import WidgetKit
import SwiftUI

/// Complications for the Apple Watch face. They read the snapshot the watch app
/// cached from the iPhone (see `WatchSnapshotCache`) — the extension never talks
/// to WatchConnectivity itself, the app reloads the timelines when new data
/// arrives.
struct WatchComplicationEntry: TimelineEntry {
    let date: Date
    let snapshot: WatchPortfolioSnapshot
}

struct WatchComplicationProvider: TimelineProvider {

    func placeholder(in context: Context) -> WatchComplicationEntry {
        WatchComplicationEntry(date: Date(), snapshot: .preview)
    }

    func getSnapshot(in context: Context, completion: @escaping (WatchComplicationEntry) -> Void) {
        let snapshot = context.isPreview ? .preview : (WatchSnapshotCache.load() ?? .preview)
        completion(WatchComplicationEntry(date: Date(), snapshot: snapshot))
    }

    func getTimeline(in context: Context, completion: @escaping (Timeline<WatchComplicationEntry>) -> Void) {
        let entry = WatchComplicationEntry(
            date: Date(),
            snapshot: WatchSnapshotCache.load() ?? .empty
        )
        // The watch app reloads timelines as soon as the phone sends new data;
        // this cadence is just a safety net for a watch that has been away from
        // its phone.
        let nextUpdate = Calendar.current.date(byAdding: .minute, value: 30, to: Date()) ?? Date()
        completion(Timeline(entries: [entry], policy: .after(nextUpdate)))
    }
}

// MARK: - Total value

struct WatchTotalValueComplication: Widget {
    var body: some WidgetConfiguration {
        StaticConfiguration(kind: "WatchTotalValue", provider: WatchComplicationProvider()) { entry in
            WatchTotalValueView(snapshot: entry.snapshot)
                .containerBackground(.fill.tertiary, for: .widget)
        }
        .configurationDisplayName("complication_total_name")
        .description("complication_total_description")
        .supportedFamilies([
            .accessoryCircular,
            .accessoryRectangular,
            .accessoryInline,
            .accessoryCorner
        ])
    }
}

struct WatchTotalValueView: View {
    @Environment(\.widgetFamily) private var family
    let snapshot: WatchPortfolioSnapshot

    private var compactTotal: String {
        WatchPortfolioSnapshot.format(
            snapshot.totalValue,
            currencyCode: snapshot.currencyCode,
            compact: true
        )
    }

    var body: some View {
        switch family {
        case .accessoryInline:
            Text("\(compactTotal) \(snapshot.formattedMonthChangePercent)")

        case .accessoryCorner:
            Text(compactTotal)
                .widgetCurvesContent()
                .widgetLabel(snapshot.formattedMonthChangePercent)

        case .accessoryRectangular:
            VStack(alignment: .leading, spacing: 1) {
                Text("complication_total_name")
                    .font(.caption2)
                    .foregroundStyle(.secondary)
                Text(compactTotal)
                    .font(.title3.bold())
                    .minimumScaleFactor(0.6)
                    .lineLimit(1)
                Text("\(snapshot.formattedMonthChange()) \(snapshot.formattedMonthChangePercent)")
                    .font(.caption2)
                    .foregroundStyle(.secondary)
            }
            .frame(maxWidth: .infinity, alignment: .leading)

        default:
            VStack(spacing: 0) {
                Image(systemName: "chart.pie.fill")
                    .font(.caption2)
                Text(compactTotal)
                    .font(.caption.bold())
                    .minimumScaleFactor(0.5)
                    .lineLimit(1)
            }
        }
    }
}

// MARK: - Goal progress

struct WatchGoalProgressComplication: Widget {
    var body: some WidgetConfiguration {
        StaticConfiguration(kind: "WatchGoalProgress", provider: WatchComplicationProvider()) { entry in
            WatchGoalProgressView(snapshot: entry.snapshot)
                .containerBackground(.fill.tertiary, for: .widget)
        }
        .configurationDisplayName("complication_goal_name")
        .description("complication_goal_description")
        .supportedFamilies([
            .accessoryCircular,
            .accessoryRectangular,
            .accessoryInline,
            .accessoryCorner
        ])
    }
}

struct WatchGoalProgressView: View {
    @Environment(\.widgetFamily) private var family
    let snapshot: WatchPortfolioSnapshot

    /// Most advanced goal still open — the one the user is about to hit.
    private var goal: WatchPortfolioSnapshot.Goal? { snapshot.featuredGoal }

    private var percentText: String {
        guard let goal else { return "—" }
        return "\(Int(goal.progress * 100))%"
    }

    var body: some View {
        switch family {
        case .accessoryInline:
            if let goal {
                Text("\(goal.name) \(percentText)")
            } else {
                Text("complication_goal_empty")
            }

        case .accessoryCorner:
            Gauge(value: goal?.progress ?? 0) {
                Text(percentText)
            }
            .gaugeStyle(.accessoryCircular)
            .widgetLabel(goal?.name ?? String(localized: "complication_goal_empty"))

        case .accessoryRectangular:
            VStack(alignment: .leading, spacing: 2) {
                Text(goal?.name ?? String(localized: "complication_goal_empty"))
                    .font(.caption.weight(.semibold))
                    .lineLimit(1)
                ProgressView(value: goal?.progress ?? 0)
                    .tint(.green)
                if let goal {
                    Text("\(WatchPortfolioSnapshot.format(goal.currentValue, currencyCode: snapshot.currencyCode, compact: true)) · \(percentText)")
                        .font(.caption2)
                        .foregroundStyle(.secondary)
                }
            }
            .frame(maxWidth: .infinity, alignment: .leading)

        default:
            Gauge(value: goal?.progress ?? 0) {
                Image(systemName: "target")
            } currentValueLabel: {
                Text(percentText)
                    .minimumScaleFactor(0.5)
            }
            .gaugeStyle(.accessoryCircularCapacity)
        }
    }
}

// MARK: - Streak / check-in

struct WatchStreakComplication: Widget {
    var body: some WidgetConfiguration {
        StaticConfiguration(kind: "WatchStreak", provider: WatchComplicationProvider()) { entry in
            WatchStreakView(snapshot: entry.snapshot)
                .containerBackground(.fill.tertiary, for: .widget)
        }
        .configurationDisplayName("complication_streak_name")
        .description("complication_streak_description")
        .supportedFamilies([
            .accessoryCircular,
            .accessoryRectangular,
            .accessoryInline,
            .accessoryCorner
        ])
    }
}

struct WatchStreakView: View {
    @Environment(\.widgetFamily) private var family
    let snapshot: WatchPortfolioSnapshot

    private var statusSymbol: String {
        snapshot.checkInDone ? "checkmark.circle.fill" : "exclamationmark.circle.fill"
    }

    private var streakText: String { "\(snapshot.currentStreak)x" }

    var body: some View {
        switch family {
        case .accessoryInline:
            Text("\(Image(systemName: "flame.fill")) \(streakText)")

        case .accessoryCorner:
            Text(streakText)
                .widgetCurvesContent()
                .widgetLabel(
                    snapshot.checkInDone
                    ? String(localized: "complication_streak_done")
                    : String(localized: "complication_streak_pending")
                )

        case .accessoryRectangular:
            VStack(alignment: .leading, spacing: 1) {
                Label(streakText, systemImage: "flame.fill")
                    .font(.caption.weight(.semibold))
                Text(snapshot.checkInDone
                     ? "complication_streak_done"
                     : "complication_streak_pending")
                    .font(.caption2)
                    .foregroundStyle(.secondary)
                if !snapshot.checkInMonthLabel.isEmpty {
                    Text(snapshot.checkInMonthLabel)
                        .font(.caption2)
                        .foregroundStyle(.secondary)
                }
            }
            .frame(maxWidth: .infinity, alignment: .leading)

        default:
            VStack(spacing: 0) {
                Image(systemName: statusSymbol)
                    .font(.caption2)
                    .foregroundStyle(snapshot.checkInDone ? Color.green : Color.orange)
                Text(streakText)
                    .font(.caption.bold())
            }
        }
    }
}

// MARK: - Bundle

@main
struct PortfolioJournalWatchWidgetBundle: WidgetBundle {
    var body: some Widget {
        WatchTotalValueComplication()
        WatchGoalProgressComplication()
        WatchStreakComplication()
    }
}

// MARK: - Previews

extension WatchPortfolioSnapshot {
    /// Sample data for widget galleries and Xcode previews.
    static var preview: WatchPortfolioSnapshot {
        WatchPortfolioSnapshot(
            generatedAt: Date(),
            currencyCode: "EUR",
            totalValue: 124_500,
            monthChange: 2_340,
            monthChangePercent: 0.019,
            sources: [
                Source(id: UUID(), name: "Indexa", categoryName: "ETFs", categoryColorHex: "#EC4899", value: 68_000),
                Source(id: UUID(), name: "Cuenta ahorro", categoryName: "Cash", categoryColorHex: "#6B7280", value: 32_500)
            ],
            goals: [
                Goal(
                    id: UUID(),
                    name: "Cash buffer",
                    categoryName: "Cash",
                    categoryIcon: "banknote.fill",
                    categoryColorHex: "#6B7280",
                    currentValue: 32_500,
                    targetValue: 100_000
                )
            ],
            currentStreak: 7,
            bestStreak: 15,
            checkInDone: true,
            checkInMonthLabel: "August 2026"
        )
    }
}