//
//  TimeUntilAlarmSection.swift
//  TheNoiseClock
//
//  Created by Matt Bruce on 9/8/25.
//

import SwiftUI

/// Component showing time until alarm and day information
struct TimeUntilAlarmSection: View {
    let alarmTime: Date
    
    var body: some View {
        VStack(spacing: 4) {
            HStack {
                Image(systemName: "calendar")
                    .foregroundColor(AppAccent.primary)
                Text(timeUntilAlarm)
                    .font(.subheadline)
                    .foregroundColor(.secondary)
            }
            
            Text(dayText)
                .font(.caption)
                .foregroundColor(.secondary)
        }
        .padding(.vertical, 12)
        .background(Color(.systemGroupedBackground))
    }
    
    private var timeUntilAlarm: String {
        let now = Date()
        let calendar = Calendar.current
        
        // Calculate the next occurrence of the alarm time
        let nextAlarmTime: Date
        if calendar.isDateInToday(alarmTime) && alarmTime < now {
            // If alarm time has passed today, calculate for tomorrow
            nextAlarmTime = calendar.date(byAdding: .day, value: 1, to: alarmTime) ?? alarmTime
        } else {
            // Use the alarm time as-is (either future today or already tomorrow+)
            nextAlarmTime = alarmTime
        }
        
        // Calculate time difference from now to next alarm
        let components = calendar.dateComponents([.hour, .minute], from: now, to: nextAlarmTime)
        if let hours = components.hour, let minutes = components.minute {
            if hours > 0 {
                return "Will turn on in \(hours)h \(minutes)m"
            } else if minutes > 0 {
                return "Will turn on in \(minutes)m"
            } else {
                return "Will turn on now"
            }
        }
        
        return "Will turn on tomorrow"
    }
    
    private var dayText: String {
        let calendar = Calendar.current
        let now = Date()
        
        // If alarm time is in the past today, show tomorrow
        if calendar.isDateInToday(alarmTime) && alarmTime < now {
            return "Tomorrow"
        } else if calendar.isDateInToday(alarmTime) {
            return "Today"
        } else if calendar.isDateInTomorrow(alarmTime) {
            return "Tomorrow"
        } else {
            let formatter = DateFormatter()
            formatter.dateFormat = "EEEE"
            return formatter.string(from: alarmTime)
        }
    }
}