如何在Swift中将当前周的第一个日期设置为星期三？

let calendar = Calendar.current

let currentDate = Date()

let currentWeek = calendar.dateComponents([.weekOfYear, .yearForWeekOfYear], from: currentDate)

let firstWeekday = calendar.component(.weekday, from: currentDate)

let offset = (4 - firstWeekday + 7) % 7

var firstDateComponents = DateComponents()
firstDateComponents.weekOfYear = currentWeek.weekOfYear
firstDateComponents.yearForWeekOfYear = currentWeek.yearForWeekOfYear
firstDateComponents.weekday = 4
let firstDate = calendar.date(byAdding: firstDateComponents, to: currentDate, wrappingComponents: false)