//
//  PodcastsView.swift
//  Mobile Music Assistant
//
//  Created by Sven Hanold on 08.04.26.
//

import SwiftUI

struct PodcastsView: View {
    @Environment(MAService.self) private var service
    @State private var errorMessage: String?
    @State private var showError = false

    private var podcasts: [MAPodcast] {
        service.libraryManager.podcasts
    }

    private var isLoading: Bool {
        service.libraryManager.isLoadingPodcasts
    }

    var body: some View {
        Group {
            if isLoading && podcasts.isEmpty {
                ProgressView()
            } else if podcasts.isEmpty {
                ContentUnavailableView(
                    "No Podcasts",
                    systemImage: "mic.fill",
                    description: Text("Your library doesn't contain any podcasts yet.")
                )
            } else {
                List {
                    ForEach(podcasts) { podcast in
                        NavigationLink(value: podcast) {
                            PodcastRow(podcast: podcast)
                        }
                    }
                }
                .listStyle(.plain)
            }
        }
        .refreshable {
            await loadPodcasts()
        }
        .task {
            await loadPodcasts(refresh: !podcasts.isEmpty)
        }
        .alert("Error", isPresented: $showError) {
            Button("OK", role: .cancel) { }
        } message: {
            if let errorMessage {
                Text(errorMessage)
            }
        }
    }

    private func loadPodcasts(refresh: Bool = true) async {
        do {
            try await service.libraryManager.loadPodcasts(refresh: refresh)
        } catch {
            errorMessage = error.localizedDescription
            showError = true
        }
    }
}

// MARK: - Podcast Row

struct PodcastRow: View {
    @Environment(MAService.self) private var service
    let podcast: MAPodcast

    var body: some View {
        HStack(spacing: 12) {
            CachedAsyncImage(url: service.imageProxyURL(path: podcast.imageUrl, provider: podcast.imageProvider, size: 128)) { image in
                image
                    .resizable()
                    .aspectRatio(contentMode: .fill)
            } placeholder: {
                RoundedRectangle(cornerRadius: 8)
                    .fill(Color.gray.opacity(0.2))
                    .overlay {
                        Image(systemName: "mic.fill")
                            .font(.title2)
                            .foregroundStyle(.secondary)
                    }
            }
            .frame(width: 64, height: 64)
            .clipShape(RoundedRectangle(cornerRadius: 8))
            .overlay(alignment: .bottomTrailing) {
                if service.libraryManager.isFavorite(uri: podcast.uri) {
                    Image(systemName: "heart.fill")
                        .font(.system(size: 10))
                        .foregroundStyle(.red)
                        .padding(3)
                }
            }

            VStack(alignment: .leading, spacing: 4) {
                Text(podcast.name)
                    .font(.headline)
                    .lineLimit(2)

                if let publisher = podcast.publisher {
                    Text(publisher)
                        .font(.caption)
                        .foregroundStyle(.secondary)
                        .lineLimit(1)
                }

                if let total = podcast.totalEpisodes {
                    Text("\(total) episodes")
                        .font(.caption2)
                        .foregroundStyle(.tertiary)
                }
            }

            Spacer()
        }
        .padding(.vertical, 4)
    }
}

#Preview {
    NavigationStack {
        PodcastsView()
            .environment(MAService())
    }
}