//
//  EncryptedStorageDemo.swift
//  SecureStorgageSample
//
//  Demonstrates encrypted file storage with LocalData package.
//

import SwiftUI
import LocalData

struct EncryptedStorageDemo: View {
    @State private var logEntry = ""
    @State private var storedLogs: [String] = []
    @State private var statusMessage = ""
    @State private var isLoading = false
    @State private var iterations = 10_000
    @FocusState private var isFieldFocused: Bool
    
    var body: some View {
        Form {
            Section {
                Text("Encrypted file storage uses AES-256-GCM encryption with PBKDF2 key derivation. Data is encrypted before being written to disk with complete file protection.")
                    .font(.caption)
                    .foregroundStyle(.secondary)
            }
            
            Section("Add Log Entry") {
                TextField("Enter log message", text: $logEntry, axis: .vertical)
                    .lineLimit(3, reservesSpace: true)
                    .focused($isFieldFocused)
                
                Stepper("PBKDF2 Iterations: \(iterations)", value: $iterations, in: 1000...100000, step: 1000)
                    .font(.caption)
                
                Text("Higher iterations = more secure but slower")
                    .font(.caption2)
                    .foregroundStyle(.secondary)
            }
            
            Section("Actions") {
                Button(action: addLogEntry) {
                    HStack {
                        Image(systemName: "plus.circle.fill")
                        Text("Add Encrypted Log Entry")
                    }
                }
                .disabled(logEntry.isEmpty || isLoading)
                
                Button(action: loadLogs) {
                    HStack {
                        Image(systemName: "lock.open.fill")
                        Text("Decrypt and Load Logs")
                    }
                }
                .disabled(isLoading)
                
                Button(action: clearLogs) {
                    HStack {
                        Image(systemName: "trash")
                        Text("Clear All Logs")
                    }
                }
                .foregroundStyle(.red)
                .disabled(isLoading)
            }
            
            if !storedLogs.isEmpty {
                Section("Decrypted Logs (\(storedLogs.count))") {
                    ForEach(Array(storedLogs.enumerated()), id: \.offset) { index, log in
                        HStack {
                            Text("\(index + 1).")
                                .foregroundStyle(.secondary)
                            Text(log)
                        }
                        .font(.system(.caption, design: .monospaced))
                    }
                }
            }
            
            if !statusMessage.isEmpty {
                Section {
                    Text(statusMessage)
                        .font(.caption)
                        .foregroundStyle(statusMessage.contains("Error") ? .red : .green)
                }
            }
            
            Section("Encryption Details") {
                LabeledContent("Algorithm", value: "AES-256-GCM")
                LabeledContent("Key Derivation", value: "PBKDF2-SHA256")
                LabeledContent("Iterations", value: "\(iterations)")
                LabeledContent("File Protection", value: "Complete")
            }
            
            Section("Key Configuration") {
                LabeledContent("Domain", value: "Encrypted File System")
                LabeledContent("Directory", value: "Caches")
                LabeledContent("Security", value: "AES-256 Encrypted")
                LabeledContent("Platform", value: "Phone Only")
            }
        }
        .navigationTitle("Encrypted Storage")
        .navigationBarTitleDisplayMode(.inline)
        .toolbar {
            ToolbarItemGroup(placement: .keyboard) {
                Spacer()
                Button("Done") {
                    isFieldFocused = false
                }
            }
        }
    }
    
    private func addLogEntry() {
        isLoading = true
        Task {
            do {
                let key = StorageKeys.SessionLogsKey(iterations: iterations)
                
                // Load existing logs
                var logs: [String]
                do {
                    logs = try await StorageRouter.shared.get(key)
                } catch StorageError.notFound {
                    logs = []
                }
                
                // Add new entry with timestamp
                let timestamp = Date().formatted(date: .abbreviated, time: .standard)
                logs.append("[\(timestamp)] \(logEntry)")
                
                // Save encrypted
                try await StorageRouter.shared.set(logs, for: key)
                
                storedLogs = logs
                logEntry = ""
                statusMessage = "✓ Entry encrypted and saved"
            } catch {
                statusMessage = "Error: \(error.localizedDescription)"
            }
            isLoading = false
        }
    }
    
    private func loadLogs() {
        isLoading = true
        Task {
            do {
                let key = StorageKeys.SessionLogsKey(iterations: iterations)
                storedLogs = try await StorageRouter.shared.get(key)
                statusMessage = "✓ Decrypted \(storedLogs.count) log entries"
            } catch StorageError.notFound {
                storedLogs = []
                statusMessage = "No encrypted logs found"
            } catch {
                statusMessage = "Error: \(error.localizedDescription)"
            }
            isLoading = false
        }
    }
    
    private func clearLogs() {
        isLoading = true
        Task {
            do {
                let key = StorageKeys.SessionLogsKey(iterations: iterations)
                try await StorageRouter.shared.remove(key)
                storedLogs = []
                statusMessage = "✓ Encrypted logs cleared"
            } catch {
                statusMessage = "Error: \(error.localizedDescription)"
            }
            isLoading = false
        }
    }
}

#Preview {
    NavigationStack {
        EncryptedStorageDemo()
    }
}