"""Common utility functions used in the compiler."""

from __future__ import annotations

import asyncio
import concurrent.futures
import traceback
from collections.abc import Sequence
from datetime import datetime
from pathlib import Path
from typing import Any
from urllib.parse import urlparse

from pydantic.v1.fields import ModelField

from reflex import constants
from reflex.components.base import (
    Body,
    Description,
    DocumentHead,
    Head,
    Html,
    Image,
    Main,
    Meta,
    NextScript,
    Title,
)
from reflex.components.component import Component, ComponentStyle, CustomComponent
from reflex.istate.storage import Cookie, LocalStorage, SessionStorage
from reflex.state import BaseState, _resolve_delta
from reflex.style import Style
from reflex.utils import console, format, imports, path_ops
from reflex.utils.exec import is_in_app_harness
from reflex.utils.imports import ImportVar, ParsedImportDict
from reflex.utils.prerequisites import get_web_dir
from reflex.vars.base import Var

# To re-export this function.
merge_imports = imports.merge_imports


def compile_import_statement(fields: list[ImportVar]) -> tuple[str, list[str]]:
    """Compile an import statement.

    Args:
        fields: The set of fields to import from the library.

    Raises:
        ValueError: If there is more than one default import.

    Returns:
        The libraries for default and rest.
        default: default library. When install "import def from library".
        rest: rest of libraries. When install "import {rest1, rest2} from library"
    """
    # ignore the ImportVar fields with render=False during compilation
    fields_set = {field for field in fields if field.render}

    # Check for default imports.
    defaults = {field for field in fields_set if field.is_default}
    if len(defaults) >= 2:
        raise ValueError("Only one default import is allowed.")

    # Get the default import, and the specific imports.
    default = next(iter({field.name for field in defaults}), "")
    rest = {field.name for field in fields_set - defaults}

    return default, list(rest)


def validate_imports(import_dict: ParsedImportDict):
    """Verify that the same Tag is not used in multiple import.

    Args:
        import_dict: The dict of imports to validate

    Raises:
        ValueError: if a conflict on "tag/alias" is detected for an import.
    """
    used_tags = {}
    for lib, _imports in import_dict.items():
        for _import in _imports:
            import_name = (
                f"{_import.tag}/{_import.alias}" if _import.alias else _import.tag
            )
            if import_name in used_tags:
                already_imported = used_tags[import_name]
                if (already_imported[0] == "$" and already_imported[1:] == lib) or (
                    lib[0] == "$" and lib[1:] == already_imported
                ):
                    used_tags[import_name] = lib if lib[0] == "$" else already_imported
                    continue
                raise ValueError(
                    f"Can not compile, the tag {import_name} is used multiple time from {lib} and {used_tags[import_name]}"
                )
            if import_name is not None:
                used_tags[import_name] = lib


def compile_imports(import_dict: ParsedImportDict) -> list[dict]:
    """Compile an import dict.

    Args:
        import_dict: The import dict to compile.

    Raises:
        ValueError: If an import in the dict is invalid.

    Returns:
        The list of import dict.
    """
    collapsed_import_dict: ParsedImportDict = imports.collapse_imports(import_dict)
    validate_imports(collapsed_import_dict)
    import_dicts = []
    for lib, fields in collapsed_import_dict.items():
        # prevent lib from being rendered on the page if all imports are non rendered kind
        if not any(f.render for f in fields):
            continue

        lib_paths: dict[str, list[ImportVar]] = {}

        for field in fields:
            lib_paths.setdefault(field.package_path, []).append(field)

        compiled = {
            path: compile_import_statement(fields) for path, fields in lib_paths.items()
        }

        for path, (default, rest) in compiled.items():
            if not lib:
                if default:
                    raise ValueError("No default field allowed for empty library.")
                if rest is None or len(rest) == 0:
                    raise ValueError("No fields to import.")
                import_dicts.extend(get_import_dict(module) for module in sorted(rest))
                continue

            # remove the version before rendering the package imports
            formatted_lib = format.format_library_name(lib) + (
                path if path != "/" else ""
            )

            import_dicts.append(get_import_dict(formatted_lib, default, rest))
    return import_dicts


def get_import_dict(lib: str, default: str = "", rest: list[str] | None = None) -> dict:
    """Get dictionary for import template.

    Args:
        lib: The importing react library.
        default: The default module to import.
        rest: The rest module to import.

    Returns:
        A dictionary for import template.
    """
    return {
        "lib": lib,
        "default": default,
        "rest": rest if rest else [],
    }


def save_error(error: Exception) -> str:
    """Save the error to a file.

    Args:
        error: The error to save.

    Returns:
        The path of the saved error.
    """
    timestamp = datetime.now().strftime("%Y-%m-%d__%H-%M-%S")
    constants.Reflex.LOGS_DIR.mkdir(parents=True, exist_ok=True)
    log_path = constants.Reflex.LOGS_DIR / f"error_{timestamp}.log"
    traceback.TracebackException.from_exception(error).print(file=log_path.open("w+"))
    return str(log_path)


def compile_state(state: type[BaseState]) -> dict:
    """Compile the state of the app.

    Args:
        state: The app state object.

    Returns:
        A dictionary of the compiled state.
    """
    initial_state = state(_reflex_internal_init=True).dict(initial=True)
    try:
        _ = asyncio.get_running_loop()
    except RuntimeError:
        pass
    else:
        if is_in_app_harness():
            # Playwright tests already have an event loop running, so we can't use asyncio.run.
            with concurrent.futures.ThreadPoolExecutor() as pool:
                resolved_initial_state = pool.submit(
                    asyncio.run, _resolve_delta(initial_state)
                ).result()
                console.warn(
                    f"Had to get initial state in a thread 🤮 {resolved_initial_state}",
                )
                return resolved_initial_state

    # Normally the compile runs before any event loop starts, we asyncio.run is available for calling.
    return asyncio.run(_resolve_delta(initial_state))


def _compile_client_storage_field(
    field: ModelField,
) -> tuple[
    type[Cookie] | type[LocalStorage] | type[SessionStorage] | None,
    dict[str, Any] | None,
]:
    """Compile the given cookie, local_storage or session_storage field.

    Args:
        field: The possible cookie field to compile.

    Returns:
        A dictionary of the compiled cookie or None if the field is not cookie-like.
    """
    for field_type in (Cookie, LocalStorage, SessionStorage):
        if isinstance(field.default, field_type):
            cs_obj = field.default
        elif isinstance(field.type_, type) and issubclass(field.type_, field_type):
            cs_obj = field.type_()
        else:
            continue
        return field_type, cs_obj.options()
    return None, None


def _compile_client_storage_recursive(
    state: type[BaseState],
) -> tuple[dict[str, dict], dict[str, dict], dict[str, dict]]:
    """Compile the client-side storage for the given state recursively.

    Args:
        state: The app state object.

    Returns:
        A tuple of the compiled client-side storage info:
            (
                cookies: dict[str, dict],
                local_storage: dict[str, dict[str, str]]
                session_storage: dict[str, dict[str, str]]
            ).
    """
    cookies = {}
    local_storage = {}
    session_storage = {}
    state_name = state.get_full_name()
    for name, field in state.__fields__.items():
        if name in state.inherited_vars:
            # only include vars defined in this state
            continue
        state_key = f"{state_name}.{name}"
        field_type, options = _compile_client_storage_field(field)
        if field_type is Cookie:
            cookies[state_key] = options
        elif field_type is LocalStorage:
            local_storage[state_key] = options
        elif field_type is SessionStorage:
            session_storage[state_key] = options
        else:
            continue
    for substate in state.get_substates():
        (
            substate_cookies,
            substate_local_storage,
            substate_session_storage,
        ) = _compile_client_storage_recursive(substate)
        cookies.update(substate_cookies)
        local_storage.update(substate_local_storage)
        session_storage.update(substate_session_storage)
    return cookies, local_storage, session_storage


def compile_client_storage(state: type[BaseState]) -> dict[str, dict]:
    """Compile the client-side storage for the given state.

    Args:
        state: The app state object.

    Returns:
        A dictionary of the compiled client-side storage info.
    """
    cookies, local_storage, session_storage = _compile_client_storage_recursive(state)
    return {
        constants.COOKIES: cookies,
        constants.LOCAL_STORAGE: local_storage,
        constants.SESSION_STORAGE: session_storage,
    }


def compile_custom_component(
    component: CustomComponent,
) -> tuple[dict, ParsedImportDict]:
    """Compile a custom component.

    Args:
        component: The custom component to compile.

    Returns:
        A tuple of the compiled component and the imports required by the component.
    """
    # Render the component.
    render = component.get_component(component)

    # Get the imports.
    imports: ParsedImportDict = {
        lib: fields
        for lib, fields in render._get_all_imports().items()
        if lib != component.library
    }

    # Concatenate the props.
    props = list(component.props)

    # Compile the component.
    return (
        {
            "name": component.tag,
            "props": props,
            "render": render.render(),
            "hooks": render._get_all_hooks(),
            "custom_code": render._get_all_custom_code(),
            "dynamic_imports": render._get_all_dynamic_imports(),
        },
        imports,
    )


def create_document_root(
    head_components: Sequence[Component] | None = None,
    html_lang: str | None = None,
    html_custom_attrs: dict[str, Var | str] | None = None,
) -> Component:
    """Create the document root.

    Args:
        head_components: The components to add to the head.
        html_lang: The language of the document, will be added to the html root element.
        html_custom_attrs: custom attributes added to the html root element.

    Returns:
        The document root.
    """
    head_components = head_components or []
    return Html.create(
        DocumentHead.create(*head_components),
        Body.create(
            Main.create(),
            NextScript.create(),
        ),
        lang=html_lang or "en",
        custom_attrs=html_custom_attrs or {},
    )


def create_theme(style: ComponentStyle) -> dict:
    """Create the base style for the app.

    Args:
        style: The style dict for the app.

    Returns:
        The base style for the app.
    """
    # Get the global style from the style dict.
    style_rules = Style({k: v for k, v in style.items() if isinstance(k, str)})

    root_style = {
        # Root styles.
        ":root": Style(
            {f"*{k}": v for k, v in style_rules.items() if k.startswith(":")}
        ),
        # Body styles.
        "body": Style(
            {k: v for k, v in style_rules.items() if not k.startswith(":")},
        ),
    }

    # Return the theme.
    return {"styles": {"global": root_style}}


def get_page_path(path: str) -> str:
    """Get the path of the compiled JS file for the given page.

    Args:
        path: The path of the page.

    Returns:
        The path of the compiled JS file.
    """
    return str(get_web_dir() / constants.Dirs.PAGES / (path + constants.Ext.JS))


def get_theme_path() -> str:
    """Get the path of the base theme style.

    Returns:
        The path of the theme style.
    """
    return str(
        get_web_dir()
        / constants.Dirs.UTILS
        / (constants.PageNames.THEME + constants.Ext.JS)
    )


def get_root_stylesheet_path() -> str:
    """Get the path of the app root file.

    Returns:
        The path of the app root file.
    """
    return str(
        get_web_dir()
        / constants.Dirs.STYLES
        / (constants.PageNames.STYLESHEET_ROOT + constants.Ext.CSS)
    )


def get_context_path() -> str:
    """Get the path of the context / initial state file.

    Returns:
        The path of the context module.
    """
    return str(get_web_dir() / (constants.Dirs.CONTEXTS_PATH + constants.Ext.JS))


def get_components_path() -> str:
    """Get the path of the compiled components.

    Returns:
        The path of the compiled components.
    """
    return str(
        get_web_dir()
        / constants.Dirs.UTILS
        / (constants.PageNames.COMPONENTS + constants.Ext.JS),
    )


def get_stateful_components_path() -> str:
    """Get the path of the compiled stateful components.

    Returns:
        The path of the compiled stateful components.
    """
    return str(
        get_web_dir()
        / constants.Dirs.UTILS
        / (constants.PageNames.STATEFUL_COMPONENTS + constants.Ext.JS)
    )


def add_meta(
    page: Component,
    title: str,
    image: str,
    meta: list[dict],
    description: str | None = None,
) -> Component:
    """Add metadata to a page.

    Args:
        page: The component for the page.
        title: The title of the page.
        image: The image for the page.
        meta: The metadata list.
        description: The description of the page.

    Returns:
        The component with the metadata added.
    """
    meta_tags = [
        item if isinstance(item, Component) else Meta.create(**item) for item in meta
    ]

    children: list[Any] = [Title.create(title)]
    if description:
        children.append(Description.create(content=description))
    children.append(Image.create(content=image))

    page.children.append(
        Head.create(
            *children,
            *meta_tags,
        )
    )

    return page


def write_page(path: str | Path, code: str):
    """Write the given code to the given path.

    Args:
        path: The path to write the code to.
        code: The code to write.
    """
    path = Path(path)
    path_ops.mkdir(path.parent)
    if path.exists() and path.read_text(encoding="utf-8") == code:
        return
    path.write_text(code, encoding="utf-8")


def empty_dir(path: str | Path, keep_files: list[str] | None = None):
    """Remove all files and folders in a directory except for the keep_files.

    Args:
        path: The path to the directory that will be emptied
        keep_files: List of filenames or foldernames that will not be deleted.
    """
    path = Path(path)

    # If the directory does not exist, return.
    if not path.exists():
        return

    # Remove all files and folders in the directory.
    keep_files = keep_files or []
    for element in path.iterdir():
        if element.name not in keep_files:
            path_ops.rm(element)


def is_valid_url(url: str) -> bool:
    """Check if a url is valid.

    Args:
        url: The Url to check.

    Returns:
        Whether url is valid.
    """
    result = urlparse(url)
    return all([result.scheme, result.netloc])