import SwiftUI
import Combine

enum AppScreen { case auth, landing, practice }

final class AppState: ObservableObject {
    @Published var token: String?
    @Published var screen: AppScreen = .auth
    @Published var showScriptsOnAppear: Bool = false

    init() {
        token = Keychain.load(key: "mimio_token")
        if let t = token, !t.isEmpty { screen = .landing }
    }

    func login(token: String) {
        self.token = token
        screen = .landing
    }

    func logout() {
        Keychain.delete(key: "mimio_token")
        UserDefaults.standard.removeObject(forKey: "mimio_user_id")
        token = nil
        screen = .auth
        showScriptsOnAppear = false
    }
}

@main
struct MimioApp: App {
    @StateObject private var appState = AppState()
    var body: some Scene { WindowGroup { screenView } }

    @ViewBuilder
    private var screenView: some View {
        switch appState.screen {
        case .auth:
            AuthView { t in appState.login(token: t) }
        case .landing:
            LandingView().environmentObject(appState)
        case .practice:
            ContentView(token: appState.token ?? "").environmentObject(appState)
        }
    }
}

struct LandingView: View {
    @EnvironmentObject var appState: AppState
    @State private var doorsOpen = false
    @State private var logoOpacity = 0.0
    @State private var taglineOpacity = 0.0
    @State private var buttonOpacity = 0.0
    @State private var animationDone = false

    private let goldColor  = Color(red: 0.788, green: 0.643, blue: 0.298)
    private let navyColor  = Color(red: 0.039, green: 0.059, blue: 0.118)
    private let stoneColor = Color(red: 0.769, green: 0.659, blue: 0.510)
    private let screenW    = UIScreen.main.bounds.width

    var body: some View {
        ZStack {
            navyColor.ignoresSafeArea()

            if !animationDone {
                ZStack {
                    if let img = UIImage(named: "mountain_door") {
                        Image(uiImage: img)
                            .resizable().scaledToFill().ignoresSafeArea()
                    }
                    Color.black.opacity(0.4).ignoresSafeArea()

                    VStack(spacing: 16) {
                        Text("MIMIO")
                            .font(.system(size: 52, weight: .black, design: .serif))
                            .foregroundColor(.white).tracking(10)
                            .shadow(color: goldColor.opacity(0.6), radius: 20)
                            .opacity(logoOpacity)
                        Text("hear yourself, clearer")
                            .font(.system(size: 14, weight: .light))
                            .foregroundColor(stoneColor.opacity(0.8)).tracking(3)
                            .opacity(taglineOpacity)
                    }

                    HStack(spacing: 0) {
                        if let left = UIImage(named: "door_left") {
                            Image(uiImage: left).resizable().scaledToFill()
                                .frame(width: screenW / 2).clipped()
                                .offset(x: doorsOpen ? -(screenW / 2) : 0)
                                .animation(.easeInOut(duration: 1.8), value: doorsOpen)
                        }
                        if let right = UIImage(named: "door_right") {
                            Image(uiImage: right).resizable().scaledToFill()
                                .frame(width: screenW / 2).clipped()
                                .offset(x: doorsOpen ? (screenW / 2) : 0)
                                .animation(.easeInOut(duration: 1.8), value: doorsOpen)
                        }
                    }.ignoresSafeArea()
                }
            }

            if animationDone {
                VStack(spacing: 0) {
                    Spacer()
                    VStack(spacing: 22) {
                        Text("MIMIO")
                            .font(.system(size: 52, weight: .black, design: .serif))
                            .foregroundColor(.white).tracking(10)
                            .shadow(color: goldColor.opacity(0.6), radius: 20)
                        Text("hear yourself, clearer")
                            .font(.system(size: 14, weight: .light))
                            .foregroundColor(stoneColor.opacity(0.8)).tracking(3)
                    }
                    Spacer()
                    Button {
                        appState.showScriptsOnAppear = true
                        appState.screen = .practice
                    } label: {
                        Text("START LEARNING")
                            .font(.system(size: 16, weight: .bold, design: .monospaced))
                            .foregroundColor(.white).frame(maxWidth: .infinity)
                            .padding(.vertical, 18)
                            .overlay(Capsule().stroke(goldColor, lineWidth: 1.5))
                    }
                    .padding(.horizontal, 40).padding(.bottom, 60).opacity(buttonOpacity)
                }
                .transition(.opacity)
            }
        }
        .onAppear {
            withAnimation(.easeIn(duration: 1.2)) { logoOpacity = 1.0 }
            withAnimation(.easeIn(duration: 1.2).delay(0.4)) { taglineOpacity = 1.0 }
            DispatchQueue.main.asyncAfter(deadline: .now() + 2.5) { doorsOpen = true }
            DispatchQueue.main.asyncAfter(deadline: .now() + 4.3) {
                withAnimation(.easeIn(duration: 0.6)) { animationDone = true }
                DispatchQueue.main.asyncAfter(deadline: .now() + 0.3) {
                    withAnimation(.easeIn(duration: 0.8)) { buttonOpacity = 1.0 }
                }
            }
        }
    }
}