app.py

import requests
import gradio as gr
from datetime import datetime
import random

USERNAME = "openfree"

def format_timestamp(timestamp):
    if not timestamp:
        return 'N/A'
    try:
        # 문자열인 경우
        if isinstance(timestamp, str):
            dt = datetime.fromisoformat(timestamp.replace('Z', '+00:00'))
        # 정수(밀리초)인 경우
        elif isinstance(timestamp, (int, float)):
            dt = datetime.fromtimestamp(timestamp / 1000)  # 밀리초를 초로 변환
        else:
            return 'N/A'
        return dt.strftime('%Y-%m-%d %H:%M')
    except Exception as e:
        print(f"Timestamp conversion error: {str(e)} for timestamp: {timestamp}")
        return 'N/A'
        

def should_exclude_space(space_name):
    """특정 스페이스를 제외하는 필터 함수"""
    exclude_keywords = [
        'mixgen3', 'ginid', 'mouse', 'flxtrainlora',
        'vidslicegpu', 'stickimg', 'ultpixgen', 'SORA',
        'badassgi', 'newsplus', 'chargen', 'news',
        'testhtml'
    ]
    
    return any(keyword.lower() in space_name.lower() for keyword in exclude_keywords)

def get_pastel_color(index):
    """Generate unique pastel colors based on index"""
    pastel_colors = [
        '#FFE6E6',  # 연한 분홍
        '#FFE6FF',  # 연한 보라
        '#E6E6FF',  # 연한 파랑
        '#E6FFFF',  # 연한 하늘
        '#E6FFE6',  # 연한 초록
        '#FFFFE6',  # 연한 노랑
        '#FFF0E6',  # 연한 주황
        '#F0E6FF',  # 연한 라벤더
        '#FFE6F0',  # 연한 로즈
        '#E6FFF0',  # 연한 민트
        '#F0FFE6',  # 연한 라임
        '#FFE6EB',  # 연한 코랄
        '#E6EBFF',  # 연한 퍼플블루
        '#FFE6F5',  # 연한 핑크
        '#E6FFF5',  # 연한 터코이즈
        '#F5E6FF',  # 연한 모브
        '#FFE6EC',  # 연한 살몬
        '#E6FFEC',  # 연한 스프링그린
        '#ECE6FF',  # 연한 페리윙클
        '#FFE6F7',  # 연한 매그놀리아
    ]
    return pastel_colors[index % len(pastel_colors)]

def get_space_card(space, index):
    """Generate HTML card for a space with colorful design and lots of emojis"""
    space_id = space.get('id', '')
    space_name = space_id.split('/')[-1]
    likes = space.get('likes', 0)
    created_at = format_timestamp(space.get('createdAt'))
    sdk = space.get('sdk', 'N/A')
    
    # SDK별 이모지 및 관련 이모지 세트
    sdk_emoji_sets = {
        'gradio': {
            'main': '🎨',
            'related': ['🖼️', '🎭', '🎪', '🎠', '🎡', '🎢', '🎯', '🎲', '🎰', '🎳']
        },
        'streamlit': {
            'main': '⚡',
            'related': ['💫', '✨', '⭐', '🌟', '💥', '⚡', '🔥', '🌈', '🎆', '🎇']
        },
        'docker': {
            'main': '🐳',
            'related': ['🐋', '🌊', '🌍', '🚢', '⛴️', '🛥️', '🐠', '🐡', '🦈', '🐬']
        },
        'static': {
            'main': '📄',
            'related': ['📝', '📰', '📑', '🗂️', '📁', '📂', '📚', '📖', '📒', '📔']
        },
        'panel': {
            'main': '📊',
            'related': ['📈', '📉', '💹', '📋', '📌', '📍', '🗺️', '🎯', '📐', '📏']
        },
        'N/A': {
            'main': '🔧',
            'related': ['🔨', '⚒️', '🛠️', '⚙️', '🔩', '⛏️', '⚡', '🔌', '💡', '🔋']
        }
    }
    
    # SDK에 따른 이모지 선택
    sdk_lower = sdk.lower()
    bg_color = get_pastel_color(index)  # 인덱스 기반 색상 선택
    emoji_set = sdk_emoji_sets.get(sdk_lower, sdk_emoji_sets['N/A'])
    main_emoji = emoji_set['main']
    
    # 랜덤하게 3개의 관련 이모지 선택
    decorative_emojis = random.sample(emoji_set['related'], 3)
    
    # 추가 장식용 이모지
    general_emojis = ['🚀', '💫', '⭐', '🌟', '✨', '💥', '🔥', '🌈', '🎯', '🎨', 
                      '🎭', '🎪', '🎢', '🎡', '🎠', '🎪', '🎭', '🎨', '🎯', '🎲']
    random_emojis = random.sample(general_emojis, 3)
    
    # 좋아요 수에 따른 하트 이모지
    heart_emoji = '❤️' if likes > 100 else '💖' if likes > 50 else '💝' if likes > 10 else '🤍'



    
    return f"""
    <div style='border: none; 
                padding: 25px; 
                margin: 15px; 
                border-radius: 20px; 
                background-color: {bg_color};
                box-shadow: 0 4px 15px rgba(0,0,0,0.1);
                transition: all 0.3s ease-in-out;
                position: relative;
                overflow: hidden;'
         onmouseover='this.style.transform="translateY(-5px) scale(1.02)"; this.style.boxShadow="0 8px 25px rgba(0,0,0,0.15)"'
         onmouseout='this.style.transform="translateY(0) scale(1)"; this.style.boxShadow="0 4px 15px rgba(0,0,0,0.1)"'>
        <div style='position: absolute; top: -15px; right: -15px; font-size: 100px; opacity: 0.1;'>
            {main_emoji}
        </div>
        <div style='position: absolute; top: 10px; right: 10px; font-size: 20px;'>
            {decorative_emojis[0]}
        </div>
        <div style='position: absolute; bottom: 10px; left: 10px; font-size: 20px;'>
            {decorative_emojis[1]}
        </div>
        <div style='position: absolute; top: 50%; right: 10px; font-size: 20px;'>
            {decorative_emojis[2]}
        </div>
        <h3 style='color: #2d2d2d; 
                   margin: 0 0 20px 0; 
                   font-size: 1.4em;
                   display: flex;
                   align-items: center;
                   gap: 10px;'>
            <span style='font-size: 1.3em'>{random_emojis[0]}</span>
            <a href='https://huggingface.co/spaces/{space_id}' target='_blank' 
               style='text-decoration: none; color: #2d2d2d;'>
                {space_name}
            </a>
            <span style='font-size: 1.3em'>{random_emojis[1]}</span>
        </h3>
        <div style='margin: 15px 0; color: #444; background: rgba(255,255,255,0.5); 
                    padding: 15px; border-radius: 12px;'>
            <p style='margin: 8px 0;'>
                <strong>SDK:</strong> {main_emoji} {sdk} {decorative_emojis[0]}
            </p>
            <p style='margin: 8px 0;'>
                <strong>Created:</strong> 📅 {created_at} ⏰
            </p>
            <p style='margin: 8px 0;'>
                <strong>Likes:</strong> {heart_emoji} {likes} {random_emojis[2]}
            </p>
        </div>
        <div style='margin-top: 20px; 
                    display: flex; 
                    justify-content: space-between; 
                    align-items: center;'>
            <a href='https://huggingface.co/spaces/{space_id}' target='_blank' 
               style='background: linear-gradient(45deg, #0084ff, #00a3ff);
                      color: white; 
                      padding: 10px 20px; 
                      border-radius: 15px; 
                      text-decoration: none; 
                      display: inline-flex;
                      align-items: center;
                      gap: 8px;
                      font-weight: 500; 
                      transition: all 0.3s;
                      box-shadow: 0 2px 8px rgba(0,132,255,0.3);'
               onmouseover='this.style.transform="scale(1.05)"; this.style.boxShadow="0 4px 12px rgba(0,132,255,0.4)"'
               onmouseout='this.style.transform="scale(1)"; this.style.boxShadow="0 2px 8px rgba(0,132,255,0.3)"'>
                <span>View Space</span> 🚀 {random_emojis[0]}
            </a>
            <span style='color: #666; font-size: 0.9em; opacity: 0.7;'>
                🆔 {space_id} {decorative_emojis[2]}
            </span>
        </div>
    </div>
    """

def get_vercel_deployments():
    """Vercel API를 통해 모든 배포된 서비스 정보 가져오기 (페이지네이션 적용)"""
    token = "A8IFZmgW2cqA4yUNlLPnci0N"
    base_url = "https://api.vercel.com/v6/deployments"
    all_deployments = []
    has_next = True
    page = 1
    until = None  # 첫 요청에서는 until 파라미터 없음
    
    headers = {
        "Authorization": f"Bearer {token}",
        "Content-Type": "application/json"
    }
    
    try:
        while has_next:
            # URL 구성 (페이지네이션 파라미터 포함)
            url = f"{base_url}?limit=100"
            if until:
                url += f"&until={until}"
            
            print(f"Fetching page {page}... URL: {url}")  # 디버깅용
            
            response = requests.get(url, headers=headers)
            if response.status_code != 200:
                print(f"Vercel API Error: {response.text}")
                break
            
            data = response.json()
            current_deployments = data.get('deployments', [])
            
            if not current_deployments:  # 더 이상 데이터가 없으면 종료
                break
                
            all_deployments.extend(current_deployments)
            
            # 다음 페이지를 위한 until 값 설정
            pagination = data.get('pagination', {})
            until = pagination.get('next')
            has_next = bool(until)  # until 값이 있으면 다음 페이지 존재
            
            print(f"Page {page} fetched. Got {len(current_deployments)} deployments")  # 디버깅용
            page += 1
        
        print(f"Total deployments fetched: {len(all_deployments)}")  # 디버깅용
        
        # 상태가 'READY'이고 'url'이 있는 배포만 필터링하고 'javis1' 제외
        active_deployments = [
            dep for dep in all_deployments 
            if dep.get('state') == 'READY' and 
               dep.get('url') and 
               'javis1' not in dep.get('name', '').lower()
        ]
        
        print(f"Active deployments after filtering: {len(active_deployments)}")  # 디버깅용
        return active_deployments
        
    except Exception as e:
        print(f"Error fetching Vercel deployments: {str(e)}")
        return []

def get_vercel_card(deployment, index):
    """Generate HTML card for a Vercel deployment with like button"""
    raw_url = deployment.get('url', '')
    
    # URL 처리 로직 수정
    if raw_url.startswith('http'):
        url = raw_url  # 전체 URL이 제공된 경우 그대로 사용
    else:
        project_name = raw_url[:6] if len(raw_url) >= 6 else raw_url
        url = f"{project_name}.vercel.app"
    
    # Hugging Face 스페이스 URL인 경우 직접 사용
    if 'huggingface.co' in url:
        final_url = url
    else:
        final_url = f"https://{url}" if not url.startswith('http') else url
    
    created = format_timestamp(deployment.get('created'))
    name = deployment.get('name', 'Unnamed Project')
    state = deployment.get('state', 'N/A')
    
    # 고유 ID 생성 (카드 식별용)
    card_id = f"vercel-card-{url.replace('.', '-').replace('/', '-')}"
    

    
    bg_color = get_pastel_color(index + 20)
    tech_emojis = ['⚡', '🚀', '🌟', '✨', '💫', '🔥', '🌈', '🎯', '🎨', '🔮']
    random_emojis = random.sample(tech_emojis, 3)


    return f"""
    <div id="{card_id}" class="vercel-card"
         data-likes="0"
         style='border: none; 
                padding: 25px; 
                margin: 15px; 
                border-radius: 20px; 
                background-color: {bg_color};
                box-shadow: 0 4px 15px rgba(0,0,0,0.1);
                transition: all 0.3s ease-in-out;
                position: relative;
                overflow: hidden;'
         onmouseover='this.style.transform="translateY(-5px) scale(1.02)"; this.style.boxShadow="0 8px 25px rgba(0,0,0,0.15)"'
         onmouseout='this.style.transform="translateY(0) scale(1)"; this.style.boxShadow="0 4px 15px rgba(0,0,0,0.1)"'>
         <!-- ... (이전 코드와 동일) ... -->
         <h3 style='color: #2d2d2d; 
                    margin: 0 0 20px 0; 
                    font-size: 1.4em;
                    display: flex;
                    align-items: center;
                    gap: 10px;'>
             <span style='font-size: 1.3em'>{random_emojis[0]}</span>
             <a href='{final_url}' target='_blank' 
                style='text-decoration: none; color: #2d2d2d;'>
                 {name}
             </a>
             <span style='font-size: 1.3em'>{random_emojis[1]}</span>
         </h3>    

        <div style='margin: 15px 0; color: #444; background: rgba(255,255,255,0.5); 
                    padding: 15px; border-radius: 12px;'>
            <p style='margin: 8px 0;'>
                <strong>Status:</strong> ✅ {state}
            </p>
            <p style='margin: 8px 0;'>
                <strong>Created:</strong> 📅 {created}
            </p>
            <p style='margin: 8px 0;'>
                <strong>URL:</strong> 🔗 https://{url}
            </p>
        </div>
         <div style='margin-top: 20px; display: flex; justify-content: space-between; align-items: center;'>
             <div class="like-section" style="display: flex; align-items: center; gap: 10px;">
                 <button onclick="toggleLike('{card_id}')" class="like-button" 
                         style="background: none; border: none; cursor: pointer; font-size: 1.5em; padding: 5px 10px;">
                     🤍
                 </button>
                 <span class="like-count" style="font-size: 1.2em; color: #666;">0</span>
             </div>
             <a href='{final_url}' target='_blank' 
                style='background: linear-gradient(45deg, #0084ff, #00a3ff);
                       color: white; 
                       padding: 10px 20px; 
                       border-radius: 15px; 
                       text-decoration: none; 
                       display: inline-flex;
                       align-items: center;
                       gap: 8px;
                       font-weight: 500; 
                       transition: all 0.3s;
                       box-shadow: 0 2px 8px rgba(0,132,255,0.3);'
                onmouseover='this.style.transform="scale(1.05)"; this.style.boxShadow="0 4px 12px rgba(0,132,255,0.4)"'
                onmouseout='this.style.transform="scale(1)"; this.style.boxShadow="0 2px 8px rgba(0,132,255,0.3)"'>
                 <span>View Deployment</span> 🚀 {random_emojis[0]}
             </a>
         </div>
    </div>
    """

# Top Best URLs 정의
TOP_BEST_URLS = [
    
    {
        "url": "dekvxz.vercel.app",
        "name": "[게임] 다이어트 헌터",
        "created": "2024-11-20 00:00",
        "state": "READY"
    },
    {
        "url": "jtufui.vercel.app",
        "name": "[게임] 테러리스트",
        "created": "2024-11-20 00:00",
        "state": "READY"
    },            
    {
        "url": "https://huggingface.co/spaces/openfree/ggumim",
        "name": "[MOUSE-II] 이미지에 한글 출력",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },      
    {
        "url": "xabtnc.vercel.app",
        "name": "[ChatGPT] 나만의 LLM",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },    
    {
        "url": "https://huggingface.co/spaces/openfree/ifbhdc",
        "name": "[게임] 보석 팡팡",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },
    {
        "url": "nxhquk.vercel.app",
        "name": "[게임] 테트리스",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },    
    {
        "url": "bydcnd.vercel.app",
        "name": "[모델] 3D 분자 모형",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },   
    {
        "url": "ijhama.vercel.app",
        "name": "투자 포트폴리오 분석",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },    
    {
        "url": "oschnl.vercel.app",
        "name": "로또 번호 분석/추천",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },      
    {
        "url": "rzwzrq.vercel.app",
        "name": "엑셀/CSV 데이터 분석",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },            
    {
        "url": "twkqre.vercel.app",
        "name": "[운세] 타로카드",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },    
    {
        "url": "htwymz.vercel.app",
        "name": "[게임] 소방헬기",
        "created": "2024-11-20 00:00",
        "state": "READY"
    },    
    {
        "url": "mktmbn.vercel.app",
        "name": "[게임] 우주전쟁",
        "created": "2024-11-19 00:00",
        "state": "READY"
    },    
    {
        "url": "euguwt.vercel.app",
        "name": "[게임] 포세이돈",
        "created": "2024-11-19 00:00",
        "state": "READY"
    },    
     {
        "url": "qmdzoh.vercel.app",
        "name": "[게임] 하늘을 지켜라",
        "created": "2024-11-19 00:00",
        "state": "READY"
    },    
    {
        "url": "kofaqo.vercel.app",
        "name": "[게임] 운석 충돌!",
        "created": "2024-11-19 00:00",
        "state": "READY"
    },    
    {
        "url": "qoqqkq.vercel.app",
        "name": "[게임] 두더쥐 잡기",
        "created": "2024-11-19 00:00",
        "state": "READY"
    },    
    {
        "url": "nmznel.vercel.app",
        "name": "[게임] 고양이 전용",
        "created": "2024-11-19 00:00",
        "state": "READY"
    },    

    
    {
        "url": "psrrtp.vercel.app",
        "name": "[대시보드] 세계 인구",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },
    {
        "url": "xxloav.vercel.app",
        "name": "[게임] 벽돌 깨기",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },
    {
        "url": "https://huggingface.co/spaces/openfree/edpaje",
        "name": "[게임] 기억력 카드",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },
    {
        "url": "https://huggingface.co/spaces/openfree/ixtidb",
        "name": "AI 요리사",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },    
    
    {
        "url": "cnlzji.vercel.app",
        "name": "국가 정보 비교",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },
    {
        "url": "fazely.vercel.app",
        "name": "Wikipedia 지식 분석",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },
    {
        "url": "pkzhbo.vercel.app",
        "name": "세계 국가별 시간대",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },    
    {
        "url": "pammgl.vercel.app",
        "name": "보도자료 배포 서비스",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },       

    
    {
        "url": "https://ktduhm.vercel.app/",
        "name": "수학을 그래프로 이해",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },    


    {
        "url": "vjmfoy.vercel.app",
        "name": "[게임] 3D 벽돌쌓기",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },  
    {
        "url": "aodakf.vercel.app",
        "name": "[버추얼] 3D 가상현실",
        "created": "2024-11-18 00:00",
        "state": "READY"
    },    
    {
        "url": "mxoeue.vercel.app",
        "name": "음성 생성(TTS),조정",
        "created": "2024-11-18 00:00",
        "state": "READY"
    }
]


def get_user_spaces():
    # 기존 Hugging Face 스페이스 가져오기
    url = f"https://huggingface.co/api/spaces?author={USERNAME}&limit=500"
    headers = {
        "Accept": "application/json",
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36"
    }

    try:
        # Hugging Face 스페이스 가져오기
        response = requests.get(url, headers=headers)
        spaces_data = response.json() if response.status_code == 200 else []
        
        # 제외할 스페이스 필터링
        user_spaces = [
            space for space in spaces_data 
            if not should_exclude_space(space.get('id', '').split('/')[-1])
        ]

        # TOP_BEST_URLS 항목 수
        top_best_count = len(TOP_BEST_URLS)
        
        # Vercel API를 통한 실제 배포 수 (디버깅을 위한 출력 추가)
        vercel_deployments = get_vercel_deployments()
        print(f"Debug - Vercel API response: {vercel_deployments}")  # 디버깅 로그
        actual_vercel_count = len(vercel_deployments) if vercel_deployments else 0

        html_content = f"""
        <div style='padding: 20px; background-color: #f5f5f5;'>
            <div style='margin-bottom: 20px;'>
                <h2 style='color: #333; margin: 0 0 5px 0;'>공개 갤러리(생성 Web/App) by MOUSE</h2>
                <p style='color: #666; margin: 0 0 15px 0; font-size: 0.9em;'>
                    프롬프트만으로 나만의 웹서비스를 즉시 생성하는 MOUSE 
                    <a href='https://openfree-mouse.hf.space' target='_blank' 
                       style='color: #0084ff; text-decoration: none;'>
                        https://openfree-mouse.hf.space
                    </a>
                </p>
                <p style='color: #666; margin: 0;'>
                    Found {actual_vercel_count} Vercel deployments and {len(user_spaces)} Hugging Face spaces<br>
                    (Plus {top_best_count} featured items in Top Best section)
                </p>
            </div>

            <!-- Top Best -->
            <h3 style='color: #333; margin: 20px 0;'>🏆 Top Best</h3>
            <div style='display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 20px;'>
                {"".join(get_vercel_card({"url": url["url"], "created": url["created"], "name": url["name"], "state": url["state"]}, idx) 
                        for idx, url in enumerate(TOP_BEST_URLS))}
            </div>
            
            <!-- Vercel Deployments -->
            {f'''
            <h3 style='color: #333; margin: 20px 0;'>⚡ Vercel Deployments</h3>
            <div id="vercel-container" style='display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 20px;'>
                {"".join(get_vercel_card(dep, idx) for idx, dep in enumerate(vercel_deployments))}
            </div>
            ''' if vercel_deployments else ''}
            
            <!-- Hugging Face Spaces -->
            <h3 style='color: #333; margin: 20px 0;'>🤗 Hugging Face Spaces</h3>
            <div style='display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 20px;'>
                {"".join(get_space_card(space, idx) for idx, space in enumerate(user_spaces))}
            </div>
        </div>
        
        <script>
        document.addEventListener('DOMContentLoaded', function() {{
            // 좋아요 상태 로드
            function loadLikes() {{
                const cards = document.querySelectorAll('.vercel-card');
                cards.forEach(card => {{
                    const cardId = card.id;
                    const likes = localStorage.getItem(cardId) || 0;
                    card.querySelector('.like-count').textContent = likes;
                    card.dataset.likes = likes;
                    updateLikeButton(card, likes > 0);
                }});
                sortCards();
            }}
            
            // 좋아요 버튼 토글
            window.toggleLike = function(cardId) {{
                const card = document.getElementById(cardId);
                const likeCount = parseInt(localStorage.getItem(cardId) || 0);
                const newCount = likeCount > 0 ? 0 : 1;
                
                localStorage.setItem(cardId, newCount);
                card.querySelector('.like-count').textContent = newCount;
                card.dataset.likes = newCount;
                updateLikeButton(card, newCount > 0);
                
                sortCards();
            }}
            
            // 좋아요 버튼 상태 업데이트
            function updateLikeButton(card, isLiked) {{
                const button = card.querySelector('.like-button');
                button.textContent = isLiked ? '❤️' : '🤍';
            }}
            
            // 카드 정렬
            function sortCards() {{
                const container = document.getElementById('vercel-container');
                const cards = Array.from(container.children);
                
                cards.sort((a, b) => {{
                    return parseInt(b.dataset.likes) - parseInt(a.dataset.likes);
                }});
                
                cards.forEach(card => container.appendChild(card));
            }}
            
            // 초기 로드
            loadLikes();
        }});
        </script>
        """

        
        return html_content

    except Exception as e:
        print(f"Error: {str(e)}")
        return f"""
        <div style='padding: 20px; text-align: center; color: #666;'>
            <h2>Error occurred while fetching spaces</h2>
            <p>Error details: {str(e)}</p>
            <p>Please try again later.</p>
        </div>
        """
        
# Creating the Gradio interface
demo = gr.Blocks()

with demo:
    html_output = gr.HTML(value=get_user_spaces())  # 초기 로드 시 직접 함수 호출

if __name__ == "__main__":
    demo.launch()