"""FastAPI 应用入口（ARCH §7）。"""

from __future__ import annotations

from collections.abc import AsyncIterator
from contextlib import asynccontextmanager

from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse
from ww_db import get_sessionmaker
from ww_shared import AppError, ErrorBody, ErrorEnvelope

from ww_api.logging_config import configure_logging, get_logger
from ww_api.middleware import request_id_middleware
from ww_api.routers import (
    foreshadow,
    health,
    jobs,
    outline,
    projects,
    settings_providers,
)
from ww_api.services.project_deps import seed_stub_user

configure_logging()
log = get_logger("ww.api")


@asynccontextmanager
async def _lifespan(app: FastAPI) -> AsyncIterator[None]:
    # 幂等 seed 单用户 stub——所有 owner_id FK 依赖它（见 memory/gotchas）。
    async with get_sessionmaker()() as session:
        await seed_stub_user(session)
    yield


def create_app() -> FastAPI:
    app = FastAPI(title="网文创作工作流 API", version="0.0.0", lifespan=_lifespan)
    app.middleware("http")(request_id_middleware)

    @app.exception_handler(AppError)
    async def _app_error_handler(request: Request, exc: AppError) -> JSONResponse:
        request_id = getattr(request.state, "request_id", None)
        log.warning("app_error", code=exc.code, message=exc.message)
        envelope = ErrorEnvelope(
            error=ErrorBody(
                code=exc.code,
                message=exc.message,
                details=exc.details,
                request_id=request_id,
            )
        )
        return JSONResponse(status_code=exc.http_status, content=envelope.model_dump())

    app.include_router(health.router)
    app.include_router(jobs.router)
    app.include_router(projects.router)
    app.include_router(foreshadow.router)
    app.include_router(outline.router)
    app.include_router(settings_providers.router)
    return app


app = create_app()