import OrderedCollections
import SwiftUI

/// A navigation stack that is driven by a store.
///
/// This view can be used to drive stack-based navigation in the Composable Architecture when passed
/// a store that is focused on ``StackState`` and ``StackAction``.
///
/// See the dedicated article on <doc:Navigation> for more information on the library's navigation
/// tools, and in particular see <doc:StackBasedNavigation> for information on using this view.
@available(
  iOS, deprecated: 9999,
  message:
    "Use 'NavigationStack.init(path:)' with a store scoped from observable state, instead. For more information, see the following article: https://swiftpackageindex.com/pointfreeco/swift-composable-architecture/main/documentation/composablearchitecture/migratingto1.7#Replacing-NavigationStackStore-with-NavigationStack]"
)
@available(
  macOS, deprecated: 9999,
  message:
    "Use 'NavigationStack.init(path:)' with a store scoped from observable state, instead. For more information, see the following article: https://swiftpackageindex.com/pointfreeco/swift-composable-architecture/main/documentation/composablearchitecture/migratingto1.7#Replacing-NavigationStackStore-with-NavigationStack]"
)
@available(
  tvOS, deprecated: 9999,
  message:
    "Use 'NavigationStack.init(path:)' with a store scoped from observable state, instead. For more information, see the following article: https://swiftpackageindex.com/pointfreeco/swift-composable-architecture/main/documentation/composablearchitecture/migratingto1.7#Replacing-NavigationStackStore-with-NavigationStack]"
)
@available(
  watchOS, deprecated: 9999,
  message:
    "Use 'NavigationStack.init(path:)' with a store scoped from observable state, instead. For more information, see the following article: https://swiftpackageindex.com/pointfreeco/swift-composable-architecture/main/documentation/composablearchitecture/migratingto1.7#Replacing-NavigationStackStore-with-NavigationStack]"
)
@available(iOS 16, macOS 13, tvOS 16, watchOS 9, *)
public struct NavigationStackStore<State, Action, Root: View, Destination: View>: View {
  private let root: Root
  private let destination: (StackState<State>.Component) -> Destination
  @ObservedObject private var viewStore: ViewStore<StackState<State>, StackAction<State, Action>>

  /// Creates a navigation stack with a store of stack state and actions.
  ///
  /// - Parameters:
  ///   - store: A store of stack state and actions to power this stack.
  ///   - root: The view to display when the stack is empty.
  ///   - destination: A view builder that defines a view to display when an element is appended to
  ///     the stack's state. The closure takes one argument, which is a store of the value to
  ///     present.
  ///   - fileID: The fileID.
  ///   - filePath: The filePath.
  ///   - line: The line.
  ///   - column: The column.
  public init(
    _ store: Store<StackState<State>, StackAction<State, Action>>,
    @ViewBuilder root: () -> Root,
    @ViewBuilder destination: @escaping (_ store: Store<State, Action>) -> Destination,
    fileID: StaticString = #fileID,
    filePath: StaticString = #filePath,
    line: UInt = #line,
    column: UInt = #column
  ) {
    func navigationDestination(
      component: StackState<State>.Component
    ) -> Destination {
      let id = store.id(
        state:
          \.[
            id: component.id,
            fileID: _HashableStaticString(rawValue: fileID),
            filePath: _HashableStaticString(rawValue: filePath),
            line: line,
            column: column
          ],
        action: \.[id: component.id]
      )
      @MainActor
      func open(
        _ core: some Core<StackState<State>, StackAction<State, Action>>
      ) -> any Core<State, Action> {
        IfLetCore(
          base: core,
          cachedState: component.element,
          stateKeyPath:
            \.[
              id: component.id,
              fileID: _HashableStaticString(rawValue: fileID),
              filePath: _HashableStaticString(rawValue: filePath),
              line: line,
              column: column
            ],
          actionKeyPath: \.[id: component.id]
        )
      }
      return destination(store.scope(id: id, childCore: open(store.core)))
    }
    self.root = root()
    self.destination = navigationDestination(component:)
    self._viewStore = ObservedObject(
      wrappedValue: ViewStore(
        store,
        observe: { $0 },
        removeDuplicates: { areOrderedSetsDuplicates($0.ids, $1.ids) }
      )
    )
  }

  /// Creates a navigation stack with a store of stack state and actions.
  ///
  /// - Parameters:
  ///   - store: A store of stack state and actions to power this stack.
  ///   - root: The view to display when the stack is empty.
  ///   - destination: A view builder that defines a view to display when an element is appended to
  ///     the stack's state. The closure takes one argument, which is the initial enum state to
  ///     present. You can switch over this value and use ``CaseLet`` views to handle each case.
  ///   - fileID: The fileID.
  ///   - filePath: The filePath.
  ///   - line: The line.
  ///   - column: The column.
  @_disfavoredOverload
  public init<D: View>(
    _ store: Store<StackState<State>, StackAction<State, Action>>,
    @ViewBuilder root: () -> Root,
    @ViewBuilder destination: @escaping (_ initialState: State) -> D,
    fileID: StaticString = #fileID,
    filePath: StaticString = #filePath,
    line: UInt = #line,
    column: UInt = #column
  ) where Destination == SwitchStore<State, Action, D> {
    func navigationDestination(
      component: StackState<State>.Component
    ) -> Destination {
      let id = store.id(
        state:
          \.[
            id: component.id,
            fileID: _HashableStaticString(rawValue: fileID),
            filePath: _HashableStaticString(rawValue: filePath),
            line: line,
            column: column
          ],
        action: \.[id: component.id]
      )
      if let child = store.children[id] as? Store<State, Action> {
        return SwitchStore(child, content: destination)
      } else {
        @MainActor
        func open(
          _ core: some Core<StackState<State>, StackAction<State, Action>>
        ) -> any Core<State, Action> {
          IfLetCore(
            base: core,
            cachedState: component.element,
            stateKeyPath:
              \.[
                id: component.id,
                fileID: _HashableStaticString(rawValue: fileID),
                filePath: _HashableStaticString(rawValue: filePath),
                line: line,
                column: column
              ],
            actionKeyPath: \.[id: component.id]
          )
        }
        return SwitchStore(store.scope(id: id, childCore: open(store.core)), content: destination)
      }
    }

    self.root = root()
    self.destination = navigationDestination(component:)
    self._viewStore = ObservedObject(
      wrappedValue: ViewStore(
        store,
        observe: { $0 },
        removeDuplicates: { areOrderedSetsDuplicates($0.ids, $1.ids) }
      )
    )
  }

  public var body: some View {
    NavigationStack(
      path: self.viewStore.binding(
        get: { $0.path },
        compactSend: { newPath in
          if newPath.count > self.viewStore.path.count, let component = newPath.last {
            return .push(id: component.id, state: component.element)
          } else if newPath.count < self.viewStore.path.count {
            return .popFrom(id: self.viewStore.path[newPath.count].id)
          } else {
            return nil
          }
        }
      )
    ) {
      self.root
        .environment(\.navigationDestinationType, State.self)
        .navigationDestination(for: StackState<State>.Component.self) { component in
          NavigationDestinationView(component: component, destination: self.destination)
        }
    }
  }
}

private struct NavigationDestinationView<State, Destination: View>: View {
  let component: StackState<State>.Component
  let destination: (StackState<State>.Component) -> Destination
  var body: some View {
    self.destination(self.component)
      .environment(\.navigationDestinationType, State.self)
      .id(self.component.id)
  }
}