//
// ActiveWorkoutGateView.swift
// Workouts Watch App
//
// Copyright 2025 Rouslan Zenetl. All Rights Reserved.
//

import SwiftUI
import SwiftData

/// Root of the watch app. The watch only runs the workout that's currently active
/// on the phone — there's no history browsing here. The "active" workout is the most
/// recent cached one that isn't finished (`notStarted` or `inProgress`); a workout is
/// created on the phone as `notStarted` the moment a split is picked, and flips to
/// `completed` once every exercise is done, at which point we fall back to the gate.
struct ActiveWorkoutGateView: View {
    @Environment(WatchConnectivityBridge.self) private var bridge
    @Environment(WorkoutSessionManager.self) private var sessionManager

    @Query(sort: \Workout.start, order: .reverse) private var workouts: [Workout]

    private var activeWorkout: Workout? {
        workouts.first { $0.status == .inProgress || $0.status == .notStarted }
    }

    var body: some View {
        NavigationStack {
            if let workout = activeWorkout {
                WorkoutLogListView(workout: workout)
            } else {
                emptyState
            }
        }
        .task {
            // Nothing to run yet — pull fresh state in case the phone just started one.
            if activeWorkout == nil { bridge.requestSync() }
        }
        .onChange(of: activeWorkout == nil) { _, noActiveWorkout in
            // The workout finished (or was cleared) — release the HealthKit session that
            // was keeping the launched app alive.
            if noActiveWorkout { sessionManager.end() }
        }
    }

    private var emptyState: some View {
        ContentUnavailableView {
            Label("Start a Workout", systemImage: "iphone")
        } description: {
            Text("Begin a workout on your iPhone to run it here.")
        } actions: {
            Button {
                bridge.requestSync()
            } label: {
                Label("Refresh", systemImage: "arrow.triangle.2.circlepath")
            }
        }
    }
}