"""Script execution API endpoints."""

import asyncio
import logging
import re
import subprocess
import time
from concurrent.futures import ThreadPoolExecutor
from typing import Any

from fastapi import APIRouter, Depends, HTTPException, status
from pydantic import BaseModel, Field

from ..auth import verify_token
from ..config import ScriptConfig, settings
from ..config_manager import config_manager
from ..services.websocket_manager import ws_manager

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

# Dedicated executor for script/subprocess execution (avoids blocking the default pool)
_script_executor = ThreadPoolExecutor(max_workers=4, thread_name_prefix="script")
logger = logging.getLogger(__name__)


class ScriptExecuteRequest(BaseModel):
    """Request model for script execution with optional arguments."""

    args: list[str] = Field(default_factory=list, description="Additional arguments")


class ScriptExecuteResponse(BaseModel):
    """Response model for script execution."""

    success: bool
    script: str
    exit_code: int | None = None
    stdout: str = ""
    stderr: str = ""
    error: str | None = None
    execution_time: float | None = None


class ScriptInfo(BaseModel):
    """Information about an available script."""

    name: str
    label: str
    command: str
    description: str
    icon: str | None = None
    timeout: int


@router.get("/list")
async def list_scripts(_: str = Depends(verify_token)) -> list[ScriptInfo]:
    """List all available scripts.

    Returns:
        List of available scripts with their descriptions
    """
    return [
        ScriptInfo(
            name=name,
            label=config.label or name.replace("_", " ").title(),
            command=config.command,
            description=config.description,
            icon=config.icon,
            timeout=config.timeout,
        )
        for name, config in settings.scripts.items()
    ]


@router.post("/execute/{script_name}")
async def execute_script(
    script_name: str,
    request: ScriptExecuteRequest | None = None,
    _: str = Depends(verify_token),
) -> ScriptExecuteResponse:
    """Execute a pre-defined script by name.

    Args:
        script_name: Name of the script to execute (must be defined in config)
        request: Optional arguments to pass to the script

    Returns:
        Execution result including stdout, stderr, and exit code
    """
    # Check if script exists
    if script_name not in settings.scripts:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Script '{script_name}' not found. Use /api/scripts/list to see available scripts.",
        )
    script_config = settings.scripts[script_name]
    args = request.args if request else []

    logger.info(f"Executing script: {script_name}")

    try:
        # Build command
        command = script_config.command
        if args:
            # Append arguments to command
            command = f"{command} {' '.join(args)}"

        # Execute in dedicated thread pool to not block the default executor
        loop = asyncio.get_event_loop()
        result = await loop.run_in_executor(
            _script_executor,
            lambda: _run_script(
                command=command,
                timeout=script_config.timeout,
                shell=script_config.shell,
                working_dir=script_config.working_dir,
            ),
        )

        return ScriptExecuteResponse(
            success=result["exit_code"] == 0,
            script=script_name,
            exit_code=result["exit_code"],
            stdout=result["stdout"],
            stderr=result["stderr"],
            execution_time=result.get("execution_time"),
        )

    except Exception as e:
        logger.error(f"Script execution error: {e}")
        return ScriptExecuteResponse(
            success=False,
            script=script_name,
            error=str(e),
        )


def _run_script(
    command: str,
    timeout: int,
    shell: bool,
    working_dir: str | None,
) -> dict[str, Any]:
    """Run a script synchronously.

    Args:
        command: Command to execute
        timeout: Timeout in seconds
        shell: Whether to run in shell
        working_dir: Working directory

    Returns:
        Dict with exit_code, stdout, stderr, execution_time
    """
    start_time = time.time()
    try:
        result = subprocess.run(
            command,
            shell=shell,
            cwd=working_dir,
            capture_output=True,
            text=True,
            timeout=timeout,
        )
        execution_time = time.time() - start_time
        return {
            "exit_code": result.returncode,
            "stdout": result.stdout[:10000],  # Limit output size
            "stderr": result.stderr[:10000],
            "execution_time": execution_time,
        }
    except subprocess.TimeoutExpired:
        execution_time = time.time() - start_time
        return {
            "exit_code": -1,
            "stdout": "",
            "stderr": f"Script timed out after {timeout} seconds",
            "execution_time": execution_time,
        }
    except Exception as e:
        execution_time = time.time() - start_time
        return {
            "exit_code": -1,
            "stdout": "",
            "stderr": str(e),
            "execution_time": execution_time,
        }


# Script management endpoints


class ScriptCreateRequest(BaseModel):
    """Request model for creating or updating a script."""

    command: str = Field(..., description="Command to execute", min_length=1)
    label: str | None = Field(default=None, description="User-friendly label")
    description: str = Field(default="", description="Script description")
    icon: str | None = Field(default=None, description="Custom MDI icon (e.g., 'mdi:power')")
    timeout: int = Field(default=30, description="Execution timeout in seconds", ge=1, le=300)
    working_dir: str | None = Field(default=None, description="Working directory")
    shell: bool = Field(default=True, description="Run command in shell")


def _validate_script_name(name: str) -> None:
    """Validate script name.

    Args:
        name: Script name to validate.

    Raises:
        HTTPException: If name is invalid.
    """
    if not name:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Script name cannot be empty",
        )

    if not re.match(r"^[a-zA-Z0-9_]+$", name):
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Script name must contain only alphanumeric characters and underscores",
        )

    if len(name) > 64:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Script name must be 64 characters or less",
        )


@router.post("/create/{script_name}")
async def create_script(
    script_name: str,
    request: ScriptCreateRequest,
    _: str = Depends(verify_token),
) -> dict[str, Any]:
    """Create a new script.

    Args:
        script_name: Name for the new script (alphanumeric + underscore only).
        request: Script configuration.

    Returns:
        Success response with script name.

    Raises:
        HTTPException: If script already exists or name is invalid.
    """
    # Validate name
    _validate_script_name(script_name)

    # Check if script already exists
    if script_name in settings.scripts:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Script '{script_name}' already exists. Use PUT /api/scripts/update/{script_name} to update it.",
        )

    # Create script config
    script_config = ScriptConfig(**request.model_dump())

    # Add to config file and in-memory
    try:
        config_manager.add_script(script_name, script_config)
    except Exception as e:
        logger.error(f"Failed to add script '{script_name}': {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Failed to add script: {str(e)}",
        )

    # Notify WebSocket clients
    await ws_manager.broadcast_scripts_changed()

    logger.info(f"Script '{script_name}' created successfully")
    return {"success": True, "script": script_name}


@router.put("/update/{script_name}")
async def update_script(
    script_name: str,
    request: ScriptCreateRequest,
    _: str = Depends(verify_token),
) -> dict[str, Any]:
    """Update an existing script.

    Args:
        script_name: Name of the script to update.
        request: Updated script configuration.

    Returns:
        Success response with script name.

    Raises:
        HTTPException: If script does not exist.
    """
    # Validate name
    _validate_script_name(script_name)

    # Check if script exists
    if script_name not in settings.scripts:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Script '{script_name}' not found. Use POST /api/scripts/create/{script_name} to create it.",
        )

    # Create updated script config
    script_config = ScriptConfig(**request.model_dump())

    # Update config file and in-memory
    try:
        config_manager.update_script(script_name, script_config)
    except Exception as e:
        logger.error(f"Failed to update script '{script_name}': {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Failed to update script: {str(e)}",
        )

    # Notify WebSocket clients
    await ws_manager.broadcast_scripts_changed()

    logger.info(f"Script '{script_name}' updated successfully")
    return {"success": True, "script": script_name}


@router.delete("/delete/{script_name}")
async def delete_script(
    script_name: str,
    _: str = Depends(verify_token),
) -> dict[str, Any]:
    """Delete a script.

    Args:
        script_name: Name of the script to delete.

    Returns:
        Success response with script name.

    Raises:
        HTTPException: If script does not exist.
    """
    # Validate name
    _validate_script_name(script_name)

    # Check if script exists
    if script_name not in settings.scripts:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Script '{script_name}' not found",
        )

    # Delete from config file and in-memory
    try:
        config_manager.delete_script(script_name)
    except Exception as e:
        logger.error(f"Failed to delete script '{script_name}': {e}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Failed to delete script: {str(e)}",
        )

    # Notify WebSocket clients
    await ws_manager.broadcast_scripts_changed()

    logger.info(f"Script '{script_name}' deleted successfully")
    return {"success": True, "script": script_name}