import WidgetKit
import SwiftUI

/// Watch complication: today's meals from the last snapshot the watch app
/// stored in the app group. Refreshed via WidgetCenter whenever the watch app
/// receives new data from the iPhone.
@main
struct MealMoodWatchWidgetBundle: WidgetBundle {
    var body: some Widget {
        MealMoodWatchWidget()
        MealMoodWatchDaysWidget()
    }
}

struct TodayEntry: TimelineEntry {
    let date: Date
    let day: WatchWeekPayload.Day?
}

struct TodayProvider: TimelineProvider {
    func placeholder(in context: Context) -> TodayEntry {
        TodayEntry(date: Date(), day: sampleDay)
    }

    func getSnapshot(in context: Context, completion: @escaping (TodayEntry) -> Void) {
        completion(TodayEntry(date: Date(), day: currentDay ?? sampleDay))
    }

    func getTimeline(in context: Context, completion: @escaping (Timeline<TodayEntry>) -> Void) {
        let entry = TodayEntry(date: Date(), day: currentDay)
        // Refresh after midnight so "today" rolls over even without new pushes.
        let nextMidnight = Calendar.current.startOfDay(for: Date()).addingTimeInterval(86_400 + 300)
        completion(Timeline(entries: [entry], policy: .after(nextMidnight)))
    }

    private var currentDay: WatchWeekPayload.Day? {
        guard let payload = WatchWeekPayload.stored() else { return nil }
        let todayOffset = (Calendar.current.component(.weekday, from: Date()) + 5) % 7
        return payload.days.first { $0.dayOfWeek == todayOffset } ?? payload.days.first(where: \.isToday)
    }

    private var sampleDay: WatchWeekPayload.Day {
        WatchWeekPayload.Day(
            dayOfWeek: 0, title: "Lun 8", isToday: true,
            meals: [
                .init(type: "lunch", label: "Comida", name: "Ensalada César"),
                .init(type: "dinner", label: "Cena", name: "Salmón al horno")
            ]
        )
    }
}

struct MealMoodWatchWidget: Widget {
    var body: some WidgetConfiguration {
        StaticConfiguration(kind: "MealMoodWatchToday", provider: TodayProvider()) { entry in
            TodayComplicationView(entry: entry)
                .containerBackground(.clear, for: .widget)
        }
        .configurationDisplayName("MealMood")
        .supportedFamilies([.accessoryRectangular, .accessoryInline, .accessoryCircular])
    }
}

struct TodayComplicationView: View {
    @Environment(\.widgetFamily) private var family
    let entry: TodayEntry

    var body: some View {
        switch family {
        case .accessoryInline:
            if let meal = nextMeal {
                Text("\(meal.label): \(meal.name ?? "—")")
            } else {
                Text("MealMood")
            }
        case .accessoryCircular:
            VStack(spacing: 0) {
                Image(systemName: WatchWeekPayload.icon(for: nextMeal?.type ?? "dinner"))
                    .font(.system(size: 14, weight: .semibold))
                Text(nextMeal?.name?.prefix(6) ?? "—")
                    .font(.system(size: 9))
                    .lineLimit(1)
            }
        default:
            VStack(alignment: .leading, spacing: 2) {
                if let day = entry.day {
                    // The rectangular slot fits ~3 lines: with fewer meals the
                    // text scales up so the space isn't wasted.
                    let meals = Array(day.meals.prefix(3))
                    let nameSize: CGFloat = meals.count <= 1 ? 17 : (meals.count == 2 ? 15 : 12)
                    ForEach(Array(meals.enumerated()), id: \.offset) { _, meal in
                        HStack(spacing: 4) {
                            Image(systemName: WatchWeekPayload.icon(for: meal.type))
                                .font(.system(size: nameSize - 3, weight: .bold))
                                .foregroundStyle(accent(for: meal.type))
                                .widgetAccentable()
                                .frame(width: nameSize)
                            Text(meal.name ?? "—")
                                .font(.system(size: nameSize, weight: .semibold, design: .rounded))
                                .lineLimit(meals.count <= 1 ? 3 : (meals.count == 2 ? 2 : 1))
                                .minimumScaleFactor(0.75)
                        }
                    }
                } else {
                    Text(verbatim: "MealMood")
                        .font(.system(size: 12, weight: .semibold, design: .rounded))
                    Image(systemName: "iphone.and.arrow.forward")
                        .font(.system(size: 10))
                        .foregroundStyle(.secondary)
                }
            }
            .frame(maxWidth: .infinity, alignment: .leading)
        }
    }

    private func accent(for mealType: String) -> Color {
        Self.accentColor(for: mealType)
    }

    static func accentColor(for mealType: String) -> Color {
        switch mealType {
        case "breakfast": return Color(red: 0.95, green: 0.68, blue: 0.25)
        case "lunch": return Color(red: 0.98, green: 0.55, blue: 0.30)
        case "snack": return Color(red: 0.62, green: 0.50, blue: 0.83)
        case "dinner": return Color(red: 0.28, green: 0.62, blue: 0.55)
        default: return Color(red: 1.0, green: 0.45, blue: 0.35)
        }
    }

    /// Lunch until 16:00 local, dinner after — simple heuristic for the small families.
    private var nextMeal: WatchWeekPayload.Meal? {
        guard let meals = entry.day?.meals, !meals.isEmpty else { return nil }
        let hour = Calendar.current.component(.hour, from: entry.date)
        if hour >= 16, let dinner = meals.last(where: { $0.name != nil }) { return dinner }
        return meals.first(where: { $0.name != nil }) ?? meals.first
    }
}

// MARK: - Next days complication

struct DaysEntry: TimelineEntry {
    let date: Date
    let days: [WatchWeekPayload.Day]
}

struct DaysProvider: TimelineProvider {
    func placeholder(in context: Context) -> DaysEntry {
        DaysEntry(date: Date(), days: sampleDays)
    }

    func getSnapshot(in context: Context, completion: @escaping (DaysEntry) -> Void) {
        let days = upcomingDays
        completion(DaysEntry(date: Date(), days: days.isEmpty ? sampleDays : days))
    }

    func getTimeline(in context: Context, completion: @escaping (Timeline<DaysEntry>) -> Void) {
        let entry = DaysEntry(date: Date(), days: upcomingDays)
        let nextMidnight = Calendar.current.startOfDay(for: Date()).addingTimeInterval(86_400 + 300)
        completion(Timeline(entries: [entry], policy: .after(nextMidnight)))
    }

    /// Today and the next two planned days (falls back to the week's first
    /// days when today is outside the planned range, e.g. weekends off).
    private var upcomingDays: [WatchWeekPayload.Day] {
        guard let payload = WatchWeekPayload.stored() else { return [] }
        let todayOffset = (Calendar.current.component(.weekday, from: Date()) + 5) % 7
        let fromToday = payload.days.filter { $0.dayOfWeek >= todayOffset }
        let source = fromToday.isEmpty ? payload.days : fromToday
        return Array(source.prefix(3))
    }

    private var sampleDays: [WatchWeekPayload.Day] {
        [
            .init(dayOfWeek: 0, title: "Lun 8", isToday: true, meals: [
                .init(type: "lunch", label: "Comida", name: "Ensalada"),
                .init(type: "dinner", label: "Cena", name: "Salmón")]),
            .init(dayOfWeek: 1, title: "Mar 9", isToday: false, meals: [
                .init(type: "dinner", label: "Cena", name: "Lentejas")]),
            .init(dayOfWeek: 2, title: "Mié 10", isToday: false, meals: [
                .init(type: "dinner", label: "Cena", name: "Pizza casera")])
        ]
    }
}

struct MealMoodWatchDaysWidget: Widget {
    var body: some WidgetConfiguration {
        StaticConfiguration(kind: "MealMoodWatchDays", provider: DaysProvider()) { entry in
            DaysComplicationView(entry: entry)
                .containerBackground(.clear, for: .widget)
        }
        .configurationDisplayName("MealMood — 3 días")
        .supportedFamilies([.accessoryRectangular])
    }
}

struct DaysComplicationView: View {
    let entry: DaysEntry

    var body: some View {
        VStack(alignment: .leading, spacing: 1) {
            if entry.days.isEmpty {
                Text(verbatim: "MealMood")
                    .font(.system(size: 12, weight: .semibold, design: .rounded))
                Image(systemName: "iphone.and.arrow.forward")
                    .font(.system(size: 10))
                    .foregroundStyle(.secondary)
            } else {
                ForEach(entry.days, id: \.dayOfWeek) { day in
                    HStack(alignment: .firstTextBaseline, spacing: 4) {
                        Text(dayAbbrev(day))
                            .font(.system(size: 11, weight: .heavy, design: .rounded))
                            .foregroundStyle(day.isToday
                                ? Color(red: 1.0, green: 0.45, blue: 0.35)
                                : .secondary)
                            .widgetAccentable()
                            .frame(width: 28, alignment: .leading)
                        Text(mealsLine(day))
                            .font(.system(size: 12, weight: .medium, design: .rounded))
                            .lineLimit(1)
                            .minimumScaleFactor(0.7)
                    }
                }
            }
        }
        .frame(maxWidth: .infinity, alignment: .leading)
    }

    private func dayAbbrev(_ day: WatchWeekPayload.Day) -> String {
        String(day.title.split(separator: " ").first ?? "").uppercased()
    }

    private func mealsLine(_ day: WatchWeekPayload.Day) -> String {
        let names = day.meals.compactMap(\.name)
        return names.isEmpty ? "—" : names.joined(separator: " · ")
    }
}