"""The tool plugin contract and registry.

A *tool* is one menu option / CLI subcommand. Subclass :class:`Tool`, decorate it with
:func:`register`, and implement :meth:`Tool.run`. The same registry drives both the
interactive menu and the Typer CLI, and :meth:`Tool.execute` wraps every invocation in a
logged ``runs`` row, so new tools get persistence and logging for free.
"""

from __future__ import annotations

from abc import ABC, abstractmethod
from dataclasses import dataclass, field
from typing import TYPE_CHECKING, Any, Optional

if TYPE_CHECKING:  # avoid importing typer/context at module load for fast startup
    import typer

    from ..context import AppContext


@dataclass(slots=True)
class ToolResult:
    """The outcome of a tool execution.

    Attributes:
        summary: JSON-serializable summary persisted to the run record.
        message: Optional human-readable closing message.
        artifacts: Paths to any files produced (e.g. generated visualizations).
    """

    summary: dict[str, Any] = field(default_factory=dict)
    message: Optional[str] = None
    artifacts: list[str] = field(default_factory=list)


class Tool(ABC):
    """Base class for all MeshTerm features.

    Class Attributes:
        name: CLI identifier (kebab-case), unique across tools.
        title: Display name shown as the interactive menu item and on the tool's result
            window. Capitalized, and kept identical to the screen the item opens so the
            menu never promises one name and delivers another. Falls back to ``name``.
        help: One-line description shown in the menu and ``--help`` (no trailing period).
        icon: Emoji drawn before the title in the interactive menu (and only there — the
            result window keeps the plain title). Single-codepoint, emoji-presentation
            glyphs only, so the two-cell width holds across terminals (see
            :mod:`meshterm.ui.tui.emoji_width`).
        category: Grouping label used to organize the interactive menu.
        order: Sort key within a category (lower sorts first).
        menu_visible: Whether the tool appears in the interactive menu. Set ``False`` for
            CLI-only tools (e.g. startup-time diagnostics with no place in a connected
            session); such tools still register a CLI subcommand as usual.
        popup: Whether the menu stays pushed while this tool runs, so the tool's prompts
            and result float over it as modal popups (the quit-dialog pattern) instead of
            replacing the screen. For quick dialog-sized tools; a tool that pushes its
            own full screen keeps the default.
    """

    name: str = ""
    title: str = ""
    help: str = ""
    icon: str = ""
    category: str = "General"
    order: int = 100
    menu_visible: bool = True
    popup: bool = False

    @abstractmethod
    async def run(self, ctx: "AppContext", params: dict[str, Any]) -> ToolResult:
        """Execute the tool's work.

        Args:
            ctx: Shared application context (console, device, repository, ...).
            params: Validated parameters for this invocation.

        Returns:
            A :class:`ToolResult` describing the outcome.
        """

    async def prompt_params(self, ctx: "AppContext") -> dict[str, Any]:
        """Interactively gather parameters for the menu.

        The default implementation requires no parameters. Tools override this to ask
        the user via ``questionary``.

        Args:
            ctx: Shared application context.

        Returns:
            A parameter dict compatible with :meth:`run`.
        """
        return {}

    def register_cli(self, app: "typer.Typer") -> None:
        """Register this tool as a Typer subcommand.

        The default registers a no-argument command. Tools with parameters override this
        to declare typed options, then delegate to :meth:`execute`.

        Args:
            app: The Typer application to add the command to.
        """
        from ..cli import run_tool_command

        @app.command(name=self.name, help=self.help)
        def _command() -> None:
            run_tool_command(self, {})

    async def execute(self, ctx: "AppContext", params: dict[str, Any]) -> ToolResult:
        """Run the tool wrapped in run-logging and error capture.

        Opens a ``runs`` row before execution and closes it with the final status and
        summary afterward, regardless of success.

        Args:
            ctx: Shared application context.
            params: Parameters for this invocation.

        Returns:
            The :class:`ToolResult` from :meth:`run`.

        Raises:
            Exception: Re-raises any error from :meth:`run` after recording it.
        """
        from ..core.connection import DeviceCommandError
        from ..core.device_config import DeviceConfigError
        from ..core.selection import DeviceSelectionError

        run_id = ctx.repo.start_run(self.name, params, ctx.profile_name)
        ctx.log.debug("run %s start: tool=%s params=%s", run_id, self.name, params)
        try:
            result = await self.run(ctx, {**params, "_run_id": run_id})
        except (DeviceSelectionError, DeviceConfigError, DeviceCommandError) as exc:
            # Expected user-facing condition (no/ambiguous device, bad config value, or
            # a transient command failure): record it but don't dump a traceback;
            # callers print the message cleanly.
            ctx.repo.finish_run(run_id, "error", {"error": str(exc)})
            ctx.log.debug("run %s aborted: %s", run_id, exc)
            raise
        except Exception as exc:  # noqa: BLE001 - we record then re-raise
            ctx.repo.finish_run(run_id, "error", {"error": str(exc)})
            ctx.log.exception("run %s failed: %s", run_id, exc)
            raise
        ctx.repo.finish_run(run_id, "ok", result.summary)
        ctx.log.debug("run %s ok", run_id)
        return result


_REGISTRY: dict[str, Tool] = {}

#: Explicit menu ordering for tool categories. Messaging leads because it holds the
#: first-class, everyday features (chat, channels, the courier); Mesh follows with
#: the views over the mesh itself (dashboard, nodes, map, atlas, watchtower,
#: adverts); the rest in a natural workflow order. Categories not listed here sort
#: last, alphabetically, so a new category still appears.
_CATEGORY_ORDER = ["Messaging", "Mesh", "Device management", "Tools"]


def _category_rank(category: str) -> int:
    """Return a category's sort rank (its position in ``_CATEGORY_ORDER``, else last)."""
    try:
        return _CATEGORY_ORDER.index(category)
    except ValueError:
        return len(_CATEGORY_ORDER)


def register(cls: type[Tool]) -> type[Tool]:
    """Class decorator that instantiates a tool and adds it to the registry.

    Args:
        cls: The :class:`Tool` subclass to register.

    Returns:
        The unchanged class (so the decorator is transparent).

    Raises:
        ValueError: If the tool has no ``name`` or the name is already registered.
    """
    instance = cls()
    if not instance.name:
        raise ValueError(f"{cls.__name__} must define a non-empty 'name'.")
    if instance.name in _REGISTRY:
        raise ValueError(f"Duplicate tool name: {instance.name!r}")
    _REGISTRY[instance.name] = instance
    return cls


def all_tools() -> list[Tool]:
    """Return all registered tools sorted by category rank, then order, then name.

    Categories are ordered by :data:`_CATEGORY_ORDER` (Mesh first), so the first-class
    Chat and Channels tools lead the menu; within a category, ``order`` then ``name`` break
    ties.

    Returns:
        The registered tool instances in stable menu order.
    """
    return sorted(
        _REGISTRY.values(),
        key=lambda t: (_category_rank(t.category), t.category, t.order, t.name),
    )


def get_tool(name: str) -> Optional[Tool]:
    """Look up a registered tool by name.

    Args:
        name: The tool's ``name``.

    Returns:
        The tool instance, or ``None`` if not registered.
    """
    return _REGISTRY.get(name)