"""Messages exchanged with web clients over the ``/ws`` websocket.

Client -> server messages are validated with pydantic. Server -> client
messages are plain dicts:

- ``{"type": "welcome", "player_id", "token", "name"}``
- ``{"type": "state", "lobby": LobbyView | null, "game": GameView | null, "events": [...]}``
- ``{"type": "error", "message", "code"?}``
- ``{"type": "server_status", "load", "accepting_games"}``
"""

from __future__ import annotations

from typing import Annotated, Any, Literal

from pydantic import BaseModel, Field, StringConstraints, TypeAdapter

PlayerName = Annotated[str, StringConstraints(strip_whitespace=True, min_length=1, max_length=20)]
LobbyCode = Annotated[str, StringConstraints(strip_whitespace=True, to_upper=True, min_length=4, max_length=12)]


class Hello(BaseModel):
    type: Literal["hello"]
    # Token of a previous session, used to reconnect after a page reload.
    token: str | None = None


class CreateLobby(BaseModel):
    type: Literal["create_lobby"]
    name: PlayerName


class JoinLobby(BaseModel):
    type: Literal["join_lobby"]
    code: LobbyCode
    name: PlayerName


class LeaveLobby(BaseModel):
    type: Literal["leave_lobby"]


class AddAI(BaseModel):
    type: Literal["add_ai"]


class RemovePlayer(BaseModel):
    type: Literal["remove_player"]
    player_id: str


class SetOptions(BaseModel):
    type: Literal["set_options"]
    hidden_bids: bool


class StartGame(BaseModel):
    type: Literal["start_game"]


class GameAction(BaseModel):
    type: Literal["action"]
    action: dict[str, Any]


class ReturnToLobby(BaseModel):
    type: Literal["return_to_lobby"]


ClientMessage = Annotated[
    Hello | CreateLobby | JoinLobby | LeaveLobby | AddAI | RemovePlayer
    | SetOptions | StartGame | GameAction | ReturnToLobby,
    Field(discriminator="type"),
]

client_message_adapter: TypeAdapter[ClientMessage] = TypeAdapter(ClientMessage)


# Machine readable error codes (the frontend reacts to them).
ERROR_BUSY = "busy"                  # server has no capacity for this right now
ERROR_RATE_LIMITED = "rate_limited"  # client sends too many messages / creates too many lobbies

# Websocket close code "Try Again Later" (RFC 6455 registry), used when full.
CLOSE_TRY_AGAIN_LATER = 1013


def error(message: str, code: str | None = None) -> dict:
    message_dict: dict = {"type": "error", "message": message}
    if code:
        message_dict["code"] = code
    return message_dict