"""Custom exceptions for textract."""

from pathlib import Path

# Command not found exit code
_NOT_INSTALLED_EXIT_CODE = 127


# traceback from exceptions that inherit from this class are suppressed
class CommandLineError(Exception):
    """The traceback of all CommandLineError's is suppressed when the
    errors occur on the command line to provide a useful command line
    interface.
    """

    def render(self, msg: str) -> str:
        return msg % vars(self)


class ExtensionNotSupported(CommandLineError):
    """This error is raised with unsupported extensions"""

    def __init__(self, ext: str) -> None:
        """Initialize with unsupported extension."""
        self.ext = ext

        from .parsers import _get_available_extensions

        available_extensions = [
            e for e in _get_available_extensions() if e.startswith(".")
        ]
        self.available_extensions_str = ", ".join(available_extensions)

    def __str__(self):
        return self.render(
            (
                "The filename extension %(ext)s is not yet supported by\n"
                "textract. Please suggest this filename extension here:\n\n"
                "    https://github.com/deanmalmgren/textract/issues\n\n"
                "Available extensions include: %(available_extensions_str)s\n"
            )
        )


class MissingFileError(CommandLineError):
    """This error is raised when the file can not be located at the
    specified path.
    """

    def __init__(self, filename: str) -> None:
        """Initialize with missing file path."""
        self.filename = filename
        p = Path(filename)
        self.root = p.stem
        self.ext = p.suffix

    def __str__(self):
        return self.render(
            (
                'The file "%(filename)s" can not be found.\n'
                "Is this the right path/to/file/you/want/to/extract%(ext)s?"
            )
        )


class UnknownMethod(CommandLineError):
    """This error is raised when the specified --method on the command
    line is unknown.
    """

    def __init__(self, method: str) -> None:
        """Initialize with unknown method name."""
        self.method = method

    def __str__(self):
        return self.render(
            ('The method "%(method)s" can not be found for this filetype.')
        )


class ShellError(CommandLineError):
    """This error is raised when a shell.run returns a non-zero exit code
    (meaning the command failed).
    """

    def __init__(
        self, command: str, exit_code: int, stdout: bytes, stderr: bytes
    ) -> None:
        """Initialize with command execution details."""
        self.command = command
        self.exit_code = exit_code
        self.stdout = stdout
        self.stderr = stderr
        self.executable = self.command.split()[0]

    def is_not_installed(self) -> bool:
        """Check if the command failed because executable is not installed."""
        return self.exit_code == _NOT_INSTALLED_EXIT_CODE

    def not_installed_message(self) -> str:
        """Format error message when executable is not installed."""
        return (
            "The command `{command}` failed because the executable\n"
            "`{executable}` is not installed on your system. Please make\n"
            "sure the appropriate dependencies are installed before using\n"
            "textract:\n\n"
            "    http://textract.readthedocs.org/en/latest/installation.html\n"
        ).format(**vars(self))

    def failed_message(self) -> str:
        """Format error message when command execution failed."""
        return (
            "The command `%(command)s` failed with exit code %(exit_code)d\n"
            "------------- stdout -------------\n"
            "%(stdout)s"
            "------------- stderr -------------\n"
            "%(stderr)s"
        ) % vars(self)

    def __str__(self) -> str:
        if self.is_not_installed():
            return self.not_installed_message()
        return self.failed_message()