<?php
declare(strict_types=1);
namespace AndroidCast\Sfu;

use PDO;

/**
 * Persistent store for SFU rooms + participant sessions (MariaDB / SQLite).
 * Schema managed by ac-platform-db sql/sfu/*.sql migrations.
 */
final class SfuRoomRepository
{
    private PDO $pdo;

    public function __construct(PDO $pdo)
    {
        $this->pdo = $pdo;
    }

    /* ── room lifecycle ─────────────────────────────────────────────── */

    public function createRoom(int $janusRoomId, int $ownerId, string $name, string $purpose = 'screen_cast'): int
    {
        $stmt = $this->pdo->prepare(
            'INSERT INTO sfu_rooms (janus_room_id, owner_id, name, purpose, created_at, updated_at)
             VALUES (:jrId, :oid, :name, :purpose, NOW(), NOW())'
        );
        $stmt->execute([
            ':jrId'    => $janusRoomId,
            ':oid'     => $ownerId,
            ':name'    => $name,
            ':purpose' => $purpose,
        ]);
        return (int) $this->pdo->lastInsertId();
    }

    public function getByJanusId(int $janusRoomId): ?array
    {
        $stmt = $this->pdo->prepare('SELECT * FROM sfu_rooms WHERE janus_room_id = :id LIMIT 1');
        $stmt->execute([':id' => $janusRoomId]);
        $row = $stmt->fetch(PDO::FETCH_ASSOC);
        return $row ?: null;
    }

    public function listActive(): array
    {
        $stmt = $this->pdo->query(
            "SELECT r.*, COUNT(p.id) AS participant_count
             FROM sfu_rooms r
             LEFT JOIN sfu_participants p ON p.room_id = r.id AND p.left_at IS NULL
             WHERE r.closed_at IS NULL
             GROUP BY r.id
             ORDER BY r.created_at DESC"
        );
        return $stmt->fetchAll(PDO::FETCH_ASSOC);
    }

    public function closeRoom(int $roomId): void
    {
        $stmt = $this->pdo->prepare('UPDATE sfu_rooms SET closed_at = NOW() WHERE id = :id');
        $stmt->execute([':id' => $roomId]);
    }

    /* ── participant tracking ───────────────────────────────────────── */

    public function joinRoom(int $roomId, int $userId, int $janusHandleId, string $role = 'publisher'): int
    {
        $stmt = $this->pdo->prepare(
            'INSERT INTO sfu_participants (room_id, user_id, janus_handle_id, role, joined_at)
             VALUES (:room, :user, :handle, :role, NOW())'
        );
        $stmt->execute([
            ':room'   => $roomId,
            ':user'   => $userId,
            ':handle' => $janusHandleId,
            ':role'   => $role,
        ]);
        return (int) $this->pdo->lastInsertId();
    }

    public function leaveRoom(int $participantId): void
    {
        $stmt = $this->pdo->prepare('UPDATE sfu_participants SET left_at = NOW() WHERE id = :id');
        $stmt->execute([':id' => $participantId]);
    }

    public function listParticipants(int $roomId): array
    {
        $stmt = $this->pdo->prepare(
            'SELECT p.*, u.email FROM sfu_participants p
             JOIN users u ON u.id = p.user_id
             WHERE p.room_id = :room AND p.left_at IS NULL'
        );
        $stmt->execute([':room' => $roomId]);
        return $stmt->fetchAll(PDO::FETCH_ASSOC);
    }

    /* ── stats hook ─────────────────────────────────────────────────── */

    /** Record a bitrate/packet-loss sample for analytics. */
    public function recordStats(int $participantId, float $bitrateKbps, float $packetLoss): void
    {
        $stmt = $this->pdo->prepare(
            'INSERT INTO sfu_stats (participant_id, bitrate_kbps, packet_loss, sampled_at)
             VALUES (:pid, :bw, :pl, NOW())'
        );
        $stmt->execute([':pid' => $participantId, ':bw' => $bitrateKbps, ':pl' => $packetLoss]);
    }
}