import SwiftUI

struct ContentView: View {
    @StateObject private var vm = DownloadViewModel()

    var body: some View {
        VStack(spacing: 16) {
            header

            GroupBox("Download") {
                VStack(alignment: .leading, spacing: 10) {
                    HStack {
                        TextField("YouTube video or playlist URL", text: $vm.urlString)
                            .textFieldStyle(.roundedBorder)

                        Button("Paste") {
                            if let s = NSPasteboard.general.string(forType: .string) {
                                vm.urlString = s.trimmingCharacters(in: .whitespacesAndNewlines)
                            }
                        }
                    }

                    HStack(spacing: 16) {
                        Toggle("Audio only (MP3)", isOn: $vm.audioOnly)

                        Picker("Quality", selection: $vm.quality) {
                            ForEach(VideoQuality.allCases, id: \.self) { q in
                                Text(q.title).tag(q)
                            }
                        }
                        .pickerStyle(.menu)

                        Spacer()
                    }

                    HStack {
                        VStack(alignment: .leading, spacing: 4) {
                            Text("Save to:")
                                .font(.caption)
                                .foregroundStyle(.secondary)

                            Text(vm.destinationPathDisplay)
                                .lineLimit(1)
                                .truncationMode(.middle)
                        }

                        Spacer()

                        Button("Choose Folder…") { vm.pickFolder() }
                    }

                    Divider()

                    HStack(spacing: 12) {
                        Button(vm.isDownloading ? "Downloading…" : "Start") {
                            vm.start()
                        }
                        .disabled(!vm.canStart)

                        Button("Cancel") {
                            vm.cancel()
                        }
                        .disabled(!vm.isDownloading)

                        Spacer()
                    }
                }
                .padding(8)
            }

            GroupBox("Progress") {
                VStack(alignment: .leading, spacing: 10) {
                    ProgressView(value: vm.progress)
                        .progressViewStyle(.linear)

                    HStack {
                        Text(vm.statusLine)
                            .font(.system(.caption, design: .monospaced))
                            .foregroundStyle(.secondary)
                            .lineLimit(2)

                        Spacer()

                        if vm.isDownloading {
                            Text(vm.percentText)
                                .font(.system(.caption, design: .monospaced))
                                .foregroundStyle(.secondary)
                        }
                    }
                }
                .padding(8)
            }

            GroupBox("Log") {
                ScrollView {
                    Text(vm.log)
                        .font(.system(.caption, design: .monospaced))
                        .frame(maxWidth: .infinity, alignment: .leading)
                        .textSelection(.enabled)
                        .padding(.vertical, 6)
                }
                .frame(height: 140)
                .padding(.horizontal, 8)
            }
        }
        .padding(18)
        .alert("Error", isPresented: $vm.showError) {
            Button("OK", role: .cancel) { }
        } message: {
            Text(vm.errorMessage)
        }
    }

    private var header: some View {
        HStack {
            VStack(alignment: .leading, spacing: 4) {
                Text("YoutubeDumper")
                    .font(.title2.bold())
                Text("Uses Homebrew yt-dlp. Supports videos, playlists, and audio-only.")
                    .foregroundStyle(.secondary)
            }
            Spacer()
            Button("Check yt-dlp") {
                vm.checkYtDlp()
            }
        }
    }
}