this->params['length_days'] === 0) {
                $this->validationErrors()->add('hide_results', '.hiding_results_forever');
            }

            if ($this->topic !== null && $this->topic->exists && !$this->canEdit()) {
                $this->validationErrors()->add(
                    'edit',
                    '.grace_period_expired',
                    ['limit' => $GLOBALS['cfg']['osu']['forum']['poll_edit_hours']]
                );
            }
        }

        return $this->validationErrors()->isEmpty();
    }

    public function save()
    {
        if (!$this->isValid()) {
            return false;
        }

        return DB::transaction(function () {
            $this->topic->update([
                'poll_title' => $this->params['title'],
                'poll_start' => Carbon::now(),
                'poll_length' => $this->params['length_days'] * 3600 * 24,
                'poll_max_options' => $this->params['max_options'],
                'poll_vote_change' => $this->params['vote_change'],
                'poll_hide_results' => $this->params['hide_results'],
            ]);

            $this
                ->topic
                ->pollVotes()
                ->delete();

            $this
                ->topic
                ->pollOptions()
                ->delete();

            foreach ($this->params['options'] as $index => $value) {
                PollOption::create([
                    'topic_id' => $this->topic->topic_id,
                    'poll_option_id' => $index,
                    'poll_option_text' => $value,
                ]);
            }

            return true;
        });
    }

    public function setTopic($topic)
    {
        $this->topic = $topic;

        return $this;
    }

    /**
     * Get the aggregate vote count of this poll, or `0` if the poll doesn't exist. If the poll
     * allows selecting more than one option, this may be greater than the number of users who voted.
     */
    public function totalVoteCount(): int
    {
        return $this->exists()
            ? $this->topic->pollOptions->sum('poll_option_total')
            : 0;
    }

    public function validationErrorsTranslationPrefix(): string
    {
        return 'forum.topic_poll';
    }

    public function votedBy($user)
    {
        if ($user === null) {
            return false;
        }

        if ($this->topic === null) {
            return false;
        }

        $userId = $user->getKey();

        if (!isset($this->votedBy[$userId])) {
            $this->votedBy[$userId] = $this->topic->pollVotes()->where('vote_user_id', $userId)->exists();
        }

        return $this->votedBy[$userId];
    }
}