from datetime import datetime
import subprocess
import xml.etree.ElementTree as ET
from typing import Optional

from .entry import Entry
from .util import escape_text_for_xml

class RepeatEntry(Entry):
    """
    Entry type for scripts that are executed on every update.
    """
    
    def __init__(self, script: str, id: str, timestamp: datetime):
        """
        Initialize a new repeat entry.
        
        Args:
            script: The script/command to execute
            id: Unique identifier for this entry
            timestamp: Creation timestamp for this entry
        """
        super().__init__(id, timestamp)
        self._script = script
        self._stdout = ""
        self._stderr = ""
        self._exit_code: Optional[int] = None

    @property
    def script(self) -> str:
        """Get the script/command being executed."""
        return self._script

    @property
    def stdout(self) -> str:
        """Get the captured standard output."""
        return self._stdout

    @property
    def stderr(self) -> str:
        """Get the captured standard error."""
        return self._stderr

    @property
    def exit_code(self) -> Optional[int]:
        """Get the exit code of the process (None if still running)."""
        return self._exit_code
        
    def update(self) -> None:
        """
        Execute the script and update the output.
        Captures stdout, stderr and exit code from each execution.
        """
        try:
            # Run script and capture output
            process = subprocess.run(
                self._script,
                shell=True,
                capture_output=True,
                text=True
            )
            
            # Store results
            self._stdout = process.stdout
            self._stderr = process.stderr
            self._exit_code = process.returncode
            
        except subprocess.SubprocessError as e:
            # Handle subprocess errors by capturing the error message
            self._stdout = ""
            self._stderr = str(e)
            self._exit_code = -1
            
        except Exception as e:
            # Handle any other errors
            self._stdout = ""
            self._stderr = f"Error executing script: {str(e)}"
            self._exit_code = -1

    def generate_context(self) -> ET.Element:
        """
        Generate an XML Element representing this repeat entry.
        
        Returns:
            ET.Element: XML element containing the entry's data
        """
        # Create root element
        element = ET.Element("repeat", {
            "id": self.id,
            "exit_code": str(self._exit_code) if self._exit_code is not None else "-1"
        })
        
        # Add script as CDATA or escaped text
        element.text = escape_text_for_xml(self.script)
        
        # Add stdout element
        stdout_elem = ET.SubElement(element, "stdout")
        stdout_elem.text = escape_text_for_xml(self._stdout)
        
        # Add stderr element
        stderr_elem = ET.SubElement(element, "stderr")
        stderr_elem.text = escape_text_for_xml(self._stderr)
        
        return element