import LChatCore
import SwiftUI
import UIKit

// The full space list — everything the home screen elides: ALL active spaces
// (favourites first, the rest below), standard List drag-to-reorder within
// each group, and the manage context menu. Archived spaces stay hidden here
// too (they live in the account — unarchive on the home page).
struct SpaceListSheet: View {
    @EnvironmentObject var app: AppState
    @Environment(\.dismiss) private var dismiss
    let activeID: String?
    var onSelect: (SavedInstance) -> Void

    private var active: [SavedInstance] { app.instances.filter { !$0.isArchived } }
    private var starred: [SavedInstance] { active.filter(\.isStarred) }
    private var others: [SavedInstance] { active.filter { !$0.isStarred } }

    var body: some View {
        NavigationStack {
            List {
                if starred.isEmpty {
                    Section {
                        ForEach(active) { row($0) }
                            .onMove { app.move(from: $0, to: $1) }
                    }
                } else {
                    // Each group drags independently (home's independent lists);
                    // without these, starring ANYTHING killed reorder entirely.
                    Section("Favourites") {
                        ForEach(starred) { row($0) }
                            .onMove { app.moveInGroup(starred: true, from: $0, to: $1) }
                    }
                    if !others.isEmpty {
                        Section("More") {
                            ForEach(others) { row($0) }
                                .onMove { app.moveInGroup(starred: false, from: $0, to: $1) }
                        }
                    }
                }
            }
            .navigationTitle("Spaces")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .confirmationAction) {
                    Button("Done") { dismiss() }
                }
            }
        }
    }

    private func row(_ inst: SavedInstance) -> some View {
        Button { onSelect(inst) } label: {
            SpaceRow(instance: inst, active: inst.id == activeID,
                     photo: app.serverAvatars[inst.id])
        }
        .foregroundStyle(.primary)
        .contextMenu { SpaceMenuItems(instance: inst) }
    }
}

// One space: avatar, name, host subtitle — shared by the home screen's lists
// (a trailing disclosure chevron: every row navigates) and the More sheet
// (a checkmark on the active one instead).
struct SpaceRow: View {
    let instance: SavedInstance
    let active: Bool
    var photo: UIImage?
    var chevron = false

    var body: some View {
        HStack(spacing: 12) {
            Avatar(name: instance.displayName, size: 36, photo: photo)
            VStack(alignment: .leading, spacing: 2) {
                Text(instance.displayName).font(.headline).lineLimit(1)
                // The host, unless the title already IS the host (no group
                // name yet) — no point showing it twice.
                if instance.displayName != instance.hostLabel {
                    Text(instance.hostLabel).font(.caption).foregroundStyle(.secondary).lineLimit(1)
                }
            }
            Spacer()
            if chevron {
                Image(systemName: "chevron.right")
                    .font(.footnote.weight(.semibold))
                    .foregroundStyle(.tertiary)
            } else if active {
                Image(systemName: "checkmark")
                    .font(.subheadline.weight(.semibold))
                    .foregroundStyle(Color.accentColor)
            }
        }
        .contentShape(Rectangle())
    }
}

// The manage menu shared by the home screen rows and the More sheet rows.
struct SpaceMenuItems: View {
    @EnvironmentObject var app: AppState
    let instance: SavedInstance

    var body: some View {
        Button { app.toggleStar(instance) } label: {
            Label(instance.isStarred ? "Unstar" : "Star",
                  systemImage: instance.isStarred ? "star.slash" : "star")
        }
        Button { app.toggleArchive(instance) } label: {
            Label(instance.isArchived ? "Unarchive" : "Archive",
                  systemImage: instance.isArchived ? "tray.and.arrow.up" : "archivebox")
        }
        Button(role: .destructive) { app.remove(instance) } label: {
            Label("Remove", systemImage: "trash")
        }
    }
}