import Cocoa
import Foundation
import SwiftUI

struct AppState {
  var selectedEvolution: StageType = .general
}

enum AppAction {
  case selectEvolution(evolution: StageType)
  case exportMapAsImage(map: Map)
  case exportMapAsText(map: Map)
  case deleteMap(map: Map)
}

func appStateReducer(state: inout AppState, action: AppAction) {

  switch action {

  case .selectEvolution(let evolution):
    state.selectedEvolution = evolution

  case .exportMapAsImage(let map):
    let window = NSWindow(
      contentRect: .init(
        origin: .zero,
        size: .init(
          width: NSScreen.main!.frame.width,
          height: NSScreen.main!.frame.height)),
      styleMask: [.closable],
      backing: .buffered,
      defer: false)

    window.title = map.title ?? "Untitled Map"
    window.isOpaque = true
    window.center()
    window.isMovableByWindowBackground = true
    window.makeKeyAndOrderFront(nil)

    let renderView = MapRenderView(
      content: Binding.constant(map.content ?? ""),
      evolution: Binding.constant(state.selectedEvolution))

    let view = NSHostingView(rootView: renderView)
    window.contentView = view

    let imageRepresentation = view.bitmapImageRepForCachingDisplay(in: view.bounds)!
    view.cacheDisplay(in: view.bounds, to: imageRepresentation)
    let image = NSImage(cgImage: imageRepresentation.cgImage!, size: view.bounds.size)

    let dialog = NSSavePanel()

    dialog.title = "Save Map"
    dialog.showsResizeIndicator = false
    dialog.canCreateDirectories = true
    dialog.showsHiddenFiles = false
    dialog.allowedContentTypes = [.png]
    dialog.nameFieldStringValue = map.title ?? "Untitled Map"

    if dialog.runModal() == NSApplication.ModalResponse.OK {
      let result = dialog.url

      if result != nil {

        image.writePNG(toURL: result!)
        print("saved at \(result!)")
      }
    } else {
      print("Cancel")
    }
    window.orderOut(nil)

  case .exportMapAsText(let map):
    let dialog = NSSavePanel()

    dialog.title = "Save Map Text"
    dialog.showsResizeIndicator = false
    dialog.canCreateDirectories = true
    dialog.showsHiddenFiles = false
    dialog.allowedContentTypes = [.text]
    dialog.nameFieldStringValue = map.title ?? "Untitled Map"

    if let content = map.content {

      if dialog.runModal() == NSApplication.ModalResponse.OK {
        let result = dialog.url

        if let result = result {
          try? content.write(to: result, atomically: true, encoding: String.Encoding.utf8)
        }
      } else {
        print("Cancel")
      }
    }
  case .deleteMap(let map):
    let context = PersistenceController.shared.container.viewContext
    context.delete(map)

    try? context.save()
  }
}

typealias AppStore = Store<AppState, AppAction>