import MusicAssistantCore
import SwiftUI

struct InstrumentBrowserView: View {
    @Binding private var project: SongProject
    private let saveProject: (SongProject) async -> Bool
    private let catalog: LocalInstrumentCatalog

    @State private var searchText = ""
    @State private var selectedFamilyCategory: String?
    @State private var selectedRegionOrigin: String?
    @State private var hasUnsavedSelectionChanges = false
    @State private var isSaving = false
    @Environment(\.dismiss) private var dismiss

    init(
        project: Binding<SongProject>,
        saveProject: @escaping (SongProject) async -> Bool = { _ in true },
        catalog: LocalInstrumentCatalog = LocalInstrumentCatalog()
    ) {
        _project = project
        self.saveProject = saveProject
        self.catalog = catalog
    }

    var body: some View {
        NavigationStack {
            VStack(spacing: 0) {
                HStack {
                    Picker("Family", selection: $selectedFamilyCategory) {
                        Text("All families").tag(String?.none)

                        ForEach(catalog.familyCategories, id: \.self) { familyCategory in
                            Text(familyCategory).tag(Optional(familyCategory))
                        }
                    }
                    .pickerStyle(.menu)

                    Spacer()

                    Picker("Region", selection: $selectedRegionOrigin) {
                        Text("All regions").tag(String?.none)

                        ForEach(catalog.regionsOfOrigin, id: \.self) { regionOrigin in
                            Text(regionOrigin).tag(Optional(regionOrigin))
                        }
                    }
                    .pickerStyle(.menu)
                }
                .padding(.horizontal)
                .padding(.vertical, 8)

                Divider()

                List(
                    catalog.instruments(
                        matching: searchText,
                        familyCategory: selectedFamilyCategory,
                        regionOrigin: selectedRegionOrigin
                    ),
                    id: \.id
                ) { instrument in
                    Toggle(isOn: selectionBinding(for: instrument)) {
                        VStack(alignment: .leading, spacing: 4) {
                            Text(instrument.name)
                                .font(.body.weight(.medium))

                            HStack(spacing: 6) {
                                Text(instrument.familyCategory)

                                if let regionOrigin = instrument.regionOrigin {
                                    Text(regionOrigin)
                                }
                            }
                            .font(.caption)
                            .foregroundStyle(.secondary)
                            .lineLimit(1)
                        }
                    }
                    .toggleStyle(.checkbox)
                    .padding(.vertical, 2)
                }
            }
            .navigationTitle("Instrument Catalog")
            .searchable(text: $searchText, prompt: "Search instruments")
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("Done") {
                        Task {
                            await saveSelectionChangesIfNeeded()
                            dismiss()
                        }
                    }
                    .disabled(isSaving)
                }

                if isSaving {
                    ToolbarItem(placement: .status) {
                        ProgressView()
                            .controlSize(.small)
                    }
                }
            }
        }
        .frame(minWidth: 460, minHeight: 520)
        .onDisappear {
            guard hasUnsavedSelectionChanges, !isSaving else { return }

            let projectToSave = project
            hasUnsavedSelectionChanges = false

            Task {
                _ = await saveProject(projectToSave)
            }
        }
    }

    private func selectionBinding(for instrument: InstrumentCatalogItem) -> Binding<Bool> {
        Binding {
            project.isInstrumentSelected(id: instrument.id)
        } set: { isSelected in
            project.setInstrumentSelected(
                id: instrument.id,
                isSelected: isSelected,
                variant: instrument.name
            )
            hasUnsavedSelectionChanges = true
        }
    }

    private func saveSelectionChangesIfNeeded() async {
        guard hasUnsavedSelectionChanges else { return }

        isSaving = true
        let didSave = await saveProject(project)
        hasUnsavedSelectionChanges = !didSave
        isSaving = false
    }
}

#Preview {
    InstrumentBrowserPreview()
}

private struct InstrumentBrowserPreview: View {
    @State private var project = SongProject(
        title: "Instrument Browser Preview",
        idea: "Browse the instrument catalog."
    )

    var body: some View {
        InstrumentBrowserView(project: $project)
    }
}