/// Copyright (c) 2019 Razeware LLC
///
/// Permission is hereby granted, free of charge, to any person obtaining a copy
/// of this software and associated documentation files (the "Software"), to deal
/// in the Software without restriction, including without limitation the rights
/// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
/// copies of the Software, and to permit persons to whom the Software is
/// furnished to do so, subject to the following conditions:
///
/// The above copyright notice and this permission notice shall be included in
/// all copies or substantial portions of the Software.
///
/// Notwithstanding the foregoing, you may not use, copy, modify, merge, publish,
/// distribute, sublicense, create a derivative work, and/or sell copies of the
/// Software in any work that is designed, intended, or marketed for pedagogical or
/// instructional purposes related to programming, coding, application development,
/// or information technology.  Permission for such use, copying, modification,
/// merger, publication, distribution, sublicensing, creation of derivative works,
/// or sale is expressly withheld.
///
/// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
/// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
/// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
/// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
/// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
/// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
/// THE SOFTWARE.

import SwiftUI

fileprivate struct SettingsBarItems: View {
    let add: () -> Void
    var body: some View {
        HStack(spacing: 20) {
            Button(action: add) {
                Image(systemName: "plus")
            }
            EditButton()
        }
    }
}

/// A settings view showing a list of filter keywrods.
struct SettingsView: View {
  
    @EnvironmentObject var settings: Settings
    @State var presentingAddKeywordSheet = false
  
    var body: some View {
        NavigationView {
            List {
                Section(header: Text("Filter keywords")) {
                  ForEach(settings.keywords) { keyword in
                    HStack(alignment: .top) {
                      Image(systemName: "star")
                        .resizable()
                        .frame(width: 24, height: 24)
                        .scaleEffect(0.67)
                        .background(Color.yellow)
                        .cornerRadius(5)
                      Text(keyword.value)
                    }
                  }
                  .onMove(perform: moveKeyword(from:to:))
                  .onDelete(perform: deleteKeyword(at:))
                }
            }
            .sheet(isPresented: $presentingAddKeywordSheet) {
                AddKeywordView(completed: { newKeyword in
                    let newFilter = FilterKeyword(value: newKeyword)
                    self.settings.keywords.append(newFilter)
                    self.presentingAddKeywordSheet = false
                }).frame(minHeight: 0, maxHeight: 400, alignment: .center)
            }
            .navigationBarTitle(Text("Settings"))
            .navigationBarItems(trailing: SettingsBarItems(add: addKeyword))
        }
    }
  
    private func addKeyword() {
        presentingAddKeywordSheet = true
    }

    private func moveKeyword(from source: IndexSet, to destination: Int) {
        guard let source = source.first,
              destination != settings.keywords.endIndex else { return }
        settings.keywords
          .swapAt(source,
                  source > destination ? destination : destination - 1)
    }

    private func deleteKeyword(at index: IndexSet) {
        guard let first = index.first else { return }
        settings.keywords.remove(at: first)
    }
}

#if DEBUG
struct SettingsView_Previews: PreviewProvider {
    static var previews: some View {
        SettingsView()
    }
}
#endif

