from __future__ import annotations

import os
from pathlib import Path

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

from .llm import LLMError, LLMNotConfigured, LLMService, LLMTimeout
from .planner import RecommendationService
from .schemas import (
    HealthResponse,
    PlanRecommendationRequest,
    RecommendationResponse,
)


try:
    from dotenv import load_dotenv

    load_dotenv(Path(__file__).resolve().parent.parent / ".env")
except ImportError:
    # Mock mode can run without python-dotenv during minimal diagnostics.
    pass


llm = LLMService()
recommendation_service = RecommendationService(llm)

app = FastAPI(
    title="光明区文旅 POI 推荐 API",
    version="0.2.0",
    description="POC：模型仅推荐客户端白名单 POI；路线和时间由客户端确定性计算。",
)
origins = [
    origin.strip()
    for origin in os.getenv(
        "CORS_ORIGINS", "http://localhost:5173,http://127.0.0.1:5173"
    ).split(",")
    if origin.strip()
]
app.add_middleware(
    CORSMiddleware,
    allow_origins=origins,
    allow_credentials=False,
    allow_methods=["GET", "POST"],
    allow_headers=["content-type"],
)


@app.get("/api/v1/health", response_model=HealthResponse)
async def health() -> HealthResponse:
    return HealthResponse(
        status="ok" if llm.ready else "degraded",
        mode=llm.mode,
        configured=llm.configured,
        ready=llm.ready,
    )


@app.post("/api/v1/plans", response_model=RecommendationResponse)
async def create_plan(
    request: PlanRecommendationRequest,
) -> RecommendationResponse:
    try:
        return await recommendation_service.create(request)
    except LLMNotConfigured as exc:
        raise HTTPException(status_code=503, detail=str(exc)) from exc
    except LLMTimeout as exc:
        raise HTTPException(status_code=504, detail=str(exc)) from exc
    except LLMError as exc:
        raise HTTPException(status_code=502, detail=str(exc)) from exc