from __future__ import annotations

from datetime import UTC, datetime, timedelta
from uuid import uuid4

from app.storage import DATA_FORMAT_VERSION, StoredTask
from app.storage.repository import JsonFileTaskRepository


def make_task(
    *,
    title: str = "Task",
    started: bool = False,
    done: bool = False,
) -> StoredTask:
    now = datetime.now(UTC)
    started_at = now + timedelta(seconds=1) if started else None
    done_at = now + timedelta(seconds=2) if done else None
    return StoredTask(
        id=uuid4(),
        title=title,
        created_at=now,
        started_at=started_at,
        done_at=done_at,
    )


def test_replace_all_replaces_empty_state_with_provided_tasks(tmp_path):
    repo = JsonFileTaskRepository(tmp_path / "tasks.json")
    task_1 = make_task(title="One")
    task_2 = make_task(title="Two")

    repo.replace_all([task_1, task_2])

    assert repo.list_tasks() == [task_1, task_2]


def test_replace_all_fully_overwrites_previous_content(tmp_path):
    repo = JsonFileTaskRepository(tmp_path / "tasks.json")
    old_task = make_task(title="Old")
    new_task = make_task(title="New")
    repo.create_task(old_task)

    repo.replace_all([new_task])

    assert repo.list_tasks() == [new_task]


def test_data_format_version_matches_constant(tmp_path):
    repo = JsonFileTaskRepository(tmp_path / "tasks.json")

    assert repo.data_format_version == DATA_FORMAT_VERSION


def test_data_format_version_is_stable_across_instances(tmp_path):
    file_path = tmp_path / "tasks.json"

    repo_1 = JsonFileTaskRepository(file_path)
    repo_2 = JsonFileTaskRepository(file_path)

    assert repo_1.data_format_version == repo_2.data_format_version == DATA_FORMAT_VERSION


def test_missing_file_is_created_automatically(tmp_path):
    file_path = tmp_path / "nested" / "tasks.json"

    repo = JsonFileTaskRepository(file_path)

    assert repo.list_tasks() == []
    assert file_path.exists()


def test_existing_valid_file_is_loaded_on_new_instance(tmp_path):
    file_path = tmp_path / "tasks.json"
    repo_1 = JsonFileTaskRepository(file_path)
    task = make_task(title="Persisted")
    repo_1.create_task(task)

    repo_2 = JsonFileTaskRepository(file_path)

    assert repo_2.list_tasks() == [task]


def test_parent_directory_is_created_if_missing(tmp_path):
    file_path = tmp_path / "deep" / "nested" / "data" / "tasks.json"

    repo = JsonFileTaskRepository(file_path)

    assert file_path.parent.exists()
    assert repo.list_tasks() == []


def test_current_version_payload_loads_as_is(tmp_path):
    file_path = tmp_path / "tasks.json"
    repo_1 = JsonFileTaskRepository(file_path)
    task = make_task(title="Versioned")
    repo_1.create_task(task)

    repo_2 = JsonFileTaskRepository(file_path)

    assert repo_2.data_format_version == DATA_FORMAT_VERSION
    assert repo_2.list_tasks() == [task]


def test_empty_current_version_payload_loads_without_backup(tmp_path):
    file_path = tmp_path / "tasks.json"
    repo = JsonFileTaskRepository(file_path)

    assert repo.list_tasks() == []
    assert not list(tmp_path.glob("tasks.json.corrupted*"))


def test_persistence_between_repository_instances(tmp_path):
    file_path = tmp_path / "tasks.json"
    repo_1 = JsonFileTaskRepository(file_path)
    task = make_task(title="Cross-session")
    repo_1.create_task(task)

    repo_2 = JsonFileTaskRepository(file_path)

    assert repo_2.get_task(task.id) == task


def test_multiple_operations_survive_restart(tmp_path):
    file_path = tmp_path / "tasks.json"
    repo_1 = JsonFileTaskRepository(file_path)

    task_1 = make_task(title="First")
    task_2 = make_task(title="Second")
    repo_1.create_task(task_1)
    repo_1.create_task(task_2)
    repo_1.delete_task(task_1.id)

    updated_task_2 = StoredTask(
        id=task_2.id,
        title="Second updated",
        created_at=task_2.created_at,
        started_at=datetime.now(UTC),
        done_at=None,
    )
    repo_1.update_task(updated_task_2)

    repo_2 = JsonFileTaskRepository(file_path)

    assert repo_2.list_tasks() == [updated_task_2]