<?php
if (!defined('_GNUBOARD_')) exit;


// 💡 [핵심 수정] 라이브러리가 어디서든 독립적으로 실행될 수 있도록 필요한 상수를 정의합니다.
// AJAX 등 다른 경로로 라이브러리만 직접 호출될 때, 상수가 정의되지 않는 문제를 해결합니다.
// if(!defined(...))로 감싸서 _common.php 등에서 이미 정의된 경우 충돌을 방지합니다.
if (!defined('SURVEY_STATUS_DRAFT'))    define('SURVEY_STATUS_DRAFT', 'draft');
if (!defined('SURVEY_STATUS_ACTIVE'))   define('SURVEY_STATUS_ACTIVE', 'active');
if (!defined('SURVEY_STATUS_CLOSED'))   define('SURVEY_STATUS_CLOSED', 'closed');
if (!defined('SURVEY_STATUS_DELETED'))  define('SURVEY_STATUS_DELETED', 'deleted');

if (!defined('RESPONSE_STATUS_STARTED'))   define('RESPONSE_STATUS_STARTED', 'started');
if (!defined('RESPONSE_STATUS_COMPLETED')) define('RESPONSE_STATUS_COMPLETED', 'completed');
if (!defined('RESPONSE_STATUS_ABANDONED')) define('RESPONSE_STATUS_ABANDONED', 'abandoned');

/**
 * 설문 관리 라이브러리 함수들
 */
/**
 * 설문지 정보 가져오기
 */
function get_survey($sv_id) {
    global $g5;
    
    $sql = "SELECT * FROM survey_master WHERE sv_id = '$sv_id'";
    return sql_fetch($sql);
}

/**
 * 설문 질문 목록 가져오기
 */
function get_survey_questions($sv_id) {
    global $g5;
    
    $sql = "SELECT * FROM survey_questions WHERE sv_id = '$sv_id' ORDER BY sq_order ASC";
    $result = sql_query($sql);
    
    $questions = array();
    while ($row = sql_fetch_array($result)) {
        if ($row['sq_options']) {
            $row['sq_options'] = json_decode($row['sq_options'], true);
        }
        if ($row['sq_validation']) {
            $row['sq_validation'] = json_decode($row['sq_validation'], true);
        }
        $questions[] = $row;
    }
    
    return $questions;
}

/**
 * 설문 응답 수 가져오기
 */
function get_survey_response_count($sv_id, $status = 'completed') {
    global $g5;
    
    $where = "sv_id = '$sv_id'";
    if ($status) {
        $where .= " AND sr_status = '$status'";
    }
    
    $sql = "SELECT COUNT(*) as cnt FROM survey_responses WHERE $where";
    $row = sql_fetch($sql);
    
    return $row['cnt'];
}

/**
 * 설문 상태 업데이트
 */
function update_survey_status($sv_id, $status) {
    global $g5;
    
    $sql = "UPDATE survey_master SET sv_status = '$status', sv_updated_at = NOW() WHERE sv_id = '$sv_id'";
    return sql_query($sql);
}

/**
 * 설문 응답 시작
 */
function start_survey_response($sv_id, $mb_id = null, $ip = '', $user_agent = '', $session_id = '') {
    global $g5;
    
    $sql = "INSERT INTO survey_responses 
            (sv_id, sr_mb_id, sr_ip, sr_user_agent, sr_session_id, sr_started_at, sr_status) 
            VALUES 
            ('$sv_id', ".($mb_id ? "'$mb_id'" : 'NULL').", '$ip', '$user_agent', '$session_id', NOW(), '".RESPONSE_STATUS_STARTED."')";
    
    sql_query($sql);
    return sql_insert_id();
}

/**
 * 설문 응답 완료
 */
function complete_survey_response($sr_id) {
    global $g5;
    
    $sql = "UPDATE survey_responses 
            SET sr_status = '".RESPONSE_STATUS_COMPLETED."', sr_completed_at = NOW() 
            WHERE sr_id = '$sr_id'";
    
    return sql_query($sql);
}

/**
 * 설문 답변 저장
 */
function save_survey_answer($sr_id, $sq_id, $value, $text = '') {
    global $g5;
    
    // 기존 답변 삭제
    $sql = "DELETE FROM survey_answers WHERE sr_id = '$sr_id' AND sq_id = '$sq_id'";
    sql_query($sql);
    
    // 새 답변 저장
    if (is_array($value)) {
        foreach ($value as $v) {
            $sql = "INSERT INTO survey_answers (sr_id, sq_id, sa_value, sa_text, sa_created_at) 
                    VALUES ('$sr_id', '$sq_id', '$v', '$text', NOW())";
            sql_query($sql);
        }
    } else {
        $sql = "INSERT INTO survey_answers (sr_id, sq_id, sa_value, sa_text, sa_created_at) 
                VALUES ('$sr_id', '$sq_id', '$value', '$text', NOW())";
        sql_query($sql);
    }
    
    return true;
}

/**
 * 설문 통계 업데이트
 */
function update_survey_statistics($sv_id) {
    global $g5;
    
    // 기존 통계 삭제
    $sql = "DELETE FROM survey_statistics WHERE sv_id = '$sv_id'";
    sql_query($sql);
    
    // 질문별 통계 생성
    $questions = get_survey_questions($sv_id);
    $total_responses = get_survey_response_count($sv_id, 'completed');
    
    foreach ($questions as $question) {
        $sq_id = $question['sq_id'];
        
        if (in_array($question['sq_type'], ['radio', 'checkbox', 'select'])) {
            // 선택형 질문 통계
            $sql = "SELECT sa_value, COUNT(*) as cnt 
                    FROM survey_answers sa 
                    JOIN survey_responses sr ON sa.sr_id = sr.sr_id 
                    WHERE sr.sv_id = '$sv_id' AND sa.sq_id = '$sq_id' AND sr.sr_status = 'completed'
                    GROUP BY sa_value";
            
            $result = sql_query($sql);
            while ($row = sql_fetch_array($result)) {
                $percentage = $total_responses > 0 ? round(($row['cnt'] / $total_responses) * 100, 2) : 0;
                
                $insert_sql = "INSERT INTO survey_statistics 
                              (sv_id, sq_id, ss_option_value, ss_count, ss_percentage) 
                              VALUES 
                              ('$sv_id', '$sq_id', '{$row['sa_value']}', '{$row['cnt']}', '$percentage')";
                sql_query($insert_sql);
            }
        } elseif ($question['sq_type'] == 'rating') {
            // 평점 질문 통계
            $sql = "SELECT sa_value, COUNT(*) as cnt 
                    FROM survey_answers sa 
                    JOIN survey_responses sr ON sa.sr_id = sr.sr_id 
                    WHERE sr.sv_id = '$sv_id' AND sa.sq_id = '$sq_id' AND sr.sr_status = 'completed'
                    GROUP BY sa_value 
                    ORDER BY CAST(sa_value AS UNSIGNED)";
            
            $result = sql_query($sql);
            while ($row = sql_fetch_array($result)) {
                $percentage = $total_responses > 0 ? round(($row['cnt'] / $total_responses) * 100, 2) : 0;
                
                $insert_sql = "INSERT INTO survey_statistics 
                              (sv_id, sq_id, ss_option_value, ss_count, ss_percentage) 
                              VALUES 
                              ('$sv_id', '$sq_id', '{$row['sa_value']}', '{$row['cnt']}', '$percentage')";
                sql_query($insert_sql);
            }
        }
    }
    
    return true;
}

/**
 * 설문 템플릿 목록 가져오기
 */
function get_survey_templates($category = '') {
    global $g5;
    
    $where = "st_is_public = 1";
    if ($category) {
        $where .= " AND st_category = '$category'";
    }
    
    $sql = "SELECT * FROM survey_templates WHERE $where ORDER BY st_created_at DESC";
    $result = sql_query($sql);
    
    $templates = array();
    while ($row = sql_fetch_array($result)) {
        $templates[] = $row;
    }
    
    return $templates;
}

/**
 * 설문 템플릿으로 설문 생성
 */
function create_survey_from_template($template_id, $title, $created_by) {
    global $g5;
    
    $template = sql_fetch("SELECT * FROM survey_templates WHERE st_id = '$template_id'");
    if (!$template) {
        return false;
    }
    
    $template_data = json_decode($template['st_data'], true);
    
    // 설문지 생성
    $sql = "INSERT INTO survey_master 
            (sv_title, sv_description, sv_start_date, sv_end_date, sv_status, sv_created_by) 
            VALUES 
            ('$title', '{$template_data['description']}', NOW(), DATE_ADD(NOW(), INTERVAL 30 DAY), '".SURVEY_STATUS_DRAFT."', '$created_by')";
    
    sql_query($sql);
    $sv_id = sql_insert_id();
    
    // 질문들 생성
    foreach ($template_data['questions'] as $index => $question) {
        $sq_order = $index + 1;
        $sq_type = $question['type'];
        $sq_title = addslashes($question['title']);
        $sq_required = isset($question['required']) && $question['required'] ? 1 : 0;
        $sq_options = isset($question['options']) ? addslashes(json_encode($question['options'])) : '';
        $sq_validation = isset($question['validation']) ? addslashes(json_encode($question['validation'])) : '';
        
        $sql = "INSERT INTO survey_questions 
                (sv_id, sq_order, sq_type, sq_title, sq_required, sq_options, sq_validation) 
                VALUES 
                ('$sv_id', '$sq_order', '$sq_type', '$sq_title', '$sq_required', '$sq_options', '$sq_validation')";
        
        sql_query($sql);
    }
    
    return $sv_id;
}

/**
 * 설문 데이터 엑셀 내보내기용 배열 생성
 */
function get_survey_export_data($sv_id) {
    global $g5;
    
    $survey = get_survey($sv_id);
    $questions = get_survey_questions($sv_id);
    
    // 헤더 생성
    $headers = ['응답ID', '응답자', 'IP주소', '시작시간', '완료시간'];
    foreach ($questions as $question) {
        $headers[] = strip_tags($question['sq_title']);
    }
    
    // 데이터 생성
    $data = array();
    $data[] = $headers;
    
    $sql = "SELECT * FROM survey_responses 
            WHERE sv_id = '$sv_id' AND sr_status = 'completed' 
            ORDER BY sr_completed_at DESC";
    
    $result = sql_query($sql);
    while ($response = sql_fetch_array($result)) {
        $row = array();
        $row[] = $response['sr_id'];
        $row[] = $response['sr_mb_id'] ?: '익명';
        $row[] = $response['sr_ip'];
        $row[] = $response['sr_started_at'];
        $row[] = $response['sr_completed_at'];
        
        // 각 질문별 답변
        foreach ($questions as $question) {
            $answer_sql = "SELECT sa_value, sa_text FROM survey_answers 
                          WHERE sr_id = '{$response['sr_id']}' AND sq_id = '{$question['sq_id']}'";
            $answer_result = sql_query($answer_sql);
            
            $answers = array();
            while ($answer = sql_fetch_array($answer_result)) {
                if ($answer['sa_text']) {
                    $answers[] = $answer['sa_value'] . ' (' . $answer['sa_text'] . ')';
                } else {
                    $answers[] = $answer['sa_value'];
                }
            }
            
            $row[] = implode(', ', $answers);
        }
        
        $data[] = $row;
    }
    
    return $data;
}

/**
 * 설문 유효성 검사
 */
function validate_survey_access($sv_id, $mb_id = null, $ip = '') {
    global $g5;
    
    $survey = get_survey($sv_id);
    if (!$survey) {
        return array('success' => false, 'message' => '존재하지 않는 설문입니다.');
    }
    
    // 상태 확인
    if ($survey['sv_status'] != SURVEY_STATUS_ACTIVE) {
        return array('success' => false, 'message' => '현재 참여할 수 없는 설문입니다.');
    }
    
    // 기간 확인
    $now = date('Y-m-d H:i:s');
    if ($now < $survey['sv_start_date']) {
        return array('success' => false, 'message' => '아직 시작되지 않은 설문입니다.');
    }
    
    if ($now > $survey['sv_end_date']) {
        return array('success' => false, 'message' => '종료된 설문입니다.');
    }
    
    // 중복 참여 확인
    if (!$survey['sv_allow_multiple']) {
        $where = "sv_id = '$sv_id' AND sr_status = 'completed'";
        
        if ($mb_id) {
            $where .= " AND sr_mb_id = '$mb_id'";
        } else {
            $where .= " AND sr_ip = '$ip'";
        }
        
        $existing = sql_fetch("SELECT COUNT(*) as cnt FROM survey_responses WHERE $where");
        if ($existing['cnt'] > 0) {
            return array('success' => false, 'message' => '이미 참여하신 설문입니다.');
        }
    }
    
    // 최대 응답 수 확인
    if ($survey['sv_max_responses']) {
        $total_responses = get_survey_response_count($sv_id, 'completed');
        if ($total_responses >= $survey['sv_max_responses']) {
            return array('success' => false, 'message' => '설문 참여 인원이 마감되었습니다.');
        }
    }
    
    return array('success' => true, 'survey' => $survey);
}