# -*- coding: utf-8 -*-
"""Runtime API routes - Control Plane for managing Gateway processes."""

from __future__ import annotations

import asyncio
import json
import logging
import os
import signal
import shutil
import subprocess
import sys
from datetime import datetime
from pathlib import Path
from typing import Any, Dict, List, Optional

logger = logging.getLogger(__name__)

from fastapi import APIRouter, BackgroundTasks, HTTPException, Request
from pydantic import BaseModel, Field

from backend.runtime.agent_runtime import AgentRuntimeState
from backend.config.bootstrap_config import (
    resolve_runtime_config,
    update_bootstrap_values_for_run,
)

router = APIRouter(prefix="/api/runtime", tags=["runtime"])

PROJECT_ROOT = Path(__file__).resolve().parents[2]


class RuntimeState:
    """Thread-safe singleton for managing runtime state.

    Encapsulates runtime_manager, _gateway_process, and _gateway_port
    with asyncio.Lock protection for concurrent access.
    """

    _instance: Optional["RuntimeState"] = None
    _lock: "threading.Lock" = __import__("threading").Lock()

    def __new__(cls) -> "RuntimeState":
        with cls._lock:
            if cls._instance is None:
                cls._instance = super().__new__(cls)
                cls._instance._initialized = False
        return cls._instance

    def __init__(self) -> None:
        if self._initialized:
            return
        self._runtime_manager: Optional[Any] = None
        self._gateway_process: Optional[subprocess.Popen] = None
        self._gateway_port: int = 8765
        self._state_lock = asyncio.Lock()
        self._initialized = True

    @property
    async def lock(self) -> asyncio.Lock:
        """Get the asyncio lock for state synchronization."""
        return self._state_lock

    @property
    def runtime_manager(self) -> Optional[Any]:
        """Get the runtime manager (no lock - read only)."""
        return self._runtime_manager

    @runtime_manager.setter
    def runtime_manager(self, value: Optional[Any]) -> None:
        """Set the runtime manager."""
        self._runtime_manager = value

    @property
    def gateway_process(self) -> Optional[subprocess.Popen]:
        """Get the gateway process (no lock - read only)."""
        return self._gateway_process

    @gateway_process.setter
    def gateway_process(self, value: Optional[subprocess.Popen]) -> None:
        """Set the gateway process."""
        self._gateway_process = value

    @property
    def gateway_port(self) -> int:
        """Get the gateway port."""
        return self._gateway_port

    @gateway_port.setter
    def gateway_port(self, value: int) -> None:
        """Set the gateway port."""
        self._gateway_port = value

    async def set_runtime_manager(self, manager: Any) -> None:
        """Set runtime manager with lock protection."""
        async with self._state_lock:
            self._runtime_manager = manager

    async def get_runtime_manager(self) -> Optional[Any]:
        """Get runtime manager with lock protection."""
        async with self._state_lock:
            return self._runtime_manager

    async def set_gateway_process(self, process: Optional[subprocess.Popen]) -> None:
        """Set gateway process with lock protection."""
        async with self._state_lock:
            self._gateway_process = process

    async def get_gateway_process(self) -> Optional[subprocess.Popen]:
        """Get gateway process with lock protection."""
        async with self._state_lock:
            return self._gateway_process

    async def set_gateway_port(self, port: int) -> None:
        """Set gateway port with lock protection."""
        async with self._state_lock:
            self._gateway_port = port

    async def get_gateway_port(self) -> int:
        """Get gateway port with lock protection."""
        async with self._state_lock:
            return self._gateway_port


# Singleton instance
_runtime_state = RuntimeState()


def get_runtime_state() -> RuntimeState:
    """Get the RuntimeState singleton instance."""
    return _runtime_state


# Backward compatibility: module-level runtime_manager for external imports
# This is set by register_runtime_manager() for backward compatibility
runtime_manager: Optional[Any] = None


class RunContextResponse(BaseModel):
    config_name: str
    run_dir: str
    bootstrap_values: Dict[str, Any]


class RuntimeAgentState(BaseModel):
    agent_id: str
    status: str
    last_session: Optional[str] = None
    last_updated: str


class RuntimeAgentsResponse(BaseModel):
    agents: List[RuntimeAgentState]


class RuntimeEvent(BaseModel):
    timestamp: str
    event: str
    details: Dict[str, Any]
    session: Optional[str]


class RuntimeEventsResponse(BaseModel):
    events: List[RuntimeEvent]


class LaunchConfig(BaseModel):
    """Configuration for launching a new trading task."""
    launch_mode: str = Field(default="fresh", description="启动形式: fresh, restore")
    restore_run_id: Optional[str] = Field(default=None, description="历史任务 run_id，用于恢复启动")
    tickers: List[str] = Field(default_factory=list, description="股票池")
    schedule_mode: str = Field(default="daily", description="调度模式: daily, interval")
    interval_minutes: int = Field(default=60, ge=1, description="间隔分钟数")
    trigger_time: str = Field(default="09:30", description="触发时间 HH:MM")
    max_comm_cycles: int = Field(default=2, ge=1, description="最大会商轮数")
    initial_cash: float = Field(default=100000.0, gt=0, description="初始资金")
    margin_requirement: float = Field(default=0.0, ge=0, description="保证金要求")
    enable_memory: bool = Field(default=False, description="是否启用长期记忆")
    mode: str = Field(default="live", description="运行模式: live, backtest")
    start_date: Optional[str] = Field(default=None, description="回测开始日期 YYYY-MM-DD")
    end_date: Optional[str] = Field(default=None, description="回测结束日期 YYYY-MM-DD")
    poll_interval: int = Field(default=10, ge=1, le=300, description="市场数据轮询间隔(秒)")
    enable_mock: bool = Field(default=False, description="是否启用模拟模式(使用模拟价格数据)")


class LaunchResponse(BaseModel):
    run_id: str
    status: str
    run_dir: str
    gateway_port: int
    message: str


class RuntimeHistoryItem(BaseModel):
    run_id: str
    run_dir: str
    updated_at: Optional[str] = None
    total_trades: int = 0
    total_asset_value: Optional[float] = None
    bootstrap: Dict[str, Any] = Field(default_factory=dict)


class RuntimeHistoryResponse(BaseModel):
    runs: List[RuntimeHistoryItem]


class StopResponse(BaseModel):
    status: str
    message: str


class CleanupResponse(BaseModel):
    status: str
    kept: int
    pruned_run_ids: List[str]


class GatewayStatusResponse(BaseModel):
    is_running: bool
    port: int
    run_id: Optional[str] = None


class RuntimeConfigResponse(BaseModel):
    run_id: str
    is_running: bool
    gateway_port: int
    bootstrap: Dict[str, Any]
    resolved: Dict[str, Any]


class RuntimeLogResponse(BaseModel):
    run_id: Optional[str] = None
    is_running: bool
    log_path: Optional[str] = None
    content: str = ""


class UpdateRuntimeConfigRequest(BaseModel):
    schedule_mode: Optional[str] = None
    interval_minutes: Optional[int] = Field(default=None, ge=1)
    trigger_time: Optional[str] = None
    max_comm_cycles: Optional[int] = Field(default=None, ge=1)
    initial_cash: Optional[float] = Field(default=None, gt=0)
    margin_requirement: Optional[float] = Field(default=None, ge=0)
    enable_memory: Optional[bool] = None


def _generate_run_id() -> str:
    """Generate timestamp-based run ID: YYYYMMDD_HHMMSS"""
    return datetime.now().strftime("%Y%m%d_%H%M%S")


def _get_run_dir(run_id: str) -> Path:
    """Return the run directory for a given run ID."""
    return PROJECT_ROOT / "runs" / run_id


def _load_run_snapshot(run_id: str) -> Dict[str, Any]:
    """Load a specific run snapshot by run_id."""
    snapshot_path = _get_run_dir(run_id) / "state" / "runtime_state.json"
    if not snapshot_path.exists():
        raise HTTPException(status_code=404, detail=f"Run snapshot not found: {run_id}")
    return json.loads(snapshot_path.read_text(encoding="utf-8"))


def _copy_path_if_exists(src: Path, dst: Path) -> None:
    if not src.exists():
        return
    if src.is_dir():
        shutil.copytree(src, dst, dirs_exist_ok=True)
    else:
        dst.parent.mkdir(parents=True, exist_ok=True)
        shutil.copy2(src, dst)


def _restore_run_assets(source_run_id: str, target_run_dir: Path) -> None:
    """Seed a fresh run directory from a historical run snapshot."""
    source_run_dir = _get_run_dir(source_run_id)
    if not source_run_dir.exists():
        raise HTTPException(status_code=404, detail=f"Source run not found: {source_run_id}")

    for relative in [
        "team_dashboard",
        "agents",
        "skills",
        "memory",
        "state/server_state.json",
        "state/runtime.db",
        "state/research.db",
    ]:
        _copy_path_if_exists(source_run_dir / relative, target_run_dir / relative)


def _list_runs(limit: int = 50) -> list[RuntimeHistoryItem]:
    runs_root = PROJECT_ROOT / "runs"
    if not runs_root.exists():
        return []

    items: list[RuntimeHistoryItem] = []
    run_dirs = sorted(
        [path for path in runs_root.iterdir() if path.is_dir()],
        key=lambda path: path.stat().st_mtime,
        reverse=True,
    )

    for run_dir in run_dirs[: max(1, int(limit))]:
        run_id = run_dir.name
        runtime_state_path = run_dir / "state" / "runtime_state.json"
        summary_path = run_dir / "team_dashboard" / "summary.json"

        bootstrap: Dict[str, Any] = {}
        updated_at: Optional[str] = None
        total_trades = 0
        total_asset_value: Optional[float] = None

        if runtime_state_path.exists():
            try:
                snapshot = json.loads(runtime_state_path.read_text(encoding="utf-8"))
                context = snapshot.get("context") or {}
                bootstrap = dict(context.get("bootstrap_values") or {})
                updated_at = snapshot.get("events", [{}])[-1].get("timestamp") if snapshot.get("events") else None
            except Exception:
                bootstrap = {}

        if summary_path.exists():
            try:
                summary = json.loads(summary_path.read_text(encoding="utf-8"))
                total_trades = int(summary.get("totalTrades") or 0)
                total_asset_value = float(summary.get("totalAssetValue")) if summary.get("totalAssetValue") is not None else None
            except Exception:
                total_trades = 0
                total_asset_value = None

        items.append(
            RuntimeHistoryItem(
                run_id=run_id,
                run_dir=str(run_dir),
                updated_at=updated_at,
                total_trades=total_trades,
                total_asset_value=total_asset_value,
                bootstrap=bootstrap,
            )
        )

    return items


def _is_timestamped_run_dir(path: Path) -> bool:
    try:
        datetime.strptime(path.name, "%Y%m%d_%H%M%S")
        return True
    except ValueError:
        return False


def _prune_old_timestamped_runs(*, keep: int = 20, exclude_run_ids: Optional[set[str]] = None) -> list[str]:
    """Prune old timestamped run directories, preserving the newest N and excluded ids."""
    exclude = exclude_run_ids or set()
    runs_root = PROJECT_ROOT / "runs"
    if not runs_root.exists():
        return []

    candidates = sorted(
        [
            path
            for path in runs_root.iterdir()
            if path.is_dir() and _is_timestamped_run_dir(path) and path.name not in exclude
        ],
        key=lambda path: path.name,
        reverse=True,
    )

    pruned: list[str] = []
    for path in candidates[max(0, keep):]:
        shutil.rmtree(path, ignore_errors=True)
        pruned.append(path.name)
    return pruned


def _find_available_port(start_port: int = 8765, max_port: int = 9000) -> int:
    """Find an available port for Gateway."""
    import socket
    for port in range(start_port, max_port):
        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
            if s.connect_ex(('localhost', port)) != 0:
                return port
    raise RuntimeError("No available port found")


def _is_gateway_running() -> bool:
    """Check if Gateway process is running."""
    process = _runtime_state.gateway_process
    if process is None:
        return False
    return process.poll() is None


def _stop_gateway() -> bool:
    """Stop the Gateway process."""
    process = _runtime_state.gateway_process
    if process is None:
        return False

    try:
        # Try graceful shutdown first
        process.terminate()
        try:
            process.wait(timeout=5)
        except subprocess.TimeoutExpired:
            # Force kill if graceful shutdown fails
            process.kill()
            process.wait()
    except Exception as e:
        logger.warning(f"Error during gateway shutdown: {e}")
    finally:
        _runtime_state.gateway_process = None

    return True


def _start_gateway_process(
    run_id: str,
    run_dir: Path,
    bootstrap: Dict[str, Any],
    port: int
) -> subprocess.Popen:
    """Start Gateway as a separate process."""
    # Prepare environment
    env = os.environ.copy()

    # Create command arguments
    cmd = [
        sys.executable,
        "-m", "backend.gateway_server",
        "--run-id", run_id,
        "--run-dir", str(run_dir),
        "--port", str(port),
        "--bootstrap", json.dumps(bootstrap)
    ]

    log_path = run_dir / "logs" / "gateway.log"
    log_path.parent.mkdir(parents=True, exist_ok=True)

    log_file = log_path.open("ab")
    try:
        process = subprocess.Popen(
            cmd,
            env=env,
            stdout=log_file,
            stderr=subprocess.STDOUT,
            cwd=PROJECT_ROOT
        )
    finally:
        log_file.close()

    return process


@router.get("/context", response_model=RunContextResponse)
async def get_run_context() -> RunContextResponse:
    """Return active runtime context, or latest persisted context when stopped."""
    snapshot = _get_active_runtime_snapshot() if _is_gateway_running() else _load_latest_runtime_snapshot()
    context = snapshot.get("context")
    if context is None:
        raise HTTPException(status_code=404, detail="Run context is not ready")

    return RunContextResponse(
        config_name=context["config_name"],
        run_dir=context["run_dir"],
        bootstrap_values=context["bootstrap_values"],
    )


@router.get("/agents", response_model=RuntimeAgentsResponse)
async def get_runtime_agents() -> RuntimeAgentsResponse:
    """Return agent states from the active runtime, or latest persisted run."""
    snapshot = _get_active_runtime_snapshot() if _is_gateway_running() else _load_latest_runtime_snapshot()
    agents = snapshot.get("agents", [])

    return RuntimeAgentsResponse(
        agents=[RuntimeAgentState(**a) for a in agents]
    )


@router.get("/events", response_model=RuntimeEventsResponse)
async def get_runtime_events() -> RuntimeEventsResponse:
    """Return events from the active runtime, or latest persisted run."""
    snapshot = _get_active_runtime_snapshot() if _is_gateway_running() else _load_latest_runtime_snapshot()
    events = snapshot.get("events", [])

    return RuntimeEventsResponse(
        events=[RuntimeEvent(**e) for e in events]
    )


@router.get("/history", response_model=RuntimeHistoryResponse)
async def get_runtime_history(limit: int = 20) -> RuntimeHistoryResponse:
    """List recent historical runs for restore/start selection."""
    return RuntimeHistoryResponse(runs=_list_runs(limit=limit))


@router.get("/gateway/status", response_model=GatewayStatusResponse)
async def get_gateway_status() -> GatewayStatusResponse:
    """Get Gateway process status and port."""
    is_running = _is_gateway_running()
    run_id = None

    if is_running:
        try:
            run_id = _get_active_runtime_context().get("config_name")
        except Exception as e:
            logger.warning(f"Failed to resolve active runtime context: {e}")

    return GatewayStatusResponse(
        is_running=is_running,
        port=_runtime_state.gateway_port,
        run_id=run_id
    )


@router.get("/gateway/port")
async def get_gateway_port(request: Request) -> Dict[str, Any]:
    """Get WebSocket Gateway port for frontend connection."""
    gateway_port = _runtime_state.gateway_port
    return {
        "port": gateway_port,
        "is_running": _is_gateway_running(),
        "ws_url": _build_gateway_ws_url(request, gateway_port),
    }


@router.get("/logs", response_model=RuntimeLogResponse)
async def get_runtime_logs() -> RuntimeLogResponse:
    """Return current runtime log tail, or the latest run log if runtime is stopped."""
    try:
        context = _get_active_runtime_context() if _is_gateway_running() else _get_runtime_context_from_latest_snapshot()
    except HTTPException:
        return RuntimeLogResponse(is_running=False, content="")

    run_id = str(context.get("config_name") or "").strip() or None
    log_path = _get_gateway_log_path_for_run(run_id) if run_id else None
    content = _read_log_tail(log_path) if log_path else ""

    return RuntimeLogResponse(
        run_id=run_id,
        is_running=_is_gateway_running(),
        log_path=str(log_path) if log_path else None,
        content=content,
    )


def _build_gateway_ws_url(request: Request, port: int) -> str:
    """Build a proxy-safe Gateway WebSocket URL."""
    forwarded_proto = request.headers.get("x-forwarded-proto", "").split(",")[0].strip()
    scheme = forwarded_proto or request.url.scheme
    ws_scheme = "wss" if scheme == "https" else "ws"

    forwarded_host = request.headers.get("x-forwarded-host", "").split(",")[0].strip()
    host = forwarded_host or request.url.hostname or "localhost"
    if ":" in host and not host.startswith("["):
        host = host.split(":", 1)[0]

    return f"{ws_scheme}://{host}:{port}"


def _load_latest_runtime_snapshot() -> Dict[str, Any]:
    """Load the latest persisted runtime snapshot."""
    snapshots = sorted(
        PROJECT_ROOT.glob("runs/*/state/runtime_state.json"),
        key=lambda p: p.stat().st_mtime,
        reverse=True,
    )
    if not snapshots:
        raise HTTPException(status_code=404, detail="No runtime information available")
    return json.loads(snapshots[0].read_text(encoding="utf-8"))


def _get_active_runtime_snapshot() -> Dict[str, Any]:
    """Return the active runtime snapshot, preferring in-memory manager state."""
    if not _is_gateway_running():
        raise HTTPException(status_code=404, detail="No runtime is currently running")

    manager = _runtime_state.runtime_manager
    if manager is not None and hasattr(manager, "build_snapshot"):
        snapshot = manager.build_snapshot()
        context = snapshot.get("context") or {}
        if context.get("config_name"):
            return snapshot

    return _load_latest_runtime_snapshot()


def _get_runtime_context_from_latest_snapshot() -> Dict[str, Any]:
    """Return the latest persisted runtime context regardless of active process state."""
    latest = _load_latest_runtime_snapshot()
    context = latest.get("context") or {}
    if not context.get("config_name"):
        raise HTTPException(status_code=404, detail="No runtime context available")
    return context


def _get_gateway_log_path_for_run(run_id: str) -> Path:
    return _get_run_dir(run_id) / "logs" / "gateway.log"


def _read_log_tail(path: Path, max_chars: int = 120_000) -> str:
    if not path.exists() or not path.is_file():
        return ""
    text = path.read_text(encoding="utf-8", errors="replace")
    if len(text) <= max_chars:
        return text
    return text[-max_chars:]


def _get_current_runtime_context() -> Dict[str, Any]:
    """Return the active runtime context from the latest snapshot."""
    if not _is_gateway_running():
        raise HTTPException(status_code=404, detail="No runtime is currently running")
    snapshot = _get_active_runtime_snapshot()
    context = snapshot.get("context") or {}
    if not context.get("config_name"):
        raise HTTPException(status_code=404, detail="No runtime context available")
    return context


def _get_active_runtime_context() -> Dict[str, Any]:
    """Return the active runtime context, preferring in-memory runtime manager state."""
    return _get_current_runtime_context()


def _resolve_runtime_response(run_id: str) -> RuntimeConfigResponse:
    """Build a normalized runtime config response for the active run."""
    context = _get_current_runtime_context()
    bootstrap = dict(context.get("bootstrap_values") or {})
    resolved = resolve_runtime_config(
        project_root=PROJECT_ROOT,
        config_name=run_id,
        enable_memory=bool(bootstrap.get("enable_memory", False)),
        schedule_mode=str(bootstrap.get("schedule_mode", "daily")),
        interval_minutes=int(bootstrap.get("interval_minutes", 60) or 60),
        trigger_time=str(bootstrap.get("trigger_time", "09:30") or "09:30"),
    )
    return RuntimeConfigResponse(
        run_id=run_id,
        is_running=True,
        gateway_port=_runtime_state.gateway_port,
        bootstrap=bootstrap,
        resolved=resolved,
    )


def _normalize_runtime_config_updates(
    request: UpdateRuntimeConfigRequest,
) -> Dict[str, Any]:
    """Validate and normalize runtime config updates."""
    updates: Dict[str, Any] = {}

    if request.schedule_mode is not None:
        schedule_mode = str(request.schedule_mode).strip().lower()
        if schedule_mode not in {"daily", "intraday"}:
            raise HTTPException(
                status_code=400,
                detail="schedule_mode must be 'daily' or 'intraday'",
            )
        updates["schedule_mode"] = schedule_mode

    if request.interval_minutes is not None:
        updates["interval_minutes"] = int(request.interval_minutes)

    if request.trigger_time is not None:
        trigger_time = str(request.trigger_time).strip()
        if trigger_time and trigger_time != "now":
            try:
                datetime.strptime(trigger_time, "%H:%M")
            except ValueError as exc:
                raise HTTPException(
                    status_code=400,
                    detail="trigger_time must use HH:MM or 'now'",
                ) from exc
        updates["trigger_time"] = trigger_time or "09:30"

    if request.max_comm_cycles is not None:
        updates["max_comm_cycles"] = int(request.max_comm_cycles)

    if request.initial_cash is not None:
        updates["initial_cash"] = float(request.initial_cash)

    if request.margin_requirement is not None:
        updates["margin_requirement"] = float(request.margin_requirement)

    if request.enable_memory is not None:
        updates["enable_memory"] = bool(request.enable_memory)

    if not updates:
        raise HTTPException(status_code=400, detail="No runtime config updates provided")

    return updates


@router.post("/start", response_model=LaunchResponse)
async def start_runtime(
    config: LaunchConfig,
    background_tasks: BackgroundTasks
) -> LaunchResponse:
    """Start a new trading runtime with the given configuration.

    1. Stop existing Gateway if running
    2. Generate run ID and directory
    3. Create runtime manager
    4. Start Gateway as subprocess (Data Plane)
    5. Return Gateway port for WebSocket connection
    """
    # Lazy import to avoid circular dependency
    from backend.runtime.manager import TradingRuntimeManager

    # 1. Stop existing Gateway
    if _is_gateway_running():
        _stop_gateway()
        await asyncio.sleep(1)  # Wait for port release

    launch_mode = str(config.launch_mode or "fresh").strip().lower()
    if launch_mode not in {"fresh", "restore"}:
        raise HTTPException(status_code=400, detail="launch_mode must be 'fresh' or 'restore'")

    # 2. Resolve run ID, directory, and bootstrap
    if launch_mode == "restore":
        restore_run_id = str(config.restore_run_id or "").strip()
        if not restore_run_id:
            raise HTTPException(status_code=400, detail="restore_run_id is required when launch_mode=restore")
        snapshot = _load_run_snapshot(restore_run_id)
        context = snapshot.get("context") or {}
        if not context.get("config_name"):
            raise HTTPException(status_code=404, detail=f"Run context not found: {restore_run_id}")
        run_id = restore_run_id
        run_dir = _get_run_dir(run_id)
        bootstrap = dict(context.get("bootstrap_values") or {})
        bootstrap["launch_mode"] = "restore"
        bootstrap["restore_run_id"] = restore_run_id
    else:
        run_id = _generate_run_id()
        run_dir = _get_run_dir(run_id)
        bootstrap = {
            "launch_mode": "fresh",
            "restore_run_id": None,
            "tickers": config.tickers,
            "schedule_mode": config.schedule_mode,
            "interval_minutes": config.interval_minutes,
            "trigger_time": config.trigger_time,
            "max_comm_cycles": config.max_comm_cycles,
            "initial_cash": config.initial_cash,
            "margin_requirement": config.margin_requirement,
            "enable_memory": config.enable_memory,
            "mode": config.mode,
            "start_date": config.start_date,
            "end_date": config.end_date,
            "poll_interval": config.poll_interval,
            "enable_mock": config.enable_mock,
        }

    retention_keep = max(1, int(os.getenv("RUNS_RETENTION_COUNT", "20") or "20"))
    pruned_run_ids = _prune_old_timestamped_runs(
        keep=retention_keep,
        exclude_run_ids={run_id},
    )
    if pruned_run_ids:
        logger.info("Pruned old run directories: %s", ", ".join(pruned_run_ids))

    # 4. Create runtime manager
    manager = TradingRuntimeManager(
        config_name=run_id,
        run_dir=run_dir,
        bootstrap=bootstrap,
    )
    manager.prepare_run()
    register_runtime_manager(manager)

    # 5. Write BOOTSTRAP.md
    _write_bootstrap_md(run_dir, bootstrap)

    # 6. Find available port and start Gateway process
    gateway_port = _find_available_port(start_port=8765)
    _runtime_state.gateway_port = gateway_port

    try:
        process = _start_gateway_process(
            run_id=run_id,
            run_dir=run_dir,
            bootstrap=bootstrap,
            port=gateway_port
        )
        _runtime_state.gateway_process = process

        # Wait briefly to check if process started successfully
        await asyncio.sleep(2)

        if not _is_gateway_running():
            _runtime_state.gateway_process = None
            log_path = _get_gateway_log_path_for_run(run_id)
            log_tail = _read_log_tail(log_path, max_chars=4000)
            raise HTTPException(
                status_code=500,
                detail=f"Gateway failed to start: {log_tail or 'Unknown error'}"
            )

    except Exception as e:
        _stop_gateway()
        raise HTTPException(status_code=500, detail=f"Failed to start Gateway: {str(e)}")

    return LaunchResponse(
        run_id=run_id,
        status="started",
        run_dir=str(run_dir),
        gateway_port=gateway_port,
        message=f"Runtime started with run_id: {run_id}, Gateway on port: {gateway_port}",
    )


@router.get("/config", response_model=RuntimeConfigResponse)
async def get_runtime_config() -> RuntimeConfigResponse:
    """Return the current runtime bootstrap and resolved settings."""
    context = _get_current_runtime_context()
    return _resolve_runtime_response(context["config_name"])


@router.put("/config", response_model=RuntimeConfigResponse)
async def update_runtime_config(
    request: UpdateRuntimeConfigRequest,
) -> RuntimeConfigResponse:
    """Persist selected runtime configuration updates for the active run."""
    context = _get_current_runtime_context()
    run_id = context["config_name"]
    updates = _normalize_runtime_config_updates(request)
    updated = update_bootstrap_values_for_run(PROJECT_ROOT, run_id, updates)

    manager = _runtime_state.runtime_manager
    if manager is not None and getattr(manager, "config_name", None) == run_id:
        manager.bootstrap.update(updates)
        if getattr(manager, "context", None) is not None:
            manager.context.bootstrap_values.update(updates)
        if hasattr(manager, "_persist_snapshot"):
            manager._persist_snapshot()

    response = _resolve_runtime_response(run_id)
    response.bootstrap = dict(updated.values)
    return response


@router.post("/stop", response_model=StopResponse)
async def stop_runtime(force: bool = True) -> StopResponse:
    """Stop the current running runtime."""
    was_running = _is_gateway_running()

    if not was_running:
        raise HTTPException(status_code=404, detail="No runtime is currently running")

    # Stop Gateway process
    _stop_gateway()

    # Unregister runtime manager
    unregister_runtime_manager()

    return StopResponse(
        status="stopped",
        message="Runtime stopped successfully",
    )


@router.post("/cleanup", response_model=CleanupResponse)
async def cleanup_old_runs(keep: int = 20) -> CleanupResponse:
    """Prune old timestamped run directories while preserving named runs."""
    keep_count = max(1, int(keep))
    exclude: set[str] = set()

    if _is_gateway_running():
        try:
            active_context = _get_active_runtime_context()
            active_run_id = str(active_context.get("config_name") or "").strip()
            if active_run_id:
                exclude.add(active_run_id)
        except HTTPException:
            pass

    pruned = _prune_old_timestamped_runs(keep=keep_count, exclude_run_ids=exclude)
    return CleanupResponse(status="ok", kept=keep_count, pruned_run_ids=pruned)


@router.post("/restart")
async def restart_runtime(
    config: LaunchConfig,
    background_tasks: BackgroundTasks
):
    """Restart the runtime with a new configuration."""
    # Stop current runtime
    await stop_runtime(force=True)

    # Start new runtime
    response = await start_runtime(config, background_tasks)

    return {
        "run_id": response.run_id,
        "status": "restarted",
        "gateway_port": response.gateway_port,
        "message": f"Runtime restarted with run_id: {response.run_id}",
    }


@router.get("/current")
async def get_current_runtime():
    """Get information about the currently running runtime."""
    if not _is_gateway_running():
        raise HTTPException(status_code=404, detail="No runtime is currently running")

    context = _get_active_runtime_context()

    return {
        "run_id": context.get("config_name"),
        "run_dir": context.get("run_dir"),
        "is_running": True,
        "gateway_port": _runtime_state.gateway_port,
        "bootstrap": context.get("bootstrap_values", {}),
    }


def register_runtime_manager(manager: Any) -> None:
    """Allow other modules to expose the runtime manager to the API."""
    global runtime_manager
    runtime_manager = manager
    # Also update the RuntimeState singleton for internal consistency
    _runtime_state.runtime_manager = manager


def unregister_runtime_manager() -> None:
    """Drop the runtime manager reference."""
    global runtime_manager
    runtime_manager = None
    # Also update the RuntimeState singleton for internal consistency
    _runtime_state.runtime_manager = None


def _write_bootstrap_md(run_dir: Path, bootstrap: Dict[str, Any]) -> None:
    """Write bootstrap configuration to BOOTSTRAP.md."""
    try:
        import yaml
    except ImportError:
        yaml = None

    bootstrap_path = run_dir / "BOOTSTRAP.md"
    bootstrap_path.parent.mkdir(parents=True, exist_ok=True)

    # Filter out None values
    values = {k: v for k, v in bootstrap.items() if v is not None}

    if yaml:
        front_matter = yaml.safe_dump(values, allow_unicode=True, sort_keys=False)
    else:
        front_matter = json.dumps(values, ensure_ascii=False, indent=2)

    content = f"---\n{front_matter}---\n"
    bootstrap_path.write_text(content, encoding="utf-8")