<?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':
    $qID = $_GET['questionID'] ?? '';
    if (!$qID) {
        http_response_code(400);
        echo json_encode(["error" => "questionID query param required"]);
        exit;
    }
    [$pdo, $tmpDb, $lockFp] = qdb_open(false);
    $stmt = $pdo->prepare("
        SELECT answerOptionID, questionID, defaultText, points, orderIndex, nextQuestionId
        FROM answer_option WHERE questionID = :qid ORDER BY orderIndex
    ");
    $stmt->execute([':qid' => $qID]);
    $options = $stmt->fetchAll(PDO::FETCH_ASSOC);
    foreach ($options as &$o) {
        $o['points']     = (int)$o['points'];
        $o['orderIndex'] = (int)$o['orderIndex'];
        $tr = $pdo->prepare("SELECT languageCode, text FROM answer_option_translation WHERE answerOptionID = :id");
        $tr->execute([':id' => $o['answerOptionID']]);
        $o['translations'] = $tr->fetchAll(PDO::FETCH_ASSOC);
    }
    unset($o);
    qdb_discard($tmpDb, $lockFp);
    echo json_encode(["success" => true, "answerOptions" => $options]);
    break;

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

    $id     = bin2hex(random_bytes(16));
    $qID    = $body['questionID'];
    $text   = trim($body['defaultText']);
    $points = (int)($body['points'] ?? 0);
    $order  = (int)($body['orderIndex'] ?? 0);
    $nextQ  = trim($body['nextQuestionId'] ?? '');

    [$pdo, $tmpDb, $lockFp] = qdb_open(true);
    try {
        $chk = $pdo->prepare("SELECT 1 FROM question WHERE questionID = :id");
        $chk->execute([':id' => $qID]);
        if (!$chk->fetch()) {
            qdb_discard($tmpDb, $lockFp);
            http_response_code(404);
            echo json_encode(["error" => "Question not found"]);
            exit;
        }
        if ($order === 0) {
            $max = $pdo->prepare("SELECT COALESCE(MAX(orderIndex),0)+1 FROM answer_option WHERE questionID = :id");
            $max->execute([':id' => $qID]);
            $order = (int)$max->fetchColumn();
        }
        $pdo->prepare("INSERT INTO answer_option (answerOptionID, questionID, defaultText, points, orderIndex, nextQuestionId)
                        VALUES (:id, :qid, :t, :p, :o, :nq)")
            ->execute([':id' => $id, ':qid' => $qID, ':t' => $text, ':p' => $points, ':o' => $order, ':nq' => $nextQ]);
        qdb_save($tmpDb, $lockFp);
        echo json_encode(["success" => true, "answerOption" => [
            "answerOptionID" => $id, "questionID" => $qID, "defaultText" => $text,
            "points" => $points, "orderIndex" => $order, "nextQuestionId" => $nextQ, "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['answerOptionID'])) {
        http_response_code(400);
        echo json_encode(["error" => "answerOptionID is required"]);
        exit;
    }
    $id = $body['answerOptionID'];

    [$pdo, $tmpDb, $lockFp] = qdb_open(true);
    try {
        $existing = $pdo->prepare("SELECT * FROM answer_option WHERE answerOptionID = :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" => "Answer option not found"]);
            exit;
        }
        $text   = trim($body['defaultText']    ?? $row['defaultText']);
        $points = (int)($body['points']        ?? $row['points']);
        $order  = (int)($body['orderIndex']    ?? $row['orderIndex']);
        $nextQ  = trim($body['nextQuestionId'] ?? $row['nextQuestionId']);

        $pdo->prepare("UPDATE answer_option SET defaultText = :t, points = :p, orderIndex = :o, nextQuestionId = :nq WHERE answerOptionID = :id")
            ->execute([':t' => $text, ':p' => $points, ':o' => $order, ':nq' => $nextQ, ':id' => $id]);
        qdb_save($tmpDb, $lockFp);
        echo json_encode(["success" => true, "answerOption" => [
            "answerOptionID" => $id, "questionID" => $row['questionID'],
            "defaultText" => $text, "points" => $points, "orderIndex" => $order,
            "nextQuestionId" => $nextQ
        ]]);
    } 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['answerOptionID'])) {
        http_response_code(400);
        echo json_encode(["error" => "answerOptionID is required"]);
        exit;
    }
    $id = $body['answerOptionID'];

    [$pdo, $tmpDb, $lockFp] = qdb_open(true);
    try {
        $pdo->exec("PRAGMA foreign_keys = OFF;");
        $pdo->beginTransaction();
        $pdo->prepare("DELETE FROM answer_option_translation WHERE answerOptionID = :id")->execute([':id' => $id]);
        $pdo->prepare("UPDATE client_answer SET answerOptionID = NULL WHERE answerOptionID = :id")->execute([':id' => $id]);
        $pdo->prepare("DELETE FROM answer_option WHERE answerOptionID = :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($body['questionID']) || !is_array($body['order'] ?? null)) {
        http_response_code(400);
        echo json_encode(["error" => "questionID and order[] required"]);
        exit;
    }

    [$pdo, $tmpDb, $lockFp] = qdb_open(true);
    try {
        $stmt = $pdo->prepare("UPDATE answer_option SET orderIndex = :o WHERE answerOptionID = :id AND questionID = :qid");
        foreach ($body['order'] as $idx => $aoid) {
            $stmt->execute([':o' => $idx, ':id' => $aoid, ':qid' => $body['questionID']]);
        }
        qdb_save($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"]);
}