from unittest import mock

import pytest

from test_fixtures.models import ExecuteResult
from test_fixtures.mysql import MySQLConnection

_SECRET = {
    'host': 'db.example.com',
    'user': 'test',
    'password': 'pass',
    'database': 'mydb',
}


def _make_connection():
    # Patches exit after __init__, but conn._conn already holds the mock reference
    # so subsequent method calls on conn still hit the mock.
    with mock.patch('test_fixtures.mysql.get_secret', return_value=_SECRET):
        with mock.patch('pymysql.connect') as mock_connect:
            conn = MySQLConnection('my/db/secret')
            return conn, mock_connect.return_value


def test_connects_with_secret_credentials():
    with mock.patch('test_fixtures.mysql.get_secret', return_value=_SECRET):
        with mock.patch('pymysql.connect') as mock_connect:
            MySQLConnection('my/db/secret')
            mock_connect.assert_called_once_with(
                host='db.example.com',
                port=3306,
                user='test',
                password='pass',
                database='mydb',
                cursorclass=mock.ANY,
                autocommit=True,
            )


def test_raises_if_secret_is_not_dict():
    with mock.patch('test_fixtures.mysql.get_secret', return_value='not-a-dict'):
        with pytest.raises(ValueError, match='must be a JSON dict'):
            MySQLConnection('my/db/secret')


def test_raises_if_secret_is_missing_required_keys():
    with mock.patch(
        'test_fixtures.mysql.get_secret', return_value={'host': 'db.example.com'}
    ):
        with pytest.raises(ValueError, match='missing required keys'):
            MySQLConnection('my/db/secret')


def test_fetchall():
    conn, mock_pymysql_conn = _make_connection()
    mock_cursor = mock_pymysql_conn.cursor.return_value.__enter__.return_value
    mock_cursor.fetchall.return_value = [{'id': 1}, {'id': 2}]
    result = conn.fetchall('SELECT * FROM foo')
    assert result == [{'id': 1}, {'id': 2}]


def test_fetchone():
    conn, mock_pymysql_conn = _make_connection()
    mock_cursor = mock_pymysql_conn.cursor.return_value.__enter__.return_value
    mock_cursor.fetchone.return_value = {'id': 1}
    result = conn.fetchone('SELECT * FROM foo WHERE id = %s', (1,))
    assert result == {'id': 1}


def test_fetchone_returns_none_when_no_row():
    conn, mock_pymysql_conn = _make_connection()
    mock_pymysql_conn.cursor.return_value.__enter__.return_value.fetchone.return_value = None
    assert conn.fetchone('SELECT * FROM foo WHERE id = %s', (999,)) is None


def test_execute_returns_rowcount_and_rows_when_description_present():
    conn, mock_pymysql_conn = _make_connection()
    mock_cursor = mock_pymysql_conn.cursor.return_value.__enter__.return_value
    mock_cursor.rowcount = 1
    mock_cursor.description = [('id',)]
    mock_cursor.fetchall.return_value = [{'id': 42}]
    result = conn.execute('INSERT INTO foo (x) VALUES (%s) RETURNING id', (1,))
    assert isinstance(result, ExecuteResult)
    assert result.rowcount == 1
    assert result.rows == [{'id': 42}]


def test_execute_rows_empty_when_no_result_set():
    conn, mock_pymysql_conn = _make_connection()
    mock_cursor = mock_pymysql_conn.cursor.return_value.__enter__.return_value
    mock_cursor.rowcount = 3
    mock_cursor.description = None
    result = conn.execute('DELETE FROM foo WHERE status = %s', ('old',))
    assert result.rowcount == 3
    assert result.rows == []
    mock_cursor.fetchall.assert_not_called()


def test_close():
    conn, mock_pymysql_conn = _make_connection()
    conn.close()
    mock_pymysql_conn.close.assert_called_once()


def test_context_manager_closes_on_exit():
    with mock.patch('test_fixtures.mysql.get_secret', return_value=_SECRET):
        with mock.patch('pymysql.connect') as mock_connect:
            with MySQLConnection('my/db/secret') as conn:
                assert conn is not None
            mock_connect.return_value.close.assert_called_once()