Tusker/Tusker/Screens/Filters/EditFilterView.swift

//
//  EditFilterView.swift
//  Tusker
//
//  Created by Shadowfacts on 12/2/22.
//  Copyright © 2022 Shadowfacts. All rights reserved.
//

import SwiftUI
import Pachyderm

struct EditFilterView: View {
    private static let expiresInOptions: [MenuPicker<TimeInterval>.Option] = {
        let f = DateComponentsFormatter()
        f.maximumUnitCount = 1
        f.unitsStyle = .full
        f.allowedUnits = [.weekOfMonth, .day, .hour, .minute]
        
        let durations: [TimeInterval] = [
                     30 * 60,
                     60 * 60,
                 6 * 60 * 60,
                24 * 60 * 60,
            3 * 24 * 60 * 60,
            7 * 24 * 60 * 60,
        ]
        return durations.map { .init(value: $0, title: f.string(from: $0)!) }
    }()
    
    @ObservedObject var filter: FilterMO
    let updateFilter: () -> Void
    @EnvironmentObject private var mastodonController: MastodonController
    @State private var edited = false
    
    init(filter: FilterMO, updateFilter: @escaping () -> Void) {
        self.filter = filter
        self.updateFilter = updateFilter
        if let expiresAt = filter.expiresAt {
            let dist = expiresAt.timeIntervalSinceNow
            self.expiresIn = Self.expiresInOptions.min(by: { a, b in
                let aDist = abs(a.value - dist)
                let bDist = abs(b.value - dist)
                return aDist < bDist
            })!.value
        } else {
            self.expiresIn = 24 * 60 * 60
        }
    }
    
    @State private var expiresIn: TimeInterval {
        didSet {
            if filter.expiresAt != nil {
                filter.expiresAt = Date(timeIntervalSinceNow: expiresIn)
            }
        }
    }
    private var expires: Binding<Bool> {
        Binding {
            filter.expiresAt != nil
        } set: { newValue in
            if newValue {
                filter.expiresAt = Date(timeIntervalSinceNow: expiresIn)
            } else {
                filter.expiresAt = nil
            }
        }
    }
    
    var body: some View {
        Form {
            Section {
                TextField("Phrase", text: $filter.phrase)
                Toggle("Whole Word", isOn: $filter.wholeWord)
            }
            
            Section {
                Toggle("Expires", isOn: expires)
                if expires.wrappedValue {
                    Picker(selection: $expiresIn) {
                        ForEach(Self.expiresInOptions, id: \.value) { option in
                            Text(option.title).tag(option.value)
                        }
                    } label: {
                        Text("Duration")
                    }
                }
            }
            
            Section {
                ForEach(Filter.Context.allCases, id: \.rawValue) { context in
                    Toggle(isOn: Binding(get: {
                        filter.contexts.contains(context)
                    }, set: { newValue in
                        if newValue {
                            if !filter.contexts.contains(context) {
                                filter.contexts.append(context)
                            }
                        } else if filter.contexts.count > 1 {
                            filter.contexts.removeAll(where: { $0 == context })
                        }
                    })) {
                        Text(context.displayName)
                    }
                    .toggleStyle(FilterContextToggleStyle())
                }
            } header: {
                Text("Contexts")
            }
        }
        .navigationTitle("Edit Filter")
        .navigationBarTitleDisplayMode(.inline)
        .onReceive(filter.objectWillChange, perform: { _ in
            edited = true
        })
        .onDisappear {
            if edited {
                updateFilter()
            }
        }
    }
}

private struct FilterContextToggleStyle: ToggleStyle {
    func makeBody(configuration: Configuration) -> some View {
        Button {
            configuration.isOn.toggle()
        } label: {
            HStack {
                configuration.label
                    .foregroundColor(.primary)
                Spacer()
                if configuration.isOn {
                    Image(systemName: "checkmark")
                }
            }
        }
    }
}

//struct EditFilterView_Previews: PreviewProvider {
//    static var previews: some View {
//        EditFilterView()
//    }
//}