import SwiftUI

#warning("Remove button types and just make styles stand-alone")

/// A name space for edit button styles.
public enum EditButtonType { }

/// A name space for info button styles.
public enum InfoButtonType { }

/// A name space for info button styles.
public enum NextButtonType { }

/// A name space for info button styles.
public enum ResetButtonType { }

/// A type erased primitive button style, used to style buttons in a namespace.
@MainActor
public struct AnyPrimitiveButtonStyle<ButtonType>: PrimitiveButtonStyle {
  private let _makeBody: (Configuration) -> AnyView

  public init<S: PrimitiveButtonStyle>(_ style: S) {
    self._makeBody = { configuration in
      AnyView(style.makeBody(configuration: configuration))
    }
  }

  public func makeBody(configuration: Configuration) -> some View {
    self._makeBody(configuration)
  }
}

/// The default info button style.
@MainActor
public struct DefaultInfoButtonStyle<Style: LabelStyle>: PrimitiveButtonStyle {
  let color: Color
  let font: Font
  let labelStyle: Style
  
  init(
    color: Color = .accentColor,
    font: Font = .title2,
    labelStyle: Style
  ) {
    self.color = color
    self.font = font
    self.labelStyle = labelStyle
  }
  
  public func makeBody(configuration: Configuration) -> some View {
    Button(role: configuration.role, action: configuration.trigger) {
      configuration.label
        .font(font)
        .foregroundStyle(color)
        .labelStyle(labelStyle)
    }
    .buttonStyle(.plain)
  }
}

public struct DefaultNextButtonStyle<ButtonStyle: PrimitiveButtonStyle, Label: LabelStyle>: PrimitiveButtonStyle {
  let buttonStyle: ButtonStyle
  let labelStyle: Label
  
  public init(buttonStyle: ButtonStyle, labelStyle: Label) {
    self.buttonStyle = buttonStyle
    self.labelStyle = labelStyle
  }
  
  public func makeBody(configuration: Configuration) -> some View {
    Button(role: configuration.role, action: configuration.trigger) {
      configuration.label
    }
    .labelStyle(labelStyle)
    .buttonStyle(buttonStyle)
  }
}

extension DefaultNextButtonStyle where ButtonStyle == BorderedProminentButtonStyle, Label == NextLabelStyle {
  init() {
    self.init(buttonStyle: .borderedProminent, labelStyle: .nextLabel())
  }
}

public struct ToolbarNextButtonStyle: PrimitiveButtonStyle {

  public func makeBody(configuration: Configuration) -> some View {
    Button(role: configuration.role, action: configuration.trigger) {
      configuration.label
        .foregroundStyle(Color.accentColor)
    }
    .labelStyle(NextLabelStyle())
    .buttonStyle(.plain)
  }
}

extension AnyPrimitiveButtonStyle<NextButtonType> {
  public static var toolbar: Self { .init(ToolbarNextButtonStyle()) }
}

private struct InfoButtonStyleKey: @preconcurrency EnvironmentKey {
  @MainActor
  static var defaultValue: AnyPrimitiveButtonStyle<InfoButtonType> {
    AnyPrimitiveButtonStyle<InfoButtonType>(DefaultInfoButtonStyle(labelStyle: .iconOnly))
  }
}

private struct NextButtonStyleKey: EnvironmentKey {
  static var defaultValue: AnyPrimitiveButtonStyle<NextButtonType> {
    MainActor.assumeIsolated {
      AnyPrimitiveButtonStyle<NextButtonType>(
        DefaultNextButtonStyle<BorderedProminentButtonStyle, NextLabelStyle>()
      )
    }
  }
}

private struct ResetButtonStyleKey: EnvironmentKey {
  static let defaultValue = MainActor.assumeIsolated {
    AnyPrimitiveButtonStyle<ResetButtonType>(.borderedProminent)
  }
}

extension EnvironmentValues {
//  @Entry var infoButtonStyle: AnyButtonStyle<InfoButtonType> = AnyButtonStyle.default

  @Entry var editButtonStyle = MainActor.assumeIsolated {
    AnyPrimitiveButtonStyle<EditButtonType>(DefaultInfoButtonStyle(labelStyle: .automatic))
  }

  var infoButtonStyle: AnyPrimitiveButtonStyle<InfoButtonType> {
    get { self[InfoButtonStyleKey.self] }
    set { self[InfoButtonStyleKey.self] = newValue }
  }
  
  var nextButtonStyle: AnyPrimitiveButtonStyle<NextButtonType> {
    get { self[NextButtonStyleKey.self] }
    set { self[NextButtonStyleKey.self] = newValue }
  }
  
  var resetButtonStyle: AnyPrimitiveButtonStyle<ResetButtonType> {
    get { self[ResetButtonStyleKey.self] }
    set { self[ResetButtonStyleKey.self] = newValue }
  }
}

extension View {

  /// Sets the button style for the ``EditButton`` type.
  public func editButtonStyle(_ style: AnyPrimitiveButtonStyle<EditButtonType>) -> some View {
    environment(\.editButtonStyle, style)
  }

  /// Sets the button style for the ``EditButton`` type.
  public func editButtonStyle<S: PrimitiveButtonStyle>(_ style: S) -> some View {
    editButtonStyle(AnyPrimitiveButtonStyle(style))
  }

  /// Sets the button style for the ``InfoButton`` type.
  public func infoButtonStyle(_ style: AnyPrimitiveButtonStyle<InfoButtonType>) -> some View {
    environment(\.infoButtonStyle, style)
  }

  /// Sets the button style for the ``InfoButton`` type.
  public func infoButtonStyle<S: PrimitiveButtonStyle>(_ style: S) -> some View {
    infoButtonStyle(AnyPrimitiveButtonStyle(style))
  }
  
  /// Sets the button style for the ``NextButton`` type.
  public func nextButtonStyle(_ style: AnyPrimitiveButtonStyle<NextButtonType>) -> some View {
    environment(\.nextButtonStyle, style)
  }
  
  /// Sets the button style for the ``NextButton`` type.
  public func nextButtonStyle<S: PrimitiveButtonStyle>(_ style: S) -> some View {
    nextButtonStyle(AnyPrimitiveButtonStyle(style))
  }
  
  /// Sets the button style for the ``ResetButton`` type.
  public func resetButtonStyle(_ style: AnyPrimitiveButtonStyle<ResetButtonType>) -> some View {
    environment(\.resetButtonStyle, style)
  }
  
  /// Sets the button style for the ``ResetButton`` type.
  public func resetButtonStyle<S: PrimitiveButtonStyle>(_ style: S) -> some View {
    resetButtonStyle(AnyPrimitiveButtonStyle(style))
  }
}