/*
 * JellyfinPlayer/Swiftfin is subject to the terms of the Mozilla Public
 * License, v2.0. If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * Copyright 2021 Aiden Vigue & Jellyfin Contributors
 */

import Combine
import JellyfinAPI
import NukeUI
import SwiftUI

struct LibraryView: View {
    @StateObject
    var viewModel: LibraryViewModel
    var title: String

    // MARK: tracks for grid

    @State
    var isShowingSearchView = false
    @State
    var isShowingFilterView = false

    @State
    private var tracks: [GridItem] = Array(repeating: .init(.flexible()), count: Int(UIScreen.main.bounds.size.width) / 125)

    func recalcTracks() {
        tracks = Array(repeating: .init(.flexible()), count: Int(UIScreen.main.bounds.size.width) / 125)
    }

    var body: some View {
        Group {
            if viewModel.isLoading == true {
                ProgressView()
            } else if !viewModel.items.isEmpty {
                VStack {
                    ScrollView(.vertical) {
                        Spacer().frame(height: 16)
                        LazyVGrid(columns: tracks) {
                            ForEach(viewModel.items, id: \.id) { item in
                                NavigationLink(destination: ItemView(item: item)) {
                                    VStack(alignment: .leading) {
                                        ImageView(src: item.getPrimaryImage(maxWidth: 100), bh: item.getPrimaryImageBlurHash())
                                            .frame(width: 100, height: 150)
                                            .cornerRadius(10)
                                        Text(item.name ?? "")
                                            .font(.caption)
                                            .fontWeight(.semibold)
                                            .foregroundColor(.primary)
                                            .lineLimit(1)
                                        if item.productionYear != nil {
                                            Text(String(item.productionYear!))
                                                .foregroundColor(.secondary)
                                                .font(.caption)
                                                .fontWeight(.medium)
                                        } else {
                                            Text(item.type ?? "")
                                        }
                                    }.frame(width: 100)
                                }
                            }
                        }.onRotate { _ in
                            recalcTracks()
                        }
                        if viewModel.isCanNextPaging || viewModel.isCanPreviousPaging {
                            HStack {
                                Spacer()
                                HStack {
                                    Button {
                                        viewModel.requestPreviousPage()
                                    } label: {
                                        Image(systemName: "chevron.left")
                                            .font(.system(size: 25))
                                    }.disabled(viewModel.isCanPreviousPaging)
                                    Text("Page \(String(viewModel.currentPage + 1)) of \(String(viewModel.totalPages))")
                                        .font(.headline)
                                        .fontWeight(.semibold)
                                    Button {
                                        viewModel.requestNextPage()
                                    } label: {
                                        Image(systemName: "chevron.right")
                                            .font(.system(size: 25))
                                    }.disabled(viewModel.isCanNextPaging)
                                }
                                Spacer()
                            }
                        }
                        Spacer().frame(height: 16)
                    }
                }
            } else {
                Text("No results.")
            }
        }
        .navigationBarTitle(title, displayMode: .inline)
        .toolbar {
            ToolbarItemGroup(placement: .navigationBarTrailing) {
                if viewModel.isCanPreviousPaging {
                    Button {
                        viewModel.requestPreviousPage()
                    } label: {
                        Image(systemName: "chevron.left")
                    }
                }
                if viewModel.isCanNextPaging {
                    Button {
                        viewModel.requestNextPage()
                    } label: {
                        Image(systemName: "chevron.right")
                    }
                }
                Button(action: {
                    isShowingFilterView = true
                }) {
                    Image(systemName: "line.horizontal.3.decrease.circle")
                }
                Button(action: {
                    isShowingSearchView = true
                }) {
                    Image(systemName: "magnifyingglass")
                }
            }
        }
        .sheet(isPresented: $isShowingFilterView) {
            LibraryFilterView(filters: $viewModel.filters, enabledFilterType: viewModel.enabledFilterType)
        }
        .background(
            NavigationLink(destination: LibrarySearchView(viewModel: .init(parentID: viewModel.parentID)),
                           isActive: $isShowingSearchView) {
                EmptyView()
            }
        )
    }
}

// stream BM^S by nicki!
//