import os
import shlex
import tempfile
import shutil

from pathlib import Path
from PIL import Image

from .utils import load_file_path
from .error import InterpreterError
from .image import GlitchImage


class Interpreter:
    """Interpreter for scritcher instructions/statements."""
    def __init__(self):
        self.orig_path = None
        self.img = None

    def _cmd_noop(self):
        pass

    def _cmd_load(self, loadpath: str):
        source_path = load_file_path(loadpath)
        self.orig_path = source_path

        # create a temporary file to hold bmp data
        handle, bmp_path = tempfile.mkstemp('.bmp')
        os.close(handle)

        self.img = GlitchImage(source_path, Path(bmp_path))
        self.img.load()

    def _cmd_quicksave(self):
        suffix = self.img.original.suffix
        name = self.img.original.name.replace(suffix, '')
        parent_folder = self.orig_path.parents[0]

        # we need to search all files that match the pattern NAME_g*
        # then we save on the one _g suffix above it.

        # e.g if the original path is "miya.png", we want to search for
        # files named "miya_g1.raw", "miya_g2.raw", and then we want to write
        # on "miya_g3.raw".
        index = 0
        for glitched_out in parent_folder.glob(f'{name}_g*'):
            try:
                idx = int(glitched_out.name.strip(name + '_g')[0])

                # glob() doesnt seem to show a stable order. anyways, we can
                # just only update our index when its the maximum found
                if idx > index:
                    index = idx
            except (IndexError, ValueError):
                continue

        # create our next glitched path
        out_path = shutil.copyfile(
            self.img.path, parent_folder / f'{name}_g{index + 1}.raw')
        print('saved to', out_path)


    def run(self, line: str):
        """Run a single line."""
        print(f'running {line!r}')

        args = shlex.split(line)
        command = args[0]

        if command != 'load' and self.img is None:
            print('warn: no file loaded.')

        try:
            method = getattr(self, f'_cmd_{command}')
        except AttributeError:
            raise InterpreterError(f'Command {command!r} not found')

        method(*args[1:])