//
//  FactsView.swift
//  Facts
//

import SwiftUI
import Foundation
import ComposableArchitecture

/// A view that displays either a progress spinner, a list of cat facts provided by an underlying feature reducer, or
/// an error message, depending on the state. Supports pull-to-refresh.
public struct FactsView: View {
    let store: StoreOf<FactsFeature>
    
    public init(store: StoreOf<FactsFeature>) {
        self.store = store
    }
    
    public var body: some View {
        VStack {
            switch store.state.mode {
            case .notLoaded:
                EmptyView()
            case .loading:
                ProgressView()
            case let .loaded(facts):
                List(facts, id: \.self) { fact in
                    Text(fact)
                }
            case let .error(error):
                Text(error.localizedDescription)
            }
        }
        .refreshable {
            // Tie the lifecycle of the PTR to the effect.
            // https://github.com/pointfreeco/swift-composable-architecture/discussions/2542
            await Task { await store.send(.pulledToRefresh).finish() }.value
        }
        .onAppear {
            store.send(.viewAppeared)
        }
    }
}

#Preview {
    FactsView(store: .init(initialState: FactsFeature.State(mode: .loaded(facts: ["One", "Two", "Three"]))) {
        FactsFeature()
    })
}