import SwiftUI
import IndieAbout
import IndieBackup

/// Backup/restore (indie-backup skill) and the About section (indie-about skill).
struct SettingsTabView: View {
    @Environment(BoardIndexStore.self) private var index
    @Environment(\.backupController) private var backupController

    var body: some View {
        NavigationStack {
            Form {
                backupSection

                // Last section by convention. The version label doubles as the changelog link,
                // which is why the changelog sits in its dedicated slot and not in `documents`.
                // Same voice as the Mac app's `AboutBox.configuration`; the changelog itself is
                // the phone app's own (see project.yml — separate product, separate 1.0).
                Section {
                    IndieAbout(configuration: .init(
                        copyrightText: "© 2026 rzen",
                        documents: [.license(extension: "md")],
                        changelogDocument: .changelog()
                    ))
                }
            }
            .navigationTitle("Settings")
        }
        // Idempotent (BoardIndexStore.start()), and harmless if BoardsTabView already called it —
        // this tab can be the first one the user opens, and `backupController` only ever appears
        // once `index.home` resolves.
        .task { index.start() }
    }

    /// `backupController` is `nil` until `MobileApp` has a resolved `CloudHome` to build one from
    /// — which is also exactly the condition under which there is a `Documents/` folder to back
    /// up. Everything short of that gets the same quiet explanation rather than a section that
    /// looks broken or, worse, a crash on a nil root.
    @ViewBuilder
    private var backupSection: some View {
        if let backupController {
            BackupsSectionView(controller: backupController)
        } else {
            Section {
                switch index.phase {
                case .idle, .loading:
                    LabeledContent("Backup") {
                        ProgressView()
                    }
                case .ready:
                    // `.ready` is both cases now: the run with no iCloud at all, and the runloop turn
                    // `backupController` lags `index.home` by (MobileApp's `.task(id:)`). Backup is
                    // still iCloud-only — a known gap now that local boards exist.
                    Label("Backup and restore need iCloud Drive.", systemImage: "icloud.slash")
                        .foregroundStyle(.secondary)
                }
            } footer: {
                Text("Sign into iCloud in Settings, then come back here to back up your boards.")
            }
        }
    }
}