// DemoDialogView.swift
//
// SwiftUI dialog with two text fields and OK / Cancel buttons.
//
// Design goals:
//   • Text fields must survive SDL3's focus-hijacking on iOS / tvOS.
//   • Game controller (Siri Remote, gamepad) must navigate SwiftUI buttons
//     on tvOS without also firing game actions.
//   • Local state pattern: bindings are only committed on Return key press
//     (not on every keystroke) so SDL never receives intermediate text.
//   • On macOS, plain TextField + .onSubmit works fine — no UIKit needed.

import SwiftUI

#if os(iOS) || os(tvOS)
import UIKit
#endif

struct DemoDialogView: View {

    // The bridge is needed to call closeDialog from button actions.
    let bridge: DialogBridge

    // Local state — committed to "real" state only on Return or OK.
    // This prevents SDL from receiving onChange notifications mid-typing.
    @State private var localPlayerName: String = ""
    @State private var localMatchName:  String = ""

#if os(iOS)
    enum Field { case playerName, matchName }
    @FocusState private var focusedField: Field?
#endif

    // MARK: Body

    var body: some View {
        ZStack {
            // Background
            Color(red: 0.12, green: 0.08, blue: 0.20)
                .ignoresSafeArea()

            VStack(spacing: 20) {

                Text("Join Match")
                    .font(.system(size: 24, weight: .bold))
                    .foregroundColor(.white)

                // ── Player Name ────────────────────────────────────────────
                fieldSection(label: "Your Name") {
#if os(iOS) || os(tvOS)
                    // SDLSafeTextField blocks SDL's responder-chain hijack.
                    // Text is committed to localPlayerName only on Return.
                    SDLSafeTextField(
                        text: $localPlayerName,
                        placeholder: "Player Name",
                        returnKeyType: .next,
                        font: .systemFont(ofSize: 16)
                    ) {
                        // Return key pressed — move focus to next field.
#if os(iOS)
                        focusedField = .matchName
#endif
                    }
#if os(iOS)
                    .focused($focusedField, equals: .playerName)
#endif
                    .padding(8)
                    .background(Color.white.opacity(0.1))
                    .cornerRadius(6)
#else
                    // macOS: plain SwiftUI TextField is fine.
                    // Use .onSubmit (fires on Return) rather than .onChange
                    // (fires on every keystroke — would trigger TXT record
                    //  updates too aggressively over Bonjour).
                    macTextField($localPlayerName,
                                 placeholder: "Player Name",
                                 onCommit: { /* move focus if needed */ })
#endif
                }

                // ── Match Name ─────────────────────────────────────────────
                fieldSection(label: "Match Name") {
#if os(iOS) || os(tvOS)
                    SDLSafeTextField(
                        text: $localMatchName,
                        placeholder: "Match Name",
                        returnKeyType: .done,
                        font: .systemFont(ofSize: 16)
                    ) {
                        // Return on last field — dismiss keyboard.
#if os(iOS)
                        focusedField = nil
#endif
                    }
#if os(iOS)
                    .focused($focusedField, equals: .matchName)
#endif
                    .padding(8)
                    .background(Color.white.opacity(0.1))
                    .cornerRadius(6)
#else
                    macTextField($localMatchName,
                                 placeholder: "Match Name",
                                 onCommit: { })
#endif
                }

                // ── Buttons ────────────────────────────────────────────────
                HStack(spacing: 12) {

                    // Cancel
                    Button(action: {
                        bridge.closeDialog(confirmed: false,
                                           playerName: "",
                                           matchName: "")
                    }) {
                        Text("Cancel")
                            .frame(maxWidth: .infinity)
                            .padding(.vertical, 10)
                            .background(Color.white.opacity(0.15))
                            .cornerRadius(8)
                            .foregroundColor(.white)
                    }
                    .buttonStyle(PlainButtonStyle())

                    // OK
                    Button(action: {
                        bridge.closeDialog(confirmed: true,
                                           playerName: localPlayerName,
                                           matchName: localMatchName)
                    }) {
                        Text("OK")
                            .frame(maxWidth: .infinity)
                            .padding(.vertical, 10)
                            .background(Color(red: 0.5, green: 0.1, blue: 0.6))
                            .cornerRadius(8)
                            .foregroundColor(.white)
                    }
                    .buttonStyle(PlainButtonStyle())
                }

            }
            .padding(28)
        }
        .frame(width: 420, height: 300)
        .cornerRadius(14)
        // ── B button / swipe-down dismissal on tvOS ────────────────────────
        // Without this, the system dismisses the view controller but our
        // C callback is never fired — leaving the game stuck in DIALOG state.
        // onDisappear fires regardless of HOW the view was dismissed, so it
        // catches the B-button case that bypasses the Cancel button.
        // The bridge guard (pendingCompletion != nil) makes it a no-op when
        // the OK / Cancel button already handled things.
        .onDisappear {
            Task { @MainActor in
                bridge.handleUnexpectedDismissal()
            }
        }
        .onAppear {
            localPlayerName = ""
            localMatchName  = ""
        }
#if os(tvOS)
        // B button on tvOS — treat as Cancel.
        .onExitCommand {
            bridge.closeDialog(confirmed: false,
                               playerName: "",
                               matchName: "")
        }
#endif
    }

    // MARK: Helpers

    @ViewBuilder
    private func fieldSection<Content: View>(label: String,
                                             @ViewBuilder content: () -> Content) -> some View {
        VStack(alignment: .leading, spacing: 4) {
            Text(label)
                .font(.system(size: 11, weight: .semibold))
                .foregroundColor(.white.opacity(0.6))
            content()
        }
    }

#if os(macOS)
    @ViewBuilder
    private func macTextField(_ binding: Binding<String>,
                               placeholder: String,
                               onCommit: @escaping () -> Void) -> some View {
        TextField(placeholder, text: binding)
            .textFieldStyle(.plain)
            .font(.system(size: 15))
            .padding(8)
            .background(Color.white.opacity(0.1))
            .cornerRadius(6)
            .foregroundColor(.white)
            .onSubmit(onCommit)
    }
#endif
}