"""The @client-decorated functions and the channel wire contracts every AFI
backend registers.

`register_fixture()` binds the functions into mizan_core.registry. The channel
classes live in each backend's own app module — the `Channel` base is
backend-specific — and bind the payload models below under `CHAT_CHANNEL` and
`USER_ALERTS_CHANNEL`.
"""

from __future__ import annotations

from pydantic import BaseModel

from mizan_core.client.function import client
from mizan_core.registry import register


# ─── Output shapes ──────────────────────────────────────────────────────────


class EchoOutput(BaseModel):
    message: str


class WhoamiOutput(BaseModel):
    email: str
    authenticated: bool


class ProfileOutput(BaseModel):
    user_id: int
    name: str


class OrderOutput(BaseModel):
    id: int
    user_id: int
    total: int


class StatusOutput(BaseModel):
    ok: bool


# ─── Channel wire contracts ─────────────────────────────────────────────────

CHAT_CHANNEL = "chat"
USER_ALERTS_CHANNEL = "user_alerts"


class ChatParams(BaseModel):
    room_id: str


class ChatClientMessage(BaseModel):
    text: str


class ChatServerMessage(BaseModel):
    text: str
    from_user: str


class UserAlertsServerMessage(BaseModel):
    body: str
    unread: int


# ─── Stored rows ────────────────────────────────────────────────────────────

_PROFILES = {5: "Ada Lovelace", 6: "Grace Hopper"}
_ORDERS = [
    OrderOutput(id=1, user_id=5, total=1200),
    OrderOutput(id=2, user_id=5, total=350),
]


# ─── Fixture functions ──────────────────────────────────────────────────────


@client
def echo(request, text: str) -> EchoOutput:
    return EchoOutput(message=f"echo: {text}")


@client
def whoami(request) -> WhoamiOutput:
    return WhoamiOutput(email="anon@example.com", authenticated=False)


@client(context="user")
def user_profile(request, user_id: int) -> ProfileOutput:
    # A context member always answers, so an unstored id reads back under a
    # name derived from the id rather than an absence.
    return ProfileOutput(
        user_id=user_id, name=_PROFILES.get(user_id, f"user {user_id}")
    )


@client(context="user")
def user_orders(request, user_id: int) -> list[OrderOutput]:
    return [order for order in _ORDERS if order.user_id == user_id]


@client(affects="user")
def update_profile(request, user_id: int, name: str) -> StatusOutput:
    return StatusOutput(ok=bool(name) and user_id in _PROFILES)


@client
def find_user(request, user_id: int) -> ProfileOutput | None:
    if user_id in _PROFILES:
        return ProfileOutput(user_id=user_id, name=_PROFILES[user_id])
    return None


@client(merge="user")
def rename_user(request, user_id: int, name: str) -> ProfileOutput:
    # The merge target's return value is what the kernel splices into the
    # `user` context, so the renamed profile is the whole result.
    return ProfileOutput(user_id=user_id, name=name)


# ─── Registration ───────────────────────────────────────────────────────────


def register_fixture() -> None:
    register(echo, "echo")
    register(whoami, "whoami")
    register(user_profile, "user_profile")
    register(user_orders, "user_orders")
    register(update_profile, "update_profile")
    register(find_user, "find_user")
    register(rename_user, "rename_user")