Sapling/Sources/SaplingUI/WorkspaceTreeView.swift

import SwiftUI
import SaplingCore

public struct WorkspaceTreeView: View {
    private let workspace: Workspace
    private let onSelectFile: (WorkspaceFile) -> Void
    private let onSelectProject: (Project) -> Void

    public init(
        workspace: Workspace,
        onSelectFile: @escaping (WorkspaceFile) -> Void,
        onSelectProject: @escaping (Project) -> Void
    ) {
        self.workspace = workspace
        self.onSelectFile = onSelectFile
        self.onSelectProject = onSelectProject
    }

    public var body: some View {
        List {
            Section(workspace.name) {
                ForEach(workspace.items) { item in
                    WorkspaceItemRow(
                        item: item,
                        onSelectFile: onSelectFile,
                        onSelectProject: onSelectProject
                    )
                }
            }
        }
        .listStyle(.sidebar)
        .navigationTitle("Workspace")
    }
}

private struct WorkspaceItemRow: View {
    let item: WorkspaceItem
    let onSelectFile: (WorkspaceFile) -> Void
    let onSelectProject: (Project) -> Void

    var body: some View {
        switch item {
        case .folder(let folder):
            DisclosureGroup {
                ForEach(folder.children) { child in
                    WorkspaceItemRow(
                        item: child,
                        onSelectFile: onSelectFile,
                        onSelectProject: onSelectProject
                    )
                }
            } label: {
                Label(folder.name, systemImage: "folder")
            }
        case .file(let file):
            Button {
                onSelectFile(file)
            } label: {
                Label(file.name, systemImage: iconName(for: file.kind))
            }
            .buttonStyle(.plain)
        case .project(let project):
            Button {
                onSelectProject(project)
            } label: {
                Label(project.name, systemImage: "point.3.connected.trianglepath.dotted")
            }
            .buttonStyle(.plain)
        case .subproject(let subproject):
            Label(subproject.name, systemImage: "rectangle.connected.to.line.below")
                .foregroundStyle(.secondary)
        }
    }

    private func iconName(for kind: WorkspaceFileKind) -> String {
        switch kind {
        case .markdown: "doc.plaintext"
        case .attachment: "paperclip"
        case .other: "doc"
        }
    }
}