import SwiftUI
import AVKit
import NukeUI

struct SightView: View {
    @StateObject private var viewModel = SightViewModel()
    @EnvironmentObject private var appState: AppState

    var body: some View {
        VStack(alignment: .leading, spacing: 4) {
            mediaSection
            
            VStack(alignment: .leading, spacing: 8) {
                // Заголовок статьи
                Text(viewModel.selectedArticle?.isReviewArticle == true
                     ? viewModel.sightName
                     : viewModel.articleHeading)
                    .font(.title2)
                    .fontWeight(.bold)
                    .foregroundColor(.white)
                    .frame(maxWidth: .infinity,
                           alignment: viewModel.selectedArticle?.isReviewArticle == true ? .center : .leading)
                    .multilineTextAlignment(viewModel.selectedArticle?.isReviewArticle == true ? .center : .leading)

                // Тело статьи
                ScrollView {
                    if viewModel.selectedArticle?.isReviewArticle == true {
                        VStack {
                            Text(viewModel.articleBody)
                                .font(.system(size: 13))
                                .foregroundColor(.white)
                                .frame(maxWidth: .infinity, maxHeight: .infinity)
                        }
                    } else {
                        Text(viewModel.articleBody)
                            .font(.system(size: 13))
                            .foregroundColor(.white)
                            .frame(maxWidth: .infinity, alignment: .leading)
                    }
                }
                
                // Список статей
                GeometryReader { geometry in
                    ScrollView(.horizontal, showsIndicators: false) {
                        HStack(spacing: 10) {
                            Spacer(minLength: 0)
                            ForEach(viewModel.allArticles) { article in
                                Text(localizedHeading(article))
                                    .font(.system(size: 12))
                                    .lineLimit(1)
                                    .padding(.vertical, 6)
                                    .padding(.horizontal, 6)
                                    .frame(minWidth: 70)
                                    .foregroundColor(.white)
                                    .overlay(
                                        Rectangle()
                                            .frame(height: 2)
                                            .foregroundColor(viewModel.selectedArticle == article ? Color.white : Color.clear),
                                        alignment: .bottom
                                    )
                                    .onTapGesture {
                                        viewModel.selectArticle(article)
                                    }
                            }
                            Spacer(minLength: 0)
                        }
                        .frame(minWidth: geometry.size.width)
                    }
                    .scrollIndicators(.hidden)
                }
                .frame(height: 34)
                .frame(maxWidth: .infinity)
            }
            .padding(.horizontal, 8)
            .padding(.bottom, 4)
        }
        // MARK: - Initial load and reload on sight change
        .task(id: appState.sightId) {
            guard let currentSightId = appState.sightId else { return }
            viewModel.setLanguage(appState.selectedLanguage)
            await viewModel.loadInitialData(sightId: currentSightId)
        }
        // MARK: - Reload on language change
        .onChange(of: appState.selectedLanguage) { newLang in
            guard let currentSightId = appState.sightId else { return }
            viewModel.setLanguage(newLang)
            Task {
                await viewModel.loadInitialData(sightId: currentSightId)
            }
        }
        .blockStyle(cornerRadius: 25)
    }

    // MARK: - Медиа
    @ViewBuilder
    private var mediaSection: some View {
        Group {
            switch viewModel.mediaState {
            case .loading:
                ZStack {
                    Color.gray.opacity(0.3)
                    if let progress = viewModel.downloadProgress {
                        VStack {
                            ProgressView(value: progress)
                                .progressViewStyle(.linear)
                                .tint(.white)
                            Text("\(Int(progress * 100))%")
                                .foregroundColor(.white)
                                .font(.caption)
                        }
                        .padding()
                    } else {
                        ProgressView()
                            .progressViewStyle(.circular)
                            .tint(.white)
                    }
                }
                .frame(maxWidth: .infinity, minHeight: 200)
                .cornerRadius(24, corners: [.topLeft, .topRight])
                .clipped()
                
            case .image(let url):
                if let uiImage = UIImage(contentsOfFile: url.path) {
                    Image(uiImage: uiImage)
                        .resizable()
                        .scaledToFit()
                        .cornerRadius(24, corners: [.topLeft, .topRight])
                        .clipped()
                } else {
                    Image(systemName: "photo")
                        .resizable()
                        .scaledToFit()
                        .foregroundColor(.gray)
                        .frame(maxWidth: .infinity, minHeight: 200)
                        .cornerRadius(24, corners: [.topLeft, .topRight])
                        .clipped()
                }
                
            case .video(let player):
                VideoPlayer(player: player)
                    .aspectRatio(16/9, contentMode: .fit)
                    .cornerRadius(24, corners: [.topLeft, .topRight])
                    .clipped()
                
            case .error:
                Image(systemName: "photo")
                    .resizable()
                    .aspectRatio(contentMode: .fit)
                    .foregroundColor(.gray)
                    .frame(maxWidth: .infinity, minHeight: 200)
                    .cornerRadius(24, corners: [.topLeft, .topRight])
                    .clipped()
            }
        }
        .padding(4)
        .frame(maxWidth: .infinity)
    }

    // MARK: - Локализованные заголовки статей
    private func localizedHeading(_ article: Article) -> String {
        if article.isReviewArticle == true {
            switch appState.selectedLanguage {
            case "ru": return "Обзор"
            case "en": return "Review"
            case "zh": return "奥布佐尔"
            default: return "Обзор"
            }
        } else {
            return article.heading
        }
    }
}