import Models
import SwiftUI
import Utils
import WebKit

public let readerViewNavBarHeight = 50.0

enum WebViewConfigurationManager {
  private static let processPool = WKProcessPool()
  static func create() -> WKWebViewConfiguration {
    let config = WKWebViewConfiguration()
    config.processPool = processPool
    #if os(iOS)
      config.allowsInlineMediaPlayback = true
    #endif
    config.mediaTypesRequiringUserActionForPlayback = .audio
    return config
  }
}

public enum WebViewManager {
  public static let sharedView = create()
  public static func shared() -> WebView {
    sharedView
  }

  public static func create() -> WebView {
    WebView(frame: CGRect.zero, configuration: WebViewConfigurationManager.create())
  }
}

#if os(iOS)
  struct WebAppView: UIViewRepresentable {
    let request: URLRequest
    let baseURL: URL
    let rawAuthCookie: String?
    let openLinkAction: (URL) -> Void
    let webViewActionHandler: (WKScriptMessage) -> Void
    let navBarVisibilityRatioUpdater: (Double) -> Void
    @Binding var annotation: String
    @Binding var annotationSaveTransactionID: UUID?
    @Binding var sendIncreaseFontSignal: Bool
    @Binding var sendDecreaseFontSignal: Bool

    func makeCoordinator() -> WebAppViewCoordinator {
      WebAppViewCoordinator()
    }

    func fontSize() -> Int {
      let storedSize = UserDefaults.standard.integer(forKey: "preferredWebFontSize")
      return storedSize <= 1 ? UITraitCollection.current.preferredWebFontSize : storedSize
    }

    func makeUIView(context: Context) -> WKWebView {
      let webView = WebViewManager.create()
      let contentController = WKUserContentController()

      webView.navigationDelegate = context.coordinator
      webView.isOpaque = false
      webView.backgroundColor = .clear
      webView.configuration.userContentController = contentController
      webView.scrollView.delegate = context.coordinator
      webView.scrollView.contentInset.top = readerViewNavBarHeight
      webView.scrollView.verticalScrollIndicatorInsets.top = readerViewNavBarHeight

      for action in WebViewAction.allCases {
        webView.configuration.userContentController.add(context.coordinator, name: action.rawValue)
      }

      webView.configuration.userContentController.add(webView, name: "viewerAction")

      webView.configureForOmnivoreAppEmbed(
        config: WebViewConfig(
          url: baseURL,
          themeId: UITraitCollection.current.userInterfaceStyle == .dark ? "Gray" : "LightGray",
          margin: 0,
          fontSize: fontSize(),
          fontFamily: "inter",
          rawAuthCookie: rawAuthCookie
        )
      )

      context.coordinator.linkHandler = openLinkAction
      context.coordinator.webViewActionHandler = webViewActionHandler
      context.coordinator.updateNavBarVisibilityRatio = navBarVisibilityRatioUpdater

      return webView
    }

    func updateUIView(_ webView: WKWebView, context: Context) {
      if context.coordinator.needsReload {
        webView.load(request)
        context.coordinator.needsReload = false
      }

      if annotationSaveTransactionID != context.coordinator.lastSavedAnnotationID {
        context.coordinator.lastSavedAnnotationID = annotationSaveTransactionID
        (webView as? WebView)?.dispatchEvent(.saveAnnotation(annotation: annotation))
      }

      if sendIncreaseFontSignal {
        sendIncreaseFontSignal = false
        (webView as? WebView)?.updateFontSize()
      }

      if sendDecreaseFontSignal {
        sendDecreaseFontSignal = false
        (webView as? WebView)?.updateFontSize()
      }
    }
  }
#endif

#if os(macOS)
  struct WebAppView: NSViewRepresentable {
    let request: URLRequest
    let baseURL: URL
    let rawAuthCookie: String?
    let openLinkAction: (URL) -> Void
    let webViewActionHandler: (WKScriptMessage) -> Void
    let navBarVisibilityRatioUpdater: (Double) -> Void
    @Binding var annotation: String
    @Binding var annotationSaveTransactionID: UUID?
    @Binding var sendIncreaseFontSignal: Bool
    @Binding var sendDecreaseFontSignal: Bool

    func makeCoordinator() -> WebAppViewCoordinator {
      WebAppViewCoordinator()
    }

    func fontSize() -> Int {
      let storedSize = UserDefaults.standard.integer(forKey: "preferredWebFontSize")
      return storedSize <= 1 ? Int(NSFont.userFont(ofSize: 16)?.pointSize ?? 16) : storedSize
    }

    func makeNSView(context: Context) -> WKWebView {
      let contentController = WKUserContentController()
      let webView = WebView(frame: CGRect.zero)

      webView.navigationDelegate = context.coordinator
      webView.configuration.userContentController = contentController
      webView.setValue(false, forKey: "drawsBackground")

      for action in WebViewAction.allCases {
        webView.configuration.userContentController.add(context.coordinator, name: action.rawValue)
      }

      webView.configureForOmnivoreAppEmbed(
        config: WebViewConfig(
          url: baseURL,
          themeId: NSApp.effectiveAppearance.name == NSAppearance.Name.darkAqua ? "Gray" : "LightGray",
          margin: 0,
          fontSize: fontSize(),
          fontFamily: "inter",
          rawAuthCookie: rawAuthCookie
        )
      )

      context.coordinator.linkHandler = openLinkAction
      context.coordinator.webViewActionHandler = webViewActionHandler

      return webView
    }

    func updateNSView(_ webView: WKWebView, context: Context) {
      if context.coordinator.needsReload {
        webView.load(request)
        context.coordinator.needsReload = false
      }

      if sendIncreaseFontSignal {
        sendIncreaseFontSignal = false
        (webView as? WebView)?.increaseFontSize()
      }

      if sendDecreaseFontSignal {
        sendDecreaseFontSignal = false
        (webView as? WebView)?.decreaseFontSize()
      }
    }
  }
#endif