import os
from typing import Optional

CONTEXT_FILE = "/home/retoor/.local/share/rp/.rcontext.txt"


def _read_context() -> str:
    if not os.path.exists(CONTEXT_FILE):
        raise FileNotFoundError(f"Context file {CONTEXT_FILE} not found.")
    with open(CONTEXT_FILE, "r") as f:
        return f.read()


def _write_context(content: str):
    with open(CONTEXT_FILE, "w") as f:
        f.write(content)


def modify_context_add(new_content: str, position: Optional[str] = None) -> str:
    """
    Add new content to the .rcontext.txt file.

    Args:
        new_content: The content to add.
        position: Optional marker to insert before (e.g., '***').
    """
    current = _read_context()
    if position and position in current:
        # Insert before the position
        parts = current.split(position, 1)
        updated = parts[0] + new_content + "\n\n" + position + parts[1]
    else:
        # Append at the end
        updated = current + "\n\n" + new_content
    _write_context(updated)
    return f"Added: {new_content[:100]}... (full addition applied). Consequences: Enhances functionality as requested."


def modify_context_replace(old_content: str, new_content: str) -> str:
    """
    Replace old content with new content in .rcontext.txt.

    Args:
        old_content: The content to replace.
        new_content: The replacement content.
    """
    current = _read_context()
    if old_content not in current:
        raise ValueError(f"Old content not found: {old_content[:50]}...")
    updated = current.replace(old_content, new_content, 1)  # Replace first occurrence
    _write_context(updated)
    return f"Replaced: '{old_content[:50]}...' with '{new_content[:50]}...'. Consequences: Changes behavior as specified; verify for unintended effects."


def modify_context_delete(content_to_delete: str, confirmed: bool = False) -> str:
    """
    Delete content from .rcontext.txt, but only if confirmed.

    Args:
        content_to_delete: The content to delete.
        confirmed: Must be True to proceed with deletion.
    """
    if not confirmed:
        raise PermissionError(
            f"Deletion not confirmed. To delete '{content_to_delete[:50]}...', you must explicitly confirm. Are you sure? This may affect system behavior permanently."
        )
    current = _read_context()
    if content_to_delete not in current:
        raise ValueError(f"Content to delete not found: {content_to_delete[:50]}...")
    updated = current.replace(content_to_delete, "", 1)
    _write_context(updated)
    return f"Deleted: '{content_to_delete[:50]}...'. Consequences: Removed specified content; system may lose referenced rules or guidelines."