"""FastAPI application factory."""

from __future__ import annotations

from contextlib import asynccontextmanager

import sentry_sdk
from fastapi import FastAPI, Request
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse
from slowapi import Limiter, _rate_limit_exceeded_handler
from slowapi.errors import RateLimitExceeded
from slowapi.util import get_remote_address

from app.api.v1.router import api_router
from app.core.config import get_settings
from app.core.exceptions import AppException
from app.core.logging import get_logger, setup_logging

logger = get_logger(__name__)


@asynccontextmanager
async def lifespan(app: FastAPI):
    """Startup / shutdown events."""
    setup_logging()
    settings = get_settings()

    # Sentry
    if settings.SENTRY_DSN:
        sentry_sdk.init(
            dsn=settings.SENTRY_DSN,
            traces_sample_rate=0.1,
            environment=settings.APP_ENV,
        )

    logger.info(
        "application_started",
        app_name=settings.APP_NAME,
        env=settings.APP_ENV,
    )
    yield
    logger.info("application_shutdown")


def create_app() -> FastAPI:
    settings = get_settings()

    app = FastAPI(
        title=f"{settings.APP_NAME} API",
        description="Marketplace API for Deals24Togo — listings, agencies, categories, and more.",
        version="1.0.0",
        docs_url="/docs" if settings.DEBUG else None,
        redoc_url="/redoc" if settings.DEBUG else None,
        lifespan=lifespan,
    )

    # ── CORS ──
    app.add_middleware(
        CORSMiddleware,
        allow_origins=settings.allowed_origins_list,
        allow_credentials=True,
        allow_methods=["*"],
        allow_headers=["*"],
    )

    # ── Rate limiter ──
    limiter = Limiter(key_func=get_remote_address)
    app.state.limiter = limiter
    app.add_exception_handler(RateLimitExceeded, _rate_limit_exceeded_handler)

    # ── Exception handlers ──
    @app.exception_handler(AppException)
    async def app_exception_handler(_request: Request, exc: AppException):
        return JSONResponse(
            status_code=exc.status_code,
            content={"detail": exc.detail},
        )

    @app.exception_handler(Exception)
    async def global_exception_handler(_request: Request, exc: Exception):
        logger.error("unhandled_exception", error=str(exc), exc_info=True)
        return JSONResponse(
            status_code=500,
            content={"detail": "Internal server error"},
        )

    # ── Routes ──
    app.include_router(api_router)

    @app.get("/health", tags=["Health"])
    def health_check():
        return {"status": "healthy", "app": settings.APP_NAME, "env": settings.APP_ENV}

    return app