from pathlib import PurePosixPath

import msgspec
import pytest

from cista.protocol import FileEntry, UpdateMessage, UpdDel, UpdIns, UpdKeep
from cista.watching import State, format_update


def decode(data: str):
    return msgspec.json.decode(data, type=UpdateMessage).update


# Helper function to create a list of FileEntry objects
def f(count, start=0):
    return [FileEntry(i, str(i), str(i), 0, 0, 0) for i in range(start, start + count)]


def test_identical_lists():
    old_list = f(3)
    new_list = old_list.copy()
    expected = [UpdKeep(3)]
    assert decode(format_update(old_list, new_list)) == expected


def test_completely_different_lists():
    old_list = f(3)
    new_list = f(3, 3)  # Different entries
    expected = [UpdDel(3), UpdIns(new_list)]
    assert decode(format_update(old_list, new_list)) == expected


def test_insertions():
    old_list = f(3)
    new_list = old_list[:2] + f(1, 10) + old_list[2:]
    expected = [UpdKeep(2), UpdIns(f(1, 10)), UpdKeep(1)]
    assert decode(format_update(old_list, new_list)) == expected


def test_deletions():
    old_list = f(3)
    new_list = [old_list[0], old_list[2]]
    expected = [UpdKeep(1), UpdDel(1), UpdKeep(1)]
    assert decode(format_update(old_list, new_list)) == expected


def test_mixed_operations():
    old_list = f(4)
    new_list = [old_list[0], old_list[2], *f(1, 10)]
    expected = [UpdKeep(1), UpdDel(1), UpdKeep(1), UpdDel(1), UpdIns(f(1, 10))]
    assert decode(format_update(old_list, new_list)) == expected


def test_empty_old_list():
    old_list = []
    new_list = f(3)
    expected = [UpdIns(new_list)]
    assert decode(format_update(old_list, new_list)) == expected


def test_empty_new_list():
    old_list = f(3)
    new_list = []
    expected = [UpdDel(3)]
    assert decode(format_update(old_list, new_list)) == expected


def test_longer_lists():
    old_list = f(6)
    new_list = f(1, 6) + old_list[1:3] + old_list[4:5] + f(2, 7)
    expected = [
        UpdDel(1),
        UpdIns(f(1, 6)),
        UpdKeep(2),
        UpdDel(1),
        UpdKeep(1),
        UpdDel(1),
        UpdIns(f(2, 7)),
    ]
    assert decode(format_update(old_list, new_list)) == expected


def sortkey(name):
    # Define the sorting key for names here
    return name.lower()


@pytest.fixture()
def state():
    entries = [
        FileEntry(0, "", "root", 0, 0, 0),
        FileEntry(1, "bar", "bar", 0, 0, 0),
        FileEntry(2, "baz", "bar/baz", 0, 0, 0),
        FileEntry(1, "foo", "foo", 0, 0, 0),
        FileEntry(1, "xxx", "xxx", 0, 0, 0),
        FileEntry(2, "yyy", "xxx/yyy", 0, 0, 1),
    ]
    s = State()
    s._listing = entries
    return s


def test_existing_directory(state):
    path = PurePosixPath("bar")
    expected_slice = slice(1, 3)  # Includes 'bar' and 'baz'
    assert state._slice(path) == expected_slice


def test_existing_file(state):
    path = PurePosixPath("xxx/yyy")
    expected_slice = slice(5, 6)  # Only includes 'yyy'
    assert state._slice(path) == expected_slice


def test_nonexistent_directory(state):
    path = PurePosixPath("zzz")
    expected_slice = slice(6, 6)  # 'zzz' would be inserted at end
    assert state._slice(path) == expected_slice


def test_nonexistent_file(state):
    path = (PurePosixPath("bar/mmm"), 1)
    expected_slice = slice(3, 3)  # A file would be inserted after 'baz' under 'bar'
    assert state._slice(path) == expected_slice


def test_root_directory(state):
    path = PurePosixPath()
    expected_slice = slice(0, 6)  # Entire tree
    assert state._slice(path) == expected_slice


def test_directory_with_subdirs_and_files(state):
    path = PurePosixPath("xxx")
    expected_slice = slice(4, 6)  # Includes 'xxx' and 'yyy'
    assert state._slice(path) == expected_slice