<?php

$tokenRec = require_valid_token_web();

switch ($method) {

case 'GET':
    $qnID = $_GET['questionnaireID'] ?? '';
    if (!$qnID) {
        json_error('BAD_REQUEST', 'questionnaireID query param required', 400);
    }
    try {
        $opened = qdb_open_read_or_fail();
        [$pdo, $tmpDb, $lockFp] = $opened;
        $stmt = $pdo->prepare("
        SELECT questionID, questionnaireID, defaultText, type, orderIndex, isRequired, configJson
        FROM question WHERE questionnaireID = :qid ORDER BY orderIndex
    ");
    $stmt->execute([':qid' => $qnID]);
    $questions = $stmt->fetchAll(PDO::FETCH_ASSOC);
    foreach ($questions as &$q) {
        $q['isRequired'] = (int)$q['isRequired'];
        $q['orderIndex'] = (int)$q['orderIndex'];
        $cfg = qdb_parse_config_json($q['configJson']);
        $q['configJson'] = json_encode($cfg, JSON_UNESCAPED_UNICODE);
        $q['questionKey'] = qdb_question_key($cfg, $q['defaultText']);
        $q['localId'] = qdb_question_local_id($q['questionID'], $qnID);
        $ao = $pdo->prepare("
            SELECT answerOptionID, questionID, defaultText, points, orderIndex, nextQuestionId
            FROM answer_option WHERE questionID = :qid ORDER BY orderIndex
        ");
        $ao->execute([':qid' => $q['questionID']]);
        $q['answerOptions'] = $ao->fetchAll(PDO::FETCH_ASSOC);
        foreach ($q['answerOptions'] as &$opt) {
            $opt['points']     = (int)$opt['points'];
            $opt['orderIndex'] = (int)$opt['orderIndex'];
            $opt['optionKey'] = qdb_option_key($opt);
            $opt['labelGerman'] = qdb_option_german_label($pdo, $opt['answerOptionID'], $opt['defaultText']);
        }
        unset($opt);
        $tr = $pdo->prepare("SELECT languageCode, text FROM question_translation WHERE questionID = :qid");
        $tr->execute([':qid' => $q['questionID']]);
        $q['translations'] = $tr->fetchAll(PDO::FETCH_ASSOC);
    }
        unset($q);
        qdb_discard($tmpDb, $lockFp);
        json_success(['questions' => $questions]);
    } catch (Throwable $e) {
        if (isset($tmpDb, $lockFp)) {
            qdb_discard($tmpDb, $lockFp);
        }
        if (function_exists('qdb_api_log_note_exception')) {
            qdb_api_log_note_exception($e);
        }
        require_once __DIR__ . '/../lib/errors.php';
        error_log('questions GET: ' . $e->getMessage());
        json_error('SERVER_ERROR', qdb_public_error_message($e, 'Load questions'), 500);
    }
    break;

case 'POST':
    require_role(['admin', 'supervisor'], $tokenRec);
    $body = read_json_body();
    if (empty($body['questionnaireID']) || !isset($body['defaultText']) || empty($body['questionKey'])) {
        json_error('BAD_REQUEST', 'questionnaireID, questionKey, and defaultText required', 400);
    }
    $qnID   = $body['questionnaireID'];
    $text   = trim($body['defaultText']);
    qdb_require_non_empty_german($text);
    $questionKey = qdb_validate_stable_key((string)$body['questionKey'], 'Question key');
    $type   = trim($body['type'] ?? '');
    $order  = (int)($body['orderIndex'] ?? 0);
    $req    = (int)($body['isRequired'] ?? 0);
    $cfg = qdb_parse_config_json($body['configJson'] ?? '{}');
    $config = qdb_normalize_question_config(
        $cfg,
        $questionKey,
        $body['noteBefore'] ?? ($cfg['noteBefore'] ?? null),
        $body['noteAfter'] ?? ($cfg['noteAfter'] ?? null)
    );
    $configJson = json_encode($config, JSON_UNESCAPED_UNICODE);
    [$pdo, $tmpDb, $lockFp] = qdb_open(true);
    try {
        $chk = $pdo->prepare("SELECT 1 FROM questionnaire WHERE questionnaireID = :id");
        $chk->execute([':id' => $qnID]);
        if (!$chk->fetch()) {
            qdb_discard($tmpDb, $lockFp);
            json_error('NOT_FOUND', 'Questionnaire not found', 404);
        }
        if ($order === 0) {
            $max = $pdo->prepare("SELECT COALESCE(MAX(orderIndex),0)+1 FROM question WHERE questionnaireID = :id");
            $max->execute([':id' => $qnID]);
            $order = (int)$max->fetchColumn();
        }
        $localId = trim($body['localId'] ?? '');
        if ($localId === '') {
            $localId = qdb_allocate_question_local_id($pdo, $qnID);
        }
        $id = qdb_make_question_id($qnID, $localId);
        $dup = $pdo->prepare('SELECT 1 FROM question WHERE questionID = :id');
        $dup->execute([':id' => $id]);
        if ($dup->fetch()) {
            qdb_discard($tmpDb, $lockFp);
            json_error('CONFLICT', "Question id \"$localId\" already exists in this questionnaire", 409);
        }
        $pdo->prepare("INSERT INTO question (questionID, questionnaireID, defaultText, type, orderIndex, isRequired, configJson)
                        VALUES (:id, :qid, :t, :ty, :o, :r, :cj)")
            ->execute([':id' => $id, ':qid' => $qnID, ':t' => $text, ':ty' => $type,
                       ':o' => $order, ':r' => $req, ':cj' => $configJson]);
        qdb_upsert_source_translation($pdo, 'question', $id, $text);
        qdb_sync_question_note_strings($pdo, $questionKey, $config);
        qdb_save($tmpDb, $lockFp);
        json_success(['question' => [
            'questionID' => $id, 'questionnaireID' => $qnID, 'defaultText' => $text,
            'questionKey' => $questionKey, 'localId' => $localId,
            'type' => $type, 'orderIndex' => $order, 'isRequired' => $req,
            'configJson' => $configJson, 'answerOptions' => [], 'translations' => [],
        ]]);
    } catch (Throwable $e) {
        qdb_discard($tmpDb, $lockFp);
        error_log($e->getMessage());
        json_error('SERVER_ERROR', 'Server error', 500);
    }
    break;

case 'PUT':
    require_role(['admin', 'supervisor'], $tokenRec);
    $body = read_json_body();
    if (empty($body['questionID'])) {
        json_error('BAD_REQUEST', 'questionID is required', 400);
    }
    $id = $body['questionID'];
    [$pdo, $tmpDb, $lockFp] = qdb_open(true);
    try {
        $existing = $pdo->prepare("SELECT * FROM question WHERE questionID = :id");
        $existing->execute([':id' => $id]);
        $row = $existing->fetch(PDO::FETCH_ASSOC);
        if (!$row) {
            qdb_discard($tmpDb, $lockFp);
            json_error('NOT_FOUND', 'Question not found', 404);
        }
        $text   = trim($body['defaultText'] ?? $row['defaultText']);
        qdb_require_non_empty_german($text);
        $type   = trim($body['type']        ?? $row['type']);
        $order  = (int)($body['orderIndex'] ?? $row['orderIndex']);
        $req    = (int)($body['isRequired'] ?? $row['isRequired']);
        $oldCfg = qdb_parse_config_json($row['configJson']);
        $questionKey = isset($body['questionKey'])
            ? qdb_validate_stable_key((string)$body['questionKey'], 'Question key')
            : qdb_question_key($oldCfg, $row['defaultText']);
        if ($questionKey === '') {
            json_error('MISSING_FIELDS', 'questionKey is required', 400);
        }
        $cfgIn = isset($body['configJson']) ? qdb_parse_config_json($body['configJson']) : $oldCfg;
        $config = qdb_normalize_question_config(
            $cfgIn,
            $questionKey,
            $body['noteBefore'] ?? ($cfgIn['noteBefore'] ?? null),
            $body['noteAfter'] ?? ($cfgIn['noteAfter'] ?? null)
        );
        $configJson = json_encode($config, JSON_UNESCAPED_UNICODE);
        $pdo->prepare("UPDATE question SET defaultText = :t, type = :ty, orderIndex = :o, isRequired = :r, configJson = :cj WHERE questionID = :id")
            ->execute([':t' => $text, ':ty' => $type, ':o' => $order, ':r' => $req, ':cj' => $configJson, ':id' => $id]);
        qdb_upsert_source_translation($pdo, 'question', $id, $text);
        qdb_sync_question_note_strings($pdo, $questionKey, $config);
        qdb_save($tmpDb, $lockFp);
        json_success(['question' => [
            'questionID' => $id, 'questionnaireID' => $row['questionnaireID'],
            'defaultText' => $text, 'questionKey' => $questionKey,
            'type' => $type, 'orderIndex' => $order, 'isRequired' => $req,
            'configJson' => $configJson,
        ]]);
    } catch (Throwable $e) {
        qdb_discard($tmpDb, $lockFp);
        error_log($e->getMessage());
        json_error('SERVER_ERROR', 'Server error', 500);
    }
    break;

case 'DELETE':
    require_role(['admin', 'supervisor'], $tokenRec);
    $body = read_json_body();
    if (empty($body['questionID'])) {
        json_error('BAD_REQUEST', 'questionID is required', 400);
    }
    $id = $body['questionID'];
    [$pdo, $tmpDb, $lockFp] = qdb_open(true);
    try {
        $pdo->exec("PRAGMA foreign_keys = OFF;");
        $pdo->beginTransaction();
        $aoIds = $pdo->prepare("SELECT answerOptionID FROM answer_option WHERE questionID = :id");
        $aoIds->execute([':id' => $id]);
        foreach ($aoIds->fetchAll(PDO::FETCH_COLUMN) as $aoid) {
            $pdo->prepare("DELETE FROM answer_option_translation WHERE answerOptionID = :id")->execute([':id' => $aoid]);
        }
        $pdo->prepare("DELETE FROM answer_option WHERE questionID = :id")->execute([':id' => $id]);
        $pdo->prepare("DELETE FROM question_translation WHERE questionID = :id")->execute([':id' => $id]);
        $pdo->prepare("DELETE FROM client_answer WHERE questionID = :id")->execute([':id' => $id]);
        $pdo->prepare("DELETE FROM question WHERE questionID = :id")->execute([':id' => $id]);
        $pdo->commit();
        $pdo->exec("PRAGMA foreign_keys = ON;");
        qdb_save($tmpDb, $lockFp);
        json_success(['deleted' => true]);
    } catch (Throwable $e) {
        if ($pdo->inTransaction()) {
            $pdo->rollBack();
        }
        qdb_discard($tmpDb, $lockFp);
        error_log($e->getMessage());
        json_error('SERVER_ERROR', 'Server error', 500);
    }
    break;

case 'PATCH':
    require_role(['admin', 'supervisor'], $tokenRec);
    $body = read_json_body();
    if (empty($body['questionnaireID']) || !is_array($body['order'] ?? null)) {
        json_error('BAD_REQUEST', 'questionnaireID and order[] required', 400);
    }
    $qnID = (string)$body['questionnaireID'];
    $orderIds = array_values(array_filter(
        array_map('strval', $body['order']),
        static fn($id) => $id !== ''
    ));
    if ($orderIds === []) {
        json_error('BAD_REQUEST', 'order[] must list at least one questionID', 400);
    }
    try {
        $opened = qdb_open_write_or_fail();
        [$pdo, $tmpDb, $lockFp] = $opened;
        $chk = $pdo->prepare('SELECT 1 FROM questionnaire WHERE questionnaireID = :id');
        $chk->execute([':id' => $qnID]);
        if (!$chk->fetch()) {
            qdb_discard($tmpDb, $lockFp);
            json_error('NOT_FOUND', 'Questionnaire not found', 404);
        }
        $ph = implode(',', array_fill(0, count($orderIds), '?'));
        $stmt = $pdo->prepare(
            "SELECT questionID FROM question WHERE questionnaireID = ? AND questionID IN ($ph)"
        );
        $stmt->execute(array_merge([$qnID], $orderIds));
        $found = $stmt->fetchAll(PDO::FETCH_COLUMN);
        if (count($found) !== count($orderIds)) {
            $missing = array_values(array_diff($orderIds, $found));
            qdb_discard($tmpDb, $lockFp);
            json_error(
                'INVALID_FIELD',
                'order[] contains questionIDs not in this questionnaire',
                400,
                ['missingQuestionIDs' => $missing]
            );
        }
        $upd = $pdo->prepare(
            'UPDATE question SET orderIndex = :o WHERE questionID = :id AND questionnaireID = :qid'
        );
        foreach ($orderIds as $idx => $qid) {
            $upd->execute([':o' => $idx, ':id' => $qid, ':qid' => $qnID]);
        }
        qdb_save($tmpDb, $lockFp);
        json_success(['reordered' => true]);
    } catch (Throwable $e) {
        if (isset($tmpDb, $lockFp)) {
            qdb_discard($tmpDb, $lockFp);
        }
        if (function_exists('qdb_api_log_note_exception')) {
            qdb_api_log_note_exception($e);
        }
        require_once __DIR__ . '/../lib/errors.php';
        error_log('questions PATCH: ' . $e->getMessage());
        json_error('SERVER_ERROR', qdb_public_error_message($e, 'Reorder questions'), 500);
    }
    break;

default:
    json_error('METHOD_NOT_ALLOWED', 'Method not allowed', 405);
}