import json
import sys
import os
import argparse
import signal
from http.server import BaseHTTPRequestHandler, HTTPServer
from urllib.parse import urlparse
from typing import Any, Dict, List, Optional, Tuple

# 保证可以导入本项目模块
sys.path.append(os.path.dirname(os.path.abspath(__file__)))

from utils.logging_config import get_logger
from agent_tools import QueryDataTool, IdentifyTool, StructureTool
from agent_process import start_daemon, stop_daemon, status_daemon

# 可选引入 LangGraph（如未安装，将在运行时优雅回退到顺序执行）
HAS_LANGGRAPH = False
try:
    from langgraph.graph import StateGraph, END
    HAS_LANGGRAPH = True
except Exception:
    HAS_LANGGRAPH = False


logger = get_logger('Agent')

PID_FILE = os.path.join(os.path.dirname(__file__), 'agent_scheduler.pid')


class ReactAgent:
    def __init__(self) -> None:
        self.identify_tool = IdentifyTool()

    def handle_request(self, request_id: str) -> Dict[str, Any]:
        items = QueryDataTool.fetch_crawl_data_list(request_id)
        if not items:
            return {"requestId": request_id, "processed": 0, "success": 0, "details": []}

        success_count = 0
        details: List[Dict[str, Any]] = []
        for idx, item in enumerate(items, start=1):
            crawl_data = item.get('crawl_data') or {}

            # Step 1: 识别
            identify_result = self.identify_tool.run(crawl_data if isinstance(crawl_data, dict) else {})

            # Step 2: 结构化并入库
            affected = StructureTool.store_parsing_result(request_id, item.get('raw') or {}, identify_result)
            ok = affected is not None and affected > 0
            if ok:
                success_count += 1

            details.append({
                "index": idx,
                "dbInserted": ok,
                "identifyError": identify_result.get('error'),
            })

        return {
            "requestId": request_id,
            "processed": len(items),
            "success": success_count,
            "details": details,
        }


AGENT = ReactAgent()


# =========================
# LangGraph 风格实现（可选）
# =========================
def build_langgraph_app():
    if not HAS_LANGGRAPH:
        return None

    # 状态：以 dict 形式承载
    # 输入: {"request_id": str}
    # 输出附加: items, details, processed, success

    def node_fetch(state: Dict[str, Any]) -> Dict[str, Any]:
        request_id = str(state.get("request_id", ""))
        items = QueryDataTool.fetch_crawl_data_list(request_id)
        return {
            **state,
            "items": items,
            "details": [],
            "processed": 0,
            "success": 0,
        }

    identify_tool = IdentifyTool()

    def node_process(state: Dict[str, Any]) -> Dict[str, Any]:
        request_id = str(state.get("request_id", ""))
        items: List[Dict[str, Any]] = state.get("items", []) or []
        details: List[Dict[str, Any]] = []
        success_count = 0

        for idx, item in enumerate(items, start=1):
            crawl_data = item.get('crawl_data') or {}
            identify_result = identify_tool.run(crawl_data if isinstance(crawl_data, dict) else {})
            affected = StructureTool.store_parsing_result(request_id, item.get('raw') or {}, identify_result)
            ok = affected is not None and affected > 0
            if ok:
                success_count += 1
            details.append({
                "index": idx,
                "dbInserted": ok,
                "identifyError": identify_result.get('error'),
            })

        return {
            **state,
            "details": details,
            "processed": len(items),
            "success": success_count,
        }

    graph = StateGraph(dict)
    graph.add_node("fetch", node_fetch)
    graph.add_node("process", node_process)

    graph.set_entry_point("fetch")
    graph.add_edge("fetch", "process")
    graph.add_edge("process", END)

    return graph.compile()


APP = build_langgraph_app()


class AgentHttpHandler(BaseHTTPRequestHandler):
    def _set_headers(self, status_code: int = 200):
        self.send_response(status_code)
        self.send_header('Content-Type', 'application/json; charset=utf-8')
        self.end_headers()

    def do_POST(self):
        parsed = urlparse(self.path)
        if parsed.path != '/trigger':
            self._set_headers(404)
            self.wfile.write(json.dumps({"error": "not found"}).encode('utf-8'))
            return

        length = int(self.headers.get('Content-Length', '0') or '0')
        body = self.rfile.read(length) if length > 0 else b''
        try:
            payload = json.loads(body.decode('utf-8')) if body else {}
        except Exception:
            self._set_headers(400)
            self.wfile.write(json.dumps({"error": "invalid json"}).encode('utf-8'))
            return

        request_id = (payload or {}).get('requestId')
        if not request_id:
            self._set_headers(400)
            self.wfile.write(json.dumps({"error": "requestId is required"}).encode('utf-8'))
            return

        try:
            logger.info(f"收到触发请求: requestId={request_id}")
            if APP is not None:
                result = APP.invoke({"request_id": str(request_id)})
                # 标准化返回
                result = {
                    "requestId": str(request_id),
                    "processed": result.get("processed", 0),
                    "success": result.get("success", 0),
                    "details": result.get("details", []),
                }
            else:
                # 回退到顺序执行
                result = AGENT.handle_request(str(request_id))
            self._set_headers(200)
            self.wfile.write(json.dumps(result, ensure_ascii=False).encode('utf-8'))
        except Exception as e:
            logger.error(f"处理失败: {e}")
            self._set_headers(500)
            self.wfile.write(json.dumps({"error": str(e)}).encode('utf-8'))

    def log_message(self, format: str, *args) -> None:
        # 重定向默认日志到我们统一的 logger
        logger.info("HTTP " + (format % args))


def run(host: str = '0.0.0.0', port: int = 8080):
    server_address = (host, port)
    httpd = HTTPServer(server_address, AgentHttpHandler)

    def _graceful_shutdown(signum, frame):
        try:
            logger.info(f"收到信号 {signum}，正在停止HTTP服务...")
            # shutdown 会在其他线程优雅停止; 这里我们直接关闭，避免阻塞
            httpd.shutdown()
        except Exception:
            pass
    for sig in (signal.SIGINT, signal.SIGTERM):
        signal.signal(sig, _graceful_shutdown)

    logger.info(f"Agent HTTP 服务已启动: http://{host}:{port}/trigger")
    try:
        httpd.serve_forever()
    finally:
        try:
            httpd.server_close()
        except Exception:
            pass
        logger.info("Agent HTTP 服务已停止")


def _write_pid_file(pid: int) -> None:
    with open(PID_FILE, 'w') as f:
        f.write(str(pid))


def _read_pid_file() -> Optional[int]:
    if not os.path.exists(PID_FILE):
        return None
    try:
        with open(PID_FILE, 'r') as f:
            content = f.read().strip()
            return int(content) if content else None
    except Exception:
        return None


def _is_process_running(pid: int) -> bool:
    try:
        os.kill(pid, 0)
        return True
    except Exception:
        return False


def start_daemon(host: str, port: int) -> Dict[str, Any]:
    old_pid = _read_pid_file()
    if old_pid and _is_process_running(old_pid):
        return {"status": "already_running", "pid": old_pid}

    python_exec = sys.executable
    script_path = os.path.abspath(__file__)
    args = [python_exec, script_path, "--serve", "--host", host, "--port", str(port)]

    with open(os.devnull, 'wb') as devnull:
        proc = subprocess.Popen(
            args,
            stdout=devnull,
            stderr=devnull,
            stdin=devnull,
            close_fds=True,
            preexec_fn=os.setsid if hasattr(os, 'setsid') else None,
        )

    _write_pid_file(proc.pid)
    # 简单等待，确认进程未立即退出
    time.sleep(0.5)
    running = _is_process_running(proc.pid)
    return {"status": "started" if running else "failed", "pid": proc.pid}


def stop_daemon(timeout: float = 5.0) -> Dict[str, Any]:
    pid = _read_pid_file()
    if not pid:
        return {"status": "not_running"}

    if not _is_process_running(pid):
        try:
            os.remove(PID_FILE)
        except Exception:
            pass
        return {"status": "not_running"}

    try:
        os.kill(pid, signal.SIGTERM)
    except Exception as e:
        return {"status": "error", "error": str(e)}

    start_time = time.time()
    while time.time() - start_time < timeout:
        if not _is_process_running(pid):
            break
        time.sleep(0.2)

    if _is_process_running(pid):
        try:
            os.kill(pid, signal.SIGKILL)
        except Exception as e:
            return {"status": "error", "error": str(e)}

    try:
        os.remove(PID_FILE)
    except Exception:
        pass

    return {"status": "stopped"}


def status_daemon() -> Dict[str, Any]:
    pid = _read_pid_file()
    if pid and _is_process_running(pid):
        return {"status": "running", "pid": pid}
    return {"status": "not_running"}


if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='Agent 服务管理')
    parser.add_argument('--serve', action='store_true', help='以前台模式启动HTTP服务')
    parser.add_argument('--host', default='0.0.0.0', help='监听地址')
    parser.add_argument('--port', type=int, default=8080, help='监听端口')
    parser.add_argument('command', nargs='?', choices=['start', 'stop', 'status'], help='守护进程管理命令')
    args = parser.parse_args()

    if args.serve:
        run(args.host, args.port)
        sys.exit(0)

    if args.command == 'start':
        res = start_daemon(args.host, args.port)
        print(json.dumps(res, ensure_ascii=False))
        sys.exit(0 if res.get('status') == 'started' else 1)
    elif args.command == 'stop':
        res = stop_daemon()
        print(json.dumps(res, ensure_ascii=False))
        sys.exit(0 if res.get('status') in ('stopped', 'not_running') else 1)
    elif args.command == 'status':
        res = status_daemon()
        print(json.dumps(res, ensure_ascii=False))
        sys.exit(0 if res.get('status') in ('running', 'not_running') else 1)
    else:
        # 默认行为：以前台启动（兼容旧用法）
        run(args.host, args.port)