import ComposableArchitecture
import DependenciesAdditions
import SharedModels
import Styleguide
import SwiftUI
import TCAExtras

#warning("Fix shared settings.")
@Reducer
public struct PressureEstimationsFeature {
  
  public init() { }
  
  @Reducer(state: .equatable)
  public enum Destination {
    case equipmentMeasurements(EquipmentMeasurementForm)
  }
  
  @ObservableState
  public struct State: Equatable {
    @Presents public var destination: Destination.State?
    @Shared(.sharedPressureEstimationSettings) var sharedSettings = SharedPressureEstimationState()
    public var equipmentSettings: EquipmentSettingsForm.State

    public init(
      destination: Destination.State? = nil,
      sharedSettings: SharedPressureEstimationState = .init()
    ) {
      self.destination = destination
      self._sharedSettings = Shared(sharedSettings)
      self._equipmentSettings = .init(sharedSettings: self._sharedSettings)
    }
  }
  
  public enum Action: ViewAction {
    case destination(PresentationAction<Destination.Action>)
    case equipmentSettings(EquipmentSettingsForm.Action)
    case view(View)
    
    @CasePathable
    public enum View {
      case nextButtonTapped
    }
  }

  @Dependency(\.logger["\(Self.self)"]) var logger

  public var body: some Reducer<State, Action> {
    Scope(state: \.equipmentSettings, action: \.equipmentSettings) {
      EquipmentSettingsForm()
    }
    Reduce<State, Action> { state, action in
      switch action {
      case .destination:
        return .none
        
      case .equipmentSettings:
        return .none
        
      case let .view(action):
        switch action {
        case .nextButtonTapped:
          return handleNextButtonTapped(&state)
        }
      }
    }
    .ifLet(\.$destination, action: \.destination)
  }

  private func handleNextButtonTapped(_ state: inout State) -> Effect<Action> {
    guard state.destination == nil else {
      return .fail(
        """
        Received next button tapped action on equipment settings form, but the destination is not nil.

        This is considered an application logic error.
        """,
        logger: logger
      )
    }
    guard state.equipmentSettings.isValid else {
      return .fail(
        """
        Received next button tapped action on equipment settings form, but the form is invalid.

        This is considered an application logic error.
        """,
        logger: logger
      )
    }
    state.destination = .equipmentMeasurements(.init(
      allowEquipmentTypeSelection: false,
      sharedSettings: state.$sharedSettings,
      equipmentType: state.equipmentSettings.equipmentType
    ))
    return .none
  }

}

@ViewAction(for: PressureEstimationsFeature.self)
public struct PressureEstimationsView: View {
  
  @Bindable public var store: StoreOf<PressureEstimationsFeature>
  
  public init(store: StoreOf<PressureEstimationsFeature>) {
    self.store = store
  }
  
  public var body: some View {
    EquipmentSettingsFormView(
      store: store.scope(state: \.equipmentSettings, action: \.equipmentSettings)
    )
    .navigationTitle("Equipment Settings")
    .toolbar {
      NextButton { send(.nextButtonTapped) }
        .nextButtonStyle(.toolbar)
        .disabled(!store.equipmentSettings.isValid)
    }
    .navigationDestination(
      item: $store.scope(
        state: \.destination?.equipmentMeasurements,
        action: \.destination.equipmentMeasurements
      )
    ) { measurementStore in
      EquipmentMeasurementFormView(store: measurementStore)
        .navigationTitle("Existing Measurements")
    }
  }
}

#Preview {
  NavigationStack {
    PressureEstimationsView(
      store: Store(initialState: PressureEstimationsFeature.State()) {
        PressureEstimationsFeature()._printChanges()
      }
    )
  }
}