"""
AI Chat API Server — 主入口（纯基础设施层）

职责：
  - 注入运行时依赖（venv site-packages）
  - 支持 OpenAI 兼容 API 网关（/v1/*）和多平台路由
  - 保留向后兼容的 /api/chat-ui/* 路由

平台适配器位置：
  - adapters/glm_adapter.py      → 智谱 GLM
  - adapters/dashscope_adapter.py → 阿里云百炼
  - adapters/openai_adapter.py    → OpenAI / Deepseek

API 端点：
  - POST /v1/chat/completions  → OpenAI 兼容网关（根据 model 自动路由）
  - GET  /v1/models            → 所有可用模型列表
  - POST /api/chat-ui/chat     → 传统聊天接口（保持兼容）
"""

import os
import sys
from datetime import datetime, timezone
from pathlib import Path

# ── 注入 venv site-packages（兼容 start.sh 用系统 python3 启动）────────
# 必须在所有第三方 import 前执行
_venv_lib = Path(__file__).parent / ".venv" / "lib"
if _venv_lib.exists():
    for _sp in sorted(_venv_lib.glob("python*/site-packages"), reverse=True):
        if _sp.exists() and str(_sp) not in sys.path:
            sys.path.insert(0, str(_sp))
            print(f"[启动] venv 注入：{_sp}")
            break

# ── 第三方导入 ────────────────────────────────────────────────────────
from dotenv import load_dotenv
from fastapi import FastAPI, File, Request, UploadFile
from fastapi.responses import JSONResponse

sys.path.append("/home/mt/project/ai-chat-ui/server")

# ── 工具/日志（与平台无关）───────────────────────────────────────────
from utils.helpers import log_response
from utils.logger import get_logger

logger = get_logger()

# ── 初始化数据库 ───────────────────────────────────────────────────────
from database import init_db

init_db()

# ── 加载环境变量 ──────────────────────────────────────────────────────
load_dotenv()

# ── 会话管理路由处理器 ────────────────────────────────────────────────
from api.conversation_routes import (add_message_handler,
                                     delete_conversation_handler,
                                     get_conversation_handler,
                                     get_conversations_handler,
                                     save_conversation_handler,
                                     serve_upload_handler,
                                     stop_generation_handler,
                                     update_conversation_handler,
                                     update_message_handler,
                                     upload_file_handler)

# ── OpenAI 兼容网关初始化 ───────────────────────────────────────────────
from api.openai_gateway import init_adapters, router as openai_router

init_adapters()

# ── FastAPI 应用 ──────────────────────────────────────────────────────
app = FastAPI(
    title="AI Chat API Gateway",
    version="4.0.0",
    description="统一 OpenAI 兼容 API 网关，支持多平台模型",
)

# 注册 OpenAI 兼容路由
app.include_router(openai_router, prefix="/v1")


@app.middleware("http")
async def logging_middleware(request: Request, call_next):
    start_time = datetime.now(timezone.utc)
    client_ip = request.client.host if request.client else "unknown"
    logger.info(f"→ {request.method} {request.url.path} | IP: {client_ip}")
    response = await call_next(request)
    ms = (datetime.now(timezone.utc) - start_time).total_seconds() * 1000
    icon = "✅" if response.status_code < 400 else "❌"
    logger.info(
        f"{icon} {request.method} {request.url.path} | 状态: {response.status_code} | 耗时: {ms:.0f}ms"
    )
    log_response(response.status_code, ms)
    response.headers["X-Process-Time"] = f"{ms:.2f}ms"
    return response


# ── 路由注册 ──────────────────────────────────────────────────────────


@app.get("/health")
async def health_check():
    from config import get_available_providers

    return {
        "status": "healthy",
        "version": "4.0.0",
        "available_providers": get_available_providers(),
        "endpoints": {
            "openai_compatible": "/v1/chat/completions",
            "models": "/v1/models",
            "conversations": "/api/chat-ui/conversations",
        },
        "timestamp": datetime.now(timezone.utc).isoformat(),
    }


@app.post("/api/chat-ui/chat")
async def chat_endpoint(request: Request):
    """聊天接口（根据 model 自动路由到对应平台）"""
    from adapters import get_adapter, get_provider_from_model
    from adapters.base import ChatCompletionRequest

    try:
        body = await request.json()
    except Exception:
        return JSONResponse({"error": "Invalid JSON body"}, status_code=400)

    # 创建请求对象
    chat_request = ChatCompletionRequest.from_dict(body)
    model = chat_request.model

    # 根据模型名称确定平台
    provider = get_provider_from_model(model)
    logger.info(f"[Legacy API] model={model} → provider={provider}")

    # 获取对应平台的适配器
    adapter = get_adapter(provider)
    if adapter is None:
        return JSONResponse(
            {"error": f"Unsupported model: {model} (provider: {provider})"},
            status_code=400,
        )

    # 检查适配器是否可用
    if not adapter.is_available():
        return JSONResponse(
            {"error": f"Provider '{provider}' is not available (API key not configured)"},
            status_code=503,
        )

    # 调用适配器处理请求
    return await adapter.chat(chat_request)


@app.get("/api/chat-ui/models")
async def get_models():
    """模型列表（聚合所有可用平台的模型）"""
    from adapters import get_all_adapters

    all_models = []
    for provider, adapter in get_all_adapters().items():
        if adapter.is_available():
            models = adapter.list_models()
            all_models.extend([m.to_dict() for m in models])

    return {"object": "list", "data": all_models}


# ── 通用路由（与平台无关）────────────────────────────────────────────


@app.get("/api/chat-ui/conversations")
async def get_conversations():
    return await get_conversations_handler()


@app.get("/api/chat-ui/conversations/{conversation_id}")
async def get_conversation(conversation_id: str):
    return await get_conversation_handler(conversation_id)


@app.post("/api/chat-ui/conversations")
async def save_conversation(request: Request):
    return await save_conversation_handler(await request.json())


@app.delete("/api/chat-ui/conversations/{conversation_id}")
async def delete_conversation(conversation_id: str):
    return await delete_conversation_handler(conversation_id)


@app.put("/api/chat-ui/conversations/{conversation_id}")
async def update_conversation(conversation_id: str, request: Request):
    return await update_conversation_handler(conversation_id, await request.json())


@app.post("/api/chat-ui/conversations/{conversation_id}/messages")
async def add_message(conversation_id: str, request: Request):
    return await add_message_handler(conversation_id, await request.json())


@app.put("/api/chat-ui/conversations/{conversation_id}/messages/{message_id}")
async def update_message(conversation_id: str, message_id: str, request: Request):
    return await update_message_handler(conversation_id, message_id, await request.json())


@app.post("/api/chat-ui/upload")
async def upload_file(file: UploadFile = File(...)):
    return await upload_file_handler(file=file)


@app.get("/uploads/{filename}")
async def serve_upload(filename: str):
    return serve_upload_handler(filename)


@app.post("/api/chat-ui/stop")
async def stop_generation():
    return await stop_generation_handler()


@app.post("/api/chat-ui/stop/{message_id}")
async def stop_generation_by_id(message_id: str):
    return await stop_generation_handler(message_id)


# ── 程序入口 ──────────────────────────────────────────────────────────
if __name__ == "__main__":
    import uvicorn

    port = int(os.getenv("PORT", 8000))

    # 获取可用平台
    from config import get_available_providers

    available = get_available_providers()

    print("=" * 60)
    print("  AI Chat API Gateway v4.0")
    print("=" * 60)
    print(f"  OpenAI 兼容端点: http://localhost:{port}/v1/chat/completions")
    print(f"  模型列表       : http://localhost:{port}/v1/models")
    print("-" * 60)
    print(f"  可用平台       : {', '.join(available) or '无（请配置 API Key）'}")
    print("-" * 60)
    print("  使用方法:")
    print("  curl -X POST http://localhost:8000/v1/chat/completions \\")
    print('       -H "Content-Type: application/json" \\')
    print('       -d \'{"model":"glm-4-flash","messages":[{"role":"user","content":"hi"}]}\'')
    print("=" * 60)

    uvicorn.run(app, host="0.0.0.0", port=port)