<?php

declare(strict_types=1);

class ReactionManager
{
    public const TYPES = ['useful', 'important', 'interesting'];

    public function __construct(private PDO $pdo)
    {
    }

    /** Ajoute ou retire une réaction. Retourne true si ajoutée, false si retirée. */
    public function toggle(string $uuid, string $type, string $visitorHash): bool
    {
        if (!in_array($type, self::TYPES, true)) {
            return false;
        }
        $st = $this->pdo->prepare(
            'SELECT id FROM article_reactions
             WHERE article_uuid = :uuid AND reaction_type = :type AND visitor_hash = :hash'
        );
        $st->execute([':uuid' => $uuid, ':type' => $type, ':hash' => $visitorHash]);
        if ($st->fetchColumn() !== false) {
            $this->pdo->prepare(
                'DELETE FROM article_reactions
                 WHERE article_uuid = :uuid AND reaction_type = :type AND visitor_hash = :hash'
            )->execute([':uuid' => $uuid, ':type' => $type, ':hash' => $visitorHash]);
            return false;
        }
        $this->pdo->prepare(
            'INSERT INTO article_reactions (article_uuid, reaction_type, visitor_hash)
             VALUES (:uuid, :type, :hash) ON CONFLICT DO NOTHING'
        )->execute([':uuid' => $uuid, ':type' => $type, ':hash' => $visitorHash]);
        return true;
    }

    /** @return array<string, int> */
    public function statsForArticle(string $uuid): array
    {
        $st = $this->pdo->prepare(
            'SELECT reaction_type, COUNT(*) AS cnt
             FROM article_reactions WHERE article_uuid = :uuid GROUP BY reaction_type'
        );
        $st->execute([':uuid' => $uuid]);
        $stats = array_fill_keys(self::TYPES, 0);
        foreach ($st->fetchAll(PDO::FETCH_ASSOC) as $row) {
            $stats[$row['reaction_type']] = (int) $row['cnt'];
        }
        return $stats;
    }

    /** @return string[] */
    public function visitorReactions(string $uuid, string $visitorHash): array
    {
        $st = $this->pdo->prepare(
            'SELECT reaction_type FROM article_reactions
             WHERE article_uuid = :uuid AND visitor_hash = :hash'
        );
        $st->execute([':uuid' => $uuid, ':hash' => $visitorHash]);
        return array_column($st->fetchAll(PDO::FETCH_ASSOC), 'reaction_type');
    }
}