"""Turning a catalog cloud image (qcow2/raw) into a VMDK vSphere can import."""

from __future__ import annotations

import hashlib
import shutil
import subprocess

import pytest

from napalm_vmware.provision import image as image_mod
from napalm_vmware.provision.image import ImageCache

URL = "https://cloud.example.org/debian-13-genericcloud-amd64.qcow2"
CONTENT = b"qcow2-bytes"
SHA = hashlib.sha256(CONTENT).hexdigest()


class _Fake:
    def __init__(self, payloads=(CONTENT,)):
        self.payloads = list(payloads)
        self.fetched = 0
        self.converted = 0

    def fetch(self, url, dest, timeout):
        dest.write_bytes(self.payloads[min(self.fetched, len(self.payloads) - 1)])
        self.fetched += 1

    def convert(self, src, dst):
        dst.write_bytes(b"vmdk:" + src.read_bytes())
        self.converted += 1

    def size(self, path):
        return 2 * 1024**3


def _cache(tmp_path, fake):
    return ImageCache(tmp_path, fetch=fake.fetch, convert=fake.convert, virtual_size=fake.size)


def test_first_use_downloads_and_converts(tmp_path):
    fake = _Fake()
    vmdk, size = _cache(tmp_path, fake).vmdk(URL, f"sha256:{SHA}", timeout=60)
    assert vmdk.read_bytes() == b"vmdk:" + CONTENT
    assert size == 2 * 1024**3
    assert (fake.fetched, fake.converted) == (1, 1)


def test_second_use_is_served_from_the_cache(tmp_path):
    fake = _Fake()
    _cache(tmp_path, fake).vmdk(URL, None, timeout=60)
    vmdk, size = _cache(tmp_path, fake).vmdk(URL, None, timeout=60)
    assert (fake.fetched, fake.converted) == (1, 1)
    assert size == 2 * 1024**3


def test_the_download_is_not_kept_after_conversion(tmp_path):
    _cache(tmp_path, _Fake()).vmdk(URL, None, timeout=60)
    assert [p.suffix for p in tmp_path.iterdir()] and not list(tmp_path.glob("*.download"))


def test_a_corrupt_download_is_retried_once(tmp_path):
    fake = _Fake(payloads=(b"truncated", CONTENT))
    vmdk, _ = _cache(tmp_path, fake).vmdk(URL, f"sha256:{SHA}", timeout=60)
    assert fake.fetched == 2
    assert vmdk.read_bytes() == b"vmdk:" + CONTENT


def test_a_persistent_mismatch_is_an_error(tmp_path):
    fake = _Fake(payloads=(b"wrong",))
    with pytest.raises(RuntimeError, match="Checksum mismatch"):
        _cache(tmp_path, fake).vmdk(URL, f"sha256:{SHA}", timeout=60)
    assert fake.converted == 0
    assert not list(tmp_path.glob("*.vmdk"))


def test_bare_hex_checksum_means_sha256(tmp_path):
    _cache(tmp_path, _Fake()).vmdk(URL, SHA, timeout=60)


def test_different_urls_do_not_share_a_cache_entry(tmp_path):
    fake = _Fake()
    cache = _cache(tmp_path, fake)
    cache.vmdk(URL, None, timeout=60)
    cache.vmdk(URL + "?v=2", None, timeout=60)
    assert fake.converted == 2


def test_missing_qemu_img_is_explained(monkeypatch, tmp_path):
    monkeypatch.setattr(image_mod.shutil, "which", lambda name: None)
    with pytest.raises(RuntimeError, match="qemu-img"):
        image_mod.convert_to_vmdk(tmp_path / "a", tmp_path / "b")


@pytest.mark.skipif(not shutil.which("qemu-img"), reason="qemu-img not installed")
def test_real_conversion_round_trip(tmp_path):
    raw = tmp_path / "disk.raw"
    subprocess.run(
        ["qemu-img", "create", "-f", "raw", str(raw), "64M"], check=True, capture_output=True
    )
    vmdk = tmp_path / "disk.vmdk"
    image_mod.convert_to_vmdk(raw, vmdk)
    info = subprocess.run(
        ["qemu-img", "info", str(vmdk)], check=True, capture_output=True, text=True
    ).stdout
    assert "streamOptimized" in info
    assert image_mod.virtual_size(raw) == 64 * 1024**2