import SwiftUI
import SFSafeSymbols

struct SettingsView: View {
    
    @EnvironmentObject
    var database: Database
    
    @Binding
    var isPresented: Bool
    
    @AppStorage("authKey")
    private var serverAuthenticationKey: String = ""
    
    @State
    private var imageCacheSize: Int = 0
    
    var body: some View {
        NavigationView {
            VStack(alignment: .leading, spacing: 3) {
                Text("Authentication")
                    .font(.footnote)
                    .textCase(.uppercase)
                    .foregroundColor(.secondary)
                    .padding(.top)
                Group {
                    FancyTextField(text: $serverAuthenticationKey, icon: .key, placeholder: "Server key")
                }.padding(.horizontal)
                Text("Statistics")
                    .font(.footnote)
                    .textCase(.uppercase)
                    .foregroundColor(.secondary)
                    .padding(.top)
                Group {
                    SettingsStatisticRow(label: "Caps", value: "\(database.numberOfCaps)")
                    SettingsStatisticRow(label: "Total images", value: "\(database.numberOfImages)")
                    SettingsStatisticRow(label: "Images per cap", value: String(format: "%.1f", database.averageImageCount))
                }.padding(.horizontal)
                Text("Classifier")
                    .font(.footnote)
                    .textCase(.uppercase)
                    .foregroundColor(.secondary)
                    .padding(.top)
                Group {
                    SettingsStatisticRow(label: "Version", value: "\(database.classifierVersion)")
                    SettingsStatisticRow(label: "Recognized caps", value: "\(database.classifierClassCount)")
                }.padding(.horizontal)
                Text("Storage")
                    .font(.footnote)
                    .textCase(.uppercase)
                    .foregroundColor(.secondary)
                    .padding(.top)
                Group {
                    SettingsStatisticRow(label: "Image cache", value: byteString(imageCacheSize))
                    SettingsStatisticRow(label: "Database", value: byteString(database.databaseSize))
                    SettingsStatisticRow(label: "Classifier", value: byteString(database.classifierSize))
                    HStack {
                        Spacer()
                        Button("Clear image cache", action: clearImageCache)
                            .padding()
                        Spacer()
                    }
                }.padding(.horizontal)
                Spacer()
            }
            .padding(.horizontal)
            .navigationTitle("Info")
            .onAppear(perform: updateImageCacheSize)
        }
    }
    
    private func updateImageCacheSize() {
        imageCacheSize = database.imageCacheSize()
    }

    private func clearImageCache() {
        Task {
            database.clearImageCache()
            DispatchQueue.main.async {
                updateImageCacheSize()
            }
        }
    }
    
    private func hide() {
        isPresented = false
    }
    
    private func byteString(_ count: Int) -> String {
        ByteCountFormatter.string(fromByteCount: Int64(count), countStyle: .file)
    }
}

struct SettingsView_Previews: PreviewProvider {
    static var previews: some View {
        SettingsView(isPresented: .constant(true))
            .environmentObject(Database.mock)
            //.previewLayout(.fixed(width: 375, height: 410))
    }
}