import os

from django.apps import apps
from django.conf import settings
from django.core.management.base import BaseCommand
from django.db.models import FileField, ImageField


class Command(BaseCommand):
    help = (
        "Loads all files on the filesystem referenced by FileFields "
        "or ImageFields into the database. This should only need to be "
        "done once, when initially migrating a legacy system."
    )

    def add_arguments(self, parser):
        parser.add_argument(
            "-m",
            "--models",
            dest="models",
            default="",
            help="A list of models to search for file fields. Default is all.",
        )

    def handle(self, *args, **options):
        show_files = int(options.get("verbosity", 1)) >= 2
        all_models = [
            _.lower().strip() for _ in options.get("models", "").split() if _.strip()
        ]
        tmp_debug = settings.DEBUG
        settings.DEBUG = False
        try:
            broken = 0  # Number of db records referencing missing files.
            for model in apps.get_models():
                key = "%s.%s" % (model._meta.app_label, model._meta.model_name)
                key = key.lower()
                if all_models and key not in all_models:
                    continue
                for field in model._meta.fields:
                    if not isinstance(field, (FileField, ImageField)):
                        continue
                    if show_files:
                        print(model.__name__, field.name)
                    # Ignore records with null or empty string values.
                    q = {"%s__isnull" % field.name: False}
                    xq = {field.name: ""}
                    for row in model.objects.filter(**q).exclude(**xq):
                        try:
                            f = getattr(row, field.name)
                            if f is None:
                                continue
                            if not f.name:
                                continue
                            if show_files:
                                print("\t", f.name)
                            if f.path and not os.path.isfile(f.path):
                                if show_files:
                                    print("Broken:", f.name)
                                broken += 1
                                continue
                            f.read()
                            row.save()
                        except IOError:
                            broken += 1
            if show_files:
                print("-" * 80)
                print("%i broken" % (broken,))
        finally:
            settings.DEBUG = tmp_debug
