"""
The AFI fixture — a small set of @client-decorated functions designed to
exercise the protocol axes both backends must agree on:

- plain function with typed input
- plain function with no input
- two context functions sharing a param (proves bundling + param elevation)
- a mutation declaring `affects` on the context

No channels, no forms, no shapes — those aren't AFI-common.

`register_fixture()` registers the functions with mizan_core.registry.
Backend test apps import this module and call register_fixture() during
their setup so each backend's schema export sees the same registrations.
"""

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


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


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


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


@client(context="user")
def user_profile(request, user_id: int) -> ProfileOutput:
    """One half of the user context."""
    return ProfileOutput(user_id=user_id, name="placeholder")


@client(context="user")
def user_orders(request, user_id: int) -> list[OrderOutput]:
    """Other half of the user context — same param, proves param elevation."""
    return []


@client(affects="user")
def update_profile(request, user_id: int, name: str) -> StatusOutput:
    """Mutation declaring affects on the user context."""
    return StatusOutput(ok=True)


@client
def find_user(request, user_id: int) -> ProfileOutput | None:
    """Optional return — exercises Pydantic `T | None` schema introspection."""
    return None


@client(merge="user")
def rename_user(request, user_id: int, name: str) -> ProfileOutput:
    """Merge target — kernel splices return value into the user context."""
    return ProfileOutput(user_id=user_id, name=name)


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


def register_fixture() -> None:
    """Register every fixture function with mizan_core.registry."""
    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")
