//
//  NearFutureWidgets.swift
//  NearFutureWidgets
//
//  Created by Nihaal Sharma on 02/01/2025.
//

import WidgetKit
import SwiftUI

// Timeline Entry for Widget
struct EventWidgetEntry: TimelineEntry {
	let date: Date
	let events: [Event]
}

// Timeline Provider to handle widget data
struct EventWidgetProvider: TimelineProvider {
	func placeholder(in context: Context) -> EventWidgetEntry {
		EventWidgetEntry(date: Date(), events: [])
	}
	
	func getSnapshot(in context: Context, completion: @escaping (EventWidgetEntry) -> ()) {
		let entry = EventWidgetEntry(date: Date(), events: getEvents())
		completion(entry)
	}
	
	func getTimeline(in context: Context, completion: @escaping (Timeline<EventWidgetEntry>) -> ()) {
		let events = getEvents()
		let currentDate = Date()
		
		// Timeline entry for the current date
		let entry = EventWidgetEntry(date: currentDate, events: events)
		
		// Set timeline to refresh every 15 minutes
		let nextUpdateDate = Calendar.current.date(byAdding: .minute, value: 15, to: currentDate)!
		let timeline = Timeline(entries: [entry], policy: .after(nextUpdateDate))
		
		completion(timeline)
	}
	
	private func getEvents() -> [Event] {
		let viewModel = EventViewModel()
		viewModel.loadEvents()
		return viewModel.events
	}
}

// Event Widget View
struct EventWidgetView: View {
	var entry: EventWidgetEntry
	@Environment(\.widgetFamily) var widgetFamily
	var showedEvents: Int {
		switch widgetFamily {
		case .systemSmall:
			return 3
		case .systemMedium:
			return 3
		case .systemLarge:
			return 6
		default:
			return 3
		}
	}
	
	var body: some View {
		let isLarge = widgetFamily == .systemLarge
		let events = entry.events
		VStack {
			Text("Upcoming Events")
				.font(.subheadline)
				.padding(.top, -12)
//				.padding(.bottom, -5)
			
			ForEach(events.prefix(showedEvents), id: \.id) { event in
				HStack {
					RoundedRectangle(cornerRadius: 5)
						.frame(width: 5)
						.frame(maxHeight: isLarge ? 50 : 30)
						.foregroundStyle(event.color.color)
						.padding(.leading, -18)
						.padding(.vertical, 2)
					VStack(alignment: .leading) {
						HStack {
							Image(systemName: event.symbol)
								.resizable()
								.scaledToFit()
								.frame(width: 15, height: 15)
								.foregroundStyle(event.color.color)
							Text("\(event.name)")
								.font(.footnote)
								.padding(.leading, -5)
						}
						
						if isLarge {
							if !event.description.isEmpty {
								Text(event.description)
									.font(.caption2)
									.foregroundColor(.gray)
									.padding(.top, -5)
							}
							Text(event.date.formatted(date: .long, time: .omitted))
								.font(.caption2)
								.foregroundColor(event.color.color)
								.padding(.top, -5)
						}
						if event.recurrence != .none {
							Text("\(event.recurrence.rawValue.capitalized)")
								.font(.caption2)
								.padding(.top, -5)
						}
					}
					.padding(.leading, -15)
					
					Spacer()
					
					Text(daysUntilEvent(event.date, short: !isLarge))
						.font(.caption)
						.foregroundColor(event.color.color)
						.padding(.trailing, -12)
				}
			}
			Spacer()
			if showedEvents < events.count {
				let xMoreEvents = events.count - showedEvents
				Text("+\(xMoreEvents) more event\(xMoreEvents == 1 ? "" : "s")")
					.font(.caption2)
					.foregroundStyle(.gray)
					.padding(.top, -5)
					.padding(.bottom, -15)
			}
		}
		.containerBackground(Color.widgetBackground, for: .widget)
	}
}

struct Widget_Previews: PreviewProvider {
	static var events = [
		Event(
			name: "Event Name",
			symbol: "gear",
			color: ColorCodable(.blue),
			description: "Event description",
			date: Date.distantFuture,
			recurrence: .yearly
		),
		Event(
			name: "A Day",
			symbol: "star",
			color: ColorCodable(.orange),
			description: "description",
			date: Date(),
			recurrence: .daily
		),
		Event(
			name: "A Day",
			symbol: "star",
			color: ColorCodable(.orange),
			description: "description",
			date: Date(),
			recurrence: .daily
		),
		Event(
			name: "A Day",
			symbol: "star",
			color: ColorCodable(.orange),
			description: "description",
			date: Date(),
			recurrence: .daily
		),
		Event(
			name: "A Day",
			symbol: "star",
			color: ColorCodable(.orange),
			description: "description",
			date: Date(),
			recurrence: .daily
		)
	]
	static var previews: some View {
		Group {
			EventWidgetView(
				entry: EventWidgetEntry(
					date: Date(),
					events: events
				)
			)
			.previewContext(WidgetPreviewContext(family: .systemLarge))
			.previewDisplayName("Large")
			EventWidgetView(
				entry: EventWidgetEntry(
					date: Date(),
					events: events
				)
			)
			.previewContext(WidgetPreviewContext(family: .systemMedium))
			.previewDisplayName("Medium")
			EventWidgetView(
				entry: EventWidgetEntry(
					date: Date(),
					events: events
				)
			)
			.previewContext(WidgetPreviewContext(family: .systemSmall))
			.previewDisplayName("Small")
		}
	}
}