ore-calendar/Sources/ContentView.swift

import SwiftUI
import EventKit

struct ContentView: View {
    @StateObject private var calendarService = CalendarService()
    @State private var scrollToToday = false
    @State private var showingSettings = false

    var body: some View {
        VStack(spacing: 0) {
            if calendarService.hasAccess {
                ScrollViewReader { proxy in
                    List {
                        ForEach(groupedEventsByDay(), id: \.date) { dayGroup in
                            Section(header: dayHeader(for: dayGroup.date)) {
                                ForEach(dayGroup.events, id: \.eventIdentifier) { event in
                                    EventRow(event: event)
                                }
                            }
                            .id(dayGroup.date)
                        }
                    }
                    .listStyle(.plain)
                    .onAppear {
                        if !scrollToToday {
                            let today = Calendar.current.startOfDay(for: Date())
                            proxy.scrollTo(today, anchor: .top)
                            scrollToToday = true
                        }
                    }
                    .onChange(of: scrollToToday) { _, newValue in
                        if newValue {
                            let today = Calendar.current.startOfDay(for: Date())
                            withAnimation {
                                proxy.scrollTo(today, anchor: .top)
                            }
                            scrollToToday = false
                        }
                    }
                }
            } else {
                VStack {
                    Text("カレンダーへのアクセス権限が必要です")
                        .font(.headline)
                    Text("システム設定からアクセスを許可してください")
                        .font(.subheadline)
                        .foregroundColor(.secondary)
                }
                .padding()
            }
        }
        .sheet(isPresented: $showingSettings) {
            SettingsView(calendarService: calendarService)
        }
        .toolbar {
            ToolbarItem(placement: .primaryAction) {
                Button(action: {
                    showingSettings = true
                }) {
                    Label("設定", systemImage: "gearshape")
                }
            }
            ToolbarItem(placement: .primaryAction) {
                Button(action: {
                    scrollToToday = true
                }) {
                    Label("今日", systemImage: "calendar")
                }
            }
        }
    }

    private func groupedEventsByDay() -> [DayGroup] {
        let calendar = Calendar.current
        let grouped = Dictionary(grouping: calendarService.events) { event in
            calendar.startOfDay(for: event.startDate)
        }

        let today = calendar.startOfDay(for: Date())
        guard let startDate = calendar.date(byAdding: .day, value: -14, to: today),
              let endDate = calendar.date(byAdding: .day, value: 14, to: today) else {
            return []
        }

        var allDates: [Date] = []
        var currentDate = startDate
        while currentDate <= endDate {
            allDates.append(currentDate)
            guard let nextDate = calendar.date(byAdding: .day, value: 1, to: currentDate) else { break }
            currentDate = nextDate
        }

        return allDates.map { date in
            DayGroup(date: date, events: grouped[date] ?? [])
        }.sorted { $0.date < $1.date }
    }

    private func dayHeader(for date: Date) -> some View {
        let calendar = Calendar.current
        let isToday = calendar.isDateInToday(date)
        let formatter = DateFormatter()
        formatter.dateFormat = "M月d日(E)"
        formatter.locale = Locale(identifier: "ja_JP")

        return HStack {
            Text(formatter.string(from: date))
                .font(.headline)
                .foregroundColor(isToday ? .blue : .primary)
            if isToday {
                Text("今日")
                    .font(.caption)
                    .padding(.horizontal, 6)
                    .padding(.vertical, 2)
                    .background(Color.blue)
                    .foregroundColor(.white)
                    .cornerRadius(4)
            }
        }
    }
}

struct DayGroup {
    let date: Date
    let events: [EKEvent]
}

struct EventRow: View {
    let event: EKEvent

    var body: some View {
        VStack(alignment: .leading, spacing: 4) {
            HStack {
                if event.isAllDay {
                    Text("終日")
                        .font(.caption)
                        .foregroundColor(.secondary)
                } else {
                    Text(timeString(from: event.startDate, to: event.endDate))
                        .font(.caption)
                        .foregroundColor(.secondary)
                }
                if let calendar = event.calendar {
                    Circle()
                        .fill(Color(calendar.color))
                        .frame(width: 8, height: 8)
                }
            }
            Text(event.title ?? "無題のイベント")
                .font(.body)
            if let location = event.location, !location.isEmpty {
                Text(location)
                    .font(.caption)
                    .foregroundColor(.secondary)
            }
        }
        .padding(.vertical, 4)
    }

    private func timeString(from start: Date, to end: Date) -> String {
        let formatter = DateFormatter()
        formatter.dateFormat = "HH:mm"
        return "\(formatter.string(from: start)) - \(formatter.string(from: end))"
    }
}