import pathlib
import subprocess

class compiler:
    """
    This class is responsible for building and bundling source code into
    result file. This could return to command line after error, or raise
    exception to handle it in build script.
    """

    def __init__(self, source: pathlib.Path, throw: bool = False) -> None:
        """
        This function create new compiler instance.

        Parameters:
            source (pathlib.Path) - Source file to build
            throw (bool) - When True failed compilation raise Exception
        """

        self.__source = source
        self.__throw = throw

    @property
    def throw(self) -> bool:
        """ When throw is True, failed command would raise Exception. """

        return self.__throw

    @property
    def source(self) -> pathlib.Path:
        """ This return source file to build. """

        return self.__source

    def build(self, result: pathlib.Path) -> None:
        """
        This function is responsible for building process.

        Parameters:
            result (pathlib.Path): Result file to store compiled code
        """

        if result.is_dir():
            self._error("Build file \"" + str(result) + "\" is directory.")

        if result.exists():
            result.unlink()

        command = self._command(self.source, result)
        returned = subprocess.run(command, capture_output = True)

        if returned.returncode == 0:
            return

        failed = result.stdout.decode("UTF-8") 
        failed = failed + returned.stderr.decode("UTF-8")

        self._error(failed)

    def _error(self, content: str) -> None:
        """
        This function raise Exception if throw flag is set, or print
        error to command line, and return there.

        Parameters:
            content (str): Content of the error
        """

        if self.throw:
            raise Exception(content)

        print("Error while compilation: ")
        print("\"" + content + "\"")

        exit(-1)

    def _command(self, source: pathlib.Path, result: pathlib.Path) -> list:
        """
        This function is responsible for creating command for compilation 
        process.

        Parameters:
            source (pathlib.Path) - Source file to compile
            result (pathlib.Path) - Result compiled file

        Returns:
            (list) - List of strings, for subprocess creation
        """

        raise TypeError("This is abstract class. Overwrite this function.")    


class sass_compiler(compiler):
    def _command(self, source: pathlib.Path, result: pathlib.Path) -> list:
        """
        This function is responsible for creating command for compilation 
        process.

        Parameters:
            source (pathlib.Path) - Source file to compile
            result (pathlib.Path) - Result compiled file

        Returns:
            (list) - List of strings, for subprocess creation
        """

        return [
            "sass",
            "--sourcemap=none",
            "-t compressed",
            str(source),
            str(result)
        ]


class esbuild_compiler(compiler):
    def _command(self, source: pathlib.Path, result: pathlib.Path) -> list:
        """
        This function is responsible for creating command for compilation 
        process.

        Parameters:
            source (pathlib.Path) - Source file to compile
            result (pathlib.Path) - Result compiled file

        Returns:
            (list) - List of strings, for subprocess creation
        """

        return [
            "esbuild", 
            str(source),
            "--bundle",
            "--outfile=" + str(result)
        ]