src/api.py

from __future__ import annotations

import logging
from contextlib import asynccontextmanager
from typing import Any, List

from fastapi import FastAPI, Query
from pydantic import BaseModel, ConfigDict, Field

from .config import settings
from .duplicate_scheduler import DuplicateScheduler
from .repositories import (
    MergeSuggestionRepository,
    build_client,
)

logger = logging.getLogger("DuplicateAPI")

mongo_client = build_client()
suggestion_repository = MergeSuggestionRepository.from_client(mongo_client)
duplicate_scheduler = DuplicateScheduler()


@asynccontextmanager
async def lifespan(app: FastAPI):
    # Startup
    duplicate_scheduler.start(mongo_client)
    logger.info("Duplicate scheduler started")
    yield
    # Shutdown
    duplicate_scheduler.shutdown()
    logger.info("Duplicate scheduler stopped")


app = FastAPI(
    title="Expense Duplicate Service",
    version="1.0.0",
    description="Detects near-duplicate expense entries and proposes merge suggestions.",
    lifespan=lifespan,
)


class Suggestion(BaseModel):
    model_config = ConfigDict(populate_by_name=True)

    id: str = Field(alias="_id")
    candidate_ids: List[str]
    message: str
    details: dict[str, Any]
    audit: dict[str, Any]
    status: str


@app.get("/health")
async def health() -> dict[str, str]:
    return {"status": "ok"}


@app.get("/suggestions", response_model=List[Suggestion])
async def list_suggestions(limit: int = Query(50, ge=1, le=500)) -> List[Suggestion]:
    docs = suggestion_repository.fetch_recent(limit)
    return [Suggestion.model_validate(doc) for doc in docs]