import functools
import os.path
import urllib.parse
from pathlib import Path
from typing import Optional, Union
from dataclasses import dataclass

from modules import shared, ui_extra_networks_user_metadata, errors, extra_networks, util
from modules.images import read_info_from_image, save_image_with_geninfo
import gradio as gr
import json
import html
from fastapi.exceptions import HTTPException

from modules.infotext_utils import image_from_url_text

extra_pages = []
allowed_dirs = set()
default_allowed_preview_extensions = ["png", "jpg", "jpeg", "webp", "gif"]

@functools.cache
def allowed_preview_extensions_with_extra(extra_extensions=None):
    return set(default_allowed_preview_extensions) | set(extra_extensions or [])


def allowed_preview_extensions():
    return allowed_preview_extensions_with_extra((shared.opts.samples_format, ))


@dataclass
class ExtraNetworksItem:
    """Wrapper for dictionaries representing ExtraNetworks items."""
    item: dict


def get_tree(paths: Union[str, list[str]], items: dict[str, ExtraNetworksItem]) -> dict:
    """Recursively builds a directory tree.

    Args:
        paths: Path or list of paths to directories. These paths are treated as roots from which
            the tree will be built.
        items: A dictionary associating filepaths to an ExtraNetworksItem instance.

    Returns:
        The result directory tree.
    """
    if isinstance(paths, (str,)):
        paths = [paths]

    def _get_tree(_paths: list[str], _root: str):
        _res = {}
        for path in _paths:
            relpath = os.path.relpath(path, _root)
            if os.path.isdir(path):
                dir_items = os.listdir(path)
                # Ignore empty directories.
                if not dir_items:
                    continue
                dir_tree = _get_tree([os.path.join(path, x) for x in dir_items], _root)
                # We only want to store non-empty folders in the tree.
                if dir_tree:
                    _res[relpath] = dir_tree
            else:
                if path not in items:
                    continue
                # Add the ExtraNetworksItem to the result.
                _res[relpath] = items[path]
        return _res

    res = {}
    # Handle each root directory separately.
    # Each root WILL have a key/value at the root of the result dict though
    # the value can be an empty dict if the directory is empty. We want these
    # placeholders for empty dirs so we can inform the user later.
    for path in paths:
        root = os.path.dirname(path)
        relpath = os.path.relpath(path, root)
        # Wrap the path in a list since that is what the `_get_tree` expects.
        res[relpath] = _get_tree([path], root)
        if res[relpath]:
            # We need to pull the inner path out one for these root dirs.
            res[relpath] = res[relpath][relpath]

    return res

def register_page(page):
    """registers extra networks page for the UI; recommend doing it in on_before_ui() callback for extensions"""

    extra_pages.append(page)
    allowed_dirs.clear()
    allowed_dirs.update(set(sum([x.allowed_directories_for_previews() for x in extra_pages], [])))


def fetch_file(filename: str = ""):
    from starlette.responses import FileResponse

    if not os.path.isfile(filename):
        raise HTTPException(status_code=404, detail="File not found")

    if not any(Path(x).absolute() in Path(filename).absolute().parents for x in allowed_dirs):
        raise ValueError(f"File cannot be fetched: {filename}. Must be in one of directories registered by extra pages.")

    ext = os.path.splitext(filename)[1].lower()[1:]
    if ext not in allowed_preview_extensions():
        raise ValueError(f"File cannot be fetched: {filename}. Extensions allowed: {allowed_preview_extensions()}.")

    # would profit from returning 304
    return FileResponse(filename, headers={"Accept-Ranges": "bytes"})


def get_metadata(page: str = "", item: str = ""):
    from starlette.responses import JSONResponse

    page = next(iter([x for x in extra_pages if x.name == page]), None)
    if page is None:
        return JSONResponse({})

    metadata = page.metadata.get(item)
    if metadata is None:
        return JSONResponse({})

    return JSONResponse({"metadata": json.dumps(metadata, indent=4, ensure_ascii=False)})


def get_single_card(page: str = "", tabname: str = "", name: str = ""):
    from starlette.responses import JSONResponse

    page = next(iter([x for x in extra_pages if x.name == page]), None)

    try:
        item = page.create_item(name, enable_filter=False)
        page.items[name] = item
    except Exception as e:
        errors.display(e, "creating item for extra network")
        item = page.items.get(name)

    page.read_user_metadata(item, use_cache=False)
    item_html = page.create_item_html(tabname, item, shared.html("extra-networks-card.html"))

    return JSONResponse({"html": item_html})


def add_pages_to_demo(app):
    app.add_api_route("/sd_extra_networks/thumb", fetch_file, methods=["GET"])
    app.add_api_route("/sd_extra_networks/metadata", get_metadata, methods=["GET"])
    app.add_api_route("/sd_extra_networks/get-single-card", get_single_card, methods=["GET"])


def quote_js(s):
    s = s.replace('\\', '\\\\')
    s = s.replace('"', '\\"')
    return f'"{s}"'

class ExtraNetworksPage:
    def __init__(self, title):
        self.title = title
        self.name = title.lower()
        # This is the actual name of the extra networks tab (not txt2img/img2img).
        self.extra_networks_tabname = self.name.replace(" ", "_")
        self.allow_prompt = True
        self.allow_negative_prompt = False
        self.metadata = {}
        self.items = {}
        self.lister = util.MassFileLister()
        # HTML Templates
        self.pane_tpl = shared.html("extra-networks-pane.html")
        self.card_tpl = shared.html("extra-networks-card.html")
        self.btn_tree_tpl = shared.html("extra-networks-tree-button.html")
        self.btn_copy_path_tpl = shared.html("extra-networks-copy-path-button.html")
        self.btn_metadata_tpl = shared.html("extra-networks-metadata-button.html")
        self.btn_edit_item_tpl = shared.html("extra-networks-edit-item-button.html")

    def refresh(self):
        pass

    def read_user_metadata(self, item, use_cache=True):
        filename = item.get("filename", None)
        metadata = extra_networks.get_user_metadata(filename, lister=self.lister if use_cache else None)

        desc = metadata.get("description", None)
        if desc is not None:
            item["description"] = desc

        item["user_metadata"] = metadata

    def link_preview(self, filename):
        quoted_filename = urllib.parse.quote(filename.replace('\\', '/'))
        mtime, _ = self.lister.mctime(filename)
        return f"./sd_extra_networks/thumb?filename={quoted_filename}&mtime={mtime}"

    def search_terms_from_path(self, filename, possible_directories=None):
        abspath = os.path.abspath(filename)
        for parentdir in (possible_directories if possible_directories is not None else self.allowed_directories_for_previews()):
            parentdir = os.path.dirname(os.path.abspath(parentdir))
            if abspath.startswith(parentdir):
                return os.path.relpath(abspath, parentdir)

        return ""

    def create_item_html(
        self,
        tabname: str,
        item: dict,
        template: Optional[str] = None,
    ) -> Union[str, dict]:
        """Generates HTML for a single ExtraNetworks Item.

        Args:
            tabname: The name of the active tab.
            item: Dictionary containing item information.
            template: Optional template string to use.

        Returns:
            If a template is passed: HTML string generated for this item.
                Can be empty if the item is not meant to be shown.
            If no template is passed: A dictionary containing the generated item's attributes.
        """
        preview = item.get("preview", None)
        style_height = f"height: {shared.opts.extra_networks_card_height}px;" if shared.opts.extra_networks_card_height else ''
        style_width = f"width: {shared.opts.extra_networks_card_width}px;" if shared.opts.extra_networks_card_width else ''
        style_font_size = f"font-size: {shared.opts.extra_networks_card_text_scale*100}%;"
        card_style = style_height + style_width + style_font_size
        background_image = f'<img src="{html.escape(preview)}" class="preview" loading="lazy">' if preview else ''

        onclick = item.get("onclick", None)
        if onclick is None:
            # Don't quote prompt/neg_prompt since they are stored as js strings already.
            onclick_js_tpl = "cardClicked('{tabname}', {prompt}, {neg_prompt}, {allow_neg});"
            onclick = onclick_js_tpl.format(
                **{
                    "tabname": tabname,
                    "prompt": item["prompt"],
                    "neg_prompt": item.get("negative_prompt", "''"),
                    "allow_neg": str(self.allow_negative_prompt).lower(),
                }
            )
            onclick = html.escape(onclick)

        btn_copy_path = self.btn_copy_path_tpl.format(**{"filename": item["filename"]})
        btn_metadata = ""
        metadata = item.get("metadata")
        if metadata:
            btn_metadata = self.btn_metadata_tpl.format(
                **{
                    "extra_networks_tabname": self.extra_networks_tabname,
                    "name": html.escape(item["name"]),
                }
            )
        btn_edit_item = self.btn_edit_item_tpl.format(
            **{
                "tabname": tabname,
                "extra_networks_tabname": self.extra_networks_tabname,
                "name": html.escape(item["name"]),
            }
        )

        local_path = ""
        filename = item.get("filename", "")
        for reldir in self.allowed_directories_for_previews():
            absdir = os.path.abspath(reldir)

            if filename.startswith(absdir):
                local_path = filename[len(absdir):]

        # if this is true, the item must not be shown in the default view, and must instead only be
        # shown when searching for it
        if shared.opts.extra_networks_hidden_models == "Always":
            search_only = False
        else:
            search_only = "/." in local_path or "\\." in local_path

        if search_only and shared.opts.extra_networks_hidden_models == "Never":
            return ""

        sort_keys = " ".join(
            [
                f'data-sort-{k}="{html.escape(str(v))}"'
                for k, v in item.get("sort_keys", {}).items()
            ]
        ).strip()

        search_terms_html = ""
        search_term_template = "<span class='hidden {class}'>{search_term}</span>"
        for search_term in item.get("search_terms", []):
            search_terms_html += search_term_template.format(
                **{
                    "class": f"search_terms{' search_only' if search_only else ''}",
                    "search_term": search_term,
                }
            )

        description = (item.get("description", "") or "" if shared.opts.extra_networks_card_show_desc else "")
        if not shared.opts.extra_networks_card_description_is_html:
            description = html.escape(description)

        # Some items here might not be used depending on HTML template used.
        args = {
            "background_image": background_image,
            "card_clicked": onclick,
            "copy_path_button": btn_copy_path,
            "description": description,
            "edit_button": btn_edit_item,
            "local_preview": quote_js(item["local_preview"]),
            "metadata_button": btn_metadata,
            "name": html.escape(item["name"]),
            "prompt": item.get("prompt", None),
            "save_card_preview": html.escape(f"return saveCardPreview(event, '{tabname}', '{item['local_preview']}');"),
            "search_only": " search_only" if search_only else "",
            "search_terms": search_terms_html,
            "sort_keys": sort_keys,
            "style": card_style,
            "tabname": tabname,
            "extra_networks_tabname": self.extra_networks_tabname,
        }

        if template:
            return template.format(**args)
        else:
            return args

    def create_tree_dir_item_html(
        self,
        tabname: str,
        dir_path: str,
        content: Optional[str] = None,
    ) -> Optional[str]:
        """Generates HTML for a directory item in the tree.

        The generated HTML is of the format:
        ```html
        <li class="tree-list-item tree-list-item--has-subitem">
            <div class="tree-list-content tree-list-content-dir"></div>
            <ul class="tree-list tree-list--subgroup">
                {content}
            </ul>
        </li>
        ```

        Args:
            tabname: The name of the active tab.
            dir_path: Path to the directory for this item.
            content: Optional HTML string that will be wrapped by this <ul>.

        Returns:
            HTML formatted string.
        """
        if not content:
            return None

        btn = self.btn_tree_tpl.format(
            **{
                "search_terms": "",
                "subclass": "tree-list-content-dir",
                "tabname": tabname,
                "extra_networks_tabname": self.extra_networks_tabname,
                "onclick_extra": "",
                "data_path": dir_path,
                "data_hash": "",
                "action_list_item_action_leading": "<i class='tree-list-item-action-chevron'></i>",
                "action_list_item_visual_leading": "🗀",
                "action_list_item_label": os.path.basename(dir_path),
                "action_list_item_visual_trailing": "",
                "action_list_item_action_trailing": "",
            }
        )
        ul = f"<ul class='tree-list tree-list--subgroup' hidden>{content}</ul>"
        return (
            "<li class='tree-list-item tree-list-item--has-subitem' data-tree-entry-type='dir'>"
            f"{btn}{ul}"
            "</li>"
        )

    def create_tree_file_item_html(self, tabname: str, file_path: str, item: dict) -> str:
        """Generates HTML for a file item in the tree.

        The generated HTML is of the format:
        ```html
        <li class="tree-list-item tree-list-item--subitem">
            <span data-filterable-item-text hidden></span>
            <div class="tree-list-content tree-list-content-file"></div>
        </li>
        ```

        Args:
            tabname: The name of the active tab.
            file_path: The path to the file for this item.
            item: Dictionary containing the item information.

        Returns:
            HTML formatted string.
        """
        item_html_args = self.create_item_html(tabname, item)
        action_buttons = "".join(
            [
                item_html_args["copy_path_button"],
                item_html_args["metadata_button"],
                item_html_args["edit_button"],
            ]
        )
        action_buttons = f"<div class=\"button-row\">{action_buttons}</div>"
        btn = self.btn_tree_tpl.format(
            **{
                "search_terms": "",
                "subclass": "tree-list-content-file",
                "tabname": tabname,
                "extra_networks_tabname": self.extra_networks_tabname,
                "onclick_extra": item_html_args["card_clicked"],
                "data_path": file_path,
                "data_hash": item["shorthash"],
                "action_list_item_action_leading": "<i class='tree-list-item-action-chevron'></i>",
                "action_list_item_visual_leading": "🗎",
                "action_list_item_label": item["name"],
                "action_list_item_visual_trailing": "",
                "action_list_item_action_trailing": action_buttons,
            }
        )
        return (
            "<li class='tree-list-item tree-list-item--subitem' data-tree-entry-type='file'>"
            f"{btn}"
            "</li>"
        )

    def create_tree_view_html(self, tabname: str) -> str:
        """Generates HTML for displaying folders in a tree view.

        Args:
            tabname: The name of the active tab.

        Returns:
            HTML string generated for this tree view.
        """
        res = ""

        # Setup the tree dictionary.
        roots = self.allowed_directories_for_previews()
        tree_items = {v["filename"]: ExtraNetworksItem(v) for v in self.items.values()}
        tree = get_tree([os.path.abspath(x) for x in roots], items=tree_items)

        if not tree:
            return res

        def _build_tree(data: Optional[dict[str, ExtraNetworksItem]] = None) -> Optional[str]:
            """Recursively builds HTML for a tree.

            Args:
                data: Dictionary representing a directory tree. Can be NoneType.
                    Data keys should be absolute paths from the root and values
                    should be subdirectory trees or an ExtraNetworksItem.

            Returns:
                If data is not None: HTML string
                Else: None
            """
            if not data:
                return None

            # Lists for storing <li> items html for directories and files separately.
            _dir_li = []
            _file_li = []

            for k, v in sorted(data.items(), key=lambda x: shared.natural_sort_key(x[0])):
                if isinstance(v, (ExtraNetworksItem,)):
                    _file_li.append(self.create_tree_file_item_html(tabname, k, v.item))
                else:
                    _dir_li.append(self.create_tree_dir_item_html(tabname, k, _build_tree(v)))

            # Directories should always be displayed before files so we order them here.
            return "".join(_dir_li) + "".join(_file_li)

        # Add each root directory to the tree.
        for k, v in sorted(tree.items(), key=lambda x: shared.natural_sort_key(x[0])):
            item_html = self.create_tree_dir_item_html(tabname, k, _build_tree(v))
            # Only add non-empty entries to the tree.
            if item_html is not None:
                res += item_html

        return f"<ul class='tree-list tree-list--tree'>{res}</ul>"

    def create_card_view_html(self, tabname: str, *, none_message) -> str:
        """Generates HTML for the network Card View section for a tab.

        This HTML goes into the `extra-networks-pane.html` <div> with
        `id='{tabname}_{extra_networks_tabname}_cards`.

        Args:
            tabname: The name of the active tab.
            none_message: HTML text to show when there are no cards.

        Returns:
            HTML formatted string.
        """
        res = []
        for item in self.items.values():
            res.append(self.create_item_html(tabname, item, self.card_tpl))

        if not res:
            dirs = "".join([f"<li>{x}</li>" for x in self.allowed_directories_for_previews()])
            res = [none_message or shared.html("extra-networks-no-cards.html").format(dirs=dirs)]

        return "".join(res)

    def create_html(self, tabname, *, empty=False):
        """Generates an HTML string for the current pane.

        The generated HTML uses `extra-networks-pane.html` as a template.

        Args:
            tabname: The name of the active tab.
            empty: create an empty HTML page with no items

        Returns:
            HTML formatted string.
        """
        self.lister.reset()
        self.metadata = {}

        items_list = [] if empty else self.list_items()
        self.items = {x["name"]: x for x in items_list}

        # Populate the instance metadata for each item.
        for item in self.items.values():
            metadata = item.get("metadata")
            if metadata:
                self.metadata[item["name"]] = metadata

            if "user_metadata" not in item:
                self.read_user_metadata(item)

        data_sortdir = shared.opts.extra_networks_card_order
        data_sortmode = shared.opts.extra_networks_card_order_field.lower().replace("sort", "").replace(" ", "_").rstrip("_").strip()
        data_sortkey = f"{data_sortmode}-{data_sortdir}-{len(self.items)}"
        tree_view_btn_extra_class = ""
        tree_view_div_extra_class = "hidden"
        tree_view_div_default_display = "none"
        extra_network_pane_content_default_display = "flex"
        if shared.opts.extra_networks_tree_view_default_enabled:
            tree_view_btn_extra_class = "extra-network-control--enabled"
            tree_view_div_extra_class = ""
            tree_view_div_default_display = "block"
            extra_network_pane_content_default_display = "grid"

        return self.pane_tpl.format(
            **{
                "tabname": tabname,
                "extra_networks_tabname": self.extra_networks_tabname,
                "data_sortmode": data_sortmode,
                "data_sortkey": data_sortkey,
                "data_sortdir": data_sortdir,
                "tree_view_btn_extra_class": tree_view_btn_extra_class,
                "tree_view_div_extra_class": tree_view_div_extra_class,
                "tree_html": self.create_tree_view_html(tabname),
                "items_html": self.create_card_view_html(tabname, none_message="Loading..." if empty else None),
                "extra_networks_tree_view_default_width": shared.opts.extra_networks_tree_view_default_width,
                "tree_view_div_default_display": tree_view_div_default_display,
                "extra_network_pane_content_default_display": extra_network_pane_content_default_display,
            }
        )

    def create_item(self, name, index=None):
        raise NotImplementedError()

    def list_items(self):
        raise NotImplementedError()

    def allowed_directories_for_previews(self):
        return []

    def get_sort_keys(self, path):
        """
        List of default keys used for sorting in the UI.
        """
        pth = Path(path)
        mtime, ctime = self.lister.mctime(path)
        return {
            "date_created": int(mtime),
            "date_modified": int(ctime),
            "name": pth.name.lower(),
            "path": str(pth).lower(),
        }

    def find_preview(self, path):
        """
        Find a preview PNG for a given path (without extension) and call link_preview on it.
        """

        potential_files = sum([[f"{path}.{ext}", f"{path}.preview.{ext}"] for ext in allowed_preview_extensions()], [])

        for file in potential_files:
            if self.lister.exists(file):
                return self.link_preview(file)

        return None

    def find_description(self, path):
        """
        Find and read a description file for a given path (without extension).
        """
        for file in [f"{path}.txt", f"{path}.description.txt"]:
            if not self.lister.exists(file):
                continue

            try:
                with open(file, "r", encoding="utf-8", errors="replace") as f:
                    return f.read()
            except OSError:
                pass
        return None

    def create_user_metadata_editor(self, ui, tabname):
        return ui_extra_networks_user_metadata.UserMetadataEditor(ui, tabname, self)


def initialize():
    extra_pages.clear()


def register_default_pages():
    from modules.ui_extra_networks_textual_inversion import ExtraNetworksPageTextualInversion
    from modules.ui_extra_networks_hypernets import ExtraNetworksPageHypernetworks
    from modules.ui_extra_networks_checkpoints import ExtraNetworksPageCheckpoints
    register_page(ExtraNetworksPageTextualInversion())
    register_page(ExtraNetworksPageHypernetworks())
    register_page(ExtraNetworksPageCheckpoints())


class ExtraNetworksUi:
    def __init__(self):
        self.pages = None
        """gradio HTML components related to extra networks' pages"""

        self.page_contents = None
        """HTML content of the above; empty initially, filled when extra pages have to be shown"""

        self.stored_extra_pages = None

        self.button_save_preview = None
        self.preview_target_filename = None

        self.tabname = None


def pages_in_preferred_order(pages):
    tab_order = [x.lower().strip() for x in shared.opts.ui_extra_networks_tab_reorder.split(",")]

    def tab_name_score(name):
        name = name.lower()
        for i, possible_match in enumerate(tab_order):
            if possible_match in name:
                return i

        return len(pages)

    tab_scores = {page.name: (tab_name_score(page.name), original_index) for original_index, page in enumerate(pages)}

    return sorted(pages, key=lambda x: tab_scores[x.name])


def create_ui(interface: gr.Blocks, unrelated_tabs, tabname):
    ui = ExtraNetworksUi()
    ui.pages = []
    ui.pages_contents = []
    ui.user_metadata_editors = []
    ui.stored_extra_pages = pages_in_preferred_order(extra_pages.copy())
    ui.tabname = tabname

    related_tabs = []

    for page in ui.stored_extra_pages:
        with gr.Tab(page.title, elem_id=f"{tabname}_{page.extra_networks_tabname}", elem_classes=["extra-page"]) as tab:
            with gr.Column(elem_id=f"{tabname}_{page.extra_networks_tabname}_prompts", elem_classes=["extra-page-prompts"]):
                pass

            elem_id = f"{tabname}_{page.extra_networks_tabname}_cards_html"
            page_elem = gr.HTML(page.create_html(tabname, empty=True), elem_id=elem_id)
            ui.pages.append(page_elem)
            editor = page.create_user_metadata_editor(ui, tabname)
            editor.create_ui()
            ui.user_metadata_editors.append(editor)
            related_tabs.append(tab)

    ui.button_save_preview = gr.Button('Save preview', elem_id=f"{tabname}_save_preview", visible=False)
    ui.preview_target_filename = gr.Textbox('Preview save filename', elem_id=f"{tabname}_preview_filename", visible=False)

    for tab in unrelated_tabs:
        tab.select(fn=None, _js=f"function(){{extraNetworksUnrelatedTabSelected('{tabname}');}}", inputs=[], outputs=[], show_progress=False)

    for page, tab in zip(ui.stored_extra_pages, related_tabs):
        jscode = (
            "function(){{"
            f"extraNetworksTabSelected('{tabname}', '{tabname}_{page.extra_networks_tabname}_prompts', {str(page.allow_prompt).lower()}, {str(page.allow_negative_prompt).lower()}, '{tabname}_{page.extra_networks_tabname}');"
            f"applyExtraNetworkFilter('{tabname}_{page.extra_networks_tabname}');"
            "}}"
        )
        tab.select(fn=None, _js=jscode, inputs=[], outputs=[], show_progress=False)

        def refresh():
            for pg in ui.stored_extra_pages:
                pg.refresh()
            create_html()
            return ui.pages_contents

        button_refresh = gr.Button("Refresh", elem_id=f"{tabname}_{page.extra_networks_tabname}_extra_refresh_internal", visible=False)
        button_refresh.click(fn=refresh, inputs=[], outputs=ui.pages).then(fn=lambda: None, _js="function(){ " + f"applyExtraNetworkFilter('{tabname}_{page.extra_networks_tabname}');" + " }").then(fn=lambda: None, _js='setupAllResizeHandles')

    def create_html():
        ui.pages_contents = [pg.create_html(ui.tabname) for pg in ui.stored_extra_pages]

    def pages_html():
        if not ui.pages_contents:
            create_html()
        return ui.pages_contents

    interface.load(fn=pages_html, inputs=[], outputs=ui.pages).then(fn=lambda: None, _js='setupAllResizeHandles')

    return ui


def path_is_parent(parent_path, child_path):
    parent_path = os.path.abspath(parent_path)
    child_path = os.path.abspath(child_path)

    return child_path.startswith(parent_path)


def setup_ui(ui, gallery):
    def save_preview(index, images, filename):
        # this function is here for backwards compatibility and likely will be removed soon

        if len(images) == 0:
            print("There is no image in gallery to save as a preview.")
            return [page.create_html(ui.tabname) for page in ui.stored_extra_pages]

        index = int(index)
        index = 0 if index < 0 else index
        index = len(images) - 1 if index >= len(images) else index

        img_info = images[index if index >= 0 else 0]
        image = image_from_url_text(img_info)
        geninfo, items = read_info_from_image(image)

        is_allowed = False
        for extra_page in ui.stored_extra_pages:
            if any(path_is_parent(x, filename) for x in extra_page.allowed_directories_for_previews()):
                is_allowed = True
                break

        assert is_allowed, f'writing to {filename} is not allowed'

        save_image_with_geninfo(image, geninfo, filename)

        return [page.create_html(ui.tabname) for page in ui.stored_extra_pages]

    ui.button_save_preview.click(
        fn=save_preview,
        _js="function(x, y, z){return [selected_gallery_index(), y, z]}",
        inputs=[ui.preview_target_filename, gallery, ui.preview_target_filename],
        outputs=[*ui.pages]
    )

    for editor in ui.user_metadata_editors:
        editor.setup_ui(gallery)
