"""
Simulation IPC communication module
Used for inter-process communication between the Flask backend and simulation scripts.

Implements a simple command/response pattern via the file system:
1. Flask writes commands to the commands/ directory
2. Simulation scripts poll the command directory, execute commands, and write responses to the responses/ directory
3. Flask polls the response directory to get results
"""

import os
import json
import time
import uuid
from typing import Dict, Any, Optional, List
from dataclasses import dataclass, field
from datetime import datetime
from enum import Enum

from ..utils.logger import get_logger

logger = get_logger('mirofish.simulation_ipc')


class CommandType(str, Enum):
    """Command type"""
    INTERVIEW = "interview"           # Single agent interview
    BATCH_INTERVIEW = "batch_interview"  # Batch interview
    CLOSE_ENV = "close_env"           # Close environment


class CommandStatus(str, Enum):
    """Command status"""
    PENDING = "pending"
    PROCESSING = "processing"
    COMPLETED = "completed"
    FAILED = "failed"


@dataclass
class IPCCommand:
    """IPC command"""
    command_id: str
    command_type: CommandType
    args: Dict[str, Any]
    timestamp: str = field(default_factory=lambda: datetime.now().isoformat())

    def to_dict(self) -> Dict[str, Any]:
        return {
            "command_id": self.command_id,
            "command_type": self.command_type.value,
            "args": self.args,
            "timestamp": self.timestamp
        }

    @classmethod
    def from_dict(cls, data: Dict[str, Any]) -> 'IPCCommand':
        return cls(
            command_id=data["command_id"],
            command_type=CommandType(data["command_type"]),
            args=data.get("args", {}),
            timestamp=data.get("timestamp", datetime.now().isoformat())
        )


@dataclass
class IPCResponse:
    """IPC response"""
    command_id: str
    status: CommandStatus
    result: Optional[Dict[str, Any]] = None
    error: Optional[str] = None
    timestamp: str = field(default_factory=lambda: datetime.now().isoformat())

    def to_dict(self) -> Dict[str, Any]:
        return {
            "command_id": self.command_id,
            "status": self.status.value,
            "result": self.result,
            "error": self.error,
            "timestamp": self.timestamp
        }

    @classmethod
    def from_dict(cls, data: Dict[str, Any]) -> 'IPCResponse':
        return cls(
            command_id=data["command_id"],
            status=CommandStatus(data["status"]),
            result=data.get("result"),
            error=data.get("error"),
            timestamp=data.get("timestamp", datetime.now().isoformat())
        )


class SimulationIPCClient:
    """
    Simulation IPC client (used by the Flask side)

    Used to send commands to the simulation process and wait for responses
    """

    def __init__(self, simulation_dir: str):
        """
        Initialize the IPC client

        Args:
            simulation_dir: simulation data directory
        """
        self.simulation_dir = simulation_dir
        self.commands_dir = os.path.join(simulation_dir, "ipc_commands")
        self.responses_dir = os.path.join(simulation_dir, "ipc_responses")

        # Ensure directories exist
        os.makedirs(self.commands_dir, exist_ok=True)
        os.makedirs(self.responses_dir, exist_ok=True)

    def send_command(
        self,
        command_type: CommandType,
        args: Dict[str, Any],
        timeout: float = 60.0,
        poll_interval: float = 0.5
    ) -> IPCResponse:
        """
        Send a command and wait for a response

        Args:
            command_type: command type
            args: command arguments
            timeout: timeout in seconds
            poll_interval: polling interval in seconds

        Returns:
            IPCResponse

        Raises:
            TimeoutError: timed out waiting for a response
        """
        command_id = str(uuid.uuid4())
        command = IPCCommand(
            command_id=command_id,
            command_type=command_type,
            args=args
        )

        # Write command file
        command_file = os.path.join(self.commands_dir, f"{command_id}.json")
        with open(command_file, 'w', encoding='utf-8') as f:
            json.dump(command.to_dict(), f, ensure_ascii=False, indent=2)

        logger.info(f"Sending IPC command: {command_type.value}, command_id={command_id}")

        # Wait for response
        response_file = os.path.join(self.responses_dir, f"{command_id}.json")
        start_time = time.time()

        while time.time() - start_time < timeout:
            if os.path.exists(response_file):
                try:
                    with open(response_file, 'r', encoding='utf-8') as f:
                        response_data = json.load(f)
                    response = IPCResponse.from_dict(response_data)

                    # Clean up command and response files
                    try:
                        os.remove(command_file)
                        os.remove(response_file)
                    except OSError:
                        pass

                    logger.info(f"Received IPC response: command_id={command_id}, status={response.status.value}")
                    return response
                except (json.JSONDecodeError, KeyError) as e:
                    logger.warning(f"Failed to parse response: {e}")

            time.sleep(poll_interval)

        # Timeout
        logger.error(f"Timed out waiting for IPC response: command_id={command_id}")

        # Clean up command file
        try:
            os.remove(command_file)
        except OSError:
            pass

        raise TimeoutError(f"Timed out waiting for command response ({timeout}s)")

    def send_interview(
        self,
        agent_id: int,
        prompt: str,
        platform: str = None,
        timeout: float = 60.0
    ) -> IPCResponse:
        """
        Send a single agent interview command

        Args:
            agent_id: Agent ID
            prompt: interview question
            platform: target platform (optional)
                - "twitter": interview only the Twitter platform
                - "reddit": interview only the Reddit platform
                - None: in dual-platform mode, interview both; in single-platform mode, interview that platform
            timeout: timeout in seconds

        Returns:
            IPCResponse with interview result in the result field
        """
        args = {
            "agent_id": agent_id,
            "prompt": prompt
        }
        if platform:
            args["platform"] = platform

        return self.send_command(
            command_type=CommandType.INTERVIEW,
            args=args,
            timeout=timeout
        )

    def send_batch_interview(
        self,
        interviews: List[Dict[str, Any]],
        platform: str = None,
        timeout: float = 120.0
    ) -> IPCResponse:
        """
        Send a batch interview command

        Args:
            interviews: list of interviews, each containing {"agent_id": int, "prompt": str, "platform": str (optional)}
            platform: default platform (optional; overridden per-item by each interview's platform)
                - "twitter": default to Twitter platform only
                - "reddit": default to Reddit platform only
                - None: in dual-platform mode, interview each agent on both platforms
            timeout: timeout in seconds

        Returns:
            IPCResponse with all interview results in the result field
        """
        args = {"interviews": interviews}
        if platform:
            args["platform"] = platform

        return self.send_command(
            command_type=CommandType.BATCH_INTERVIEW,
            args=args,
            timeout=timeout
        )

    def send_close_env(self, timeout: float = 30.0) -> IPCResponse:
        """
        Send a close-environment command

        Args:
            timeout: timeout in seconds

        Returns:
            IPCResponse
        """
        return self.send_command(
            command_type=CommandType.CLOSE_ENV,
            args={},
            timeout=timeout
        )

    def check_env_alive(self) -> bool:
        """
        Check whether the simulation environment is alive

        Determined by checking the env_status.json file
        """
        status_file = os.path.join(self.simulation_dir, "env_status.json")
        if not os.path.exists(status_file):
            return False

        try:
            with open(status_file, 'r', encoding='utf-8') as f:
                status = json.load(f)
            return status.get("status") == "alive"
        except (json.JSONDecodeError, OSError):
            return False


class SimulationIPCServer:
    """
    Simulation IPC server (used by the simulation script side)

    Polls the command directory, executes commands, and returns responses
    """

    def __init__(self, simulation_dir: str):
        """
        Initialize the IPC server

        Args:
            simulation_dir: simulation data directory
        """
        self.simulation_dir = simulation_dir
        self.commands_dir = os.path.join(simulation_dir, "ipc_commands")
        self.responses_dir = os.path.join(simulation_dir, "ipc_responses")

        # Ensure directories exist
        os.makedirs(self.commands_dir, exist_ok=True)
        os.makedirs(self.responses_dir, exist_ok=True)

        # Environment status
        self._running = False

    def start(self):
        """Mark the server as running"""
        self._running = True
        self._update_env_status("alive")

    def stop(self):
        """Mark the server as stopped"""
        self._running = False
        self._update_env_status("stopped")

    def _update_env_status(self, status: str):
        """Update the environment status file"""
        status_file = os.path.join(self.simulation_dir, "env_status.json")
        with open(status_file, 'w', encoding='utf-8') as f:
            json.dump({
                "status": status,
                "timestamp": datetime.now().isoformat()
            }, f, ensure_ascii=False, indent=2)

    def poll_commands(self) -> Optional[IPCCommand]:
        """
        Poll the command directory and return the first pending command

        Returns:
            IPCCommand or None
        """
        if not os.path.exists(self.commands_dir):
            return None

        # Get command files sorted by modification time
        command_files = []
        for filename in os.listdir(self.commands_dir):
            if filename.endswith('.json'):
                filepath = os.path.join(self.commands_dir, filename)
                command_files.append((filepath, os.path.getmtime(filepath)))

        command_files.sort(key=lambda x: x[1])

        for filepath, _ in command_files:
            try:
                with open(filepath, 'r', encoding='utf-8') as f:
                    data = json.load(f)
                return IPCCommand.from_dict(data)
            except (json.JSONDecodeError, KeyError, OSError) as e:
                logger.warning(f"Failed to read command file: {filepath}, {e}")
                continue

        return None

    def send_response(self, response: IPCResponse):
        """
        Send a response

        Args:
            response: IPC response
        """
        response_file = os.path.join(self.responses_dir, f"{response.command_id}.json")
        with open(response_file, 'w', encoding='utf-8') as f:
            json.dump(response.to_dict(), f, ensure_ascii=False, indent=2)

        # Delete the command file
        command_file = os.path.join(self.commands_dir, f"{response.command_id}.json")
        try:
            os.remove(command_file)
        except OSError:
            pass

    def send_success(self, command_id: str, result: Dict[str, Any]):
        """Send a success response"""
        self.send_response(IPCResponse(
            command_id=command_id,
            status=CommandStatus.COMPLETED,
            result=result
        ))

    def send_error(self, command_id: str, error: str):
        """Send an error response"""
        self.send_response(IPCResponse(
            command_id=command_id,
            status=CommandStatus.FAILED,
            error=error
        ))