Schedule list example

Schedule.swift

//
//  ScrollToItem.swift
//  SwiftUIArchitectureSample
//
//  Created by Ivan Andreyshev on 04.10.2024.
//

import SwiftUI

struct ScheduleView: View {
    @StateObject
    private var viewModel = ScheduleViewModel()
    @State
    private var scrolledID: Int?

    var body: some View {
        VStack(spacing: 0) {
            HStack(alignment: .top) {
                ForEach(0..<viewModel.state.days.count, id: \.self) { index in
                    let day = viewModel.state.days[index]

                    Button(day.date.titleForDaysList()) {
                        withAnimation {
                            scrolledID = day.itemPosToScroll
                        }
                    }
                    .font(.title)
                    .frame(maxWidth: .infinity)
                }
            }
            .padding(.vertical, 20)
            .background(.red)

            ScrollView {
                LazyVStack(spacing: 20) {
                    ForEach(0..<viewModel.state.meetings.count, id: \.self) { index in
                        let item = viewModel.state.meetings[index]

                        VStack(spacing: 0) {
                            switch item {
                            case .emptyDay(let date):
                                Text(date.formatted(date: .complete, time: .omitted))
                                    .padding(.vertical, 20)
                                    .id(index)
                                Text("В этот день нет пар, радуйтесь")
                            case .meeting(let meeting):
                                if meeting.isFirst {
                                    Text(meeting.startTime.formatted(date: .complete, time: .omitted))
                                        .padding(.vertical, 20)
                                        .id(index)
                                }
                                HStack {
                                    VStack {
                                        Text(meeting.title)
                                            .font(.title)
                                        Text(meeting.startTime.formatted(date: .long, time: .shortened))
                                    }
                                    .padding(.vertical, 80)
                                    .frame(maxWidth: .infinity)
                                    .background(.blue)
                                }
                                .clipShape(
                                    RoundedRectangle(cornerRadius: 12)
                                )
                                .overlay(
                                    RoundedRectangle(cornerRadius: 12)
                                        .stroke(.red, lineWidth: 2)
                                )
                                .padding(.horizontal, 20)
                            }
                        }
                    }
                }
            }
            .scrollPosition(id: $scrolledID)
        }
        .frame(maxWidth: .infinity)
    }
}

struct ScheduleState {
    var days: [Day] = []
    var meetings: [MeetingItem] = []
}

struct Day {
    var date: Date
    var itemPosToScroll: Int
}

struct Meeting {
    var title: String
    var startTime: Date
    var isFirst: Bool = false
}

enum MeetingItem {
    case emptyDay(Date)
    case meeting(Meeting)
}

class ScheduleViewModel: ObservableObject {
    @Published
    var state: ScheduleState = createState()
}

private func createState() -> ScheduleState {
    let meetings: [MeetingItem] = [
        // Position 0
        .meeting(Meeting(title: "Русский язык", startTime: Date(timeIntervalSince1970: 1727769600), isFirst: true)),
        .meeting(Meeting(title: "Литература", startTime: Date(timeIntervalSince1970: 1727773200))),
        .meeting(Meeting(title: "Программирование", startTime: Date(timeIntervalSince1970: 1727776800))),
        .meeting(Meeting(title: "Ужин", startTime: Date(timeIntervalSince1970: 1727780400))),
        .meeting(Meeting(title: "Вечернее ООП", startTime: Date(timeIntervalSince1970: 1727784000))),

        // Position 5
        .emptyDay(Date(timeIntervalSince1970: 1727856000)),

        // Position 6
        .meeting(Meeting(title: "Поход в честер", startTime: Date(timeIntervalSince1970: 1727942400), isFirst: true)),
        .meeting(Meeting(title: "Сангрита", startTime: Date(timeIntervalSince1970: 1727960400))),
        .meeting(Meeting(title: "Шави", startTime: Date(timeIntervalSince1970: 1727967600))),
        .meeting(Meeting(title: "Кальянная", startTime: Date(timeIntervalSince1970: 1727974800))),
        .meeting(Meeting(title: "Вечерний Ассемблер", startTime: Date(timeIntervalSince1970: 1727982000))),

        // Position 11
        .meeting(Meeting(title: "Зарядка", startTime: Date(timeIntervalSince1970: 1728028800), isFirst: true)),
        .meeting(Meeting(title: "Растяжка", startTime: Date(timeIntervalSince1970: 1728043200))),
        .meeting(Meeting(title: "Велогонки", startTime: Date(timeIntervalSince1970: 1728050400))),
        .meeting(Meeting(title: "Автогонки", startTime: Date(timeIntervalSince1970: 1728064800))),
        .meeting(Meeting(title: "Полёт в космос", startTime: Date(timeIntervalSince1970: 1728075600)))
    ]

    return .init(
        days: [
            Day(date: Date(timeIntervalSince1970: 1727769600), itemPosToScroll: 0),
            Day(date: Date(timeIntervalSince1970: 1727856000), itemPosToScroll: 5),
            Day(date: Date(timeIntervalSince1970: 1727942400), itemPosToScroll: 6),
            Day(date: Date(timeIntervalSince1970: 1728028800), itemPosToScroll: 11)
        ],
        meetings: meetings
    )
}

extension Date {
    func titleForDaysList() -> String {
        let components = Calendar.current.dateComponents([.day, .weekday], from: self)
        let weekDayStr = DateFormatter().shortWeekdaySymbols[components.weekday ?? 0]

        return "\(components.day ?? 0)\n\(weekDayStr)"
    }
}

#Preview {
    ScheduleView()
}