import SwiftUI
import AVFoundation
#if os(macOS)
import AppKit
#else
import UIKit
#endif

// MARK: - 网络共享文件项
struct NetworkFileItem: Identifiable, Hashable {
    let id = UUID()
    let url: URL
    let name: String
    let isDirectory: Bool
    let fileSize: Int64?
    let hasMatchingASS: Bool
    
    var isMediaFile: Bool {
        let ext = url.pathExtension.lowercased()
        return ["mp4", "mov", "m4v", "mkv", "avi", "mp3", "wav", "m4a", "flac", "aac", "webm", "ts", "m3u8"].contains(ext)
    }
}

// MARK: - 跨平台入口
struct NetworkFilePanel: View {
    @ObservedObject var bridge: PlayerBridge
    @Binding var isPresented: Bool
    
    var body: some View {
        #if os(macOS)
        NetworkFileBrowserMac(bridge: bridge, isPresented: $isPresented)
        #else
        NetworkFileBrowserIOS(bridge: bridge, isPresented: $isPresented)
        #endif
    }
}

// MARK: - macOS 版本
#if os(macOS)
struct NetworkFileBrowserMac: View {
    @ObservedObject var bridge: PlayerBridge
    @Binding var isPresented: Bool
    
    @State private var currentURL: URL?
    @State private var items: [NetworkFileItem] = []
    @State private var pathStack: [URL] = []
    @State private var isLoading = false
    @State private var errorMessage: String?
    @State private var connectURL = ""
    @State private var showConnectSheet = false
    
    private var rootItems: [NetworkFileItem] {
        let vols = FileManager.default.mountedVolumeURLs(includingResourceValuesForKeys: nil,
                                                          options: [.skipHiddenVolumes]) ?? []
        return vols.sorted { $0.lastPathComponent < $1.lastPathComponent }
            .map { NetworkFileItem(url: $0, name: $0.lastPathComponent,
                                   isDirectory: true, fileSize: nil, hasMatchingASS: false) }
    }
    
    var body: some View {
        VStack(spacing: 0) {
            HStack(spacing: 8) {
                Button(action: goUp) {
                    Image(systemName: "chevron.left").font(.system(size: 14, weight: .medium))
                }.buttonStyle(.plain).disabled(pathStack.isEmpty).opacity(pathStack.isEmpty ? 0.3 : 1)
                Text(currentURL?.path ?? "/Volumes").font(.system(size: 13)).foregroundColor(.secondary)
                    .lineLimit(1).truncationMode(.head)
                Spacer()
                Button(action: { showConnectSheet = true }) {
                    Image(systemName: "network.badge.shield.half.filled").font(.system(size: 14))
                }.buttonStyle(.plain).help("Connect (SMB/NFS)")
            }.padding(.horizontal, 12).padding(.vertical, 8)
                .background(Color(NSColor.controlBackgroundColor))
            Divider()
            
            if isLoading { Spacer(); ProgressView("Loading..."); Spacer() }
            else if let e = errorMessage {
                Spacer(); VStack(spacing: 12) {
                    Image(systemName: "exclamationmark.triangle").font(.largeTitle).foregroundColor(.orange)
                    Text(e).foregroundColor(.secondary).multilineTextAlignment(.center)
                }.padding(); Spacer()
            } else {
                ScrollView {
                    LazyVStack(spacing: 0) {
                        ForEach(currentItems) { item in
                            NetworkFileRow(item: item) { handleSelect(item) }
                            Divider().padding(.leading, 8)
                        }
                    }
                }
            }
        }
        .frame(minWidth: 500, minHeight: 400)
        .sheet(isPresented: $showConnectSheet) {
            ConnectSheet(connectURL: $connectURL, onConnect: connectToShare)
        }
        .onAppear { if currentURL == nil { navigateToRoot() } }
    }
    
    private var currentItems: [NetworkFileItem] { currentURL == nil ? rootItems : items }
    
    private func navigateToRoot() { pathStack.removeAll(); currentURL = nil; items = []; errorMessage = nil }
    
    private func navigateTo(_ url: URL) {
        isLoading = true; errorMessage = nil
        DispatchQueue.global(qos: .userInitiated).async {
            do {
                let contents = try FileManager.default.contentsOfDirectory(
                    at: url, includingPropertiesForKeys: [.isDirectoryKey, .fileSizeKey],
                    options: [.skipsHiddenFiles])
                let assNames = Set(contents
                    .filter { $0.pathExtension.lowercased() == "ass" }
                    .map { $0.deletingPathExtension().lastPathComponent.lowercased() })
                let fileItems = buildFileItems(contents, assNames: assNames)
                DispatchQueue.main.async { self.items = fileItems; self.currentURL = url; self.isLoading = false }
            } catch {
                DispatchQueue.main.async { self.errorMessage = error.localizedDescription; self.isLoading = false }
            }
        }
    }
    
    private func goUp() {
        guard let _ = currentURL else { return }
        if pathStack.isEmpty { navigateToRoot() }
        else { let parent = pathStack.removeLast(); currentURL = nil; DispatchQueue.main.async { self.navigateTo(parent) } }
    }
    
    private func handleSelect(_ item: NetworkFileItem) {
        if item.isDirectory { if let cur = currentURL { pathStack.append(cur) }; navigateTo(item.url) }
        else if item.isMediaFile { playFile(item) }
    }
    
    private func playFile(_ item: NetworkFileItem) {
        bridge.addItem(url: item.url, name: item.name, type: "network")
        if item.hasMatchingASS { bridge.loadExternalSubtitle(url: item.url.deletingPathExtension().appendingPathExtension("ass")) }
        isPresented = false
    }
    
    private func connectToShare() {
        let trimmed = connectURL.trimmingCharacters(in: .whitespaces)
        guard !trimmed.isEmpty, let url = URL(string: trimmed) else { return }
        let config = NSWorkspace.OpenConfiguration()
        NSWorkspace.shared.open(url, configuration: config) { _, error in
            if let error = error {
                DispatchQueue.main.async { self.errorMessage = "Mount failed: \(error.localizedDescription)" }
            } else {
                DispatchQueue.main.asyncAfter(deadline: .now() + 2.0) {
                    self.navigateToRoot(); self.showConnectSheet = false
                }
            }
        }
    }
}

struct NetworkFileRow: View {
    let item: NetworkFileItem; let action: () -> Void
    var body: some View {
        Button(action: action) {
            HStack(spacing: 8) {
                Image(systemName: item.isDirectory ? "folder.fill" : iconFor(item.url))
                    .font(.system(size: 16)).frame(width: 24)
                    .foregroundColor(item.isDirectory ? .accentColor : .secondary)
                VStack(alignment: .leading, spacing: 2) {
                    Text(item.name).font(.system(size: 13)).foregroundColor(.primary).lineLimit(1)
                    if !item.isDirectory, let s = item.fileSize { Text(fmtSize(s)).font(.system(size: 10)).foregroundColor(.secondary) }
                }
                Spacer()
                if item.hasMatchingASS { Text("ASS").font(.system(size: 8, weight: .bold)).foregroundColor(.white)
                    .padding(.horizontal, 4).padding(.vertical, 2).background(Color.green.opacity(0.8)).cornerRadius(3) }
                if item.isDirectory { Image(systemName: "chevron.right").font(.system(size: 12)).foregroundColor(.secondary) }
            }.padding(.horizontal, 12).padding(.vertical, 6).contentShape(Rectangle())
        }.buttonStyle(.plain)
    }
    private func iconFor(_ u: URL) -> String {
        switch u.pathExtension.lowercased() {
        case "mp4","mov","m4v","mkv","avi","webm","ts": return "film"
        case "mp3","wav","m4a","flac","aac": return "music.note"
        case "m3u8": return "antenna.radiowaves.left.and.right"
        case "ass","srt","vtt": return "captions.bubble"
        default: return "doc"
        }
    }
    private func fmtSize(_ s: Int64) -> String {
        if s < 1024 { return "\(s) B" }
        if s < 1024*1024 { return String(format: "%.1f KB", Double(s)/1024) }
        if s < 1024*1024*1024 { return String(format: "%.1f MB", Double(s)/(1024*1024)) }
        return String(format: "%.1f GB", Double(s)/(1024*1024*1024))
    }
}

struct ConnectSheet: View {
    @Binding var connectURL: String; let onConnect: () -> Void
    @State private var recents: [String] = UserDefaults.standard.stringArray(forKey: "MiniPlayer.recentNetworkURLs") ?? []
    var body: some View {
        VStack(spacing: 16) {
            Text("Connect to Network Share").font(.headline)
            VStack(alignment: .leading, spacing: 6) {
                Text("SMB or NFS URL:").font(.caption).foregroundColor(.secondary)
                HStack {
                    TextField("smb://192.168.1.100/share", text: $connectURL).textFieldStyle(.roundedBorder).onSubmit(onConnect)
                    Button("Connect", action: onConnect).keyboardShortcut(.defaultAction)
                }
            }
            if !recents.isEmpty {
                VStack(alignment: .leading, spacing: 4) {
                    Text("Recent:").font(.caption).foregroundColor(.secondary)
                    ForEach(recents, id: \.self) { u in Button(u) { connectURL = u; onConnect() }.buttonStyle(.link).font(.system(size: 12)) }
                }.frame(maxWidth: .infinity, alignment: .leading)
            }
            Text("Example:\nsmb://192.168.1.14/sambashare").font(.system(size: 11)).foregroundColor(.secondary)
        }.padding(24).frame(width: 420).onDisappear {
            let t = connectURL.trimmingCharacters(in: .whitespaces)
            guard !t.isEmpty else { return }
            var u = recents.filter { $0 != t }; u.insert(t, at: 0)
            recents = Array(u.prefix(10))
            UserDefaults.standard.set(recents, forKey: "MiniPlayer.recentNetworkURLs")
        }
    }
}
#endif

// MARK: - 共享工具函数
private func buildFileItems(_ contents: [URL], assNames: Set<String>) -> [NetworkFileItem] {
    contents.filter { url in
        let name = url.lastPathComponent
        guard !name.hasPrefix("."), !name.hasSuffix(".DS_Store") else { return false }
        var isDir: ObjCBool = false
        FileManager.default.fileExists(atPath: url.path, isDirectory: &isDir)
        if isDir.boolValue { return true }
        return ["mp4","mov","m4v","mkv","avi","mp3","wav","m4a","flac","aac","webm","ts","m3u8","ass","srt","vtt"].contains(url.pathExtension.lowercased())
    }
    .sorted { a, b in
        var ad: ObjCBool = false, bd: ObjCBool = false
        FileManager.default.fileExists(atPath: a.path, isDirectory: &ad)
        FileManager.default.fileExists(atPath: b.path, isDirectory: &bd)
        if ad.boolValue != bd.boolValue { return ad.boolValue }
        return a.lastPathComponent.localizedStandardCompare(b.lastPathComponent) == .orderedAscending
    }
    .compactMap { url -> NetworkFileItem? in
        var isDir: ObjCBool = false
        FileManager.default.fileExists(atPath: url.path, isDirectory: &isDir)
        let base = url.deletingPathExtension().lastPathComponent.lowercased()
        return NetworkFileItem(url: url, name: url.lastPathComponent,
                               isDirectory: isDir.boolValue,
                               fileSize: isDir.boolValue ? nil : (try? url.resourceValues(forKeys: [.fileSizeKey]))?.fileSize.map(Int64.init),
                               hasMatchingASS: assNames.contains(base))
    }
}

// MARK: - iOS 版本
#if os(iOS)
import UniformTypeIdentifiers

struct NetworkFileBrowserIOS: View {
    @ObservedObject var bridge: PlayerBridge
    @Binding var isPresented: Bool
    
    @State private var smbURL = ""
    @State private var isConnecting = false
    @State private var connectError: String?
    @State private var browseURL: URL?
    @State private var items: [NetworkFileItem] = []
    @State private var pathStack: [URL] = []
    @State private var isLoading = false
    @State private var streamURL = ""
    @State private var showFileImporter = false
    @State private var copyingFile = false
    @State private var copyProgress = ""
    
    var body: some View {
        NavigationView {
            VStack(spacing: 0) {
                if browseURL != nil { browseView } else { connectView }
            }
            .navigationTitle(browseURL != nil ? "Browsing" : "Network Files")
            .navigationBarTitleDisplayMode(.inline)
            .overlay {
                if copyingFile {
                    Color.black.opacity(0.6).ignoresSafeArea()
                    VStack(spacing: 12) {
                        ProgressView()
                        Text(copyProgress).foregroundColor(.white)
                    }
                }
            }
            .toolbar {
                if browseURL != nil {
                    ToolbarItem(placement: .navigationBarLeading) {
                        Button("Back") { browseURL = nil; pathStack.removeAll(); items = [] }
                    }
                }
                ToolbarItem(placement: .navigationBarTrailing) {
                    Button("Close") { isPresented = false }
                }
            }
            .fileImporter(isPresented: $showFileImporter,
                          allowedContentTypes: [.movie, .video, .audio, .mpeg4Movie, .quickTimeMovie, .mp3, .wav, .mpeg4Audio],
                          allowsMultipleSelection: false) { result in
                switch result {
                case .success(let urls):
                    guard let url = urls.first else { return }
                    let didStart = url.startAccessingSecurityScopedResource()
                    bridge.addItem(url: url, name: url.lastPathComponent, type: "network")
                    let ass = url.deletingPathExtension().appendingPathExtension("ass")
                    if FileManager.default.fileExists(atPath: ass.path) { bridge.loadExternalSubtitle(url: ass) }
                    if didStart { url.stopAccessingSecurityScopedResource() }
                    isPresented = false
                case .failure(let e): bridge.showToastMsg(e.localizedDescription)
                }
            }
        }
    }
    
    private var connectView: some View {
        ScrollView {
            VStack(spacing: 20) {
                Spacer().frame(height: 20)
                VStack(spacing: 10) {
                    Image(systemName: "network").font(.system(size: 40)).foregroundColor(.accentColor)
                    Text("Connect to Server").font(.title3).fontWeight(.medium)
                    VStack(spacing: 8) {
                        TextField("smb://192.168.1.14/sambashare", text: $smbURL)
                            .textFieldStyle(.roundedBorder).keyboardType(.URL)
                            .autocapitalization(.none).disableAutocorrection(true).padding(.horizontal, 20)
                        Button(action: connectToSMB) {
                            HStack { if isConnecting { ProgressView().scaleEffect(0.8) }; Text("Connect") }.frame(maxWidth: 280)
                        }.buttonStyle(.borderedProminent).disabled(smbURL.trimmingCharacters(in: .whitespaces).isEmpty || isConnecting)
                        if let e = connectError { Text(e).font(.caption).foregroundColor(.red).multilineTextAlignment(.center).padding(.horizontal) }
                    }
                }
                Divider().padding(.horizontal, 40)
                VStack(spacing: 10) {
                    Text("Or browse connected servers").font(.subheadline).foregroundColor(.secondary)
                    Button(action: { showFileImporter = true }) { Label("Browse Files", systemImage: "folder").frame(maxWidth: 280) }.buttonStyle(.bordered)
                }
                Divider().padding(.horizontal, 40)
                VStack(spacing: 10) {
                    Text("Play stream URL").font(.subheadline).foregroundColor(.secondary)
                    HStack {
                        TextField("https://...", text: $streamURL).textFieldStyle(.roundedBorder)
                            .keyboardType(.URL).autocapitalization(.none).disableAutocorrection(true)
                        Button("Open") {
                            let t = streamURL.trimmingCharacters(in: .whitespaces)
                            guard !t.isEmpty, URL(string: t) != nil else { return }
                            bridge.addURL(t); isPresented = false
                        }.buttonStyle(.borderedProminent).disabled(streamURL.trimmingCharacters(in: .whitespaces).isEmpty)
                    }.padding(.horizontal, 20)
                }
                Spacer().frame(height: 20)
            }
        }
        .onAppear { if let last = UserDefaults.standard.string(forKey: "MiniPlayer.lastSMBURL") { smbURL = last } }
    }
    
    private var browseView: some View {
        VStack(spacing: 0) {
            HStack(spacing: 8) {
                Button(action: goUp) { Image(systemName: "chevron.left").font(.system(size: 14, weight: .medium)) }
                    .disabled(pathStack.isEmpty).opacity(pathStack.isEmpty ? 0.3 : 1)
                Text(browseURL?.path ?? "").font(.system(size: 13)).foregroundColor(.secondary).lineLimit(1).truncationMode(.head)
                Spacer()
            }.padding(.horizontal, 12).padding(.vertical, 8)
            Divider()
            if isLoading { Spacer(); ProgressView(); Spacer() }
            else if let e = connectError { Spacer(); Text(e).foregroundColor(.secondary).padding(); Spacer() }
            else {
                List { ForEach(items) { item in
                    Button(action: { handleSelect(item) }) {
                        HStack(spacing: 8) {
                            Image(systemName: item.isDirectory ? "folder.fill" : (["mp4","mov","m4v","mkv","avi","webm","ts"].contains(item.url.pathExtension.lowercased()) ? "film" : "doc"))
                                .foregroundColor(item.isDirectory ? .accentColor : .secondary)
                            VStack(alignment: .leading) {
                                Text(item.name).foregroundColor(.primary)
                                if !item.isDirectory, let s = item.fileSize { Text(fmtSize(s)).font(.caption).foregroundColor(.secondary) }
                            }
                            Spacer()
                            if item.hasMatchingASS { Text("ASS").font(.caption2.bold()).foregroundColor(.white)
                                .padding(.horizontal, 4).padding(.vertical, 2).background(Color.green).cornerRadius(3) }
                            if item.isDirectory { Image(systemName: "chevron.right").font(.caption).foregroundColor(.secondary) }
                        }
                    }
                }}.listStyle(.plain)
            }
        }
    }
    
    private func connectToSMB() {
        let t = smbURL.trimmingCharacters(in: .whitespaces)
        guard !t.isEmpty, let url = URL(string: t) else { return }
        isConnecting = true; connectError = nil
        DispatchQueue.global(qos: .userInitiated).async {
            do {
                let contents = try FileManager.default.contentsOfDirectory(at: url, includingPropertiesForKeys: [.isDirectoryKey, .fileSizeKey], options: [.skipsHiddenFiles])
                let assNames = Set(contents.filter { $0.pathExtension.lowercased() == "ass" }.map { $0.deletingPathExtension().lastPathComponent.lowercased() })
                let fi = buildFileItems(contents, assNames: assNames)
                DispatchQueue.main.async { self.items = fi; self.browseURL = url; self.isConnecting = false; UserDefaults.standard.set(t, forKey: "MiniPlayer.lastSMBURL") }
            } catch {
                DispatchQueue.main.async {
                    self.isConnecting = false; self.connectError = "Cannot connect directly. Opening Files app..."
                    DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
                        UIApplication.shared.open(url) { ok in
                            self.connectError = ok ? "Login in Files app, then come back → Browse Files" : "Failed to open Files app.\nCheck: smb://server/share"
                        }
                    }
                }
            }
        }
    }
    
    private func goUp() {
        guard let cur = browseURL else { return }
        if pathStack.isEmpty { browseURL = nil; items = [] }
        else { let p = pathStack.removeLast(); navigateTo(p) }
    }
    
    private func navigateTo(_ url: URL) {
        isLoading = true; connectError = nil
        DispatchQueue.global(qos: .userInitiated).async {
            do {
                let contents = try FileManager.default.contentsOfDirectory(at: url, includingPropertiesForKeys: [.isDirectoryKey, .fileSizeKey], options: [.skipsHiddenFiles])
                let assNames = Set(contents.filter { $0.pathExtension.lowercased() == "ass" }.map { $0.deletingPathExtension().lastPathComponent.lowercased() })
                let fi = buildFileItems(contents, assNames: assNames)
                DispatchQueue.main.async { self.items = fi; self.browseURL = url; self.isLoading = false }
            } catch {
                DispatchQueue.main.async { self.connectError = error.localizedDescription; self.isLoading = false }
            }
        }
    }
    
    private func handleSelect(_ item: NetworkFileItem) {
        if item.isDirectory { if let cur = browseURL { pathStack.append(cur) }; navigateTo(item.url) }
        else if item.isMediaFile {
            // SMB 文件需要复制到本地，AVPlayer 不认 smb:// 协议
            if item.url.scheme == "smb" {
                copyFromSMBAndPlay(item)
            } else {
                playMedia(item)
            }
        }
    }
    
    private func playMedia(_ item: NetworkFileItem) {
        bridge.addItem(url: item.url, name: item.name, type: "network")
        if item.hasMatchingASS { bridge.loadExternalSubtitle(url: item.url.deletingPathExtension().appendingPathExtension("ass")) }
        isPresented = false
    }
    
    private func copyFromSMBAndPlay(_ item: NetworkFileItem) {
        copyingFile = true
        copyProgress = "Copying \(item.name)..."
        
        DispatchQueue.global(qos: .userInitiated).async {
            let docs = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
            let localURL = docs.appendingPathComponent(item.name)
            
            // 删除旧副本
            try? FileManager.default.removeItem(at: localURL)
            
            do {
                try FileManager.default.copyItem(at: item.url, to: localURL)
                
                // 同时复制同名 ASS
                var assLocal: URL?
                if item.hasMatchingASS {
                    let assURL = item.url.deletingPathExtension().appendingPathExtension("ass")
                    let assDest = docs.appendingPathComponent(assURL.lastPathComponent)
                    if (try? FileManager.default.copyItem(at: assURL, to: assDest)) != nil {
                        assLocal = assDest
                    }
                }
                
                DispatchQueue.main.async {
                    self.copyingFile = false
                    bridge.addItem(url: localURL, name: item.name, type: "network")
                    if let al = assLocal { bridge.loadExternalSubtitle(url: al) }
                    isPresented = false
                }
            } catch {
                DispatchQueue.main.async {
                    self.copyingFile = false
                    self.connectError = "Copy failed: \(error.localizedDescription)"
                }
            }
        }
    }
    
    private func fmtSize(_ s: Int64) -> String {
        if s < 1024 { return "\(s) B" }; if s < 1024*1024 { return String(format: "%.1f KB", Double(s)/1024) }
        if s < 1024*1024*1024 { return String(format: "%.1f MB", Double(s)/(1024*1024)) }; return String(format: "%.1f GB", Double(s)/(1024*1024*1024))
    }
}
#endif