import WidgetKit
import SwiftUI
import Foundation

// MARK: - Shared data model (mirrors WidgetDataStore in main app)

private struct TodayMealData: Codable {
    struct Meal: Codable {
        let type: String
        let label: String
        let name: String?
    }

    let meals: [Meal]
    let weekdayName: String
    let updatedAt: Date
}

private enum WidgetStore {
    static let appGroupID = "group.com.alexandrevazquez.mealmood"
    static let key = "mealmood.today_meals"

    static func read() -> TodayMealData? {
        guard let defaults = UserDefaults(suiteName: appGroupID),
              let data = defaults.data(forKey: key) else { return nil }
        return try? JSONDecoder().decode(TodayMealData.self, from: data)
    }
}

// MARK: - Timeline

struct MealItem: Hashable {
    let type: String
    let label: String
    let name: String?

    var icon: String {
        switch type {
        case "breakfast": return "cup.and.saucer.fill"
        case "lunch": return "sun.max.fill"
        case "snack": return "carrot.fill"
        default: return "moon.stars.fill"
        }
    }

    var color: Color {
        switch type {
        case "breakfast": return .mmBreakfastAmber
        case "lunch": return .mmLunchOrange
        case "snack": return .mmSnackPurple
        default: return .mmDinnerBlue
        }
    }
}

struct TodayMealEntry: TimelineEntry {
    let date: Date
    let meals: [MealItem]
    let weekdayName: String

    /// Compact families show the "main" meals when the list is long.
    var compactMeals: [MealItem] {
        guard meals.count > 2 else { return meals }
        let main = meals.filter { $0.type == "lunch" || $0.type == "dinner" }
        return main.isEmpty ? Array(meals.prefix(2)) : Array(main.prefix(2))
    }
}

struct Provider: TimelineProvider {
    func placeholder(in context: Context) -> TodayMealEntry {
        TodayMealEntry(
            date: Date(),
            meals: [
                MealItem(type: "lunch", label: "Comida", name: "Pasta al pesto"),
                MealItem(type: "dinner", label: "Cena", name: "Salmón al horno")
            ],
            weekdayName: "Lunes"
        )
    }

    func getSnapshot(in context: Context, completion: @escaping (TodayMealEntry) -> Void) {
        completion(entry(from: WidgetStore.read()))
    }

    func getTimeline(in context: Context, completion: @escaping (Timeline<TodayMealEntry>) -> Void) {
        let nextMidnight = Calendar.current.startOfDay(for: Calendar.current.date(byAdding: .day, value: 1, to: Date())!)
        completion(Timeline(entries: [entry(from: WidgetStore.read())], policy: .after(nextMidnight)))
    }

    private func entry(from data: TodayMealData?) -> TodayMealEntry {
        TodayMealEntry(
            date: Date(),
            meals: (data?.meals ?? []).map {
                MealItem(type: $0.type, label: $0.label, name: $0.name)
            },
            weekdayName: data?.weekdayName ?? ""
        )
    }
}

// MARK: - Colors

private extension Color {
    static let mmCoral    = Color(red: 0.93, green: 0.42, blue: 0.31)
    static let mmBgWarm   = Color(red: 1.00, green: 0.94, blue: 0.91)
    static let mmBgMint   = Color(red: 0.93, green: 0.98, blue: 0.95)
    static let mmText     = Color(red: 0.13, green: 0.13, blue: 0.13)
    static let mmSubtext  = Color(red: 0.55, green: 0.55, blue: 0.55)
}

extension Color {
    static let mmBreakfastAmber = Color(red: 0.76, green: 0.55, blue: 0.18)
    static let mmLunchOrange    = Color(red: 0.90, green: 0.55, blue: 0.18)
    static let mmSnackPurple    = Color(red: 0.51, green: 0.39, blue: 0.69)
    static let mmDinnerBlue     = Color(red: 0.36, green: 0.48, blue: 0.78)
}

// MARK: - Small widget

private struct SmallWidgetView: View {
    let entry: TodayMealEntry

    var body: some View {
        VStack(alignment: .leading, spacing: 0) {
            HStack(spacing: 4) {
                Image(systemName: "fork.knife")
                    .font(.system(size: 10, weight: .bold))
                    .foregroundColor(.mmCoral)
                Text("MealMood")
                    .font(.system(size: 11, weight: .bold))
                    .foregroundColor(.mmCoral)
                Spacer()
            }

            Text(entry.weekdayName)
                .font(.system(size: 10, weight: .medium))
                .foregroundColor(.mmSubtext)
                .lineLimit(1)
                .padding(.top, 2)
                .padding(.bottom, 10)

            Spacer()

            let rows = entry.compactMeals
            ForEach(Array(rows.enumerated()), id: \.element) { index, meal in
                mealRow(meal)
                    .padding(.bottom, index < rows.count - 1 ? 8 : 0)
            }
            if rows.isEmpty {
                Text("—")
                    .font(.system(size: 13, weight: .semibold))
                    .foregroundColor(.mmSubtext)
            }
        }
        .padding(12)
        .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .leading)
        .background(
            LinearGradient(colors: [.mmBgWarm, .mmBgMint],
                           startPoint: .topLeading, endPoint: .bottomTrailing)
        )
    }

    private func mealRow(_ meal: MealItem) -> some View {
        HStack(spacing: 8) {
            Image(systemName: meal.icon)
                .font(.system(size: 13))
                .foregroundColor(meal.color)
                .frame(width: 18)
            VStack(alignment: .leading, spacing: 1) {
                Text(meal.label.uppercased())
                    .font(.system(size: 8, weight: .semibold))
                    .foregroundColor(.mmSubtext)
                Text(meal.name ?? "—")
                    .font(.system(size: 13, weight: .semibold))
                    .foregroundColor(.mmText)
                    .lineLimit(2)
                    .minimumScaleFactor(0.75)
            }
        }
    }
}

// MARK: - Medium widget

private struct MediumWidgetView: View {
    let entry: TodayMealEntry

    var body: some View {
        HStack(spacing: 0) {
            VStack(alignment: .leading, spacing: 6) {
                Image(systemName: "fork.knife")
                    .font(.system(size: 18, weight: .bold))
                    .foregroundColor(.mmCoral)
                Spacer()
                Text(entry.weekdayName)
                    .font(.system(size: 16, weight: .bold))
                    .foregroundColor(.mmText)
                    .lineLimit(1)
                    .minimumScaleFactor(0.7)
                Text(Date(), style: .date)
                    .font(.system(size: 11, weight: .medium))
                    .foregroundColor(.mmSubtext)
            }
            .padding(14)
            .frame(width: 112)
            .frame(maxHeight: .infinity, alignment: .leading)
            .background(Color.mmBgWarm)

            Rectangle()
                .fill(Color.mmCoral.opacity(0.2))
                .frame(width: 1)

            let rows = entry.meals.isEmpty ? entry.compactMeals : entry.meals
            VStack(alignment: .leading, spacing: rows.count > 2 ? 8 : 14) {
                ForEach(Array(rows.enumerated()), id: \.element) { index, meal in
                    mediumRow(meal, compact: rows.count > 2)
                    if index < rows.count - 1 {
                        Divider()
                    }
                }
                if rows.isEmpty {
                    Text("—")
                        .font(.system(size: 15, weight: .semibold))
                        .foregroundColor(.mmSubtext)
                }
            }
            .padding(14)
            .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .leading)
            .background(Color.white)
        }
    }

    private func mediumRow(_ meal: MealItem, compact: Bool) -> some View {
        HStack(spacing: 10) {
            Image(systemName: meal.icon)
                .font(.system(size: compact ? 13 : 16))
                .foregroundColor(meal.color)
                .frame(width: 22)
            if compact {
                Text(meal.label.uppercased())
                    .font(.system(size: 9, weight: .semibold))
                    .foregroundColor(.mmSubtext)
                    .frame(width: 70, alignment: .leading)
                Text(meal.name ?? "—")
                    .font(.system(size: 13, weight: .semibold))
                    .foregroundColor(.mmText)
                    .lineLimit(1)
            } else {
                VStack(alignment: .leading, spacing: 2) {
                    Text(meal.label.uppercased())
                        .font(.system(size: 9, weight: .semibold))
                        .foregroundColor(.mmSubtext)
                    Text(meal.name ?? "—")
                        .font(.system(size: 15, weight: .semibold))
                        .foregroundColor(.mmText)
                        .lineLimit(2)
                }
            }
        }
    }
}

// MARK: - Lock Screen widgets

private struct AccessoryRectangularView: View {
    let entry: TodayMealEntry

    var body: some View {
        VStack(alignment: .leading, spacing: 2) {
            HStack(spacing: 3) {
                Image(systemName: "fork.knife")
                    .font(.system(size: 10, weight: .bold))
                Text(entry.weekdayName.isEmpty ? "MealMood" : entry.weekdayName)
                    .font(.system(size: 12, weight: .bold))
                    .lineLimit(1)
            }
            .widgetAccentable()

            let rows = entry.compactMeals.filter { $0.name != nil }
            ForEach(rows.prefix(2), id: \.self) { meal in
                Text("\(Image(systemName: meal.icon)) \(meal.name ?? "")")
                    .font(.system(size: 12))
                    .lineLimit(1)
            }
            if rows.isEmpty {
                Text("—")
                    .font(.system(size: 12))
            }
        }
        .frame(maxWidth: .infinity, alignment: .leading)
    }
}

private struct AccessoryInlineView: View {
    let entry: TodayMealEntry

    var body: some View {
        // Inline is a single line: prefer the last main meal with a dish.
        let name = entry.compactMeals.reversed().compactMap(\.name).first
        Label(name ?? "MealMood", systemImage: "fork.knife")
    }
}

// MARK: - Widget entry view

struct MealMoodWidgetView: View {
    var entry: Provider.Entry
    @Environment(\.widgetFamily) var family

    var body: some View {
        Group {
            switch family {
            case .systemMedium:
                MediumWidgetView(entry: entry)
                    .containerBackground(for: .widget) { Color.white }
            case .accessoryRectangular:
                AccessoryRectangularView(entry: entry)
                    .containerBackground(for: .widget) { Color.clear }
            case .accessoryInline:
                AccessoryInlineView(entry: entry)
                    .containerBackground(for: .widget) { Color.clear }
            default:
                SmallWidgetView(entry: entry)
                    .containerBackground(for: .widget) { Color.white }
            }
        }
        // Deep-link into the app's current week ("today") when tapped.
        .widgetURL(URL(string: "mealmood://today"))
    }
}

// MARK: - Widget definition

@main
struct MealMoodWidget: Widget {
    let kind = "MealMoodWidget"

    var body: some WidgetConfiguration {
        StaticConfiguration(kind: kind, provider: Provider()) { entry in
            MealMoodWidgetView(entry: entry)
        }
        .configurationDisplayName("MealMood")
        .description("Today's meals at a glance.")
        .supportedFamilies([.systemSmall, .systemMedium, .accessoryRectangular, .accessoryInline])
    }
}