import SwiftUI
import AVKit

// MARK: - API Response Models
struct MaterialResponse: Decodable {
    let code: Int
    let data: MaterialData
    
    struct MaterialData: Decodable {
        let items: [MemoryItem]
    }
}

struct MemoryItem: Identifiable, Decodable {
    let id: String
    let name: String
    let description: String
    let fileInfo: FileInfo
    
    var title: String { name }
    var subtitle: String { description }
    var mediaType: MemoryMediaType { .image(fileInfo.url) }
    var aspectRatio: CGFloat { 1.0 } // Default to square, adjust based on actual image dimensions if needed
    
    enum CodingKeys: String, CodingKey {
        case id, name, description
        case fileInfo = "file_info"
    }
}

struct FileInfo: Decodable {
    let id: String
    let fileName: String
    let url: String
    
    enum CodingKeys: String, CodingKey {
        case id
        case fileName = "file_name"
        case url
    }
}

enum MemoryMediaType: Equatable {
    case image(String)
    case video(String)
}

struct MemoriesView: View {
    @State private var memories: [MemoryItem] = []
    @State private var isLoading = false
    @State private var errorMessage: String?
    
    let columns = [
        GridItem(.flexible(), spacing: 1),
        GridItem(.flexible(), spacing: 1)
    ]
    
    var body: some View {
        NavigationView {
            Group {
                if isLoading {
                    ProgressView()
                        .scaleEffect(1.5)
                } else if let error = errorMessage {
                    Text("Error: \(error)")
                        .foregroundColor(.red)
                } else {
                    ScrollView {
                        LazyVGrid(columns: columns, spacing: 4) {
                            ForEach(memories) { memory in
                                MemoryCard(memory: memory)
                                    .padding(.horizontal, 2)
                            }
                        }
                        .padding(.top, 4)
                        .padding(.horizontal, 4)
                    }
                }
            }
            .navigationTitle("My Memories")
            .navigationBarTitleDisplayMode(.inline)
            .onAppear {
                fetchMemories()
            }
        }
    }
    
    private func fetchMemories() {
        isLoading = true
        errorMessage = nil
        
        NetworkService.shared.get(path: "/material/list") { [self] (result: Result<MaterialResponse, NetworkError>) in
            DispatchQueue.main.async { [self] in
                self.isLoading = false
                
                switch result {
                case .success(let response):
                    print("✅ Successfully fetched \(response.data.items.count) memory items")
                    response.data.items.forEach { item in
                        print("📝 Item ID: \(item.id), Title: \(item.name), URL: \(item.fileInfo.url)")
                    }
                    self.memories = response.data.items
                case .failure(let error):
                    self.errorMessage = error.localizedDescription
                    print("❌ Failed to fetch memories: \(error.localizedDescription)")
                }
            }
        }
    }
}

struct MemoryCard: View {
    let memory: MemoryItem
    
    var body: some View {
        VStack(alignment: .leading, spacing: 4) {
            ZStack {
                // Media content
                Group {
                    switch memory.mediaType {
                    case .image(let urlString):
                        if let url = URL(string: urlString) {
                            AsyncImage(url: url) { phase in
                                if let image = phase.image {
                                    image
                                        .resizable()
                                        .aspectRatio(contentMode: .fill)
                                } else if phase.error != nil {
                                    Color.gray.opacity(0.3)
                                } else {
                                    ProgressView()
                                }
                            }
                        }
                        
                    case .video(let urlString):
                        if let url = URL(string: urlString) {
                            VideoPlayer(player: AVPlayer(url: url))
                                .aspectRatio(memory.aspectRatio, contentMode: .fill)
                                .onAppear {
                                    // The video will be shown with a play button overlay
                                    // and will only play when tapped
                                }
                        } else {
                            Color.gray.opacity(0.3)
                                .aspectRatio(memory.aspectRatio, contentMode: .fill)
                        }
                    }
                }
                .frame(width: (UIScreen.main.bounds.width / 2) - 24, height: (UIScreen.main.bounds.width / 2 - 24) * (1/memory.aspectRatio))
                .clipped()
                .cornerRadius(12)
                .overlay(
                    Group {
                        if case .video = memory.mediaType {
                            Image(systemName: "play.circle.fill")
                                .font(.system(size: 40))
                                .foregroundColor(.white.opacity(0.9))
                        }
                    }
                )
            }
            
            // Title and Subtitle
            VStack(alignment: .leading, spacing: 1) {
                Text(memory.title)
                    .font(.subheadline)
                    .lineLimit(1)
                
                Text(memory.subtitle)
                    .font(.caption)
                    .foregroundColor(.secondary)
                    .lineLimit(1)
            }
            .padding(.horizontal, 2)
            .padding(.bottom, 4)
        }
    }
}

// Helper extension to pause video
private extension AVPlayer {
    func pause() {
        self.pause()
    }
}

#Preview {
    MemoriesView()
}