"""Скачивание образов по ссылке и из каталога: парсер контрольных сумм,
проверка ссылок, фоновая загрузка с локального http-сервера, отмена."""
import hashlib
import lzma
import threading
import time
from http.server import SimpleHTTPRequestHandler, ThreadingHTTPServer
from pathlib import Path
from types import SimpleNamespace
from urllib.parse import unquote

import pytest

import app  # noqa: F401 — подключает features.downloads к приложению
import catalog
import core
import features.downloads as downloads

FIXTURES = Path(__file__).resolve().parent / "fixtures"
MB = 1024 * 1024
SLOW_TOTAL = 4 * MB


class Handler(SimpleHTTPRequestHandler):
    """Раздаёт файлы из каталога www; /slow.iso отдаёт 4 МБ по 64 КБ с паузами, /redirect.iso — перенаправляет."""

    root = ""

    def __init__(self, *args, **kwargs):
        super().__init__(*args, directory=self.root, **kwargs)

    def log_message(self, *args):  # noqa: D102 — тише в тестах
        pass

    def do_GET(self):
        if self.path == "/redirect.iso":
            self.send_response(302)
            self.send_header("Location", "/small.iso")
            self.end_headers()
            return
        if self.path == "/slow.iso":
            self.send_response(200)
            self.send_header("Content-Type", "application/octet-stream")
            self.send_header("Content-Length", str(SLOW_TOTAL))
            self.end_headers()
            try:
                for _ in range(SLOW_TOTAL // (64 * 1024)):
                    self.wfile.write(b"\0" * 64 * 1024)
                    self.wfile.flush()
                    time.sleep(0.05)
            except (BrokenPipeError, ConnectionResetError):
                pass
            return
        super().do_GET()


@pytest.fixture()
def www(tmp_path):
    root = tmp_path / "www"
    root.mkdir()
    (root / "small.iso").write_bytes(b"ISO" * 5000)
    handler = type("TestHandler", (Handler,), {"root": str(root)})
    server = ThreadingHTTPServer(("127.0.0.1", 0), handler)
    thread = threading.Thread(target=server.serve_forever, daemon=True)
    thread.start()
    yield SimpleNamespace(root=root, url=f"http://127.0.0.1:{server.server_port}")
    server.shutdown()
    server.server_close()


def wait_for(operation_id: str, timeout: float = 20.0) -> dict:
    deadline = time.monotonic() + timeout
    while time.monotonic() < deadline:
        operation = core.read_operation(operation_id)
        if operation and operation.get("status") in ("success", "error"):
            return operation
        time.sleep(0.05)
    raise AssertionError("операция не завершилась вовремя")


def wait_until(predicate, timeout: float = 10.0) -> None:
    deadline = time.monotonic() + timeout
    while time.monotonic() < deadline:
        if predicate():
            return
        time.sleep(0.05)
    raise AssertionError("условие не наступило вовремя")


# ---------------------------------------------------------------- parsers & formatting
def test_parse_checksums_ubuntu_star_format():
    text = (FIXTURES / "SHA256SUMS").read_text()
    assert downloads.parse_checksums(text, "resolute-server-cloudimg-amd64.img") == "5861314d7fccb39c2192173240eab44fa35ca66426201ca2acd0630a6258dd51"
    assert downloads.parse_checksums(text, "resolute-server-cloudimg-arm64.img").startswith("f6916295")
    assert downloads.parse_checksums(text, "missing.img") is None


def test_parse_checksums_debian_two_spaces_and_comments():
    text = (FIXTURES / "SHA512SUMS").read_text()
    assert downloads.parse_checksums(text, "debian-13-genericcloud-amd64.qcow2").startswith("1412d62c2d55")
    assert downloads.parse_checksums(text, "debian-13-genericcloud-arm64.qcow2").startswith("27c03aab0b5e")


def test_parse_checksums_alpine_bare_hash_and_bsd_style():
    bare = (FIXTURES / "nocloud_alpine-3.23.0-x86_64-uefi-cloudinit-r0.qcow2.sha512").read_text()
    assert downloads.parse_checksums(bare, "anything.qcow2") == bare.strip().lower()
    bsd = "SHA256 (disk.qcow2) = ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789\n"
    assert downloads.parse_checksums(bsd, "disk.qcow2") == "abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789"
    assert downloads.parse_checksums(bsd, "other.qcow2") is None
    assert downloads.parse_checksums("not a checksum file\n", "disk.qcow2") is None


def test_human_size_and_eta():
    assert downloads.human_size(0) == "0 Б"
    assert downloads.human_size(1023) == "1023 Б"
    assert downloads.human_size(1536) == "1,5 КБ"
    assert downloads.human_size(245 * MB) == "245 МБ"
    assert downloads.human_size(int(3.1 * 1024 * MB)) == "3,1 ГБ"
    assert downloads.human_size(10 * MB) == "10 МБ"
    assert downloads.human_eta(45) == "45 с"
    assert downloads.human_eta(244) == "4 мин"
    assert downloads.human_eta(3700) == "1 ч 2 мин"
    assert downloads.human_eta(7200) == "2 ч"


def test_progress_message():
    assert downloads.progress_message(245 * MB, int(3.1 * 1024 * MB), 12 * MB) == "245 МБ из 3,1 ГБ · 12 МБ/с · осталось 4 мин"
    assert downloads.progress_message(245 * MB, None, 12 * MB) == "245 МБ · 12 МБ/с"
    assert downloads.progress_message(0, 100 * MB, None) == "0 Б из 100 МБ"


# ---------------------------------------------------------------- validation
@pytest.mark.parametrize("url", ["", "ftp://example.org/x.iso", "file:///etc/passwd", "javascript:alert(1)", "http://", "http:///x.iso", "http://example.org/a b.iso"])
def test_validate_url_rejects(url):
    with pytest.raises(downloads.DownloadError):
        downloads.validate_url(url)


def test_filename_from_url_sanitises_and_checks_suffix():
    assert downloads.filename_from_url("https://h.example/a%20b%20(1).ISO?x=1#frag", "iso") == "a-b-_1.iso"
    assert downloads.filename_from_url("https://h.example/dir/debian-13.qcow2", "disk") == "debian-13.qcow2"
    assert downloads.filename_from_url("https://h.example/rpi/2026-01-01-raspios.img.xz", "disk") == "2026-01-01-raspios.img.xz"
    assert downloads.filename_from_url("https://h.example/../../etc.iso", "iso") == "etc.iso"
    for url, kind in (("https://h.example/", "iso"), ("https://h.example/setup.exe", "iso"), ("https://h.example/x.iso", "disk"), ("https://h.example/x.qcow2", "iso")):
        with pytest.raises(downloads.DownloadError):
            downloads.filename_from_url(url, kind)


def test_start_download_refuses_existing_file(data_dirs):
    (data_dirs["iso"] / "small.iso").write_bytes(b"x")
    with pytest.raises(downloads.DownloadError, match="уже есть"):
        downloads.start_download("http://127.0.0.1:9/small.iso", "iso")


def test_start_download_checks_free_space(data_dirs, monkeypatch):
    monkeypatch.setattr(downloads.shutil, "disk_usage", lambda path: SimpleNamespace(free=1000, total=1000, used=0))
    with pytest.raises(downloads.DownloadError, match="мало места"):
        downloads.start_download("http://127.0.0.1:9/small.iso", "iso")


def test_image_candidates():
    assert downloads.image_candidates("a.img.xz") == ["a.img.xz", "a.img", "a.qcow2"]
    assert downloads.image_candidates("a.img") == ["a.img", "a.qcow2"]
    assert downloads.image_candidates("a.qcow2") == ["a.qcow2"]


# ---------------------------------------------------------------- background download
def test_download_iso_success_refreshes_pool(data_dirs, www, monkeypatch):
    calls = []
    monkeypatch.setattr(downloads, "run_cmd", lambda cmd, timeout=12: calls.append(cmd) or {"ok": True, "stdout": "", "stderr": ""})
    operation = downloads.start_download(f"{www.url}/small.iso", "iso")
    assert operation["type"] == "download" and operation["download_kind"] == "iso"
    done = wait_for(operation["id"])
    assert done["status"] == "success", done
    assert done["progress"] == 100
    assert done["total_bytes"] == 15000 and done["downloaded_bytes"] == 15000
    assert (data_dirs["iso"] / "small.iso").read_bytes() == b"ISO" * 5000
    assert not (data_dirs["iso"] / ".small.iso.part").exists()
    assert ["virsh", "pool-refresh", "virtuality-iso"] in calls
    assert "Готово" in done["message"]


def test_download_follows_redirect(data_dirs, www):
    operation = downloads.start_download(f"{www.url}/redirect.iso", "iso")
    done = wait_for(operation["id"])
    assert done["status"] == "success", done
    assert (data_dirs["iso"] / "redirect.iso").stat().st_size == 15000
    assert "Перенаправление" in done["log_tail"]


def test_download_missing_file_fails(data_dirs, www):
    operation = downloads.start_download(f"{www.url}/nope.iso", "iso")
    done = wait_for(operation["id"])
    assert done["status"] == "error"
    assert "404" in done["message"]
    assert not list(data_dirs["iso"].iterdir())


def test_download_refuses_when_disk_fills_up(data_dirs, www, monkeypatch):
    real = downloads.free_space_ok
    seen = []

    def fake(directory, needed):
        seen.append(needed)
        return real(directory, needed) if len(seen) == 1 else (False, 42)

    monkeypatch.setattr(downloads, "free_space_ok", fake)
    operation = downloads.start_download(f"{www.url}/small.iso", "iso")
    done = wait_for(operation["id"])
    assert done["status"] == "error"
    assert "мало места" in done["message"] and "42 Б" in done["message"]
    assert not list(data_dirs["iso"].iterdir())


def test_download_cancel(data_dirs, www, logged_in):
    operation = downloads.start_download(f"{www.url}/slow.iso", "iso")
    wait_until(lambda: (core.read_operation(operation["id"]) or {}).get("status") == "running")
    wait_until(lambda: (data_dirs["iso"] / ".slow.iso.part").exists())
    response = logged_in.post(f"/api/operations/{operation['id']}/cancel")
    assert response.status_code == 200 and response.json()["ok"] is True
    done = wait_for(operation["id"])
    assert done["status"] == "error"
    assert done["message"] == "Скачивание отменено"
    assert done["cancelled"] is True and done["cancel_requested"] is True
    assert not (data_dirs["iso"] / ".slow.iso.part").exists()
    assert not (data_dirs["iso"] / "slow.iso").exists()
    assert not downloads.cancel_requested(operation["id"])


def test_catalog_download_verifies_checksum(data_dirs, www):
    payload = b"QCOW2 image bytes" * 100
    (www.root / "disk.qcow2").write_bytes(payload)
    (www.root / "SHA256SUMS").write_text(f"{hashlib.sha256(payload).hexdigest()} *disk.qcow2\n")
    operation = downloads.start_download(f"{www.url}/disk.qcow2", "disk", sums_url=f"{www.url}/SHA256SUMS", algo="sha256", catalog_id="test")
    done = wait_for(operation["id"])
    assert done["status"] == "success", done
    assert "совпала" in done["log_tail"]
    assert (data_dirs["disk_images"] / "disk.qcow2").read_bytes() == payload


def test_catalog_download_checksum_mismatch_deletes_file(data_dirs, www):
    (www.root / "disk.qcow2").write_bytes(b"corrupted" * 100)
    (www.root / "SHA512SUMS").write_text(f"{'0' * 128}  disk.qcow2\n")
    operation = downloads.start_download(f"{www.url}/disk.qcow2", "disk", sums_url=f"{www.url}/SHA512SUMS", algo="sha512")
    done = wait_for(operation["id"])
    assert done["status"] == "error"
    assert "Контрольная сумма не совпала" in done["message"]
    assert not list(data_dirs["disk_images"].iterdir())


def test_catalog_download_fails_without_sums_entry(data_dirs, www):
    (www.root / "disk.qcow2").write_bytes(b"data")
    (www.root / "SHA256SUMS").write_text(f"{'a' * 64} *other.qcow2\n")
    operation = downloads.start_download(f"{www.url}/disk.qcow2", "disk", sums_url=f"{www.url}/SHA256SUMS", algo="sha256")
    done = wait_for(operation["id"])
    assert done["status"] == "error"
    assert "нет записи" in done["message"]
    assert not list(data_dirs["disk_images"].iterdir())


def test_disk_download_extracts_xz_and_starts_conversion(data_dirs, www, monkeypatch):
    raw = bytes(range(256)) * 256
    (www.root / "pi.img.xz").write_bytes(lzma.compress(raw))
    started = []
    monkeypatch.setattr(app, "start_disk_convert_operation", lambda path: started.append(path) or {"id": "conv-1"})
    operation = downloads.start_download(f"{www.url}/pi.img.xz", "disk")
    done = wait_for(operation["id"])
    assert done["status"] == "success", done
    assert (data_dirs["disk_images"] / "pi.img").read_bytes() == raw
    assert not (data_dirs["disk_images"] / "pi.img.xz").exists()
    assert started == [data_dirs["disk_images"] / "pi.img"]
    assert done["convert_operation_id"] == "conv-1"
    assert "qcow2" in done["message"]


def test_qcow2_download_needs_no_conversion(data_dirs, www, monkeypatch):
    (www.root / "ready.qcow2").write_bytes(b"q" * 10)
    monkeypatch.setattr(app, "start_disk_convert_operation", lambda path: None)
    done = wait_for(downloads.start_download(f"{www.url}/ready.qcow2", "disk")["id"])
    assert done["status"] == "success" and "convert_operation_id" not in done
    assert done["result_path"] == str(data_dirs["disk_images"] / "ready.qcow2")


# ---------------------------------------------------------------- routes
def test_url_route_starts_download(logged_in, data_dirs, www):
    response = logged_in.post("/downloads/url", data={"url": f"{www.url}/small.iso", "kind": "iso"}, follow_redirects=False)
    assert response.status_code == 303
    location = unquote(response.headers["location"])
    assert location.startswith("/iso?download_message=") and "small.iso" in location
    running = downloads.active_downloads("iso")
    assert len(running) == 1 and running[0]["filename"] == "small.iso"
    assert wait_for(running[0]["id"])["status"] == "success"
    assert (data_dirs["iso"] / "small.iso").exists()


def test_url_route_rejects_bad_links(logged_in, data_dirs):
    response = logged_in.post("/downloads/url", data={"url": "ftp://example.org/x.iso", "kind": "iso"}, follow_redirects=False)
    assert response.status_code == 303
    assert "download_error=" in response.headers["location"] and response.headers["location"].startswith("/iso?")
    response = logged_in.post("/downloads/url", data={"url": "https://example.org/setup.exe", "kind": "disk"}, follow_redirects=False)
    assert response.headers["location"].startswith("/disk-images?download_error=")
    assert not core.running_operations("download")


def test_url_route_requires_login(client):
    assert client.post("/downloads/url", data={"url": "https://example.org/x.iso"}, follow_redirects=False).headers["location"] == "/login"
    assert client.post("/api/operations/x/cancel").status_code == 401


def test_catalog_route(logged_in, data_dirs, www, monkeypatch):
    payload = b"debian" * 1000
    (www.root / "debian-13-genericcloud-amd64.qcow2").write_bytes(payload)
    (www.root / "SHA512SUMS").write_text(f"{hashlib.sha512(payload).hexdigest()}  debian-13-genericcloud-amd64.qcow2\n")
    entry = {"id": "debian-13", "title": "Debian 13", "hint": "x", "login": "debian", "arches": {"x86_64": {"url": f"{www.url}/debian-13-genericcloud-amd64.qcow2", "sums": f"{www.url}/SHA512SUMS", "algo": "sha512"}}}
    monkeypatch.setattr(catalog, "CLOUD_IMAGES", [entry])
    monkeypatch.setattr(downloads, "host_arch", lambda: "x86_64")
    monkeypatch.setattr(app, "start_disk_convert_operation", lambda path: None)

    assert unquote(logged_in.post("/downloads/catalog/nope", follow_redirects=False).headers["location"]).startswith("/disk-images?download_error=Такого образа нет")
    response = logged_in.post("/downloads/catalog/debian-13", follow_redirects=False)
    assert response.status_code == 303 and "download_message=" in response.headers["location"]
    page = logged_in.get("/disk-images").text
    assert "Скачивается" in page
    running = downloads.active_downloads("disk")
    assert running[0]["catalog_id"] == "debian-13"
    assert wait_for(running[0]["id"])["status"] == "success"
    assert (data_dirs["disk_images"] / "debian-13-genericcloud-amd64.qcow2").read_bytes() == payload
    page = logged_in.get("/disk-images").text
    assert "Загружен" in page and "/vm/create?image=debian-13-genericcloud-amd64.qcow2" in page
    # второй раз — файл уже есть
    response = logged_in.post("/downloads/catalog/debian-13", follow_redirects=False)
    assert "download_error=" in response.headers["location"]


def test_catalog_route_skips_missing_arch(logged_in, data_dirs, monkeypatch):
    monkeypatch.setattr(catalog, "CLOUD_IMAGES", [{"id": "only-arm", "title": "ARM only", "arches": {"aarch64": {"url": "https://example.org/a.qcow2"}}}])
    monkeypatch.setattr(downloads, "host_arch", lambda: "x86_64")
    location = unquote(logged_in.post("/downloads/catalog/only-arm", follow_redirects=False).headers["location"])
    assert "не выпускается для процессора x86_64" in location
    assert downloads.catalog_entries() == []
    assert "готовых образов в каталоге нет" in logged_in.get("/disk-images").text


def test_cancel_api_rules(logged_in, data_dirs):
    assert logged_in.post("/api/operations/00000000-0000-0000-0000-000000000000/cancel").status_code == 404
    other = core.new_operation("vm_create", "Создание VM x")
    response = logged_in.post(f"/api/operations/{other['id']}/cancel")
    assert response.status_code == 400 and "только скачивание" in response.json()["error"]
    finished = core.new_operation("download", "Скачивание x", download_kind="iso", filename="x.iso")
    core.finish_operation(finished, True, "Готово")
    assert logged_in.post(f"/api/operations/{finished['id']}/cancel").status_code == 409
    running = core.new_operation("download", "Скачивание y", download_kind="disk", filename="y.qcow2")
    core.update_operation(running, status="running")
    response = logged_in.post(f"/api/operations/{running['id']}/cancel")
    assert response.status_code == 200 and response.json()["operation"]["cancel_requested"] is True
    assert downloads.cancel_requested(running["id"])
    downloads.clear_cancel(running["id"])


def test_cancel_form_redirects_to_page(logged_in, data_dirs):
    running = core.new_operation("download", "Скачивание y", download_kind="disk", filename="y.qcow2")
    core.update_operation(running, status="running")
    response = logged_in.post(f"/downloads/{running['id']}/cancel", follow_redirects=False)
    assert response.status_code == 303
    assert unquote(response.headers["location"]).startswith("/disk-images?download_message=Останавливаем скачивание y.qcow2")
    assert unquote(logged_in.post("/downloads/nope/cancel", follow_redirects=False).headers["location"]).startswith("/iso?download_error=")
    downloads.clear_cancel(running["id"])


def test_pages_show_download_cards(logged_in, data_dirs):
    iso_page = logged_in.get("/iso").text
    assert "Скачать по ссылке" in iso_page and 'name="kind" value="iso"' in iso_page
    assert "Скачиваем на сервер" not in iso_page
    disk_page = logged_in.get("/disk-images").text
    assert "Каталог готовых систем" in disk_page and "Рекомендуем" in disk_page and 'name="kind" value="disk"' in disk_page
    running = core.new_operation("download", "Скачивание big.iso", download_kind="iso", filename="big.iso", url="https://example.org/big.iso", total_bytes=None)
    core.update_operation(running, status="running", progress=0, message="Подключаемся к серверу…")
    iso_page = logged_in.get("/iso?download_message=Скачиваем").text
    assert "Скачиваем на сервер" in iso_page and "big.iso" in iso_page and "indeterminate" in iso_page
    assert f"/downloads/{running['id']}/cancel" in iso_page and "Скачиваем</span>" in iso_page
    assert "big.iso" not in logged_in.get("/disk-images").text