# server.py from typing import List, Dict, Optional, Tuple from fastapi import FastAPI, HTTPException from flask import Flask, request, render_template_string, jsonify from pydantic import BaseModel, Field from sklearn.neighbors import KDTree import numpy as np import os import uvicorn # Configurable number of scales NUM_SCALES = 8 # Pydantic models class Profile(BaseModel): id: str scales: List[float] = Field(..., min_items=NUM_SCALES, max_items=NUM_SCALES) class Content(BaseModel): id: str scales: List[float] = Field(..., min_items=NUM_SCALES, max_items=NUM_SCALES) metadata: Optional[Dict] = None class Recommendation(BaseModel): content_id: str distance: float # Abstract repository interface class DataRepository: def add_user(self, user: Profile): ... def add_content(self, content: Content): ... def get_user(self, user_id: str) -> Profile: ... def query_region(self, mins: List[float], maxs: List[float]) -> List[Content]: ... # In-memory implementation class InMemoryRepo(DataRepository): def __init__(self): self.users: Dict[str, Profile] = {} self.contents: Dict[str, Content] = {} def add_user(self, user: Profile): self.users[user.id] = user def add_content(self, content: Content): self.contents[content.id] = content def get_user(self, user_id: str) -> Profile: user = self.users.get(user_id) if not user: raise ValueError("User not found") return user def query_region(self, mins: List[float], maxs: List[float]) -> List[Content]: # Filter contents by N-dimensional bounding box return [ c for c in self.contents.values() if all(mn <= v <= mx for v, mn, mx in zip(c.scales, mins, maxs)) ] # FastAPI setup # app = FastAPI() app = Flask(__name__) repo = InMemoryRepo() @app.post("/users", response_model=Profile) def create_user(user: Profile): repo.add_user(user) return user @app.post("/contents", response_model=Content) def create_content(content: Content): repo.add_content(content) return content @app.get("/recommendations/{user_id}", response_model=List[Recommendation]) def recommend(user_id: str, region_radius: float = 0.2, top_k: int = 5): try: user = repo.get_user(user_id) except ValueError: raise HTTPException(status_code=404, detail="User not found") # Build bounding region mins = [max(0.0, v - region_radius) for v in user.scales] maxs = [min(1.0, v + region_radius) for v in user.scales] # Query region candidates = repo.query_region(mins, maxs) if not candidates: return [] # Build KDTree over candidates to find nearest neighbors mat = np.array([c.scales for c in candidates]) tree = KDTree(mat) dist, idx = tree.query(np.array(user.scales).reshape(1, -1), k=min(top_k, len(candidates))) return [ Recommendation(content_id=candidates[i].id, distance=float(d)) for d, i in zip(dist[0], idx[0]) ] # Sample test data when run directly # Create random test users and content repo.add_user(Profile(id="user1", scales=list(np.random.rand(NUM_SCALES)))) for i in range(1, 21): repo.add_content(Content( id=f"content{i}", scales=list(np.random.rand(NUM_SCALES)), metadata={"title": f"Item {i}"} )) print(recommend("user1")) print("ran") if __name__ == "__main__": port = int(os.environ.get("PORT", 7860)) app.run(host="0.0.0.0", port=port)