vimr/VimR/FileMonitorReducer.swift

/**
 * Tae Won Ha - http://taewon.de - @hataewon
 * See LICENSE
 */

import Foundation
import RxSwift

class FileMonitorReducer: Reducer {

  typealias Pair = StateActionPair<AppState, FileMonitor.Action>

  func reduce(_ source: Observable<Pair>) -> Observable<Pair> {
    return source.map { pair in
      var state = pair.state

      switch pair.action {

      case let .change(in: url):
        guard let fileItem = FileItemUtils.item(for: url, root: state.root, create: false) else {
          return pair
        }

        fileItem.needsScanChildren = true

        state.mainWindows
          .filter { (uuid, mainWindow) in url == mainWindow.cwd || url.isContained(in: mainWindow.cwd) }
          .map { $0.0 }
          .forEach { uuid in
            state.mainWindows[uuid]?.lastFileSystemUpdate = Marked(fileItem)
          }

      }

      return StateActionPair(state: state, action: pair.action)
    }
  }
}