<?php
ob_start();
try { require_once __DIR__ . '/../../includes/auth.php'; } catch(Throwable $e) { ob_end_clean(); header('Content-Type: application/json'); echo json_encode(['success'=>false,'error'=>'Server error']); exit; }
ob_end_clean();
header('Content-Type: application/json');

if (!isLoggedIn()) { echo json_encode(['success'=>false,'error'=>'Not authenticated']); exit; }

$action  = $_GET['action'] ?? 'list';
$userId  = (int)$_SESSION['user_id'];
$isAdmin = !empty($_SESSION['is_admin']);

switch ($action) {

    // ── List broadcasts for this user ─────────────────────
    case 'list':
        // Get broadcasts targeting this user
        $stmt = db()->prepare("
            SELECT b.*,
                   u.username AS sender_name,
                   u.alias    AS sender_alias,
                   (SELECT COUNT(*) FROM broadcast_replies WHERE broadcast_id=b.id) AS reply_count,
                   (SELECT COUNT(*) FROM broadcast_reads WHERE broadcast_id=b.id AND user_id=?) AS is_read,
                   (SELECT COUNT(*) FROM broadcast_reads WHERE broadcast_id=b.id) AS read_count
            FROM broadcasts b
            JOIN users u ON b.admin_id = u.id
            WHERE b.target = 'all'
               OR (b.target = 'verified'   AND EXISTS(SELECT 1 FROM users WHERE id=? AND email_verified=1 AND is_admin=0))
               OR (b.target = 'unverified' AND EXISTS(SELECT 1 FROM users WHERE id=? AND email_verified=0))
               OR (b.target = 'admins'     AND ?)
            ORDER BY b.sent_at DESC
        ");
        $stmt->execute([$userId, $userId, $userId, $isAdmin ? 1 : 0]);
        echo json_encode(['success'=>true, 'broadcasts'=>$stmt->fetchAll()]);
        break;

    // ── Mark as read ──────────────────────────────────────
    case 'mark_read':
        if ($_SERVER['REQUEST_METHOD'] !== 'POST') { echo json_encode(['success'=>false]); exit; }
        $d  = json_decode(file_get_contents('php://input'), true);
        $bid= (int)($d['broadcast_id'] ?? 0);
        if (!$bid) { echo json_encode(['success'=>false]); exit; }
        db()->prepare("INSERT IGNORE INTO broadcast_reads (broadcast_id,user_id) VALUES (?,?)")->execute([$bid,$userId]);
        echo json_encode(['success'=>true]);
        break;

    // ── Get replies for a broadcast ───────────────────────
    case 'replies':
        $bid = (int)($_GET['broadcast_id'] ?? 0);
        if (!$bid) { echo json_encode(['success'=>false]); exit; }
        $stmt = db()->prepare("
            SELECT br.*, u.username, u.alias, u.is_admin
            FROM broadcast_replies br
            JOIN users u ON br.user_id = u.id
            WHERE br.broadcast_id = ?
            ORDER BY br.created_at ASC
        ");
        $stmt->execute([$bid]);
        echo json_encode(['success'=>true,'replies'=>$stmt->fetchAll()]);
        break;

    // ── Post a reply ──────────────────────────────────────
    case 'reply':
        if ($_SERVER['REQUEST_METHOD'] !== 'POST') { echo json_encode(['success'=>false]); exit; }
        $d   = json_decode(file_get_contents('php://input'), true);
        $bid = (int)($d['broadcast_id'] ?? 0);
        $msg = substr(trim($d['message'] ?? ''), 0, 1000);
        if (!$bid || !$msg) { echo json_encode(['success'=>false,'error'=>'broadcast_id and message required']); exit; }
        db()->prepare("INSERT INTO broadcast_replies (broadcast_id,user_id,message) VALUES (?,?,?)")->execute([$bid,$userId,$msg]);
        db()->prepare("INSERT IGNORE INTO broadcast_reads (broadcast_id,user_id) VALUES (?,?)")->execute([$bid,$userId]);
        echo json_encode(['success'=>true,'id'=>db()->lastInsertId()]);
        break;

    // ── Unread count ──────────────────────────────────────
    case 'unread_count':
        $stmt = db()->prepare("
            SELECT COUNT(*) FROM broadcasts b
            WHERE (b.target='all' OR (b.target='verified' AND EXISTS(SELECT 1 FROM users WHERE id=? AND email_verified=1 AND is_admin=0))
                   OR (b.target='unverified' AND EXISTS(SELECT 1 FROM users WHERE id=? AND email_verified=0))
                   OR (b.target='admins' AND ?))
            AND NOT EXISTS (SELECT 1 FROM broadcast_reads WHERE broadcast_id=b.id AND user_id=?)
        ");
        $stmt->execute([$userId,$userId,$isAdmin?1:0,$userId]);
        echo json_encode(['success'=>true,'count'=>(int)$stmt->fetchColumn()]);
        break;

    default:
        echo json_encode(['success'=>false,'error'=>'Unknown action']);
}