import logging
import os
import sys
import warnings
from importlib.metadata import EntryPoint, Distribution
from importlib.metadata import entry_points
from sys import version_info
from typing import Any
from typing import Callable
from typing import Dict
from typing import List
from typing import Optional
from typing import Tuple
from typing import cast
from typing import Set
from typing import Union

import typer
from rich.table import Table
from typer.models import DefaultPlaceholder

from anaconda_cli_base.console import console, select_from_list
from anaconda_cli_base import __version__

log = logging.getLogger(__name__)

PLUGIN_GROUP_NAME = "anaconda_cli.subcommand"

# Plugins which are available but hidden from help text
HIDDEN_PLUGINS = ["cloud"]

# Type aliases
PluginName = str
ModuleName = str
SiteName = str
SiteDisplayName = str


def _load_entry_points_for_group(
    group: str,
) -> List[Tuple[PluginName, ModuleName, typer.Typer, Union[Distribution, None]]]:
    # The API was changed in Python 3.10, see https://docs.python.org/3/library/importlib.metadata.html#entry-points
    found_entry_points: Tuple[EntryPoint, ...]
    if version_info.major == 3 and version_info.minor <= 9:
        found_entry_points = cast(
            Tuple[EntryPoint, ...],
            entry_points().get(group, tuple()),  # type:ignore
        )
    else:
        found_entry_points = tuple(entry_points().select(group=group))  # type: ignore

    loaded = []
    for entry_point in found_entry_points:
        with warnings.catch_warnings():
            # Suppress anaconda-cloud-auth rename warnings just during entrypoint load
            warnings.filterwarnings("ignore", category=DeprecationWarning)
            module: typer.Typer = entry_point.load()
        loaded.append((entry_point.name, entry_point.value, module, entry_point.dist))

    return loaded


AUTH_HANDLER_ALIASES = {
    "cloud": "anaconda.com",
    "org": "anaconda.org",
}


def _select_auth_handler_and_args(
    *,
    ctx: typer.Context,
    at: Optional[str],
    hostname: Optional[str],
    username: Optional[str],
    password: Optional[str],
    help: bool,
    auth_handlers: Dict[str, typer.Typer],
    auth_handlers_dropdown: List[Tuple[SiteName, SiteDisplayName]],
) -> Tuple[Callable, list[str]]:
    """Select the appropriate auth handler, and construct its arguments, depending on
    user input. Isolated to enable better testing to support legacy anaconda.org login
    flows.
    """
    # If we use one of the legacy anaconda-client parameters, we implicitly select
    # anaconda.org for the user.
    if (
        hostname
        or username
        or password
        or ctx.obj.params.get("site", None)
        or ctx.obj.params.get("token", None)
    ):
        at = "anaconda.org"

    # Present a picker if the user doesn't use the --at site option
    if at is None:
        if len(auth_handlers_dropdown) > 1:
            at = select_from_list("choose destination:", auth_handlers_dropdown)
        else:
            # If only one is available, we don't need a picker
            (default_auth_handler,) = auth_handlers_dropdown
            (at, _) = default_auth_handler

    if at not in auth_handlers:
        handlers = "".join(
            [f"\n* {display_name}" for _, display_name in auth_handlers_dropdown]
        )
        msg = f"{at} is not an allowed value for --at. Use one of {handlers}"
        console.print(msg)
        raise typer.Abort()

    handler = auth_handlers[at]

    # Consolidate the arguments to pass into the handler function
    if help:
        args = ["--help"]
    elif at == "anaconda.org":
        # In order to support legacy anaconda-client login arguments, we need to do some
        # manual argument parsing to pass into the handler function

        # Reconstruct the valid options
        legacy_client_args = []
        if hostname:
            legacy_client_args.extend(["--hostname", hostname])
        if username:
            legacy_client_args.extend(["--username", username])
        if password:
            legacy_client_args.extend(["--password", password])

        # We reconstruct sys.argv, dropping everything after the
        # "login/logout/whoami" subcommand, and replacing with any passed options
        def _find_subcommand_index(subcommands: list[str]) -> int:
            subcommands_str = "/".join(subcommands)
            for s in subcommands:
                try:
                    return sys.argv.index(s)
                except ValueError:
                    pass

            raise ValueError(f"Must use a valid subcommand '{subcommands_str}'")

        # Extend sys.argv so we grab everything including the entrypoint and
        # the subcommand, but drop any options
        subcommand_index = _find_subcommand_index(["login", "logout", "whoami"])
        sys.argv = sys.argv[: subcommand_index + 1] + legacy_client_args

        # Now remove the '--at <value>' if it still appears in the sys.argv
        # While still preserving any top-level args like '--verbose' or '--token <>'
        try:
            at_index = sys.argv.index("--at")
            sys.argv = sys.argv[:at_index] + sys.argv[at_index + 2 :]
        except ValueError:
            pass

        args = legacy_client_args
    else:
        args = ctx.args

        # Set globally to propagate to site config
        os.environ["ANACONDA_DEFAULT_SITE"] = at
    return handler, args


def _add_auth_actions_to_app(
    app: typer.Typer,
    auth_handlers: Dict[str, typer.Typer],
    auth_handlers_dropdown: List[Tuple[SiteName, SiteDisplayName]],
) -> None:
    # this ensures that we can reach the help message
    # for the handler chosen by the --at flag if it appears
    # before --help
    def handler_help(ctx: typer.Context, _: Any, at: Optional[str]) -> Optional[str]:
        show_help = ctx.params.get("help", False) is True
        if show_help:
            help_str = ctx.get_help()
            console.print(help_str)
            raise typer.Exit()

        return at

    # Extract site names for help text
    site_names = [site_name for site_name, _ in auth_handlers_dropdown]

    def _action(
        ctx: typer.Context,
        at: Optional[str] = typer.Option(
            None, help=f"Choose from {site_names}", callback=handler_help
        ),
        # Legacy options from anaconda-client login subcommand
        hostname: Optional[str] = typer.Option(None, hidden=True),
        username: Optional[str] = typer.Option(None, hidden=True),
        password: Optional[str] = typer.Option(None, hidden=True),
        help: bool = typer.Option(False, "--help", "-h"),
    ) -> None:
        ctx_at = ctx.obj.params.get("at")
        if ctx_at and at:
            raise ValueError("--at was specified twice")

        handler, args = _select_auth_handler_and_args(
            ctx=ctx,
            at=ctx_at or at,
            hostname=hostname,
            username=username,
            password=password,
            help=help,
            auth_handlers=auth_handlers,
            auth_handlers_dropdown=auth_handlers_dropdown,
        )
        return handler(args=[ctx.command.name, *args], obj=ctx.obj)

    help_doc = {
        "login": "Sign into Anaconda services",
        "logout": "Sign out from Anaconda services",
        "whoami": "Display account information",
    }

    for action in "login", "logout", "whoami":
        decorator = app.command(
            action,
            context_settings={"allow_extra_args": True, "ignore_unknown_options": True},
            rich_help_panel="Authentication",
            help=help_doc[action],
        )
        decorator(_action)


def _load_auth_handler(
    subcommand_app: typer.Typer,
    name: PluginName,
    auth_handlers: Dict[PluginName, typer.Typer],
    auth_handler_selectors: List[Tuple[SiteName, SiteDisplayName]],
) -> None:
    """Load a specific auth handler, populating the dropdown and auth_handlers
    mappings as we go. This allows users to dynamically select a specific
    implementation when logging in or out.
    """
    auth_handlers[name] = subcommand_app
    # this means anaconda-auth is available
    if name == "auth":
        try:
            # Type hints are missing temporarily
            from anaconda_auth.config import AnacondaAuthSitesConfig  # type: ignore

            site_config = AnacondaAuthSitesConfig()
            for site_name, site in site_config.sites.root.items():
                display_name = site_name
                if site_name != site.domain:
                    display_name += f" ({site.domain})"

                if site_name == site_config.default_site:
                    display_name += " [cyan]\\[default][/cyan]"

                auth_handlers[site_name] = subcommand_app
                auth_handler_selectors.append((site_name, display_name))

        except ImportError as e:
            raise e
    elif name == "cloud":
        # This plugin alias duplicates anaconda.com, so we skip it
        pass
    elif alias := AUTH_HANDLER_ALIASES.get(name):
        auth_handlers[alias] = subcommand_app
        auth_handler_selectors.append((alias, alias))


def _sort_selectors(
    item: Tuple[SiteName, SiteDisplayName],
) -> Tuple[int, Tuple[SiteName, SiteDisplayName]]:
    name, display_name = item
    if "default" in display_name:
        return (0, item)
    if display_name == "anaconda.com":
        return (1, item)
    if display_name == "anaconda.org":
        return (2, item)
    else:
        return (3, item)


def load_registered_subcommands(app: typer.Typer) -> None:
    """Load all subcommands from plugins."""
    subcommand_entry_points = _load_entry_points_for_group(PLUGIN_GROUP_NAME)
    auth_handlers: Dict[PluginName, typer.Typer] = {}
    auth_handler_selectors: List[Tuple[SiteName, SiteDisplayName]] = []
    plugin_versions: Set[Tuple[str, str]] = {
        ("anaconda-cli-base", __version__),
    }

    for name, value, subcommand_app, distribution in subcommand_entry_points:
        # Allow plugins to disable this if they explicitly want to, but otherwise make True the default

        if distribution is not None:
            plugin_versions.add((distribution.name, distribution.version))

        if isinstance(subcommand_app.info.no_args_is_help, DefaultPlaceholder):
            subcommand_app.info.no_args_is_help = True

        if "login" in [cmd.name for cmd in subcommand_app.registered_commands]:
            _load_auth_handler(
                subcommand_app, name, auth_handlers, auth_handler_selectors
            )

        app.add_typer(
            subcommand_app,
            name=name,
            hidden=name in HIDDEN_PLUGINS,
            rich_help_panel="Plugins",
        )

    if auth_handlers:
        auth_handlers_dropdown = sorted(auth_handler_selectors, key=_sort_selectors)
        _add_auth_actions_to_app(
            app=app,
            auth_handlers=auth_handlers,
            auth_handlers_dropdown=auth_handlers_dropdown,
        )

        log.debug(
            "Loaded subcommand '%s' from '%s'",
            name,
            value,
        )

    @app.command("versions", hidden=True)
    def versions() -> None:
        table = Table("Package", "Version", header_style="bold green")
        for plugin, version in plugin_versions:
            table.add_row(plugin, version)
        console.print(table)
        raise typer.Exit()