# -*- coding: utf-8 -*-
"""
Gradio Web Interface for City Map Poster Generator
"""

import os
import json
import tempfile

# Monkey-patch gradio_client bug before importing gradio
# Fix for: TypeError: argument of type 'bool' is not iterable
# and APIInfoParseError: Cannot parse schema True
try:
    import gradio_client.utils as client_utils

    # Patch _json_schema_to_python_type to handle boolean schemas
    _original_json_schema_to_python_type = client_utils._json_schema_to_python_type

    def _patched_json_schema_to_python_type(schema, defs):
        # Handle boolean schema (e.g., additionalProperties: true/false)
        if schema is True:
            return "Any"
        if schema is False:
            return "None"
        return _original_json_schema_to_python_type(schema, defs)

    client_utils._json_schema_to_python_type = _patched_json_schema_to_python_type
except Exception as e:
    print(f"Warning: Could not patch gradio_client: {e}")

import gradio as gr

# Import from the main module
from cities_data import (
    get_countries,
    get_provinces,
    get_cities,
    get_districts,
    translate,
    get_country_key,
)


# --- Constants ---
THEMES_DIR = "themes"
FONTS_DIR = "fonts"
POSTERS_DIR = "posters"

# Layer Constants
LAYERS_EN = ["Motorway", "Primary Roads", "Secondary Roads", "Water", "Parks"]
LAYERS_CN = ["高速公路", "主干道", "次干道", "水域", "公园"]
LAYER_KEYS = ["motorway", "primary", "secondary", "water", "parks"]


def get_available_themes():
    """Scans the themes directory and returns a list of available theme names."""
    if not os.path.exists(THEMES_DIR):
        return []

    themes = []
    for file in sorted(os.listdir(THEMES_DIR)):
        if file.endswith(".json"):
            theme_name = file[:-5]
            themes.append(theme_name)
    return themes


def get_theme_choices(lang="en"):
    """Return a list of (Display Name, Internal Name) tuples for themes."""
    internal_names = get_available_themes()
    choices = []

    for internal_name in internal_names:
        theme_info = load_theme_info(internal_name)
        if theme_info:
            proper_name = theme_info.get("name", internal_name)
            display_name = translate(proper_name, lang)
            choices.append((display_name, internal_name))
        else:
            choices.append((internal_name, internal_name))

    return choices


def load_theme_info(theme_name):
    """Load theme details for preview."""
    theme_file = os.path.join(THEMES_DIR, f"{theme_name}.json")
    if os.path.exists(theme_file):
        with open(theme_file, "r") as f:
            return json.load(f)
    return None


def get_theme_preview_html(theme_name, lang="en"):
    """Generate HTML preview for a theme."""
    theme = load_theme_info(theme_name)
    lang_code = "en" if lang == "English" else "cn"

    if not theme:
        return f"<p>{'Theme load failed' if lang_code == 'en' else '主题加载失败'}</p>"

    # Translated labels
    labels = {
        "bg": "Background" if lang_code == "en" else "背景",
        "text": "Text" if lang_code == "en" else "文字",
        "motorway": "Motorway" if lang_code == "en" else "高速公路",
        "primary": "Primary Road" if lang_code == "en" else "主干道",
        "secondary": "Secondary Road" if lang_code == "en" else "次干道",
        "water": "Water" if lang_code == "en" else "水域",
        "parks": "Parks" if lang_code == "en" else "公园",
    }

    # Create color swatches
    colors = [
        (labels["bg"], theme.get("bg", "#FFFFFF")),
        (labels["text"], theme.get("text", "#000000")),
        (labels["motorway"], theme.get("road_motorway", "#000000")),
        (labels["primary"], theme.get("road_primary", "#333333")),
        (labels["secondary"], theme.get("road_secondary", "#666666")),
        (labels["water"], theme.get("water", "#C0C0C0")),
        (labels["parks"], theme.get("parks", "#F0F0F0")),
    ]

    display_name = translate(theme.get("name", theme_name), lang_code)
    description = theme.get("description", "")
    # Optional: translate description if we really want to, but might be too much work

    html = f"""
    <div style="padding: 12px; background: {theme.get("bg", "#FFFFFF")}; border-radius: 8px; border: 1px solid #ddd;">
        <h4 style="color: {theme.get("text", "#000000")}; margin: 0 0 8px 0; font-size: 14px;">
            {display_name}
        </h4>
        <p style="color: {theme.get("text", "#000000")}; opacity: 0.7; margin: 0 0 12px 0; font-size: 12px;">
            {description}
        </p>
        <div style="display: flex; flex-wrap: wrap; gap: 6px;">
    """

    for label, color in colors:
        html += f"""
            <div style="display: flex; align-items: center; gap: 4px;">
                <div style="width: 20px; height: 20px; background: {color}; border-radius: 4px; border: 1px solid #ccc;"></div>
                <span style="font-size: 10px; color: {theme.get("text", "#000")}; opacity: 0.8;">{label}</span>
            </div>
        """

    html += "</div></div>"
    return html


def generate_poster(
    location_mode,
    custom_lat,
    custom_lon,
    custom_city_name,
    custom_country_name,
    country_display,
    province,
    city_dropdown,
    district_dropdown,
    theme_name,
    distance,
    width,
    height,
    output_format,
    no_crop,
    show_text,
    poster_lang,
    layers_selection,
    progress=gr.Progress(),
):
    """
    Generate the map poster with given parameters.
    """
    # Import here to avoid circular imports and ensure THEME is set correctly
    import create_map_poster as cmp

    # Decode layer selection
    show_motorway = any(x in ["Motorway", "高速公路"] for x in layers_selection)
    show_primary = any(x in ["Primary Roads", "主干道"] for x in layers_selection)
    show_secondary = any(x in ["Secondary Roads", "次干道"] for x in layers_selection)
    show_water = any(x in ["Water", "水域"] for x in layers_selection)
    show_parks = any(x in ["Parks", "公园"] for x in layers_selection)

    # Determine display names based on poster_lang
    lang_code = "en" if poster_lang == "English" else "cn"
    actual_distance = distance
    display_city = ""
    display_country = ""
    coords = None

    progress(0.1, desc="正在加载主题...")
    # Load theme
    cmp.THEME = cmp.load_theme(theme_name)

    if location_mode == "自定义坐标" or location_mode == "Custom Coordinates":
        lat_val = float(custom_lat)
        lon_val = float(custom_lon)
        
        # Basic validation: Latitude must be between -90 and 90
        if lat_val < -90 or lat_val > 90:
            return None, f"❌ 纬度超出范围 (-90 到 90)。你是否填反了经纬度？(当前填入: {lat_val})"

        coords = (lat_val, lon_val)
        display_city = custom_city_name if custom_city_name else ""
        display_country = custom_country_name if custom_country_name else ""

        # Determine output filename component
        selected_location = display_city

    else:
        # Standard Dropdown Logic
        # Parse country
        # Since we now use (Display, Value) tuples where Value is the key,
        # country_display is likely already the key. get_country_key remains for safety.
        selected_country = get_country_key(country_display)

        # Use dropdown selection
        # If district is selected and isn't "整个城市", use its coordinates
        selected_location = (
            district_dropdown
            if (district_dropdown and district_dropdown != city_dropdown)
            else city_dropdown
        )

        # Detect if we are selecting an entire province
        is_whole_province = False
        if selected_country == "中国" and selected_location:
            if selected_location.endswith("_WHOLE"):
                is_whole_province = True
                selected_location = selected_location.replace("_WHOLE", "")

        if not selected_location:
            return None, "❌ 请选择城市或区县名称"

        if not selected_country:
            return None, "❌ 请选择国家"

        # For whole province, we might want to override the distance if it's too small
        if is_whole_province:
            # A province is much larger than a city. Default 10km is way too small.
            # We'll use a larger default or just trust the user if they've slid it up,
            # but let's ensure it's at least 150km for a province.
            if distance < 100000:
                actual_distance = 200000  # 200km default for province
                print(
                    f"Whole province detected ({selected_location}). Increasing distance to {actual_distance}m"
                )

        if selected_country == "中国" and lang_code == "cn":
            if is_whole_province:
                display_city = selected_location
                display_country = "中国"
            # Hierarchical logic for China (Chinese language)
            elif district_dropdown and district_dropdown != city_dropdown:
                # Case 3 & 4: District selected
                display_city = district_dropdown
                if province == city_dropdown:
                    # Case 3: District of Municipality
                    display_country = f"中国 {province}"
                else:
                    # Case 4: District of Regular City
                    display_country = f"中国 {province} {city_dropdown}"
            else:
                # Case 1 & 2: City selected (or "Whole City")
                display_city = city_dropdown
                if province == city_dropdown:
                    # Case 1: Municipality
                    display_country = "中国"
                else:
                    # Case 2: Regular City
                    display_country = f"中国 {province}"
        else:
            # Standard logic for International or English posters
            display_city = translate(selected_location, lang_code)
            display_country = translate(selected_country, lang_code)

        progress(0.2, desc="正在获取坐标...")

        try:
            # We search coordinates using the selection
            # CMP might need the "original" names if OSM behaves better with them
            # For China, "广州" is better than "Guangzhou" for geopy sometimes, but geopy is usually good.
            # Let's ensure we use the 'original' internal key if possible for best OSM matching
            # However, for cities, we don't have a strict key map like for countries.
            # We can try to translate to CN if it's a Chinese city.
            search_city = selected_location
            search_country = selected_country
            # Use city as parent if searching for a district, otherwise use province
            search_parent = (
                city_dropdown
                if (district_dropdown and district_dropdown != city_dropdown)
                else province
            )

            coords = cmp.get_coordinates(
                search_city, search_country, parent=search_parent
            )
        except Exception as e:
            return None, f"❌ 无法找到城市坐标: {str(e)}"

    progress(0.3, desc="正在生成海报...")

    # Generate output filename (using English/Slugified names)
    en_city = translate(selected_location, "en")
    temp_dir = tempfile.gettempdir()
    output_file = cmp.generate_output_filename(
        en_city, theme_name, output_format, directory=temp_dir
    )

    try:
        # Wrap the generator to yield status updates and final result
        for status in cmp.create_poster(
            display_city,  # Pass translated names for display
            display_country,
            coords,
            actual_distance,
            output_file,
            output_format,
            width=width,
            height=height,
            no_crop=no_crop,
            show_text=show_text,
            show_motorway=show_motorway,
            show_primary=show_primary,
            show_secondary=show_secondary,
            show_water=show_water,
            show_parks=show_parks,
        ):
            # Translate common status messages if possible
            status_display = status
            if lang_code == "cn":
                if "Downloading street network" in status:
                    status_display = "正在下载街道数据..."
                elif "Downloading features" in status:
                    status_display = "正在下载水域和公园数据..."
                elif "Rendering map" in status:
                    status_display = "正在渲染地图..."
                elif "Applying road styles" in status:
                    status_display = "正在应用样式..."
                elif "Saving to" in status:
                    status_display = "正在保存海报..."
                elif "Done" in status:
                    status_display = "完成！"

            yield None, f"⏳ {status_display}", None

        progress(1.0, desc="完成!")

        yield output_file, f"✅ 海报生成成功！保存至: {output_file}", output_file

    except Exception as e:
        import traceback

        traceback.print_exc()
        yield None, f"❌ 生成失败: {str(e)}", None


def update_provinces(country, lang="en"):
    """Update province dropdown based on country selection and language."""
    # country is the internal key
    lang_code = "en" if lang == "English" else "cn"
    provinces = get_provinces(country, lang_code)
    if provinces:
        return gr.update(choices=provinces, value=provinces[0][1], visible=True)
    return gr.update(choices=[], value=None, visible=False)


def update_cities(country, province, lang="en"):
    """Update city dropdown based on province selection and language."""
    # country and province are internal keys
    lang_code = "en" if lang == "English" else "cn"
    cities = get_cities(country, province, lang_code)
    if cities:
        # For China, if it's a municipality, get_cities returns [province_name]
        # We should automatically trigger update_districts then.
        return gr.update(choices=cities, value=cities[0][1])
    return gr.update(choices=[], value=None)


def update_districts(country, province, city, lang="en"):
    """Update district dropdown based on city selection."""
    if country != "中国" or not city or city.endswith("_WHOLE"):
        return gr.update(choices=[], value=None, visible=False)

    lang_code = "en" if lang == "English" else "cn"
    districts = get_districts(country, province, city, lang_code)
    if districts:
        return gr.update(choices=districts, value=districts[0][1], visible=True)
    return gr.update(choices=[], value=None, visible=False)


def on_theme_change(theme_name, lang="en"):
    """Update theme preview when theme changes."""
    return get_theme_preview_html(theme_name, lang)


# --- Build Gradio Interface ---
def create_interface():
    """Create and return the Gradio interface."""

    # Get initial data (Default English)
    # Get initial data (Default English)
    default_lang_code = "cn"
    default_lang_radio = "中文"
    countries = get_countries(default_lang_code)
    theme_choices = get_theme_choices(default_lang_code)

    default_country_key = "中国"
    default_provinces = get_provinces(default_country_key, default_lang_code)
    default_province_key = default_provinces[0][1] if default_provinces else None
    default_cities = (
        get_cities(default_country_key, default_province_key, default_lang_code)
        if default_province_key
        else []
    )
    default_city_key = default_cities[0][1] if default_cities else None
    
    # Handle district initialization carefully to avoid "Value not in choices" error
    default_districts = (
        get_districts(
            default_country_key,
            default_province_key,
            default_city_key,
            default_lang_code,
        )
        if default_city_key
        else []
    )
    default_district_key = default_districts[0][1] if default_districts else None
    
    default_theme = theme_choices[0][1] if theme_choices else "feature_based"
    default_theme = theme_choices[0][1] if theme_choices else "feature_based"

    with gr.Blocks(
        title="城市地图海报生成器",
        theme=gr.themes.Default(),
        css="""
        .header-title {
            text-align: center;
            font-size: 2em;
            font-weight: bold;
            margin-bottom: 0.5em;
            background: linear-gradient(135deg, #FF8C00 0%, #FFA500 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }
        .header-subtitle {
            text-align: center;
            color: #666;
            margin-bottom: 1.5em;
        }
        .section-title {
            font-weight: 600;
            font-size: 1.1em;
            margin-bottom: 0.5em;
            color: #333;
        }
        .output-image {
            border-radius: 12px;
            box-shadow: 0 4px 12px rgba(0,0,0,0.1);
        }
        """,
    ) as demo:
        # Header
        gr.HTML("""
            <div class="header-title">城市地图海报生成器</div>
            <div class="header-subtitle">选择任意城市，自定义主题风格，生成精美地图海报</div>
            
            <div style="max-width: 800px; margin: 0 auto 20px auto; padding: 12px; background: #fff5f5; border: 1px solid #feb2b2; border-radius: 8px; text-align: left; font-size: 13px; line-height: 1.6; color: #c53030;">
                <b>⚠️ 注意!</b><br>
                • <b>特大城市</b>（如北京）: 当城市面积过大时，中心定位可能不准。<br>
                • <b>省级行政区生成超级慢！</b>: 正在优化中。<br>
                • <b>地点中英文不完善</b> : 由于地点中英文翻译数据量过大，未能显示完善。<br>
                • <b>小城市</b> : 由于 OpenStreetMap 数据缺失，部分图层（如公园/水域）可能无法显示。<br>
                • <b>生成速度</b> : 国外地点使用国外服务器数据且渲染逻辑较基础，下载和生成速度可能较慢。<br>
                • <b>数据来源</b> : © OpenStreetMap contributors
            </div>
        """)

        with gr.Row():
            # Left Column - Controls
            with gr.Column(scale=1):
                # City Selection Section
                gr.HTML('<div class="section-title">📍 城市选择</div>')

                lang_radio = gr.Radio(
                    choices=["中文", "English"],
                    value="中文",
                    label="海报语言",
                    info="选择海报及界面的显示语言",
                )

                location_mode = gr.Radio(
                    choices=["城市选择", "自定义坐标"],
                    value="城市选择",
                    label="定位方式",
                    info="选择通过列表选择城市或输入自定义经纬度",
                )

                with gr.Group(visible=True) as city_selection_group:
                    country_dropdown = gr.Dropdown(
                        choices=countries,
                        value=default_country_key,
                        label="选择国家",
                        interactive=True,
                    )

                    province_dropdown = gr.Dropdown(
                        choices=default_provinces,
                        value=default_province_key,
                        label="选择省份/州",
                        interactive=True,
                    )

                    city_dropdown = gr.Dropdown(
                        choices=default_cities,
                        value=default_city_key,
                        label="选择城市",
                        interactive=True,
                    )

                    district_dropdown = gr.Dropdown(
                        choices=default_districts,
                        value=default_district_key,
                        label="选择区县",
                        interactive=True,
                        visible=(default_country_key == "中国" and default_district_key is not None),
                    )

                with gr.Group(visible=False) as custom_coords_group:
                    custom_coords_info = gr.Markdown(
                        "💡 **填写指南**：\n"
                        "- **纬度 (Latitude)**: 南北向坐标，范围 -90 至 90 (中国约 18~53)。\n"
                        "- **经度 (Longitude)**: 东西向坐标，范围 -180 至 180 (中国约 73~135)。\n\n"
                        "您可以访问 [坐标拾取系统](https://map.jiqrxx.com/jingweidu/) 获取精确数值。"
                    )
                    with gr.Row():
                        custom_lat = gr.Number(
                            label="纬度 (Latitude)", value=None, precision=6
                        )
                        custom_lon = gr.Number(
                            label="经度 (Longitude)", value=None, precision=6
                        )
                    custom_city_name = gr.Textbox(
                        label="主标题 (Main Title)", placeholder="如: Shanghai 或 '我们的家'"
                    )
                    custom_country_name = gr.Textbox(
                        label="副标题 (Subtitle)",
                        placeholder="如: China 或 '2024.10.20'",
                        value="",
                    )

                gr.HTML("<hr style='margin: 20px 0; border-color: #eee;'>")

                # Theme Section
                gr.HTML('<div class="section-title">🎨 主题风格</div>')

                theme_dropdown = gr.Dropdown(
                    choices=theme_choices,
                    value=default_theme,
                    label="选择主题",
                    interactive=True,
                )

                theme_preview = gr.HTML(
                    value=get_theme_preview_html(default_theme, default_lang_radio),
                    label="主题预览",
                )

                gr.HTML("<hr style='margin: 20px 0; border-color: #eee;'>")

                # Parameters Section
                gr.HTML('<div class="section-title">⚙️ 参数设置</div>')

                distance_slider = gr.Slider(
                    minimum=4000,
                    maximum=30000,
                    value=10000,
                    step=1000,
                    label="地图范围 (米)",
                    info="4000-6000: 小城区 | 8000-12000: 中等城市 | 15000+: 大都市 (范围越大生成越慢)",
                )

                with gr.Row():
                    width_input = gr.Number(
                        value=12.0, label="宽度 (英寸)", minimum=6, maximum=24
                    )
                    height_input = gr.Number(
                        value=16.0, label="高度 (英寸)", minimum=8, maximum=32
                    )

                format_radio = gr.Radio(
                    choices=["png", "svg", "pdf"],
                    value="png",
                    label="输出格式",
                    info="PNG: 适合打印 | SVG: 矢量图 | PDF: 文档",
                )

                no_crop_checkbox = gr.Checkbox(
                    value=False,
                    label="保留边距 (不裁剪)",
                    info="勾选后保留海报边缘背景",
                )

                show_text_checkbox = gr.Checkbox(
                    value=True,
                    label="显示文字",
                    info="在海报上显示城市名和经纬度",
                )

                layers_checkbox = gr.CheckboxGroup(
                    choices=LAYERS_EN,
                    value=LAYERS_EN,
                    label="图层显示",
                    info="选择需要显示的地图元素",
                )

                # Generate Button
                generate_btn = gr.Button("🚀 生成海报", variant="primary", size="lg")

            # Right Column - Output
            with gr.Column(scale=1):
                gr.HTML('<div class="section-title">🖼️ 生成结果</div>')

                output_image = gr.Image(
                    label="海报预览",
                    type="filepath",
                    elem_classes=["output-image"],
                    height=600,
                    interactive=False,
                )

                output_status = gr.Textbox(label="状态", interactive=False)

                download_btn = gr.DownloadButton(label="📥 下载海报", visible=False)
                poster_state = gr.State()

        # --- Event Handlers ---

        # Language change -> update all dropdowns
        def on_lang_change(
            lang,
            current_country,
            current_province,
            current_city,
            current_district,
            current_theme,
            current_layers,
        ):
            lang_code = "en" if lang == "English" else "cn"
            new_countries = get_countries(lang_code)

            # Use keys to maintain selection
            new_provinces = get_provinces(current_country, lang_code)
            new_cities = (
                get_cities(current_country, current_province, lang_code)
                if current_province
                else []
            )
            new_districts = (
                get_districts(
                    current_country, current_province, current_city, lang_code
                )
                if current_city
                else []
            )
            
            # Ensure district value is valid for new choices
            valid_district = None
            if new_districts:
                if any(v == current_district for d, v in new_districts):
                    valid_district = current_district
                else:
                    valid_district = new_districts[0][1]

            # Themes
            new_theme_choices = get_theme_choices(lang_code)
            new_preview = get_theme_preview_html(current_theme, lang)

            # Layers
            map_en_to_key = dict(zip(LAYERS_EN, LAYER_KEYS))
            map_cn_to_key = dict(zip(LAYERS_CN, LAYER_KEYS))
            map_key_to_en = dict(zip(LAYER_KEYS, LAYERS_EN))
            map_key_to_cn = dict(zip(LAYER_KEYS, LAYERS_CN))

            current_keys = []
            for x in current_layers:
                if x in map_en_to_key:
                    current_keys.append(map_en_to_key[x])
                elif x in map_cn_to_key:
                    current_keys.append(map_cn_to_key[x])

            target_map = map_key_to_en if lang == "English" else map_key_to_cn
            new_layer_choices = LAYERS_EN if lang == "English" else LAYERS_CN
            new_layer_values = [target_map[k] for k in current_keys if k in target_map]

            return (
                gr.update(
                    choices=new_countries,
                    value=current_country,
                    label="Select Country" if lang == "English" else "选择国家",
                ),
                gr.update(
                    choices=new_provinces,
                    value=current_province,
                    label="Select Province/State"
                    if lang == "English"
                    else "选择省份/州",
                ),
                gr.update(
                    choices=new_cities,
                    value=current_city,
                    label="Select City" if lang == "English" else "选择城市",
                ),
                gr.update(
                    choices=new_districts,
                    value=valid_district,
                    visible=(current_country == "中国" and valid_district is not None),
                    label="Select District" if lang == "English" else "选择区县",
                ),
                gr.update(
                    choices=new_theme_choices,
                    label="Select Theme" if lang == "English" else "选择主题",
                ),
                new_preview,
                gr.update(
                    choices=new_layer_choices,
                    value=new_layer_values,
                    label="Layers" if lang == "English" else "图层显示",
                ),
                gr.update(
                    label="Map Range (m)" if lang == "English" else "地图范围 (米)",
                    info="4000-6000: Small | 8000-12000: Medium | 15000+: Large"
                    if lang == "English"
                    else "4000-6000: 小城区 | 8000-12000: 中等城市 | 15000+: 大都市 (范围越大生成越慢)",
                ),
                gr.update(label="Width (inch)" if lang == "English" else "宽度 (英寸)"),
                gr.update(
                    label="Height (inch)" if lang == "English" else "高度 (英寸)"
                ),
                gr.update(
                    label="Format" if lang == "English" else "输出格式",
                    info="PNG: Print | SVG: Vector | PDF: Doc"
                    if lang == "English"
                    else "PNG: 适合打印 | SVG: 矢量图 | PDF: 文档",
                ),
                gr.update(
                    label="No Crop (Keep Margins)"
                    if lang == "English"
                    else "保留边距 (不裁剪)",
                    info="Keep background margins"
                    if lang == "English"
                    else "勾选后保留海报边缘背景",
                ),
                gr.update(
                    label="Show Text" if lang == "English" else "显示文字",
                    info="Show city name and coordinates on poster"
                    if lang == "English"
                    else "在海报上显示城市名和经纬度",
                ),
                gr.update(
                    value="🚀 Generate Poster" if lang == "English" else "🚀 生成海报"
                ),
                gr.update(
                    label="📥 Download Poster" if lang == "English" else "📥 下载海报"
                ),
                gr.update(
                    label="Main Title" if lang == "English" else "主标题 (Main Title)",
                    placeholder="e.g. Shanghai or 'Our Home'" if lang == "English" else "如: Shanghai 或 '我们的家'"
                ),
                gr.update(
                    label="Subtitle" if lang == "English" else "副标题 (Subtitle)",
                    placeholder="e.g. China or '2024.10.20'" if lang == "English" else "如: China 或 '2024.10.20'"
                ),
                gr.update(
                    value="💡 **Guide**:\n"
                        "- **Latitude**: North-South, range -90 to 90 (China: ~18~53).\n"
                        "- **Longitude**: East-West, range -180 to 180 (China: ~73~135).\n\n"
                        "Use [Coordinate Picker](https://map.jiqrxx.com/jingweidu/) to find exact values."
                    if lang == "English" else
                    "💡 **填写指南**：\n"
                        "- **纬度 (Latitude)**: 南北向坐标，范围 -90 至 90 (中国约 18~53)。\n"
                        "- **经度 (Longitude)**: 东西向坐标，范围 -180 至 180 (中国约 73~135)。\n\n"
                        "您可以访问 [坐标拾取系统](https://map.jiqrxx.com/jingweidu/) 获取精确数值。"
                )
            )

        lang_radio.change(
            fn=on_lang_change,
            inputs=[
                lang_radio,
                country_dropdown,
                province_dropdown,
                city_dropdown,
                district_dropdown,
                theme_dropdown,
                layers_checkbox,
            ],
            outputs=[
                country_dropdown,
                province_dropdown,
                city_dropdown,
                district_dropdown,
                theme_dropdown,
                theme_preview,
                layers_checkbox,
                distance_slider,
                width_input,
                height_input,
                format_radio,
                no_crop_checkbox,
                show_text_checkbox,
                generate_btn,
                download_btn,
                custom_city_name,
                custom_country_name,
                custom_coords_info,
            ],
        )

        def toggle_location_mode(mode):
            is_custom = mode in ["自定义坐标", "Custom Coordinates"]
            return {
                city_selection_group: gr.update(visible=not is_custom),
                custom_coords_group: gr.update(visible=is_custom),
            }

        location_mode.change(
            fn=toggle_location_mode,
            inputs=[location_mode],
            outputs=[city_selection_group, custom_coords_group],
        )

        # Country change -> update provinces
        country_dropdown.change(
            fn=update_provinces,
            inputs=[country_dropdown, lang_radio],
            outputs=[province_dropdown],
        )

        # Province change -> update cities
        province_dropdown.change(
            fn=update_cities,
            inputs=[country_dropdown, province_dropdown, lang_radio],
            outputs=[city_dropdown],
        ).then(  # Update districts after city changes
            fn=update_districts,
            inputs=[country_dropdown, province_dropdown, city_dropdown, lang_radio],
            outputs=[district_dropdown],
        )

        # City change -> update districts
        city_dropdown.change(
            fn=update_districts,
            inputs=[country_dropdown, province_dropdown, city_dropdown, lang_radio],
            outputs=[district_dropdown],
        )

        # Theme change -> update preview
        theme_dropdown.change(
            fn=on_theme_change,
            inputs=[theme_dropdown, lang_radio],
            outputs=[theme_preview],
        )

        # Generate button click
        def on_generate_complete(filepath, status):
            """Handle generate completion - show download button if successful."""
            if filepath and os.path.exists(filepath):
                return filepath, status, gr.update(visible=True, value=filepath)
            return filepath, status, gr.update(visible=False)

        generate_btn.click(
            fn=generate_poster,
            inputs=[
                location_mode,
                custom_lat,
                custom_lon,
                custom_city_name,
                custom_country_name,
                country_dropdown,
                province_dropdown,
                city_dropdown,
                district_dropdown,
                theme_dropdown,
                distance_slider,
                width_input,
                height_input,
                format_radio,
                no_crop_checkbox,
                show_text_checkbox,
                lang_radio,
                layers_checkbox,
            ],
            outputs=[output_image, output_status, poster_state],
        ).then(
            fn=on_generate_complete,
            inputs=[poster_state, output_status],
            outputs=[output_image, output_status, download_btn],
        )

        # Footer
        gr.HTML("""
            <div style="text-align: center; margin-top: 24px; padding: 20px; color: #666; font-size: 13px; border-top: 1px solid #eee;">
                <p>项目地址: <a href="https://github.com/IsaacHuo/maptoposter" target="_blank" style="color: #764ba2; text-decoration: none; font-weight: bold;">GitHub - IsaacHuo/maptoposter</a></p>
                <p>✨ 欢迎提 <b>Issue</b> 和 <b>PR</b> | 鸣谢：该项目基于 <a href="https://github.com/originalankur/maptoposter" target="_blank" style="color: #666;">originalankur/maptoposter</a> 开发</p>
            </div>
        """)

    return demo


# --- Main Entry ---
if __name__ == "__main__":
    demo = create_interface()
    demo.launch(server_name="0.0.0.0", server_port=7860, ssr_mode=False)