Decoder2704/python-chatbot-jay

1"""2FastAPI entrypoint: loads retrieval artifacts at startup (Chatbot-V5.ipynb parity).3"""4 5from __future__ import annotations6 7import logging8import os9from contextlib import asynccontextmanager10 11from fastapi import FastAPI12from fastapi.middleware.cors import CORSMiddleware13 14from .frontend_spa import register_frontend_spa15from .models.schemas import HealthResponse16from .paths import (17    ARTIFACTS_DIR,18    ARTIFACT_CHATBOT_DF_PATH,19    ARTIFACT_QUESTION_VECTORS_PATH,20    ARTIFACT_VECTORIZER_PATH,21    BACKEND_DIR,22    ensure_data_and_artifacts_dirs,23    resolve_frontend_dist_dir,24)25from .routes import chat26from .services import retriever27 28logging.basicConfig(29    level=logging.INFO,30    format="%(levelname)s: %(name)s: %(message)s",31)32logger = logging.getLogger(__name__)33 34 35def _log_artifact_filesystem_probe() -> None:36    """Deployment diagnostics only — does not change retrieval behavior."""37    root = BACKEND_DIR.resolve()38    art = ARTIFACTS_DIR.resolve()39    logger.info("Deploy probe: BACKEND_DIR=%s", root)40    logger.info("Deploy probe: ARTIFACTS_DIR=%s exists=%s", art, art.is_dir())41    if art.is_dir():42        try:43            names = sorted(p.name for p in art.iterdir() if p.is_file())44            logger.info("Deploy probe: artifact directory file names: %s", names)45        except OSError as e:46            logger.warning("Deploy probe: could not list artifact directory: %s", e)47    for label, path in (48        ("vectorizer.pkl", ARTIFACT_VECTORIZER_PATH),49        ("question_vectors.pkl", ARTIFACT_QUESTION_VECTORS_PATH),50        ("chatbot_df.pkl", ARTIFACT_CHATBOT_DF_PATH),51    ):52        try:53            exists = path.is_file()54            size = path.stat().st_size if exists else None55            logger.info("Deploy probe: %s path=%s exists=%s bytes=%s", label, path, exists, size)56        except OSError as e:57            logger.warning("Deploy probe: %s stat failed: %s", label, e)58 59 60def _cors_allow_origins() -> list[str]:61    """Local dev origins plus optional comma-separated production origins (CORS_EXTRA_ORIGINS)."""62    base = [63        "http://localhost:3000",64        "http://127.0.0.1:3000",65        "http://localhost:5173",66        "http://127.0.0.1:5173",67    ]68    extra = os.environ.get("CORS_EXTRA_ORIGINS", "")69    if not extra.strip():70        return base71    more = [o.strip() for o in extra.split(",") if o.strip()]72    seen: set[str] = set()73    out: list[str] = []74    for o in base + more:75        if o not in seen:76            seen.add(o)77            out.append(o)78    return out79 80 81@asynccontextmanager82async def lifespan(app: FastAPI):83    ensure_data_and_artifacts_dirs()84    _log_artifact_filesystem_probe()85    logger.info(86        "Startup: loading retrieval artifacts from %s (data dir: %s)",87        retriever.ARTIFACTS_DIR,88        retriever.DATA_DIR,89    )90    retriever.load_artifacts()91    logger.info("Startup complete")92    yield93    logger.info("Shutdown")94 95 96app = FastAPI(97    title="PyBot API",98    description="REST API mirroring Chatbot-V5.ipynb retrieval flow",99    lifespan=lifespan,100)101 102app.add_middleware(103    CORSMiddleware,104    allow_origins=_cors_allow_origins(),105    allow_credentials=False,106    allow_methods=["*"],107    allow_headers=["*"],108)109 110app.include_router(chat.router)111 112 113@app.get("/health", response_model=HealthResponse, tags=["health"])114async def health():115    return HealthResponse(status="ok")116 117 118# React SPA after all API routes: /chat, /health, /docs, openapi.json, etc. stay on FastAPI.119_spa_dir = resolve_frontend_dist_dir()120if _spa_dir is not None:121    register_frontend_spa(app, _spa_dir)122else:123    logger.warning(124        "No React build found — API only. Build to frontend/dist or frontend/build, "125        "or set FRONTEND_DIST_DIR (see app.paths.resolve_frontend_dist_dir).",126    )127