import SwiftUI

struct SearchView: View {
    @EnvironmentObject var serverManager: ServerManager
    @EnvironmentObject var audioPlayer: AudioPlayer
    @EnvironmentObject var offlineManager: OfflineManager
    @ObservedObject private var libraryCache = LibraryCache.shared
    @ObservedObject private var watchManager = WatchConnectivityManager.shared

    @State private var searchText          = ""
    @State private var searchArtists: [Artist]  = []
    @State private var searchAlbums:  [Album]   = []
    @State private var searchSongs:   [Song]    = []
    @State private var isSearching             = false

    // All-songs browse state
    @State private var allSongs:        [Song]  = []
    @State private var isLoadingSongs          = false
    @State private var songsLoaded             = false

    // Long-press menu
    @State private var menuSong:          Song?    = nil
    @State private var showMenu                    = false
    @State private var playlistPickerSongId: String? = nil
    @State private var availablePlaylists: [Playlist] = []
    @State private var showPlaylistPicker          = false

    @FocusState private var searchFocused: Bool

    private let accentPink = Color(red: 1.0, green: 0.176, blue: 0.333)
    private var isSearchActive: Bool { !searchText.isEmpty }

    // MARK: - Body

    var body: some View {
        NavigationStack {
            VStack(spacing: 0) {
                // Search bar
                HStack(spacing: 10) {
                    Image(systemName: "magnifyingglass").foregroundColor(.gray)
                    TextField("Artists, Songs, Albums", text: $searchText)
                        .foregroundColor(.white)
                        .autocapitalization(.none)
                        .disableAutocorrection(true)
                        .focused($searchFocused)
                        .onSubmit { performSearch() }
                        .onChange(of: searchText) { _, new in
                            if new.count >= 2 { performSearch() }
                            else if new.isEmpty { clearSearch() }
                        }
                        .toolbar {
                            ToolbarItemGroup(placement: .keyboard) {
                                Spacer()
                                Button("Done") { searchFocused = false }
                                    .foregroundColor(accentPink)
                            }
                        }
                    if !searchText.isEmpty {
                        Button(action: { searchText = ""; clearSearch() }) {
                            Image(systemName: "xmark.circle.fill").foregroundColor(.gray)
                        }
                    }
                }
                .padding(10)
                .background(Color.white.opacity(0.08))
                .cornerRadius(10)
                .padding(.horizontal, 16)
                .padding(.top, 10)
                .padding(.bottom, 8)

                if isSearchActive {
                    searchResultsView
                } else {
                    allSongsView
                }
            }
            .background(Color(white: 0.06))
            .navigationTitle("Songs")
            .sheet(isPresented: $showPlaylistPicker) {
                AddToPlaylistSheet(songId: playlistPickerSongId, playlists: availablePlaylists)
            }
            .task { await loadAllSongs() }
        }
    }

    // MARK: - All Songs Browse

    private var allSongsView: some View {
        Group {
            if isLoadingSongs {
                Spacer()
                ProgressView().tint(accentPink)
                Spacer()
            } else if allSongs.isEmpty {
                Spacer()
                VStack(spacing: 12) {
                    Image(systemName: "music.note.list")
                        .font(.system(size: 40)).foregroundColor(.gray)
                    Text("No songs found")
                        .font(.system(size: 16)).foregroundColor(.gray)
                }
                Spacer()
            } else {
                ScrollView {
                    LazyVStack(spacing: 0) {
                        // Download All banner (offline only — explicit user action)
                        downloadAllBanner
                        ForEach(allSongs) { song in
                            songRow(song, queue: allSongs)
                            Divider()
                                .background(Color.white.opacity(0.06))
                                .padding(.leading, 72)
                        }
                        Color.clear.frame(height: 120)
                    }
                }
            }
        }
    }

    private var downloadAllBanner: some View {
        HStack {
            VStack(alignment: .leading, spacing: 2) {
                Text("\(allSongs.count) Songs")
                    .font(.system(size: 13, weight: .semibold))
                    .foregroundColor(.white)
                let downloaded = allSongs.filter { offlineManager.isSongDownloaded($0.id) }.count
                if downloaded > 0 {
                    Text("\(downloaded) downloaded")
                        .font(.system(size: 11)).foregroundColor(.gray)
                }
            }
            Spacer()
            Button(action: downloadAll) {
                HStack(spacing: 5) {
                    Image(systemName: "arrow.down.circle")
                        .font(.system(size: 14))
                    Text("Download All")
                        .font(.system(size: 13, weight: .medium))
                }
                .foregroundColor(accentPink)
                .padding(.horizontal, 12).padding(.vertical, 6)
                .background(accentPink.opacity(0.12))
                .cornerRadius(16)
            }
        }
        .padding(.horizontal, 16)
        .padding(.vertical, 10)
        .background(Color.white.opacity(0.03))
    }

    // MARK: - Search Results

    private var searchResultsView: some View {
        Group {
            if isSearching {
                Spacer()
                ProgressView().tint(accentPink)
                Spacer()
            } else if searchArtists.isEmpty && searchAlbums.isEmpty && searchSongs.isEmpty {
                Spacer()
                VStack(spacing: 12) {
                    Image(systemName: "magnifyingglass")
                        .font(.system(size: 36)).foregroundColor(.gray)
                    Text("No results for \"\(searchText)\"")
                        .font(.system(size: 15)).foregroundColor(.gray)
                }
                Spacer()
            } else {
                ScrollView {
                    LazyVStack(alignment: .leading, spacing: 0) {
                        if !searchArtists.isEmpty {
                            sectionHeader("Artists")
                            ForEach(searchArtists) { artist in
                                NavigationLink(destination: ArtistDetailView(artistId: artist.id)) {
                                    HStack(spacing: 12) {
                                        AsyncCoverArt(coverArtId: artist.coverArt, size: 44)
                                            .frame(width: 44, height: 44).clipShape(Circle())
                                        Text(artist.name)
                                            .font(.system(size: 15)).foregroundColor(.white)
                                        Spacer()
                                        Image(systemName: "chevron.right")
                                            .font(.system(size: 12)).foregroundColor(.gray)
                                    }
                                    .padding(.horizontal, 16).padding(.vertical, 8)
                                }
                            }
                        }
                        if !searchAlbums.isEmpty {
                            sectionHeader("Albums")
                            ForEach(searchAlbums) { album in
                                NavigationLink(destination: AlbumDetailView(albumId: album.id)) {
                                    HStack(spacing: 12) {
                                        AsyncCoverArt(coverArtId: album.coverArt, size: 48)
                                            .frame(width: 48, height: 48).cornerRadius(4)
                                        VStack(alignment: .leading, spacing: 2) {
                                            Text(album.name)
                                                .font(.system(size: 15)).foregroundColor(.white).lineLimit(1)
                                            Text(album.artist ?? "")
                                                .font(.system(size: 12)).foregroundColor(.gray)
                                        }
                                        Spacer()
                                        Image(systemName: "chevron.right")
                                            .font(.system(size: 12)).foregroundColor(.gray)
                                    }
                                    .padding(.horizontal, 16).padding(.vertical, 8)
                                }
                            }
                        }
                        if !searchSongs.isEmpty {
                            sectionHeader("Songs")
                            ForEach(searchSongs) { song in
                                songRow(song, queue: searchSongs)
                                Divider()
                                    .background(Color.white.opacity(0.06))
                                    .padding(.leading, 72)
                            }
                        }
                        Color.clear.frame(height: 120)
                    }
                }
            }
        }
    }

    // MARK: - Song Row (shared, with long-press menu)

    private func songRow(_ song: Song, queue: [Song]) -> some View {
        let available    = offlineManager.isSongDownloaded(song.id) || libraryCache.isServerAvailable
        let isDownloaded = offlineManager.isSongDownloaded(song.id)
        let isOnWatch    = WatchConnectivityManager.shared.isSongOnWatch(song.id)
        let dlState      = offlineManager.downloads[song.id]
        let isCurrent    = audioPlayer.currentSong?.id == song.id

        return Button(action: {
            if available { audioPlayer.play(song: song, fromQueue: queue) }
        }) {
            HStack(spacing: 12) {
                // Artwork + download progress overlay
                ZStack {
                    AsyncCoverArt(coverArtId: song.coverArt, size: 44)
                        .frame(width: 44, height: 44).cornerRadius(3)
                        .opacity(available ? 1.0 : 0.4)
                    if case .downloading(let progress) = dlState {
                        RoundedRectangle(cornerRadius: 3)
                            .fill(Color.black.opacity(0.5)).frame(width: 44, height: 44)
                        Circle().trim(from: 0, to: progress)
                            .stroke(accentPink, style: StrokeStyle(lineWidth: 2.5, lineCap: .round))
                            .frame(width: 24, height: 24).rotationEffect(.degrees(-90))
                    } else if case .queued = dlState {
                        RoundedRectangle(cornerRadius: 3)
                            .fill(Color.black.opacity(0.4)).frame(width: 44, height: 44)
                        ProgressView().tint(accentPink).scaleEffect(0.6)
                    }
                }

                VStack(alignment: .leading, spacing: 2) {
                    Text(song.title)
                        .font(.system(size: 15))
                        .foregroundColor(!available ? .gray.opacity(0.35) : isCurrent ? accentPink : .white)
                        .lineLimit(1)
                    Text("\(song.artist ?? "") • \(song.album ?? "")")
                        .font(.system(size: 12))
                        .foregroundColor(available ? .gray : .gray.opacity(0.3))
                        .lineLimit(1)
                    if case .downloading(let progress) = dlState {
                        GeometryReader { geo in
                            ZStack(alignment: .leading) {
                                Capsule().fill(Color.white.opacity(0.08)).frame(height: 2)
                                Capsule().fill(accentPink)
                                    .frame(width: geo.size.width * progress, height: 2)
                            }
                        }.frame(height: 2)
                    }
                }

                Spacer()

                // Status badges
                HStack(spacing: 4) {
                    if isOnWatch {
                        Image(systemName: "applewatch")
                            .font(.system(size: 9)).foregroundColor(.blue.opacity(0.7))
                    }
                    if isDownloaded {
                        Image(systemName: "arrow.down.circle.fill")
                            .font(.system(size: 11)).foregroundColor(.green.opacity(0.6))
                    }
                }

                Text(song.durationFormatted)
                    .font(.system(size: 13))
                    .foregroundColor(available ? .gray : .gray.opacity(0.3))
            }
            .padding(.horizontal, 16).padding(.vertical, 9)
        }
        .contextMenu {
            Button(action: { audioPlayer.playNow(song) }) {
                Label("Play Now", systemImage: "play.fill")
            }
            Button(action: { audioPlayer.playNext(song) }) {
                Label("Play Next", systemImage: "text.line.first.and.arrowtriangle.forward")
            }
            Button(action: { audioPlayer.playLater(song) }) {
                Label("Add to Queue", systemImage: "text.line.last.and.arrowtriangle.forward")
            }
            Divider()
            if isDownloaded {
                Button(role: .destructive, action: { offlineManager.removeSong(song.id) }) {
                    Label("Remove Download", systemImage: "trash")
                }
            } else {
                Button(action: {
                    if let server = serverManager.activeServer {
                        offlineManager.downloadSong(song, server: server)
                    }
                }) {
                    Label("Download", systemImage: "arrow.down.circle")
                }
            }
            Button(action: {
                if !isOnWatch { _ = WatchConnectivityManager.shared.sendSongToWatch(song) }
            }) {
                Label(isOnWatch ? "On Watch ✓" : "Send to Watch",
                      systemImage: isOnWatch ? "applewatch.checkmark" : "applewatch.and.arrow.forward")
            }
            .disabled(isOnWatch)
            Divider()
            Button(action: {
                playlistPickerSongId = song.id
                Task {
                    availablePlaylists = (try? await serverManager.client.getPlaylists()) ?? []
                    showPlaylistPicker = true
                }
            }) {
                Label("Add to Playlist...", systemImage: "text.badge.plus")
            }
        }
    }

    // MARK: - Helpers

    private func sectionHeader(_ title: String) -> some View {
        Text(title)
            .font(.system(size: 20, weight: .bold)).foregroundColor(.white)
            .padding(.horizontal, 16).padding(.top, 20).padding(.bottom, 8)
    }

    private func clearSearch() {
        searchArtists = []; searchAlbums = []; searchSongs = []
    }

    private func performSearch() {
        guard searchText.count >= 2 else { return }
        isSearching = true
        Task {
            do {
                let result = try await serverManager.client.search3(query: searchText)
                await MainActor.run {
                    searchArtists = result?.artist ?? []
                    searchAlbums  = result?.album  ?? []
                    searchSongs   = result?.song   ?? []
                    isSearching   = false
                }
            } catch {
                await MainActor.run { isSearching = false }
            }
        }
    }

    private func loadAllSongs() async {
        guard !songsLoaded else { return }
        isLoadingSongs = true

        // Cache hit → instant display
        if let cached = libraryCache.load([Song].self, key: "all_songs_sorted") {
            await MainActor.run {
                allSongs      = cached
                isLoadingSongs = false
                songsLoaded    = true
            }
            return
        }

        // Use search3 with empty query to fetch all songs directly.
        // This is a single paginated call per 500 songs vs. 1 call per album
        // (144 albums = 144 sequential requests, many of which fail silently).
        do {
            var collected: [Song] = []
            var offset = 0
            let pageSize = 500
            while true {
                let result = try await serverManager.client.search3(
                    query:       "",
                    artistCount: 0, artistOffset: 0,
                    albumCount:  0, albumOffset:  0,
                    songCount:   pageSize,
                    songOffset:  offset
                )
                let page = result?.song ?? []
                collected.append(contentsOf: page)
                if page.count < pageSize { break }
                offset += pageSize
            }
            let sorted = collected.sorted {
                $0.title.localizedCaseInsensitiveCompare($1.title) == .orderedAscending
            }
            libraryCache.save(sorted, key: "all_songs_sorted")
            await MainActor.run {
                allSongs       = sorted
                isLoadingSongs = false
                songsLoaded    = true
            }
        } catch {
            await MainActor.run { isLoadingSongs = false }
        }
    }

    private func downloadAll() {
        guard let server = serverManager.activeServer else { return }
        for song in allSongs where !offlineManager.isSongDownloaded(song.id) {
            offlineManager.downloadSong(song, server: server)
        }
    }
}