""" Miscellaneous utilities. """

import os
import tempfile
import pathlib
from collections import defaultdict

# ---------------------------------------------------------------------

class MsgStore:
    """Store different types of messages."""

    def __init__( self ):
        self._msgs = None
        self.reset()

    def reset( self ):
        """Reset the MsgStore."""
        self._msgs = defaultdict( list )

    def info( self, msg, *args, **kwargs ):
        """Add an informational message."""
        self._add_msg( "info", msg, *args, **kwargs )

    def warning( self, msg, *args, **kwargs ):
        """Add a warning message."""
        self._add_msg( "warning", msg, *args, **kwargs )

    def error( self, msg, *args, **kwargs ):
        """Add an error message."""
        self._add_msg( "error", msg, *args, **kwargs )

    def get_msgs( self, msg_type ):
        """Get stored messages."""
        return self._msgs[ msg_type ]

    def _add_msg( self, msg_type, msg, *args, **kwargs ):
        """Add a message to the store."""
        logger = kwargs.pop( "logger", None )
        msg = msg.format( *args, **kwargs )
        self._msgs[ msg_type ].append( msg )
        if logger:
            func = getattr( logger, "warn" if msg_type == "warning" else msg_type )
            func( msg )

# ---------------------------------------------------------------------

class TempFile:
    """Manage a temp file that can be closed while it's still being used."""

    def __init__( self, mode="wb", extn=None ):
        self.mode = mode
        self.extn = extn
        self.temp_file = None
        self.name = None

    def __enter__( self ):
        """Allocate a temp file."""
        self.temp_file = tempfile.NamedTemporaryFile( mode=self.mode, suffix=self.extn, delete=False )
        self.name = self.temp_file.name
        return self

    def __exit__( self, exc_type, exc_val, exc_tb ):
        """Clean up the temp file."""
        self.close()
        os.unlink( self.temp_file.name )

    def write( self, data ):
        """Write data to the temp file."""
        self.temp_file.write( data )

    def close( self ):
        """Close the temp file."""
        self.temp_file.close()

# ---------------------------------------------------------------------

def change_extn( fname, extn ):
    """Change a filename's extension."""
    return pathlib.Path( fname ).with_suffix( extn )

def is_image_file( fname ):
    """Check if a file is an image."""
    if fname.startswith( "." ):
        extn = fname
    else:
        extn = os.path.splitext( fname )[0]
    return extn.lower() in (".png",".jpg",".jpeg",".gif")

# ---------------------------------------------------------------------

class SimpleError( Exception ):
    """Represents a simple error that doesn't require a stack trace (e.g. bad configuration)."""
    pass