"""
backend/main.py
---------------
FastAPI application entry point for Notiflow.

Startup:
  1. Loads .env file from project root (python-dotenv)
  2. Configures logging
  3. Mounts the notification API router
  4. Exposes health check endpoint

Run:
    uvicorn backend.main:app --reload

The server expects to be started from the project root so that
all relative imports (app/, agent/, services/, etc.) resolve correctly.
"""

from __future__ import annotations

import logging
import sys
from pathlib import Path

# ---------------------------------------------------------------------------
# .env loader — must happen BEFORE any app.config import
# ---------------------------------------------------------------------------

try:
    from dotenv import load_dotenv
    _env_path = Path(__file__).parent.parent / ".env"
    load_dotenv(dotenv_path=_env_path, override=False)
except ImportError:
    pass   # python-dotenv not installed; env vars must be set externally

# ---------------------------------------------------------------------------
# Ensure project root is on sys.path when running via uvicorn
# ---------------------------------------------------------------------------

_PROJECT_ROOT = str(Path(__file__).parent.parent)
if _PROJECT_ROOT not in sys.path:
    sys.path.insert(0, _PROJECT_ROOT)

# ---------------------------------------------------------------------------
# Logging
# ---------------------------------------------------------------------------

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s  %(levelname)-8s  %(name)s — %(message)s",
    datefmt="%H:%M:%S",
)
logger = logging.getLogger(__name__)

# ---------------------------------------------------------------------------
# FastAPI app
# ---------------------------------------------------------------------------

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware

from api.notification_routes import router as notification_router

app = FastAPI(
    title       = "Notiflow API",
    description = (
        "AI operations assistant for small businesses.\n\n"
        "Converts informal Hinglish business notifications into "
        "structured operations — powered by Amazon Nova 2 Lite."
    ),
    version = "1.0.0",
    docs_url    = "/docs",
    redoc_url   = "/redoc",
)

# ---------------------------------------------------------------------------
# CORS — allow all origins for hackathon demo
# ---------------------------------------------------------------------------

app.add_middleware(
    CORSMiddleware,
    allow_origins     = ["*"],
    allow_credentials = True,
    allow_methods     = ["*"],
    allow_headers     = ["*"],
)

# ---------------------------------------------------------------------------
# Routers
# ---------------------------------------------------------------------------

app.include_router(notification_router)

# ---------------------------------------------------------------------------
# Health check
# ---------------------------------------------------------------------------

@app.get("/health", tags=["Meta"])
async def health():
    """
    Basic health check.

    Returns service status and configuration summary.
    """
    from app.config import DEMO_MODE, BEDROCK_MODEL_ID, GEMINI_API_KEY, EXCEL_SYNC_FILE
    return {
        "status":          "ok",
        "demo_mode":       DEMO_MODE,
        "bedrock_model":   BEDROCK_MODEL_ID,
        "gemini_enabled":  bool(GEMINI_API_KEY),
        "excel_file":      str(EXCEL_SYNC_FILE),
    }


# ---------------------------------------------------------------------------
# Frontend static files or root redirect
# ---------------------------------------------------------------------------

# ---------------------------------------------------------------------------
# Frontend static files or root redirect
# ---------------------------------------------------------------------------

from fastapi.staticfiles import StaticFiles
from fastapi.responses import FileResponse

_frontend_dist = Path(_PROJECT_ROOT) / "dashboard" / "dist"

if _frontend_dist.is_dir():

    # Serve Vite assets
    app.mount(
        "/assets",
        StaticFiles(directory=str(_frontend_dist / "assets")),
        name="assets"
    )

    # Serve frontend index
    @app.get("/", include_in_schema=False)
    async def root():
        return FileResponse(_frontend_dist / "index.html")

else:
    @app.get("/", include_in_schema=False)
    async def root():
        from fastapi.responses import RedirectResponse
        return RedirectResponse(url="/docs")


# ---------------------------------------------------------------------------
# Startup / shutdown events
# ---------------------------------------------------------------------------

@app.on_event("startup")
async def on_startup():
    from app.config import DEMO_MODE, GEMINI_API_KEY, EXCEL_SYNC_FILE
    logger.info("=" * 55)
    logger.info("  Notiflow API starting up")
    logger.info("  Demo mode   : %s", DEMO_MODE)
    logger.info("  Gemini      : %s", "enabled" if GEMINI_API_KEY else "disabled (no API key)")
    logger.info("  Excel file  : %s", EXCEL_SYNC_FILE)
    logger.info("=" * 55)


@app.on_event("shutdown")
async def on_shutdown():
    logger.info("Notiflow API shutting down.")