import csv
import io

import pytest
from django.contrib.auth.models import User
from django.core.management import CommandError, call_command

from dnscms.models import GaltinnUser

pytestmark = pytest.mark.django_db


def write_csv(tmp_path, rows):
    path = tmp_path / "users.csv"
    with path.open("w", newline="") as f:
        writer = csv.DictWriter(f, fieldnames=["cms_id", "username", "galtinn_id"])
        writer.writeheader()
        writer.writerows(rows)
    return str(path)


def run(*args):
    out = io.StringIO()
    call_command("galtinn_users", *args, stdout=out)
    return out.getvalue()


@pytest.fixture
def kari():
    return User.objects.create_user(username="kari", email="kari@neuf.test", password="pw")


@pytest.fixture
def ola():
    return User.objects.create_superuser(username="ola", email="ola@neuf.test", password="pw")


def test_export_lists_users_with_existing_links(kari, ola):
    GaltinnUser.objects.create(user=kari, galtinn_id="42")

    rows = list(csv.DictReader(io.StringIO(run("export"))))

    assert [(row["username"], row["galtinn_id"], row["is_superuser"]) for row in rows] == [
        ("kari", "42", "0"),
        ("ola", "", "1"),
    ]
    assert rows[0]["cms_id"] == str(kari.pk)
    assert rows[0]["email"] == "kari@neuf.test"


def test_link_is_a_dry_run_by_default(tmp_path, kari):
    path = write_csv(tmp_path, [{"cms_id": kari.pk, "username": "kari", "galtinn_id": "42"}])

    output = run("link", path)

    assert "kari -> Galtinn #42" in output
    assert "Dry run" in output
    assert not GaltinnUser.objects.exists()


def test_link_apply_links_filled_rows_and_keeps_passwords(tmp_path, kari, ola):
    path = write_csv(
        tmp_path,
        [
            {"cms_id": kari.pk, "username": "kari", "galtinn_id": " 42 "},
            {"cms_id": ola.pk, "username": "ola", "galtinn_id": ""},
        ],
    )

    run("link", path, "--apply")

    assert GaltinnUser.objects.get().galtinn_id == "42"
    assert kari.galtinn_user.galtinn_id == "42"
    kari.refresh_from_db()
    assert kari.has_usable_password()


def test_link_apply_is_repeatable(tmp_path, kari):
    path = write_csv(tmp_path, [{"cms_id": kari.pk, "username": "kari", "galtinn_id": "42"}])

    run("link", path, "--apply")
    output = run("link", path, "--apply")

    assert "Linked 0 users" in output
    assert GaltinnUser.objects.count() == 1


@pytest.mark.parametrize(
    ("rows", "message"),
    [
        ([{"cms_id": 999, "username": "ghost", "galtinn_id": "1"}], "does not exist"),
        (
            [{"cms_id": "KARI", "username": "someone-else", "galtinn_id": "1"}],
            "not 'someone-else'",
        ),
        ([{"cms_id": "KARI", "username": "kari", "galtinn_id": "7"}], "already linked"),
        (
            [
                {"cms_id": "OLA", "username": "ola", "galtinn_id": "1"},
                {"cms_id": "OLA2", "username": "ola2", "galtinn_id": "1"},
            ],
            "more than one user",
        ),
        ([{"cms_id": "OLA", "username": "ola", "galtinn_id": "42"}], "more than one user"),
    ],
)
def test_link_refuses_the_whole_file_on_any_bad_row(tmp_path, kari, ola, rows, message):
    GaltinnUser.objects.create(user=kari, galtinn_id="42")
    ola2 = User.objects.create_user(username="ola2")
    ids = {"KARI": kari.pk, "OLA": ola.pk, "OLA2": ola2.pk}
    good = {"cms_id": ola2.pk, "username": "ola2", "galtinn_id": "500"}
    rows = [{**row, "cms_id": ids.get(row["cms_id"], row["cms_id"])} for row in rows]

    with pytest.raises(CommandError, match=message):
        run("link", write_csv(tmp_path, [*rows, good]), "--apply")

    assert GaltinnUser.objects.count() == 1