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

header('Content-Type: application/json; charset=UTF-8');

$tokenRec = require_valid_token();
$method   = $_SERVER['REQUEST_METHOD'];

switch ($method) {

case 'GET':
    $qnID = $_GET['questionnaireID'] ?? '';
    if (!$qnID) {
        http_response_code(400);
        echo json_encode(["error" => "questionnaireID query param required"]);
        exit;
    }
    [$pdo, $tmpDb, $lockFp] = qdb_open(false);

    $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'];
        $q['configJson'] = $q['configJson'] ?: '{}';
        $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'];
        }

        $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);
    echo json_encode(["success" => true, "questions" => $questions]);
    break;

case 'POST':
    require_role(['admin', 'supervisor'], $tokenRec);
    $body = json_decode(file_get_contents('php://input'), true);
    if (!$body || empty($body['questionnaireID']) || !isset($body['defaultText'])) {
        http_response_code(400);
        echo json_encode(["error" => "questionnaireID and defaultText required"]);
        exit;
    }

    $id     = bin2hex(random_bytes(16));
    $qnID   = $body['questionnaireID'];
    $text   = trim($body['defaultText']);
    $type   = trim($body['type'] ?? '');
    $order  = (int)($body['orderIndex'] ?? 0);
    $req    = (int)($body['isRequired'] ?? 0);
    $config = $body['configJson'] ?? '{}';

    [$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);
            http_response_code(404);
            echo json_encode(["error" => "Questionnaire not found"]);
            exit;
        }

        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();
        }

        $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' => $config]);
        qdb_save($tmpDb, $lockFp);
        echo json_encode(["success" => true, "question" => [
            "questionID" => $id, "questionnaireID" => $qnID, "defaultText" => $text,
            "type" => $type, "orderIndex" => $order, "isRequired" => $req,
            "configJson" => $config, "answerOptions" => [], "translations" => []
        ]]);
    } catch (Throwable $e) {
        qdb_discard($tmpDb, $lockFp);
        http_response_code(500);
        error_log($e->getMessage());
        echo json_encode(["error" => "Server error"]);
    }
    break;

case 'PUT':
    require_role(['admin', 'supervisor'], $tokenRec);
    $body = json_decode(file_get_contents('php://input'), true);
    if (!$body || empty($body['questionID'])) {
        http_response_code(400);
        echo json_encode(["error" => "questionID is required"]);
        exit;
    }
    $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);
            http_response_code(404);
            echo json_encode(["error" => "Question not found"]);
            exit;
        }

        $text   = trim($body['defaultText'] ?? $row['defaultText']);
        $type   = trim($body['type']        ?? $row['type']);
        $order  = (int)($body['orderIndex'] ?? $row['orderIndex']);
        $req    = (int)($body['isRequired'] ?? $row['isRequired']);
        $config = $body['configJson']       ?? $row['configJson'];

        $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' => $config, ':id' => $id]);
        qdb_save($tmpDb, $lockFp);
        echo json_encode(["success" => true, "question" => [
            "questionID" => $id, "questionnaireID" => $row['questionnaireID'],
            "defaultText" => $text, "type" => $type, "orderIndex" => $order, "isRequired" => $req,
            "configJson" => $config
        ]]);
    } catch (Throwable $e) {
        qdb_discard($tmpDb, $lockFp);
        http_response_code(500);
        error_log($e->getMessage());
        echo json_encode(["error" => "Server error"]);
    }
    break;

case 'DELETE':
    require_role(['admin', 'supervisor'], $tokenRec);
    $body = json_decode(file_get_contents('php://input'), true);
    if (!$body || empty($body['questionID'])) {
        http_response_code(400);
        echo json_encode(["error" => "questionID is required"]);
        exit;
    }
    $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);
        echo json_encode(["success" => true]);
    } catch (Throwable $e) {
        if ($pdo->inTransaction()) $pdo->rollBack();
        qdb_discard($tmpDb, $lockFp);
        http_response_code(500);
        error_log($e->getMessage());
        echo json_encode(["error" => "Server error"]);
    }
    break;

case 'PATCH':
    require_role(['admin', 'supervisor'], $tokenRec);
    $body = json_decode(file_get_contents('php://input'), true);
    if (!$body || empty($body['questionnaireID']) || !is_array($body['order'] ?? null)) {
        http_response_code(400);
        echo json_encode(["error" => "questionnaireID and order[] required"]);
        exit;
    }

    [$pdo, $tmpDb, $lockFp] = qdb_open(true);
    try {
        $stmt = $pdo->prepare("UPDATE question SET orderIndex = :o WHERE questionID = :id AND questionnaireID = :qid");
        foreach ($body['order'] as $idx => $qid) {
            $stmt->execute([':o' => $idx, ':id' => $qid, ':qid' => $body['questionnaireID']]);
        }
        qdb_save($tmpDb, $lockFp);
        echo json_encode(["success" => true]);
    } catch (Throwable $e) {
        qdb_discard($tmpDb, $lockFp);
        http_response_code(500);
        error_log($e->getMessage());
        echo json_encode(["error" => "Server error"]);
    }
    break;

default:
    http_response_code(405);
    echo json_encode(["error" => "Method not allowed"]);
}