// Settings tab: bridge connection, playback buffer, prefetch-ahead policy, and
// offline storage management.

import SwiftUI
import LilithDesignTokens

struct SettingsScreen: View {
    @EnvironmentObject private var settings: BridgeSettings
    @EnvironmentObject private var downloads: DownloadManager

    @State private var portText = ""

    var body: some View {
        NavigationStack {
            Form {
                Section {
                    LabeledContent("Host") {
                        TextField("10.0.0.11", text: $settings.host)
                            .textInputAutocapitalization(.never)
                            .autocorrectionDisabled()
                            .multilineTextAlignment(.trailing)
                            .accessibilityHint("Home LAN address of the bridge — saved on this device")
                    }
                    LabeledContent("Fallback host") {
                        TextField("10.9.0.4", text: $settings.fallbackHost)
                            .textInputAutocapitalization(.never)
                            .autocorrectionDisabled()
                            .multilineTextAlignment(.trailing)
                            .accessibilityHint("WireGuard mesh address — used automatically when home LAN is unreachable")
                    }
                    LabeledContent("Port") {
                        TextField("8787", text: $portText)
                            .keyboardType(.numberPad)
                            .multilineTextAlignment(.trailing)
                            .accessibilityHint("Bridge HTTP port — saved on this device")
                            .onChange(of: portText) { _, new in
                                if let p = Int(new), p > 0, p < 65536 { settings.port = p }
                            }
                    }
                    LabeledContent("Token") {
                        SecureField("optional", text: $settings.token)
                            .multilineTextAlignment(.trailing)
                            .accessibilityHint("Optional bridge auth token — saved on this device")
                    }
                } header: {
                    Text("Bridge")
                } footer: {
                    Text("Host is tried first on the home LAN; fallback (WireGuard) takes over when you open the app off-LAN. Connected via \(settings.activeHost). All bridge fields persist on this phone.")
                }

                Section {
                    VStack(alignment: .leading) {
                        Text("Buffer: \(settings.networkCachingMs) ms")
                        Slider(
                            value: Binding(
                                get: { Double(settings.networkCachingMs) },
                                set: { settings.networkCachingMs = Int($0) }
                            ),
                            in: 300...8000, step: 100
                        )
                        .accessibilityHint("VLCKit network buffer — higher absorbs jitter but slows seeking")
                    }
                } header: {
                    Text("Playback")
                } footer: {
                    Text("Higher buffer absorbs more network jitter but makes seeking slower. 1500 ms is a good default over the mesh. Saved on this device.")
                }

                Section {
                    Toggle("Prefetch ahead", isOn: $settings.prefetchEnabled)
                        .accessibilityHint("Download the next episodes while you watch a series")
                    if settings.prefetchEnabled {
                        Stepper("Keep next \(settings.prefetchCount) episode\(settings.prefetchCount == 1 ? "" : "s")",
                                value: $settings.prefetchCount, in: 1...10)
                        .accessibilityHint("How many upcoming episodes to keep downloaded")
                    }
                } header: {
                    Text("Offline")
                } footer: {
                    Text("While you watch a series, the next episodes download automatically so they're ready offline. Settings persist on this device.")
                }

                Section {
                    Toggle("Auto-pack on open", isOn: $settings.packEnabled)
                        .accessibilityHint("Run flight pack when the app opens")
                    Stepper("Next \(settings.packEpisodesPerShow) per show",
                            value: $settings.packEpisodesPerShow, in: 1...10)
                    .accessibilityHint("Episodes per in-progress show to keep downloaded")
                    Stepper("Budget: \(settings.packBudgetGB) GB",
                            value: $settings.packBudgetGB, in: 5...100, step: 5)
                    .accessibilityHint("Total storage cap for flight pack downloads")
                } header: {
                    Text("Flight pack")
                } footer: {
                    Text("Keeps the next episodes of every show you're watching downloaded, up to the budget. Watched episodes are evicted to make room; unwatched never are. Run it manually from Downloads. All values persist on this device.")
                }

                Section("Storage") {
                    LabeledContent("Downloaded", value: "\(downloads.entries.count) episodes")
                    LabeledContent("On disk", value: ByteCountFormatter.string(fromByteCount: downloads.totalBytes, countStyle: .file))
                    if !downloads.entries.isEmpty {
                        Button("Delete all offline", role: .destructive) {
                            for e in downloads.entries { downloads.delete(episodeId: e.episodeId) }
                        }
                        .accessibilityHint("Remove every downloaded episode from this phone")
                    }
                }
            }
            .navigationTitle("Settings")
            .onAppear { portText = String(settings.port) }
        }
    }
}