//
//  ContentView.swift
//  MyPass
//
//  Created by Christophe Vila on 21/05/2026.
//

import SwiftUI
import MyPassCore
#if os(macOS)
import AppKit
#endif

struct ContentView: View {
    @StateObject private var session = VaultSession()

    var body: some View {
        SwiftUI.Group {
            if session.isLocked {
                UnlockView(vm: UnlockViewModel(session: session))
            } else {
                VaultRootView(session: session)
            }
        }
        .onReceive(
            NotificationCenter.default.publisher(for: sceneBackgroundNotification)
        ) { _ in
            session.lock()
        }
    }

    private var sceneBackgroundNotification: Notification.Name {
        #if os(iOS)
        UIScene.didEnterBackgroundNotification
        #else
        NSApplication.didResignActiveNotification
        #endif
    }
}

/// Owns the vault/group-filter view models for as long as the vault stays unlocked -- their
/// state (search query, group filter selection) persists across re-renders but resets if the
/// vault locks and is unlocked again (a fresh VaultRootView is created), which matches the
/// expected "locking clears your filter" behavior.
private struct VaultRootView: View {
    @StateObject private var vaultVM: VaultViewModel
    @StateObject private var filterVM: GroupFilterViewModel
    #if os(macOS)
    @State private var columnVisibility: NavigationSplitViewVisibility = .all
    #else
    @State private var showFilterSheet = false
    #endif

    init(session: VaultSession) {
        _vaultVM = StateObject(wrappedValue: VaultViewModel(session: session))
        _filterVM = StateObject(wrappedValue: GroupFilterViewModel(session: session))
    }

    var body: some View {
        content
            .onChange(of: filterVM.selectedGroupIds) { _, newValue in
                vaultVM.selectedGroupIds = newValue
            }
            .onChange(of: filterVM.lastToggledGroupId) { _, newValue in
                vaultVM.lastToggledGroupId = newValue
            }
    }

    #if os(macOS)
    // macOS has room for a persistent sidebar; NavigationSplitView's columnVisibility
    // toggle works correctly at regular width.
    private var content: some View {
        NavigationSplitView(columnVisibility: $columnVisibility) {
            if let root = vaultVM.session.database?.root {
                GroupFilterView(vm: filterVM, rootGroup: root)
            }
        } detail: {
            NavigationStack {
                EntryListView(vm: vaultVM)
                    .toolbar {
                        ToolbarItem(placement: .navigation) {
                            Button {
                                columnVisibility = columnVisibility == .all ? .detailOnly : .all
                            } label: {
                                Image(systemName: "line.3.horizontal")
                            }
                        }
                    }
            }
        }
    }
    #else
    // NavigationSplitView's compact-width collapse only pushes to detail when the
    // sidebar drives navigation via row selection. Our sidebar is a multi-select
    // filter, not a picker, so on iPhone it would just show the sidebar forever with
    // no way to reach the entry list. Use a plain stack with the entry list as the
    // root, and present the group filter as a sheet instead.
    private var content: some View {
        NavigationStack {
            EntryListView(vm: vaultVM)
                .toolbar {
                    ToolbarItem(placement: .navigation) {
                        Button {
                            showFilterSheet = true
                        } label: {
                            Image(systemName: "line.3.horizontal")
                        }
                    }
                }
        }
        .sheet(isPresented: $showFilterSheet) {
            NavigationStack {
                if let root = vaultVM.session.database?.root {
                    GroupFilterView(vm: filterVM, rootGroup: root)
                        .toolbar {
                            ToolbarItem(placement: .confirmationAction) {
                                Button("Done") { showFilterSheet = false }
                            }
                        }
                }
            }
        }
    }
    #endif
}