//
//  PlatformSyncDemo.swift
//  SecureStorgageSample
//
//  Demonstrates platform availability and sync policies with LocalData package.
//

import SwiftUI
import LocalData

struct PlatformSyncDemo: View {
    @State private var settingValue = ""
    @State private var storedValue = ""
    @State private var statusMessage = ""
    @State private var isLoading = false
    @State private var selectedPlatform: PlatformAvailability = .all
    @State private var selectedSync: SyncPolicy = .never
    @FocusState private var isFieldFocused: Bool
    
    var body: some View {
        Form {
            Section {
                Text("Platform availability controls which devices can access data. Sync policy determines how data is shared between iPhone and Apple Watch via WatchConnectivity.")
                    .font(.caption)
                    .foregroundStyle(.secondary)
            }
            
            Section("Platform Availability") {
                Picker("Available On", selection: $selectedPlatform) {
                    Text("All (iPhone + Watch)").tag(PlatformAvailability.all)
                    Text("Phone Only").tag(PlatformAvailability.phoneOnly)
                    Text("Watch Only").tag(PlatformAvailability.watchOnly)
                    Text("Phone w/ Watch Sync").tag(PlatformAvailability.phoneWithWatchSync)
                }
                .pickerStyle(.menu)
                
                platformDescription
            }
            
            Section("Sync Policy") {
                Picker("Sync Behavior", selection: $selectedSync) {
                    Text("Never").tag(SyncPolicy.never)
                    Text("Manual").tag(SyncPolicy.manual)
                    Text("Automatic (Small Data)").tag(SyncPolicy.automaticSmall)
                }
                .pickerStyle(.menu)
                
                syncDescription
            }
            
            Section("Test Data") {
                TextField("Enter a value to store", text: $settingValue)
                    .focused($isFieldFocused)
            }
            
            Section("Actions") {
                Button(action: saveValue) {
                    HStack {
                        Image(systemName: "icloud.and.arrow.up")
                        Text("Save with Current Settings")
                    }
                }
                .disabled(settingValue.isEmpty || isLoading)
                
                Button(action: loadValue) {
                    HStack {
                        Image(systemName: "icloud.and.arrow.down")
                        Text("Load Value")
                    }
                }
                .disabled(isLoading)
                
                Button(action: testPlatformError) {
                    HStack {
                        Image(systemName: "exclamationmark.triangle")
                        Text("Test Platform Restriction")
                    }
                }
                .foregroundStyle(.orange)
                .disabled(isLoading)
            }
            
            if !storedValue.isEmpty {
                Section("Retrieved Value") {
                    Text(storedValue)
                        .font(.system(.body, design: .monospaced))
                }
            }
            
            if !statusMessage.isEmpty {
                Section {
                    Text(statusMessage)
                        .font(.caption)
                        .foregroundStyle(statusMessage.contains("Error") ? .red : 
                                        statusMessage.contains("⚠") ? .orange : .green)
                }
            }
            
            Section("Current Configuration") {
                LabeledContent("Platform", value: selectedPlatform.displayName)
                LabeledContent("Sync", value: selectedSync.displayName)
                LabeledContent("Max Auto-Sync Size", value: "100 KB")
            }
        }
        .navigationTitle("Platform & Sync")
        .navigationBarTitleDisplayMode(.inline)
        .toolbar {
            ToolbarItemGroup(placement: .keyboard) {
                Spacer()
                Button("Done") {
                    isFieldFocused = false
                }
            }
        }
    }
    
    @ViewBuilder
    private var platformDescription: some View {
        switch selectedPlatform {
        case .all:
            Text("Data accessible on both iPhone and Apple Watch")
                .font(.caption)
                .foregroundStyle(.secondary)
        case .phoneOnly:
            Text("Data only accessible on iPhone. Watch access throws error.")
                .font(.caption)
                .foregroundStyle(.secondary)
        case .watchOnly:
            Text("Data only accessible on Watch. iPhone access throws error.")
                .font(.caption)
                .foregroundStyle(.secondary)
        case .phoneWithWatchSync:
            Text("Stored on iPhone, synced to Watch via WatchConnectivity")
                .font(.caption)
                .foregroundStyle(.secondary)
        }
    }
    
    @ViewBuilder
    private var syncDescription: some View {
        switch selectedSync {
        case .never:
            Text("Data stays local, never synced")
                .font(.caption)
                .foregroundStyle(.secondary)
        case .manual:
            Text("Sync triggered explicitly by app code")
                .font(.caption)
                .foregroundStyle(.secondary)
        case .automaticSmall:
            Text("Auto-sync if data ≤ 100KB, otherwise throws error")
                .font(.caption)
                .foregroundStyle(.secondary)
        }
    }
    
    private func saveValue() {
        isLoading = true
        Task {
            do {
                let key = StorageKeys.SyncableSettingKey(
                    availability: selectedPlatform,
                    syncPolicy: selectedSync
                )
                try await StorageRouter.shared.set(settingValue, for: key)
                statusMessage = "✓ Saved with \(selectedPlatform.displayName) availability and \(selectedSync.displayName) sync"
            } catch StorageError.dataTooLargeForSync {
                statusMessage = "Error: Data too large for automatic sync (max 100KB)"
            } catch {
                statusMessage = "Error: \(error.localizedDescription)"
            }
            isLoading = false
        }
    }
    
    private func loadValue() {
        isLoading = true
        Task {
            do {
                let key = StorageKeys.SyncableSettingKey(
                    availability: selectedPlatform,
                    syncPolicy: selectedSync
                )
                storedValue = try await StorageRouter.shared.get(key)
                statusMessage = "✓ Loaded value"
            } catch StorageError.notFound {
                storedValue = ""
                statusMessage = "No value stored"
            } catch {
                statusMessage = "Error: \(error.localizedDescription)"
            }
            isLoading = false
        }
    }
    
    private func testPlatformError() {
        isLoading = true
        Task {
            // Try to access a watchOnly key from iPhone
            let key = StorageKeys.WatchVibrationKey()
            do {
                _ = try await StorageRouter.shared.get(key)
                statusMessage = "⚠ Accessed successfully (running on Watch?)"
            } catch StorageError.watchOnlyKeyAccessedOnPhone(let name) {
                statusMessage = "⚠ Expected Error: Key '\(name)' is watchOnly, accessed from iPhone"
            } catch {
                statusMessage = "Error: \(error.localizedDescription)"
            }
            isLoading = false
        }
    }
}

// MARK: - Display Names

extension PlatformAvailability {
    var displayName: String {
        switch self {
        case .all: return "All"
        case .phoneOnly: return "Phone Only"
        case .watchOnly: return "Watch Only"
        case .phoneWithWatchSync: return "Phone + Watch Sync"
        }
    }
}

extension SyncPolicy {
    var displayName: String {
        switch self {
        case .never: return "Never"
        case .manual: return "Manual"
        case .automaticSmall: return "Automatic"
        }
    }
}

#Preview {
    NavigationStack {
        PlatformSyncDemo()
    }
}