import asyncio
import logging
import os
import sys
from contextlib import asynccontextmanager

from alembic import command
from alembic.config import Config as AlembicConfig
from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import FileResponse
from fastapi.staticfiles import StaticFiles

from config import settings

# Настройка логов до импорта приложения: uvicorn ставит свои handlers
# на root-logger, поэтому basicConfig в lifespan уже не срабатывает
# (handlers есть — basicConfig no-op). force=True перебивает.
logging.basicConfig(
    level=getattr(logging, settings.log_level.upper(), logging.INFO),
    format="%(asctime)s %(levelname)-7s %(name)s: %(message)s",
    datefmt="%H:%M:%S",
    handlers=[logging.StreamHandler(sys.stderr)],
    force=True,
)

from db.session import SessionLocal  # noqa: E402
from services import config_service, intent_service, intent_step_graph_service, intent_step_service  # noqa: E402
from services.embeddings import EmbeddingService  # noqa: E402
from services.llm_client import LLMClient  # noqa: E402
from services.router_client import RouterClient  # noqa: E402
from services.vectorstore import VectorStoreService  # noqa: E402

logger = logging.getLogger(__name__)

embedding_service: EmbeddingService | None = None
vectorstore_service: VectorStoreService | None = None
llm_client: LLMClient | None = None
router_client: RouterClient | None = None


def _run_migrations() -> None:
    """Автоматически подтягиваем схему до последней ревизии при старте."""
    os.makedirs(os.path.dirname(settings.sqlite_path), exist_ok=True)
    cfg = AlembicConfig("alembic.ini")
    command.upgrade(cfg, "head")


@asynccontextmanager
async def lifespan(app: FastAPI):
    global embedding_service, vectorstore_service, llm_client, router_client
    logger.info("Running DB migrations…")
    await asyncio.to_thread(_run_migrations)
    logger.info("Loading embedding model: %s", settings.embedding_model)
    embedding_service = EmbeddingService(settings.embedding_model)
    logger.info("Embedding model loaded")
    vectorstore_service = VectorStoreService(
        persist_dir=settings.chroma_persist_dir,
        embedding_service=embedding_service,
    )
    logger.info("ChromaDB initialized at %s", settings.chroma_persist_dir)
    llm_client = LLMClient()
    router_client = RouterClient()
    logger.info("LLM + Router clients ready (model=%s)", llm_client.model)

    async with SessionLocal() as session:
        await intent_service.ensure_seed_intents(session)
        await intent_service.migrate_intent_copy(session)
        await config_service.migrate_legacy_config_to_general_info(session)
        await config_service.ensure_seed_configs(session)
        await config_service.migrate_exit_conditions_to_field(session)
        await intent_step_service.ensure_seed_steps(session)
        await intent_step_service.ensure_seed_guards(session)
        await intent_step_service.migrate_new_booking_allowed_next_v2(session)
        await intent_step_graph_service.ensure_seed_graphs(session)

    yield
    logger.info("Shutting down")


app = FastAPI(
    title="Chat Agent for Patients — Tuning Tool",
    description="RAG-ядро и инструмент настройки пациентского чат-агента",
    version="0.1.0",
    lifespan=lifespan,
)

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

from routers import chat, configs, documents, eval as eval_router, health, intents, query, threads  # noqa: E402

app.include_router(health.router)
app.include_router(documents.router)
app.include_router(query.router)
app.include_router(chat.router)
app.include_router(threads.router)
app.include_router(configs.router)
app.include_router(intents.router)
app.include_router(eval_router.router)


@app.get("/api/docs/examples/{name}")
def get_example_markdown(name: str):
    safe = "".join(c for c in name if c.isalnum() or c in "_-")
    if safe != name:
        raise HTTPException(status_code=400, detail="invalid example name")
    path = os.path.join("docs", "examples", f"{safe}.md")
    if not os.path.isfile(path):
        raise HTTPException(status_code=404, detail="example not found")
    return FileResponse(path, media_type="text/markdown; charset=utf-8")


app.mount("/", StaticFiles(directory="static", html=True), name="static")