from fastapi import FastAPI
from routes import base, data, nlp
from motor.motor_asyncio import AsyncIOMotorClient
#to call database name/url
from helpers.config import get_settings
from stores.LLM.LLMProviderFActory import LLMProviderfactory
#import provider factory
from stores.vectordb.VectorDBProviderFactory import VectorDBProviderFactory
from stores.LLM.templates.template_parser import TemplateParser 
from sqlalchemy.ext.asyncio import create_async_engine
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.asyncio import AsyncSession

# import metrics 
from utils import setup_metrics

app = FastAPI()

# setup metrics
setup_metrics(app)

@app.on_event("startup")
async def startup_span():
    settings = get_settings()
    # create conniction 
    postgres_conn = f"postgresql+asyncpg://{settings.POSTGRES_USERNAME}:{settings.POSTGRES_PASSWORD}@{settings.POSTGRES_HOST}:{settings.POSTGRES_PORT}/{settings.POSTGRES_MAIN_DATABASE}"

    app.db_engine = create_async_engine(postgres_conn)

    app.db_client = sessionmaker(
        bind=app.db_engine, class_ = AsyncSession,expire_on_commit=False
    )
    
    llm_provider_factory = LLMProviderfactory(settings)
    vectordb_provider_factory = VectorDBProviderFactory(config=settings,db_client=app.db_client)

    #generate client
    app.generation_client = llm_provider_factory.create(provider=settings.GENERATION_BACKEND)
    app.generation_client.set_generation_model(model_id=settings.GENERATION_MODEL_ID)

    # embedding client 
    app.embedding_client = llm_provider_factory.create(provider=settings.EMBEDDING_BACKEND)
    app.embedding_client.set_embedding_model(model_id=settings.EMBEDDING_MODEL_ID,
                                             embedding_size=settings.EMBEDDING_MODEL_SIZE)
    

    # vectordb client 
    app.vectordb_client = vectordb_provider_factory.create(
        provider=settings.VECTOR_DB_BACKEND
    )
    await app.vectordb_client.connect()

    app.template_parser = TemplateParser(
        lnaguage = settings.PRIMARY_LANG,default_language=settings.DEFAULT_LANG
    )



@app.on_event("shutdown")
async def shutdown_span():
    app.db_engine.dispose()
    await app.vectordb_client.disconnect()



app.include_router(base.base_router)
app.include_router(data.data_router)
app.include_router(nlp.nlp_router)