import io

from django.core.files.storage import InMemoryStorage
from django.db import models
from PIL import Image

from netbox_export.services import importer as importer_module
from netbox_export.services.importer import _cleanup_files, _set_files


class ImageAsset(models.Model):
    image = models.ImageField(
        upload_to="test-images",
        height_field="image_height",
        width_field="image_width",
    )
    image_height = models.PositiveSmallIntegerField()
    image_width = models.PositiveSmallIntegerField()

    class Meta:
        app_label = "file_import_tests"


def image_bytes(width=3, height=2):
    output = io.BytesIO()
    Image.new("RGB", (width, height), color="white").save(output, format="PNG")
    return output.getvalue()


def image_record():
    return {
        "files": {
            "image": {
                "path": "assets/extras.imageattachment_17/image/server-room.png",
                "name": "image-attachments/location_2_Serverraum.jpg",
            }
        }
    }


def test_dry_run_derives_required_image_dimensions_without_storing_file():
    obj = ImageAsset()
    assets = {"assets/extras.imageattachment_17/image/server-room.png": image_bytes()}
    saved_files = []

    _set_files(obj, image_record(), assets, saved_files, dry_run=True)

    assert (obj.image_width, obj.image_height) == (3, 2)
    assert not obj.image
    assert saved_files == []


def test_file_import_keeps_derived_dimensions_after_storage_save(monkeypatch):
    field = ImageAsset._meta.get_field("image")
    storage = InMemoryStorage()
    monkeypatch.setattr(field, "storage", storage)
    obj = ImageAsset()
    assets = {"assets/extras.imageattachment_17/image/server-room.png": image_bytes(5, 4)}
    saved_files = []

    _set_files(obj, image_record(), assets, saved_files, dry_run=False)

    assert (obj.image_width, obj.image_height) == (5, 4)
    assert storage.exists(obj.image.name)
    assert saved_files == [(storage, obj.image.name)]

    _cleanup_files(saved_files)
    assert not storage.exists(obj.image.name)


def test_oversized_image_is_resized_after_pillow_bomb_error(monkeypatch):
    monkeypatch.setattr(importer_module, "NETBOX_IMAGE_MAX_PIXELS", 50)
    monkeypatch.setattr(importer_module, "IMPORTED_IMAGE_TARGET_PIXELS", 40)
    monkeypatch.setattr(importer_module, "IMPORTED_IMAGE_SOURCE_MAX_PIXELS", 200)
    monkeypatch.setattr(Image, "MAX_IMAGE_PIXELS", 50)
    field = ImageAsset._meta.get_field("image")
    storage = InMemoryStorage()
    monkeypatch.setattr(field, "storage", storage)
    obj = ImageAsset()
    record = image_record()
    record["id"] = "extras.imageattachment:17"
    assets = {"assets/extras.imageattachment_17/image/server-room.png": image_bytes(11, 10)}
    import_warnings = []
    saved_files = []

    _set_files(
        obj,
        record,
        assets,
        saved_files,
        dry_run=False,
        import_warnings=import_warnings,
    )

    assert obj.image_width * obj.image_height <= 40
    with storage.open(obj.image.name, "rb") as stored_file, Image.open(stored_file) as stored_image:
        assert stored_image.size == (obj.image_width, obj.image_height)
        assert stored_image.format == "PNG"
    assert import_warnings == [
        (
            f"Bild für extras.imageattachment:17 wurde von 11×10 auf "
            f"{obj.image_width}×{obj.image_height} Pixel verkleinert."
        )
    ]
    assert Image.MAX_IMAGE_PIXELS == 50

    _cleanup_files(saved_files)