import SharedModels
import Styleguide
import SwiftUI

/// Represents the status of a flagged value, which is stylable using the
/// `.flaggedStatusLabelStyle` modifier on a view.
///
/// By default the status label is colored using the default status color.
public struct FlaggedStatusLabel: View {
  @Environment(\.flaggedStatusLabelStyle) private var style
  let status: Flagged.CheckResult.Status

  public init(status: Flagged.CheckResult.Status) {
    self.status = status
  }

  public var body: some View {
    style.makeBody(
      configuration: FlaggedStatusLabelStyleConfiguration(
        status: status
      )
    )
  }
}


public protocol FlaggedStatusLabelStyle {
  associatedtype Body: View
  typealias Configuration = FlaggedStatusLabelStyleConfiguration
  
  func makeBody(configuration: Self.Configuration) -> Self.Body
}

public struct FlaggedStatusLabelStyleConfiguration {
  public let status: Flagged.CheckResult.Status
}

public struct AnyFlaggedStatusLabelStyle: FlaggedStatusLabelStyle {
  private let _makeBody: (Configuration) -> AnyView
  
  internal init(makeBody: @escaping (Configuration) -> AnyView) {
    self._makeBody = makeBody
  }
  
  public init<Style: FlaggedStatusLabelStyle>(_ style: Style) {
    self.init { configuration in
      AnyView(style.makeBody(configuration: configuration))
    }
  }
  
  public func makeBody(configuration: Configuration) -> some View {
    _makeBody(configuration)
  }
}

public struct FlaggedStatusTextLabelStyle: FlaggedStatusLabelStyle {
  
  let textLabelStyle: AnyTextLabelStyle?
  
  public func makeBody(configuration: Configuration) -> some View {
    TextLabel(configuration.status.title)
      .textLabelStyle(
        textLabelStyle
        ?? AnyTextLabelStyle(
          style: .colored(configuration.status.color).font(.caption, fontWeight: .bold)
        )
      )
  }
}

private struct FlaggedStatusLabelStyleKey: EnvironmentKey {
  static var defaultValue = AnyFlaggedStatusLabelStyle(
    FlaggedStatusTextLabelStyle(
      textLabelStyle: AnyTextLabelStyle(
        style: .font(.callout, fontWeight: .bold)
      )
    )
  )
}

extension FlaggedStatusLabelStyle where Self == FlaggedStatusTextLabelStyle {
  
  public static var textLabel: Self { textLabel() }
  
  public static func textLabel(
    _ style: AnyTextLabelStyle? = nil
  ) -> Self {
    .init(textLabelStyle: style)
  }
  
  public static func textLabel<S: TextLabelStyle>(
    _ style: S
  ) -> Self {
    .init(textLabelStyle: AnyTextLabelStyle(style: style))
  }
}

public struct FlaggedStatusPillStyle: FlaggedStatusLabelStyle {
  let labelStyle: AnyTextLabelStyle?
  let opacity: Double
  
  public func makeBody(configuration: Configuration) -> some View {
    TextLabel(configuration.status.title)
      .textLabelStyle(labelStyle ?? AnyTextLabelStyle(
        style: .font(.caption, fontWeight: .bold).combining(.colored(.white))
        )
      )
      .padding(.horizontal, 10)
      .padding(.vertical, 5)
      .background {
        Capsule()
          .foregroundStyle(configuration.status.color.opacity(opacity))
      }
  }
}

extension FlaggedStatusLabelStyle where Self == FlaggedStatusPillStyle {
  
  public static var pill: Self { .pill() }
  
  public static func pill(
    _ style: AnyTextLabelStyle? = nil,
    opacity: Double = 1
  ) -> Self {
    .init(labelStyle: style, opacity: opacity)
  }
  
  public static func pill<S: TextLabelStyle>(_ style: S, opacity: Double = 1) -> Self {
    .init(labelStyle: AnyTextLabelStyle(style: style), opacity: opacity)
  }
}

extension EnvironmentValues {
  public var flaggedStatusLabelStyle: AnyFlaggedStatusLabelStyle {
    get { self[FlaggedStatusLabelStyleKey.self] }
    set { self[FlaggedStatusLabelStyleKey.self] = newValue }
  }
}

extension View {
  public func flaggedStatusLabelStyle(
    _ style: AnyFlaggedStatusLabelStyle
  ) -> some View {
    environment(
      \.flaggedStatusLabelStyle,
       style
    )
    
  }

  public func flaggedStatusLabelStyle<S: FlaggedStatusLabelStyle>(_ style: S) -> some View {
    flaggedStatusLabelStyle(AnyFlaggedStatusLabelStyle(style))
  }
}

#Preview {
  VStack {
    FlaggedStatusLabel(status: .warning)
      .flaggedStatusLabelStyle(.textLabel(.heavyTitle2))
    
    FlaggedStatusLabel(status: .warning)
      .flaggedStatusLabelStyle(.pill)
    
//    FlaggedStatusLabel(status: .warning
//      .flaggedStatusLabelStyle(.pill(.heavyTitle2))
  }
}