//
//  RecipeTabView.swift
//  Nextcloud Cookbook iOS Client
//
//  Created by Vincent Meilinger on 23.01.24.
//

import Foundation
import OSLog
import SwiftUI


struct RecipeTabView: View {
    @EnvironmentObject var appState: AppState
    @EnvironmentObject var groceryList: GroceryList
    @EnvironmentObject var viewModel: RecipeTabView.ViewModel
    @Environment(\.horizontalSizeClass) private var horizontalSizeClass

    private let gridColumns = [GridItem(.adaptive(minimum: 160), spacing: 12)]

    var body: some View {
        NavigationSplitView {
            ScrollView {
                VStack(alignment: .leading, spacing: 20) {
                    // Recently Viewed
                    if !appState.recentRecipes.isEmpty {
                        RecentRecipesSection()
                    }

                    // Categories header
                    if !appState.categories.isEmpty {
                        Text("Categories")
                            .font(.title2)
                            .bold()
                            .padding(.horizontal)
                    }

                    // Category grid
                    if appState.categories.isEmpty {
                        VStack(spacing: 12) {
                            Image(systemName: "book.closed")
                                .font(.system(size: 48))
                                .foregroundStyle(.secondary)
                            Text("No cookbooks found")
                                .font(.headline)
                                .foregroundStyle(.secondary)
                            Text("Pull to refresh or check your server connection.")
                                .font(.subheadline)
                                .foregroundStyle(.tertiary)
                                .multilineTextAlignment(.center)
                        }
                        .frame(maxWidth: .infinity)
                        .padding(.top, 40)
                    } else {
                        LazyVGrid(columns: gridColumns, spacing: 12) {
                            ForEach(appState.categories) { category in
                                Button {
                                    viewModel.selectedCategory = category
                                    if horizontalSizeClass == .compact {
                                        viewModel.navigateToCategory = true
                                    }
                                } label: {
                                    CategoryCardView(
                                        category: category,
                                        isSelected: viewModel.selectedCategory?.name == category.name
                                    )
                                }
                                .buttonStyle(.plain)
                            }
                        }
                        .padding(.horizontal)
                    }
                }
                .padding(.vertical)
            }
            .navigationTitle("Recipes")
            .toolbar {
                RecipeTabViewToolBar()
            }
            .navigationDestination(isPresented: $viewModel.presentSettingsView) {
                SettingsView()
                    .environmentObject(appState)
            }
            .navigationDestination(isPresented: $viewModel.presentEditView) {
                RecipeView(viewModel: RecipeView.ViewModel())
                    .environmentObject(appState)
                    .environmentObject(groceryList)
            }
            .navigationDestination(for: Recipe.self) { recipe in
                RecipeView(viewModel: RecipeView.ViewModel(recipe: recipe))
                    .environmentObject(appState)
                    .environmentObject(groceryList)
            }
            .navigationDestination(isPresented: $viewModel.navigateToCategory) {
                if let category = viewModel.selectedCategory {
                    RecipeListView(
                        categoryName: category.name,
                        showEditView: $viewModel.presentEditView
                    )
                    .id(category.id)
                    .environmentObject(appState)
                    .environmentObject(groceryList)
                }
            }
        } detail: {
            NavigationStack {
                if let category = viewModel.selectedCategory {
                    RecipeListView(
                        categoryName: category.name,
                        showEditView: $viewModel.presentEditView
                    )
                    .id(category.id)
                }
            }
        }
        .tint(.nextcloudBlue)
        .task {
            let connection = await appState.checkServerConnection()
            DispatchQueue.main.async {
                viewModel.serverConnection = connection
            }
        }
        .refreshable {
            let connection = await appState.checkServerConnection()
            DispatchQueue.main.async {
                viewModel.serverConnection = connection
            }
            await appState.getCategories()
            for category in appState.categories {
                await appState.getCategory(named: category.name, fetchMode: .preferServer)
                await appState.getCategoryImage(for: category.name)
            }
        }
    }
    
    class ViewModel: ObservableObject {
        @Published var presentEditView: Bool = false
        @Published var presentSettingsView: Bool = false
        @Published var navigateToCategory: Bool = false

        @Published var presentLoadingIndicator: Bool = false
        @Published var presentConnectionPopover: Bool = false
        @Published var serverConnection: Bool = false

        @Published var selectedCategory: Category? = nil
    }
}



fileprivate struct RecipeTabViewToolBar: ToolbarContent {
    @EnvironmentObject var appState: AppState
    @EnvironmentObject var viewModel: RecipeTabView.ViewModel
    
    var body: some ToolbarContent {
        // Top left menu toolbar item
        ToolbarItem(placement: .topBarLeading) {
            Menu {
                Button {
                    Task {
                        viewModel.presentLoadingIndicator = true
                        UserSettings.shared.lastUpdate = Date.distantPast
                        await appState.getCategories()
                        for category in appState.categories {
                            await appState.getCategory(named: category.name, fetchMode: .preferServer)
                        }
                        await appState.updateAllRecipeDetails()
                        viewModel.presentLoadingIndicator = false
                    }
                } label: {
                    Text("Refresh all")
                    Image(systemName: "icloud.and.arrow.down")
                }
                
                Button {
                    viewModel.presentSettingsView = true
                } label: {
                    Text("Settings")
                    Image(systemName: "gearshape")
                }
            } label: {
                Image(systemName: "ellipsis.circle")
            }
        }
        
        // Server connection indicator
        ToolbarItem(placement: .topBarTrailing) {
            Button {
                Logger.view.debug("Check server connection")
                viewModel.presentConnectionPopover = true
            } label: {
                if viewModel.presentLoadingIndicator {
                    ProgressView()
                } else if viewModel.serverConnection {
                    Image(systemName: "checkmark.icloud")
                } else {
                    Image(systemName: "xmark.icloud")
                }
            }.popover(isPresented: $viewModel.presentConnectionPopover) {
                VStack(alignment: .leading) {
                    Text(viewModel.serverConnection ? LocalizedStringKey("Connected to server.") : LocalizedStringKey("Unable to connect to server."))
                        .bold()
                        
                    Text("Last updated: \(DateFormatter.utcToString(date: UserSettings.shared.lastUpdate))")
                        .font(.caption)
                        .foregroundStyle(Color.secondary)
                }
                .padding()
                .presentationCompactAdaptation(.popover)
            }
        }
        
        // Create new recipes
        ToolbarItem(placement: .topBarTrailing) {
            Button {
                Logger.view.debug("Add new recipe")
                viewModel.presentEditView = true
            } label: {
                Image(systemName: "plus.circle.fill")
            }
        }
    
    }
}