from fastapi import FastAPI, HTTPException, Depends, Header
from fastapi.middleware.cors import CORSMiddleware
import uvicorn
import os
import logging
import httpx

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

app = FastAPI(title="FreeLLMAPI")

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_methods=["*"],
    allow_headers=["*"],
)

# ──────────────────────────────────────────
# 从环境变量读取所有配置（重启永不丢失）
# ──────────────────────────────────────────

def load_config():
    """
    Secrets 格式约定：

    API Keys（允许访问的用户）:
      API_KEYS = "key1,key2,key3"

    Providers（上游 LLM 服务）:
      PROVIDER_1_NAME    = "openai"
      PROVIDER_1_APIKEY  = "sk-xxxx"
      PROVIDER_1_BASEURL = "https://api.openai.com/v1"
      PROVIDER_1_MODELS  = "gpt-4o,gpt-4o-mini"

      PROVIDER_2_NAME    = "deepseek"
      PROVIDER_2_APIKEY  = "sk-yyyy"
      PROVIDER_2_BASEURL = "https://api.deepseek.com/v1"
      PROVIDER_2_MODELS  = "deepseek-chat,deepseek-coder"

      # 最多支持 20 个 Provider
    """

    # ── 读取 API Keys ──
    raw_keys = os.getenv("API_KEYS", "")
    api_keys = set(
        k.strip() for k in raw_keys.split(",") if k.strip()
    )

    # ── 读取 Providers ──
    providers = {}
    for i in range(1, 21):
        name    = os.getenv(f"PROVIDER_{i}_NAME")
        api_key = os.getenv(f"PROVIDER_{i}_APIKEY")
        baseurl = os.getenv(f"PROVIDER_{i}_BASEURL")
        models  = os.getenv(f"PROVIDER_{i}_MODELS", "")

        if not name or not api_key or not baseurl:
            continue  # 该编号未配置，跳过

        providers[name] = {
            "api_key":  api_key,
            "base_url": baseurl.rstrip("/"),
            "models":   [m.strip() for m in models.split(",") if m.strip()],
        }

    logger.info(f"✅ 加载了 {len(api_keys)} 个 API Key")
    logger.info(f"✅ 加载了 {len(providers)} 个 Provider: {list(providers.keys())}")

    return api_keys, providers


# 启动时加载一次
API_KEYS, PROVIDERS = load_config()

# ──────────────────────────────────────────
# 鉴权
# ──────────────────────────────────────────

def verify_api_key(authorization: str = Header(...)):
    token = authorization.removeprefix("Bearer ").strip()
    if token not in API_KEYS:
        raise HTTPException(status_code=401, detail="Invalid API key")
    return token

# ──────────────────────────────────────────
# 路由
# ──────────────────────────────────────────

@app.get("/health")
async def health():
    return {
        "status":    "ok",
        "keys":      len(API_KEYS),
        "providers": list(PROVIDERS.keys()),
    }


@app.get("/v1/models")
async def list_models(_: str = Depends(verify_api_key)):
    data = []
    for p_cfg in PROVIDERS.values():
        for m in p_cfg["models"]:
            data.append({"id": m, "object": "model"})
    return {"object": "list", "data": data}


@app.post("/v1/chat/completions")
async def chat_completions(
    body: dict,
    _: str = Depends(verify_api_key)
):
    model    = body.get("model", "")
    provider = None

    # 找到支持该 model 的 provider
    for p_cfg in PROVIDERS.values():
        if model in p_cfg["models"]:
            provider = p_cfg
            break

    if not provider:
        raise HTTPException(
            status_code=404,
            detail=f"没有 Provider 支持模型: {model}"
        )

    # 转发到上游
    async with httpx.AsyncClient(timeout=60) as client:
        resp = await client.post(
            f"{provider['base_url']}/chat/completions",
            headers={"Authorization": f"Bearer {provider['api_key']}"},
            json=body,
        )
        return resp.json()


# ──────────────────────────────────────────
# 入口
# ──────────────────────────────────────────

if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=7860)