# -*- coding: utf-8 -*-
"""
AI Free Chat - Flask 主应用
提供聊天页面和 SSE 流式接口
"""
import os
import json
from flask import Flask, render_template, request, Response, stream_with_context
from dotenv import load_dotenv

from services.doubao import DoubaoService
from services.deepseek import DeepSeekService

# 加载环境变量
load_dotenv()

app = Flask(__name__)

# 初始化服务
services = {
    "doubao": DoubaoService(),
    "deepseek": DeepSeekService(),
}


@app.route("/")
def index():
    """渲染聊天页面"""
    return render_template("index.html")


@app.route("/api/chat", methods=["POST"])
def chat():
    """
    SSE 流式聊天接口
    请求体: { provider: 'doubao'|'deepseek', messages: [{role, content}] }
    响应: text/event-stream
    """
    data = request.get_json(silent=True) or {}
    provider = data.get("provider", "deepseek")
    messages = data.get("messages", [])

    if provider not in services:
        return Response(
            f"data: {json.dumps({'error': '未知的 provider'})}\n\n",
            mimetype="text/event-stream",
        )

    if not messages:
        return Response(
            f"data: {json.dumps({'error': 'messages 不能为空'})}\n\n",
            mimetype="text/event-stream",
        )

    service = services[provider]

    def generate():
        """生成 SSE 事件流"""
        try:
            for chunk in service.stream_chat(messages):
                payload = json.dumps({"content": chunk}, ensure_ascii=False)
                yield f"data: {payload}\n\n"
            yield "data: [DONE]\n\n"
        except Exception as e:  # noqa: BLE001
            err = json.dumps({"error": str(e)}, ensure_ascii=False)
            yield f"data: {err}\n\n"

    headers = {
        "Cache-Control": "no-cache",
        "X-Accel-Buffering": "no",
        "Connection": "keep-alive",
    }
    return Response(
        stream_with_context(generate()),
        mimetype="text/event-stream",
        headers=headers,
    )


if __name__ == "__main__":
    port = int(os.getenv("PORT", "5000"))
    app.run(host="0.0.0.0", port=port, debug=True, threaded=True)