Files
suixinkan_uikit/suixinkan/Features/OfflineCollection/Models/OfflineCollectionCalendarModel.swift
T

111 lines
4.8 KiB
Swift

import Foundation
/// 日清日历的展示模式。
enum OfflineCollectionCalendarMode: Sendable, Equatable {
case week
case month
}
/// 周/月日历日期运算状态,不依赖 UIKit,便于单元测试。
struct OfflineCollectionCalendarState: Sendable, Equatable {
private let calendar: Calendar
private(set) var selectedDate: Date
private(set) var maximumDate: Date
private(set) var mode: OfflineCollectionCalendarMode
init(
selectedDate: Date,
maximumDate: Date,
mode: OfflineCollectionCalendarMode = .week,
calendar: Calendar = OfflineCollectionDate.calendar
) {
self.calendar = calendar
self.maximumDate = calendar.startOfDay(for: maximumDate)
self.selectedDate = min(calendar.startOfDay(for: selectedDate), self.maximumDate)
self.mode = mode
}
/// 切换周历和月历并保留选中日期。
mutating func toggleMode() {
mode = mode == .week ? .month : .week
}
/// 选择不晚于服务端今日的日期。
mutating func select(_ date: Date) -> Bool {
let value = calendar.startOfDay(for: date)
guard value <= maximumDate else { return false }
selectedDate = value
return true
}
/// 横滑一个周或一个月,并返回新的选中日期。
@discardableResult
mutating func movePage(_ offset: Int) -> Date {
let candidate: Date
switch mode {
case .week:
candidate = calendar.date(byAdding: .day, value: offset * 7, to: selectedDate) ?? selectedDate
case .month:
let current = calendar.dateComponents([.year, .month, .day], from: selectedDate)
let monthStart = calendar.date(from: DateComponents(year: current.year, month: current.month, day: 1)) ?? selectedDate
let targetMonth = calendar.date(byAdding: .month, value: offset, to: monthStart) ?? monthStart
let days = calendar.range(of: .day, in: .month, for: targetMonth)?.count ?? 1
candidate = calendar.date(byAdding: .day, value: min(current.day ?? 1, days) - 1, to: targetMonth) ?? targetMonth
}
selectedDate = min(calendar.startOfDay(for: candidate), maximumDate)
return selectedDate
}
/// 判断指定方向是否存在不晚于服务端今日的周或月页面。
func canMovePage(_ offset: Int) -> Bool {
guard offset != 0 else { return false }
if offset < 0 { return true }
switch mode {
case .week:
guard let candidate = calendar.date(byAdding: .day, value: offset * 7, to: selectedDate) else { return false }
let weekday = calendar.component(.weekday, from: candidate)
let daysFromMonday = (weekday + 5) % 7
let targetMonday = calendar.date(byAdding: .day, value: -daysFromMonday, to: candidate) ?? candidate
return calendar.startOfDay(for: targetMonday) <= maximumDate
case .month:
let current = calendar.dateComponents([.year, .month], from: selectedDate)
guard let monthStart = calendar.date(from: current),
let targetMonth = calendar.date(byAdding: .month, value: offset, to: monthStart) else { return false }
let maximumMonth = calendar.date(
from: calendar.dateComponents([.year, .month], from: maximumDate)
) ?? maximumDate
return targetMonth <= maximumMonth
}
}
/// 当前周的周一至周日。
var weekDates: [Date] {
let weekday = calendar.component(.weekday, from: selectedDate)
let daysFromMonday = (weekday + 5) % 7
let monday = calendar.date(byAdding: .day, value: -daysFromMonday, to: selectedDate) ?? selectedDate
return (0 ..< 7).compactMap { calendar.date(byAdding: .day, value: $0, to: monday) }
}
/// 当前月份固定六行、周一开周的 42 个日期。
var monthDates: [Date] {
let parts = calendar.dateComponents([.year, .month], from: selectedDate)
let first = calendar.date(from: parts) ?? selectedDate
let weekday = calendar.component(.weekday, from: first)
let leading = (weekday + 5) % 7
let start = calendar.date(byAdding: .day, value: -leading, to: first) ?? first
return (0 ..< 42).compactMap { calendar.date(byAdding: .day, value: $0, to: start) }
}
/// 当前选中日期所在周在固定六行月历中的零基行号。
var selectedWeekRowIndex: Int {
let index = monthDates.firstIndex { calendar.isDate($0, inSameDayAs: selectedDate) } ?? 0
return index / 7
}
/// 当前选中月份标题。
var monthTitle: String {
let parts = calendar.dateComponents([.year, .month], from: selectedDate)
return "\(parts.year ?? 0)年\(parts.month ?? 0)月"
}
}