"""
演示 HTTP 服务
- GET  /get           普通 GET 请求演示
- POST /post          普通 POST 请求演示
- GET  /stream/<n>    流式响应演示（逐行返回 n 条 JSON）

运行方式：
  pip install flask
  python app.py

默认监听 0.0.0.0:8080，局域网内 Android 设备通过 http://<本机IP>:8080 访问
"""

import json
import time
from flask import Flask, request, Response, jsonify

app = Flask(__name__)

PORT = 8080


def cors(response):
    response.headers["Access-Control-Allow-Origin"] = "*"
    response.headers["Access-Control-Allow-Headers"] = "Content-Type, Authorization"
    response.headers["Access-Control-Allow-Methods"] = "GET, POST, OPTIONS"
    return response


@app.after_request
def after_request(response):
    return cors(response)


# ── GET /get ──────────────────────────────────────────────────────────────────

@app.route("/get", methods=["GET", "OPTIONS"])
def demo_get():
    data = {
        "code": 0,
        "message": "GET 请求成功",
        "data": {
            "method": "GET",
            "url": request.url,
            "args": dict(request.args),
            "headers": dict(request.headers),
            "timestamp": int(time.time()),
        },
    }
    return jsonify(data)


# ── POST /post ────────────────────────────────────────────────────────────────

@app.route("/post", methods=["POST", "OPTIONS"])
def demo_post():
    body = {}
    raw = ""
    try:
        body = request.get_json(force=True) or {}
        raw = json.dumps(body, ensure_ascii=False)
    except Exception:
        raw = request.data.decode("utf-8", errors="replace")

    data = {
        "code": 0,
        "message": "POST 请求成功",
        "data": {
            "method": "POST",
            "url": request.url,
            "body": body,
            "raw": raw,
            "headers": dict(request.headers),
            "timestamp": int(time.time()),
        },
    }
    return jsonify(data)


# ── GET /stream/<n> ───────────────────────────────────────────────────────────

@app.route("/stream/<int:n>", methods=["GET"])
def demo_stream(n):
    """
    逐行输出 n 条 JSON，每条之间延迟 500ms，模拟流式响应。
    客户端用 @Streaming + ResponseBody 逐行读取即可。
    """
    n = min(max(n, 1), 20)  # 限制 1~20 条

    def generate():
        for i in range(n):
            line = json.dumps(
                {
                    "index": i + 1,
                    "total": n,
                    "message": f"流式数据第 {i + 1} 条",
                    "timestamp": int(time.time()),
                },
                ensure_ascii=False,
            )
            yield line + "\n"
            time.sleep(0.5)

    return Response(
        generate(),
        status=200,
        mimetype="application/octet-stream",
        headers={"X-Accel-Buffering": "no"},
    )


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

if __name__ == "__main__":
    print(f"Demo server running on http://0.0.0.0:{PORT}")
    print("  GET  http://<本机IP>:8080/get")
    print("  POST http://<本机IP>:8080/post")
    print("  GET  http://<本机IP>:8080/stream/5")
    app.run(host="0.0.0.0", port=PORT, debug=False, threaded=True)