<?php
// /var/www/html/db_download.php
require_once __DIR__ . '/db_init.php';

$tokenRec = require_valid_token_web();

$dbPath = QDB_PATH;
if (!file_exists($dbPath)) { http_response_code(404); echo "Database not found"; exit; }
$enc = file_get_contents($dbPath);
if ($enc === false) { http_response_code(500); echo "Read error"; exit; }

try {
    $plain = aes256_cbc_decrypt_bytes($enc, get_master_key_bytes());
} catch (Throwable $e) {
    http_response_code(500); echo "Decryption failed"; exit;
}

$role = $tokenRec['role'] ?? '';
if ($role !== 'admin') {
    $tmpFilter = tempnam(sys_get_temp_dir(), 'qdb_filt_');
    file_put_contents($tmpFilter, $plain);
    try {
        $fpdo = new PDO("sqlite:$tmpFilter");
        $fpdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        $fpdo->exec("PRAGMA foreign_keys = OFF;");
        [$clause, $params] = rbac_client_filter($tokenRec);
        $delStmt = $fpdo->prepare("DELETE FROM client WHERE NOT ($clause)");
        foreach ($params as $k => $v) $delStmt->bindValue($k, $v);
        $delStmt->execute();
        $fpdo->exec("DELETE FROM client_answer WHERE clientCode NOT IN (SELECT clientCode FROM client)");
        $fpdo->exec("DELETE FROM completed_questionnaire WHERE clientCode NOT IN (SELECT clientCode FROM client)");
        // Remove sensitive tables that non-admin users should never receive
        foreach (['users', 'admin', 'supervisor', 'coach'] as $tbl) {
            $fpdo->exec("DELETE FROM $tbl");
        }
        $fpdo = null;
        $plain = file_get_contents($tmpFilter);
    } finally {
        @unlink($tmpFilter);
    }
}

header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename="questionnaire.sqlite"');
header('Content-Length: ' . strlen($plain));
echo $plain;