import pytest
import yaml

from modules.inventory import common as inventory_common
from modules.inventory.migrate import migrate_legacy_inventory, normalize_unit


def test_normalize_unit():
    assert normalize_unit('pound') == 'lb'
    assert normalize_unit('pounds') == 'lb'
    assert normalize_unit('lbs') == 'lb'
    # Already-valid mathjs units pass through unchanged.
    assert normalize_unit('oz') == 'oz'
    assert normalize_unit('gallon') == 'gallon'
    assert normalize_unit(None) is None


def _write_legacy(config, inventories):
    legacy_file = config.get_directory().parent / 'inventories.yaml'
    legacy_file.parent.mkdir(parents=True, exist_ok=True)
    with legacy_file.open('wt') as fh:
        yaml.dump(dict(version=1, inventories=inventories), fh)
    return legacy_file


def test_migrate_legacy_yaml(test_inventory_configs):
    config = test_inventory_configs
    legacy_file = _write_legacy(config, [
        dict(name='Food Storage', created_at='2024-01-01', deleted_at=None, items=[
            dict(id=1, inventory_id=1, brand='Ocean', name='Salt', item_size='25', unit='pound', count='8',
                 category='cooking ingredients', subcategory='salt', expiration_date='2030-01-01'),
            dict(id=2, inventory_id=1, brand='deleted', name='Old', item_size='1', unit='oz', count='1',
                 deleted_at='2020-01-01'),
        ]),
    ])

    assert migrate_legacy_inventory(config) is True
    config.import_all()

    inventories = config.all_inventories()
    assert len(inventories) == 1
    slug = inventories[0]['slug']
    inventory = config.get_inventory(slug)
    assert inventory['name'] == 'Food Storage'
    assert inventory['type'] == 'food'
    # The soft-deleted legacy item is dropped.
    assert len(inventory['items']) == 1
    item = inventory['items'][0]
    assert item['name'] == 'Salt'
    # Legacy pint unit 'pound' is normalized to mathjs 'lb'.
    assert item['item_size_unit'] == 'lb'

    # The legacy file is retired (renamed) and backed up so it is not migrated again.
    assert not legacy_file.is_file()
    assert legacy_file.with_suffix('.yaml.migrated').is_file()


def test_migrate_is_idempotent(test_inventory_configs):
    config = test_inventory_configs
    _write_legacy(config, [dict(name='Food', items=[])])
    assert migrate_legacy_inventory(config) is True
    config.import_all()
    # Second run does nothing because per-inventory files now exist.
    assert migrate_legacy_inventory(config) is False
    config.import_all()
    assert len(config.all_inventories()) == 1


def test_migrate_no_legacy_data(test_inventory_configs):
    config = test_inventory_configs
    assert migrate_legacy_inventory(config) is False
    assert config.all_inventories() == []


def test_migrate_dedupes_same_named_inventories(test_inventory_configs):
    """Multiple inventories with the same name get distinct slugs (food, food-2, food-3) with no data loss."""
    config = test_inventory_configs
    _write_legacy(config, [
        dict(name='Food', items=[]),
        dict(name='Food', items=[]),
        dict(name='Food', items=[]),
    ])
    assert migrate_legacy_inventory(config) is True
    config.import_all()
    slugs = sorted(i['slug'] for i in config.all_inventories())
    assert slugs == ['food', 'food-2', 'food-3']
    assert len(config.all_inventories()) == 3  # none dropped


@pytest.mark.asyncio
async def test_import_seeds_defaults_when_empty(test_inventory_configs, async_client):
    """A fresh install with no legacy data seeds the default example inventory."""
    config = test_inventory_configs
    inventory_common.import_inventories_config()
    inventories = config.all_inventories()
    assert any(i['name'] == 'Food Storage' for i in inventories)