from unittest import mock

import pytest

from test_fixtures.crud import (
    clone_row,
    delete_entity,
    get_entity,
    insert_entity,
    update_entity,
)
from test_fixtures.models import ExecuteResult


def _conn():
    conn = mock.Mock()
    conn.execute.return_value = ExecuteResult(rowcount=1, rows=[])
    conn.fetchone.return_value = None
    return conn


def test_get_entity_builds_where_clause():
    conn = _conn()
    conn.fetchone.return_value = {'id': 1, 'name': 'a'}
    result = get_entity(conn, 'widget', {'vendor_id': 7, 'status': 'new'})
    assert result == {'id': 1, 'name': 'a'}
    conn.fetchone.assert_called_once_with(
        'SELECT * FROM `widget` WHERE `vendor_id` = %s AND `status` = %s',
        (7, 'new'),
    )


def test_get_entity_no_conditions_selects_all():
    conn = _conn()
    get_entity(conn, 'widget', {})
    conn.fetchone.assert_called_once_with('SELECT * FROM `widget`', ())


def test_get_entity_none_condition_uses_is_null():
    conn = _conn()
    get_entity(conn, 'widget', {'deleted_at': None})
    conn.fetchone.assert_called_once_with(
        'SELECT * FROM `widget` WHERE `deleted_at` IS NULL', ()
    )


def test_insert_entity_without_id_column_returns_none():
    conn = _conn()
    result = insert_entity(conn, 'widget', {'name': 'a', 'vendor_id': 7})
    assert result is None
    conn.execute.assert_called_once_with(
        'INSERT INTO `widget` (`name`, `vendor_id`) VALUES (%s, %s)',
        ('a', 7),
    )
    conn.fetchone.assert_not_called()


def test_insert_entity_fetches_by_last_insert_id_for_autoincrement():
    conn = _conn()
    conn.fetchone.return_value = {'widget_id': 42, 'name': 'a'}
    result = insert_entity(conn, 'widget', {'name': 'a'}, id_column='widget_id')
    assert result == {'widget_id': 42, 'name': 'a'}
    conn.fetchone.assert_called_once_with(
        'SELECT * FROM `widget` WHERE `widget_id` = LAST_INSERT_ID()'
    )


def test_insert_entity_fetches_by_supplied_id():
    conn = _conn()
    conn.fetchone.return_value = {'widget_id': 'abc', 'name': 'a'}
    result = insert_entity(
        conn, 'widget', {'widget_id': 'abc', 'name': 'a'}, id_column='widget_id'
    )
    assert result == {'widget_id': 'abc', 'name': 'a'}
    conn.fetchone.assert_called_once_with(
        'SELECT * FROM `widget` WHERE `widget_id` = %s', ('abc',)
    )


def test_insert_entity_requires_values():
    conn = _conn()
    with pytest.raises(ValueError, match='at least one column'):
        insert_entity(conn, 'widget', {})


def test_update_entity_returns_rowcount():
    conn = _conn()
    conn.execute.return_value = ExecuteResult(rowcount=2, rows=[])
    affected = update_entity(
        conn, 'widget', {'vendor_id': 7}, {'status': 'done', 'name': 'b'}
    )
    assert affected == 2
    conn.execute.assert_called_once_with(
        'UPDATE `widget` SET `status` = %s, `name` = %s WHERE `vendor_id` = %s',
        ('done', 'b', 7),
    )


def test_update_entity_requires_conditions():
    conn = _conn()
    with pytest.raises(ValueError, match='conditions'):
        update_entity(conn, 'widget', {}, {'status': 'done'})


def test_update_entity_requires_values():
    conn = _conn()
    with pytest.raises(ValueError, match='at least one column'):
        update_entity(conn, 'widget', {'vendor_id': 7}, {})


def test_delete_entity_returns_rowcount():
    conn = _conn()
    conn.execute.return_value = ExecuteResult(rowcount=3, rows=[])
    affected = delete_entity(conn, 'widget', {'vendor_id': 7})
    assert affected == 3
    conn.execute.assert_called_once_with(
        'DELETE FROM `widget` WHERE `vendor_id` = %s', (7,)
    )


def test_delete_entity_requires_conditions():
    conn = _conn()
    with pytest.raises(ValueError, match='conditions'):
        delete_entity(conn, 'widget', {})
    conn.execute.assert_not_called()


def test_clone_row_drops_id_and_applies_overrides():
    conn = _conn()
    # First fetchone: source row. Second fetchone: inserted clone.
    conn.fetchone.side_effect = [
        {'widget_id': 1, 'name': 'a', 'vendor_id': 7},
        {'widget_id': 2, 'name': 'a', 'vendor_id': 8},
    ]
    result = clone_row(
        conn,
        'widget',
        {'widget_id': 1},
        overrides={'vendor_id': 8},
        id_column='widget_id',
    )
    assert result == {'widget_id': 2, 'name': 'a', 'vendor_id': 8}
    # The INSERT omits widget_id (auto-generated) and carries the override.
    conn.execute.assert_called_once_with(
        'INSERT INTO `widget` (`name`, `vendor_id`) VALUES (%s, %s)',
        ('a', 8),
    )


def test_clone_row_raises_when_source_missing():
    conn = _conn()
    conn.fetchone.return_value = None
    with pytest.raises(LookupError, match='to clone'):
        clone_row(conn, 'widget', {'widget_id': 999}, id_column='widget_id')


def test_identifier_injection_is_rejected():
    conn = _conn()
    with pytest.raises(ValueError, match='Invalid SQL identifier'):
        get_entity(conn, 'widget`; DROP TABLE users; --', {'id': 1})


def test_empty_identifier_is_rejected():
    conn = _conn()
    with pytest.raises(ValueError, match='Invalid SQL identifier'):
        get_entity(conn, '', {'id': 1})
    with pytest.raises(ValueError, match='Invalid SQL identifier'):
        insert_entity(conn, 'widget', {'': 1})