"""FastAPI：把 ck_post / ck_knowledge_item 暴露给 web 可视化，并托管单页前端。

启动：
    CK_ENV_FILE=/path/.env uvicorn creation_knowledge.api:app --host 0.0.0.0 --port 8900
API 在 /api/*，前端单页在 /。
"""
from __future__ import annotations

import os
from functools import lru_cache
from pathlib import Path

from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from fastapi.staticfiles import StaticFiles

from creation_knowledge.config import PgConfig
from creation_knowledge.integrations.db import CkStore

WEB_DIR = Path(__file__).resolve().parent.parent / "web"


@lru_cache(maxsize=1)
def _store() -> CkStore:
    env_file = os.getenv("CK_ENV_FILE", ".env")
    return CkStore(PgConfig.from_env(env_file))


app = FastAPI(title="创作知识")
app.add_middleware(
    CORSMiddleware, allow_origins=["*"], allow_methods=["*"], allow_headers=["*"]
)


@app.get("/api/posts")
def list_posts() -> list[dict]:
    return _store().posts_overview()


@app.get("/api/posts/{post_id}")
def get_post(post_id: str) -> dict:
    post = _store().read_post(post_id)
    if not post:
        raise HTTPException(status_code=404, detail="post not found")
    return post


@app.get("/api/posts/{post_id}/items")
def get_items(post_id: str) -> list[dict]:
    return _store().read_items(post_id)


# 单页前端挂在最后（catch-all），不影响上面的 /api 路由
if WEB_DIR.exists():
    app.mount("/", StaticFiles(directory=str(WEB_DIR), html=True), name="web")