from __future__ import annotations

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

import pytest
from pydantic import ValidationError

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


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 make_repo(tmp_path) -> JsonFileTaskRepository:
    return JsonFileTaskRepository(tmp_path / "tasks.json")


def test_create_task_in_empty_storage(tmp_path):
    repo = make_repo(tmp_path)
    task = make_task(title="First task")

    created = repo.create_task(task)
    tasks = repo.list_tasks()

    assert created == task
    assert len(tasks) == 1
    assert tasks[0] == task


def test_create_task_sequentially_preserves_insertion_order(tmp_path):
    repo = make_repo(tmp_path)
    task_1 = make_task(title="First")
    task_2 = make_task(title="Second")

    repo.create_task(task_1)
    repo.create_task(task_2)

    tasks = repo.list_tasks()

    assert [task.id for task in tasks] == [task_1.id, task_2.id]


def test_create_task_invalid_model_rejected_before_repository_call(tmp_path):
    repo = make_repo(tmp_path)

    with pytest.raises(ValidationError):
        StoredTask(
            id=uuid4(),
            title="",
            created_at=datetime.now(UTC),
        )

    assert repo.list_tasks() == []


def test_list_tasks_returns_empty_list_for_fresh_storage(tmp_path):
    repo = make_repo(tmp_path)

    assert repo.list_tasks() == []


def test_list_tasks_returns_persisted_tasks(tmp_path):
    repo = make_repo(tmp_path)
    task_1 = make_task(title="One")
    task_2 = make_task(title="Two")
    repo.create_task(task_1)
    repo.create_task(task_2)

    tasks = repo.list_tasks()

    assert tasks == [task_1, task_2]


def test_get_task_returns_existing_task(tmp_path):
    repo = make_repo(tmp_path)
    task = make_task(title="Lookup me")
    repo.create_task(task)

    found = repo.get_task(task.id)

    assert found == task


def test_get_task_returns_none_for_missing_id(tmp_path):
    repo = make_repo(tmp_path)
    repo.create_task(make_task(title="Other task"))

    found = repo.get_task(uuid4())

    assert found is None


def test_get_task_with_wrong_runtime_type_returns_none_and_does_not_change_storage(tmp_path):
    repo = make_repo(tmp_path)
    task = make_task(title="Type safety")
    repo.create_task(task)

    found = repo.get_task("not-a-uuid")  # type: ignore[arg-type]

    assert found is None
    assert repo.list_tasks() == [task]


def test_update_task_replaces_existing_fields(tmp_path):
    repo = make_repo(tmp_path)
    original = make_task(title="Old title")
    repo.create_task(original)

    updated = StoredTask(
        id=original.id,
        title="New title",
        created_at=original.created_at,
        started_at=original.started_at,
        done_at=original.done_at,
    )

    result = repo.update_task(updated)

    assert result == updated
    assert repo.get_task(original.id) == updated


def test_update_task_persists_transition_related_fields(tmp_path):
    repo = make_repo(tmp_path)
    original = make_task(title="Workflow")
    repo.create_task(original)

    now = datetime.now(UTC)
    updated = StoredTask(
        id=original.id,
        title=original.title,
        created_at=original.created_at,
        started_at=now,
        done_at=now + timedelta(minutes=5),
    )

    repo.update_task(updated)
    reloaded = repo.get_task(original.id)

    assert reloaded is not None
    assert reloaded.started_at == updated.started_at
    assert reloaded.done_at == updated.done_at


def test_update_task_raises_for_missing_task(tmp_path):
    repo = make_repo(tmp_path)
    missing = make_task(title="Missing")

    with pytest.raises(StorageTaskNotFoundError):
        repo.update_task(missing)

    assert repo.list_tasks() == []


def test_delete_task_removes_existing_task(tmp_path):
    repo = make_repo(tmp_path)
    task = make_task(title="Delete me")
    repo.create_task(task)

    deleted = repo.delete_task(task.id)

    assert deleted is True
    assert repo.list_tasks() == []


def test_delete_task_only_affects_requested_task(tmp_path):
    repo = make_repo(tmp_path)
    task_1 = make_task(title="Keep me")
    task_2 = make_task(title="Delete me")
    repo.create_task(task_1)
    repo.create_task(task_2)

    deleted = repo.delete_task(task_2.id)

    assert deleted is True
    assert repo.list_tasks() == [task_1]


def test_delete_task_returns_false_for_missing_task(tmp_path):
    repo = make_repo(tmp_path)
    task = make_task(title="Existing")
    repo.create_task(task)

    deleted = repo.delete_task(uuid4())

    assert deleted is False
    assert repo.list_tasks() == [task]