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: "Server Version", value: "\(database.serverClassifierVersion)")
                    SettingsStatisticRow(label: "Local Version", value: "\(database.localClassifierVersion)")
                    SettingsStatisticRow(label: "Recognized caps", value: "\(database.classifierClassCount)")
                    HStack {
                        Spacer()
                        Button(action: updateClassifierVersion) {
                            Label("Refresh", systemSymbol: .arrowCounterclockwise)
                        }
                        .disabled(database.classifierDownloadProgress != nil)
                        .padding()
                        if database.localClassifierVersion != database.serverClassifierVersion {
                            Button(action: downloadNewClassifier) {
                                Label("Download", systemSymbol: .squareAndArrowDown)
                            }
                            .disabled(database.classifierDownloadProgress != nil)
                            .padding()
                        }
                        Spacer()
                    }
                    if let progress = database.classifierDownloadProgress {
                        ClassifierDownloadView(progress: progress)
                    }
                }.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(action: clearImageCache) {
                            Label("Clear image cache", systemSymbol: .trash)
                        }
                            .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 downloadNewClassifier() {
        Task {
            // Ensure that correct version is saved
            await database.updateServerClassifierVersion()
            await database.downloadClassifier()
        }
    }
    
    private func updateClassifierVersion() {
        Task {
            await database.updateServerClassifierVersion()
        }
    }
    
    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))
    }
}