NavidromeApp/iOS/Views/Settings/BackupRestoreView.swift

import SwiftUI
import ConfettiSwiftUI

// ──────────────────────────────────────────────────────────────────────
// BackupRestoreView.swift
// Settings section: Export Backup (share sheet), Import Backup (file picker),
// pending operations count, and confetti on successful import.
// ──────────────────────────────────────────────────────────────────────

struct BackupRestoreSection: View {
    @ObservedObject private var pendingOps = PendingOperationsQueue.shared
    @State private var showExportSheet = false
    @State private var showImportPicker = false
    @State private var showImportSuccess = false
    @State private var showError = false
    @State private var errorMessage = ""
    @State private var importedManifest: BackupManifest?
    @State private var exportURL: URL?
    @State private var confettiTrigger = 0
    @State private var isExporting = false
    
    private let accentPink = Color(red: 1.0, green: 0.176, blue: 0.333)
    
    var body: some View {
        Section("Backup & Restore") {
            // Export
            Button {
                exportBackup()
            } label: {
                HStack {
                    Label("Export Backup", systemImage: "square.and.arrow.up")
                    Spacer()
                    if isExporting {
                        ProgressView()
                            .scaleEffect(0.8)
                    }
                }
            }
            .disabled(isExporting)
            
            // Import
            Button {
                showImportPicker = true
            } label: {
                Label("Import Backup", systemImage: "square.and.arrow.down")
            }
            
            // Pending operations
            if !pendingOps.isEmpty {
                NavigationLink {
                    PendingOperationsListView()
                } label: {
                    HStack {
                        Label("Pending Operations", systemImage: "clock.arrow.circlepath")
                        Spacer()
                        Text("\(pendingOps.count)")
                            .font(.system(size: 14, weight: .semibold))
                            .foregroundStyle(.white)
                            .padding(.horizontal, 8)
                            .padding(.vertical, 2)
                            .background(accentPink.cornerRadius(10))
                    }
                }
            }
        }
        .sheet(isPresented: $showExportSheet) {
            if let url = exportURL {
                ShareSheet(items: [url])
            }
        }
        .fileImporter(
            isPresented: $showImportPicker,
            allowedContentTypes: [.init(filenameExtension: "nvdbackup")!],
            allowsMultipleSelection: false
        ) { result in
            handleImport(result)
        }
        .alert("Import Successful", isPresented: $showImportSuccess) {
            Button("OK") {
                confettiTrigger += 1
            }
        } message: {
            if let m = importedManifest {
                Text("Restored from \(m.deviceName) (\(m.deviceModel))\n\(formattedDate(m.exportDate))\n\nPlease re-enter your server password.")
            }
        }
        .alert("Backup Error", isPresented: $showError) {
            Button("OK", role: .cancel) {}
        } message: {
            Text(errorMessage)
        }
        .overlay {
            // ConfettiCannon as overlay prevents it from interfering with List row layout
            EmptyView().confettiCannon(trigger: $confettiTrigger, num: 50, radius: 400)
        }
    }
    
    private func exportBackup() {
        isExporting = true
        Task {
            do {
                let url = try BackupManager.shared.exportBackup()
                await MainActor.run {
                    exportURL = url
                    isExporting = false
                    showExportSheet = true
                }
            } catch {
                await MainActor.run {
                    isExporting = false
                    errorMessage = error.localizedDescription
                    showError = true
                }
            }
        }
    }
    
    private func handleImport(_ result: Result<[URL], Error>) {
        switch result {
        case .success(let urls):
            guard let url = urls.first else { return }
            do {
                let manifest = try BackupManager.shared.importBackup(from: url)
                importedManifest = manifest
                showImportSuccess = true
            } catch {
                errorMessage = error.localizedDescription
                showError = true
            }
        case .failure(let error):
            errorMessage = error.localizedDescription
            showError = true
        }
    }
    
    private func formattedDate(_ date: Date) -> String {
        let df = DateFormatter()
        df.dateStyle = .medium
        df.timeStyle = .short
        return df.string(from: date)
    }
}

// MARK: - Share Sheet (UIKit wrapper)

struct ShareSheet: UIViewControllerRepresentable {
    let items: [Any]
    
    func makeUIViewController(context: Context) -> UIActivityViewController {
        UIActivityViewController(activityItems: items, applicationActivities: nil)
    }
    
    func updateUIViewController(_ vc: UIActivityViewController, context: Context) {}
}

// MARK: - Pending Operations List

struct PendingOperationsListView: View {
    @ObservedObject private var queue = PendingOperationsQueue.shared
    
    var body: some View {
        List {
            if queue.isEmpty {
                Text("No pending operations")
                    .foregroundStyle(.secondary)
            } else {
                ForEach(queue.operations) { op in
                    VStack(alignment: .leading, spacing: 4) {
                        Text(op.displayDescription)
                            .font(.system(size: 14, weight: .medium))
                        
                        HStack {
                            Text(op.type.rawValue)
                                .font(.system(size: 11))
                                .foregroundStyle(.secondary)
                            
                            Spacer()
                            
                            Text("Retry \(op.retryCount)/\(op.maxRetries)")
                                .font(.system(size: 11, weight: .medium).monospacedDigit())
                                .foregroundStyle(op.retryCount >= 3 ? .red : .secondary)
                        }
                        
                        Text(op.createdAt, style: .relative)
                            .font(.system(size: 11))
                            .foregroundStyle(.tertiary)
                    }
                    .padding(.vertical, 2)
                }
                .onDelete { offsets in
                    for offset in offsets {
                        queue.remove(queue.operations[offset])
                    }
                }
                
                Section {
                    Button("Retry All Now") {
                        queue.processAll()
                    }
                    .disabled(queue.isEmpty)
                    
                    Button("Clear All", role: .destructive) {
                        queue.clearAll()
                    }
                    .disabled(queue.isEmpty)
                }
            }
        }
        .navigationTitle("Pending Operations")
    }
}