from __future__ import annotations

import json
from datetime import UTC, datetime
from uuid import uuid4

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


def make_task(title: str = "Task") -> StoredTask:
    return StoredTask(
        id=uuid4(),
        title=title,
        created_at=datetime.now(UTC),
        started_at=None,
        done_at=None,
    )


def test_corrupted_json_triggers_backup_and_reset(tmp_path):
    file_path = tmp_path / "tasks.json"
    file_path.write_text('{"version": 1, "tasks": [', encoding="utf-8")

    repo = JsonFileTaskRepository(file_path)

    assert repo.list_tasks() == []

    backups = list(tmp_path.glob("tasks.json.corrupted*"))
    assert len(backups) == 1
    assert backups[0].read_text(encoding="utf-8") == '{"version": 1, "tasks": ['

    restored = json.loads(file_path.read_text(encoding="utf-8"))
    assert restored["version"] == DATA_FORMAT_VERSION
    assert restored["tasks"] == []


def test_invalid_schema_triggers_backup_and_reset(tmp_path):
    file_path = tmp_path / "tasks.json"
    file_path.write_text(
        json.dumps(
            {
                "version": 1,
                "tasks": [
                    {
                        "id": str(uuid4()),
                        "created_at": datetime.now(UTC).isoformat(),
                    },
                ],
            },
        ),
        encoding="utf-8",
    )

    repo = JsonFileTaskRepository(file_path)

    assert repo.list_tasks() == []
    backups = list(tmp_path.glob("tasks.json.corrupted*"))
    assert len(backups) == 1


def test_repository_remains_writable_after_recovery(tmp_path):
    file_path = tmp_path / "tasks.json"
    file_path.write_text("not valid json", encoding="utf-8")
    repo = JsonFileTaskRepository(file_path)

    task = make_task("Recovered")
    repo.create_task(task)

    assert repo.list_tasks() == [task]


def test_unsupported_version_creates_backup_and_resets_state(tmp_path):
    file_path = tmp_path / "tasks.json"
    file_path.write_text(
        json.dumps({"version": 999, "tasks": []}),
        encoding="utf-8",
    )

    repo = JsonFileTaskRepository(file_path)

    assert repo.list_tasks() == []
    backups = list(tmp_path.glob("tasks.json.corrupted*"))
    assert len(backups) == 1

    restored = json.loads(file_path.read_text(encoding="utf-8"))
    assert restored["version"] == DATA_FORMAT_VERSION
    assert restored["tasks"] == []


def test_restart_after_corrupted_persisted_state_does_not_crash(tmp_path):
    file_path = tmp_path / "tasks.json"
    repo_1 = JsonFileTaskRepository(file_path)
    repo_1.create_task(make_task("Initial"))

    file_path.write_text("{broken", encoding="utf-8")

    repo_2 = JsonFileTaskRepository(file_path)

    assert repo_2.list_tasks() == []
    assert len(list(tmp_path.glob("tasks.json.corrupted*"))) == 1