<?php
require_once __DIR__ . '/../common.php';
require_once __DIR__ . '/../db_init.php';

$tokenRec = require_valid_token_web();

if ($_SERVER['REQUEST_METHOD'] !== 'GET') {
    header('Content-Type: application/json; charset=UTF-8');
    http_response_code(405);
    echo json_encode(["error" => "Method not allowed"]);
    exit;
}

if (!empty($_GET['bundle'])) {
    $role = $tokenRec['role'] ?? '';
    if (!in_array($role, ['admin', 'supervisor'], true)) {
        header('Content-Type: application/json; charset=UTF-8');
        http_response_code(403);
        echo json_encode(["error" => "Permission denied"]);
        exit;
    }
    [$pdo, $tmpDb, $lockFp] = qdb_open(false);
    $bundle = qdb_export_all_questionnaires_bundle($pdo);
    qdb_discard($tmpDb, $lockFp);
    $filename = 'questionnaires_bundle_' . date('Y-m-d_His') . '.json';
    header('Content-Type: application/json; charset=UTF-8');
    header('Content-Disposition: attachment; filename="' . $filename . '"');
    echo json_encode($bundle, JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT);
    exit;
}

$qnID   = $_GET['questionnaireID'] ?? '';
$format = strtolower($_GET['format'] ?? 'csv');

if (!$qnID) {
    header('Content-Type: application/json; charset=UTF-8');
    http_response_code(400);
    echo json_encode(["error" => "questionnaireID query param required"]);
    exit;
}

[$pdo, $tmpDb, $lockFp] = qdb_open(false);

// Questionnaire metadata
$qn = $pdo->prepare("SELECT * FROM questionnaire WHERE questionnaireID = :id");
$qn->execute([':id' => $qnID]);
$questionnaire = $qn->fetch(PDO::FETCH_ASSOC);
if (!$questionnaire) {
    qdb_discard($tmpDb, $lockFp);
    header('Content-Type: application/json; charset=UTF-8');
    http_response_code(404);
    echo json_encode(["error" => "Questionnaire not found"]);
    exit;
}

// Questions ordered
$qStmt = $pdo->prepare("SELECT questionID, defaultText, type, orderIndex, configJson FROM question WHERE questionnaireID = :id ORDER BY orderIndex");
$qStmt->execute([':id' => $qnID]);
$questions = $qStmt->fetchAll(PDO::FETCH_ASSOC);
$questionIDs = array_column($questions, 'questionID');
$resultColumns = qdb_results_export_columns($questions, $qnID);

// Build answer-option lookup for resolving display text
$optionTextMap = [];
foreach ($questionIDs as $qid) {
    $aoStmt = $pdo->prepare("SELECT answerOptionID, defaultText FROM answer_option WHERE questionID = :qid");
    $aoStmt->execute([':qid' => $qid]);
    foreach ($aoStmt->fetchAll(PDO::FETCH_ASSOC) as $ao) {
        $optionTextMap[$ao['answerOptionID']] = $ao['defaultText'];
    }
}

// RBAC filter
[$rbacClause, $rbacParams] = rbac_client_filter($tokenRec, 'cl');

$sql = "
    SELECT cl.clientCode, cl.coachID,
           co.username AS coachUsername,
           sv.username AS supervisorUsername,
           cq.status, cq.sumPoints, cq.startedAt, cq.completedAt
    FROM client cl
    INNER JOIN completed_questionnaire cq ON cq.clientCode = cl.clientCode AND cq.questionnaireID = :qnid
    LEFT JOIN coach co ON co.coachID = cl.coachID
    LEFT JOIN supervisor sv ON sv.supervisorID = co.supervisorID
    WHERE $rbacClause
    ORDER BY cl.clientCode
";
$params = array_merge([':qnid' => $qnID], $rbacParams);
$cStmt = $pdo->prepare($sql);
$cStmt->execute($params);
$clients = $cStmt->fetchAll(PDO::FETCH_ASSOC);

// Fetch answers for each client
$qPlaceholders = !empty($questionIDs) ? implode(',', array_fill(0, count($questionIDs), '?')) : "'__none__'";
$answerStmt = $pdo->prepare("
    SELECT questionID, answerOptionID, freeTextValue, numericValue
    FROM client_answer
    WHERE clientCode = ? AND questionID IN ($qPlaceholders)
");

$rows = [];
foreach ($clients as $c) {
    $row = [
        'clientCode' => $c['clientCode'],
        'coach'      => $c['coachUsername'] ?? $c['coachID'],
        'supervisor' => $c['supervisorUsername'] ?? '',
        'status'     => $c['status'],
        'sumPoints'  => $c['sumPoints'],
        'startedAt'  => $c['startedAt'] ? date('Y-m-d H:i', (int)$c['startedAt']) : '',
        'completedAt'=> $c['completedAt'] ? date('Y-m-d H:i', (int)$c['completedAt']) : '',
    ];

    $bindParams = array_merge([$c['clientCode']], $questionIDs);
    $answerStmt->execute($bindParams);
    $answers = $answerStmt->fetchAll(PDO::FETCH_ASSOC);
    $answerMap = [];
    foreach ($answers as $a) $answerMap[$a['questionID']] = $a;

    foreach ($resultColumns as $col) {
        $qid = $col['questionID'];
        $a = $answerMap[$qid] ?? null;
        $row[$col['header']] = qdb_results_column_cell_value($col, $a, $optionTextMap);
    }
    $rows[] = $row;
}

qdb_discard($tmpDb, $lockFp);

// Output CSV
$safeName = preg_replace('/[^a-zA-Z0-9_-]/', '_', $questionnaire['name']);
$filename = $safeName . '_v' . $questionnaire['version'] . '.csv';

header('Content-Type: text/csv; charset=UTF-8');
header('Content-Disposition: attachment; filename="' . $filename . '"');

$out = fopen('php://output', 'w');
// BOM for Excel UTF-8 recognition
fwrite($out, "\xEF\xBB\xBF");

if (!empty($rows)) {
    fputcsv($out, array_keys($rows[0]));
    foreach ($rows as $row) {
        fputcsv($out, array_values($row));
    }
} else {
    $header = ['clientCode', 'coach', 'supervisor', 'status', 'sumPoints', 'startedAt', 'completedAt'];
    foreach ($resultColumns as $col) {
        $header[] = $col['header'];
    }
    fputcsv($out, $header);
}
fclose($out);