"""
Get the image file.
"""
import logging
import os
import random
import sys

from .settings import CACHE_DIR
from . import util
from . import wallpaper


def get_random_image(img_dir):
    """Pick a random image file from a directory."""
    current_wall = wallpaper.get()
    current_wall = os.path.basename(current_wall)

    file_types = (".png", ".jpg", ".jpeg", ".jpe", ".gif")

    images = [img for img in os.scandir(img_dir)
              if img.name.lower().endswith(file_types)]

    if len(images) > 2 and current_wall in images:
        images.remove(current_wall)

    elif not images:
        logging.error("No images found in directory.")
        sys.exit(1)

    random.shuffle(images)

    return os.path.join(img_dir, images[0].name)


def get(img, cache_dir=CACHE_DIR):
    """Validate image input."""
    if os.path.isfile(img):
        wal_img = img

    elif os.path.isdir(img):
        wal_img = get_random_image(img)

    else:
        logging.error("No valid image file found.")
        sys.exit(1)

    wal_img = os.path.abspath(wal_img)

    # Cache the image file path.
    util.save_file(wal_img, os.path.join(cache_dir, "wal"))

    logging.info("Using image %s.", wal_img)
    return wal_img