import SwiftUI

enum Route: Hashable {
    case terms, policy
    case registration, loginEmail
}

struct AuthFlowView: View {
    @Binding var root: RootFlow
    @Binding var selectedTab: MainTab
    let tokenStore: TokenStore
    @Binding var appState: AppState
    
    @State var path: [Route] = []

    var body: some View {
        NavigationStack(path: $path) {
            LoginView(root: $root, selectedTab: $selectedTab, tokenStore: tokenStore, appState: $appState) { route in
                path.append(route)
            }
            .navigationDestination(for: Route.self) { route in
                switch route {
                case .terms:
                    TermsOfUseView()
                case .policy:
                    PrivacyPolicyView()
                case .registration:
                    RegistrationView(root: $root, selectedTab: $selectedTab, tokenStore: tokenStore, appState: $appState, navigate: { route in path.append(route) })
                case .loginEmail:
                    LoginEmailView(root: $root, selectedTab: $selectedTab, tokenStore: tokenStore, appState: $appState)
                }
            }
        }
    }
}

struct LoginView: View {
    @Binding var root: RootFlow
    @Binding var selectedTab: MainTab
    let tokenStore: TokenStore
    @Binding var appState: AppState
    @Environment(\.colorScheme) var colorScheme
    let navigate: (Route) -> Void
    
    @ViewBuilder private var logoImage: some View {
#if os(Android)
        Image(colorScheme == .dark ? "pedifoods_dark" : "pedifoods", bundle: .module)
            .resizable()
#else
        SwiftUI.Image("pedifoods")
            .resizable()
#endif
    }

    @ViewBuilder private var pinHeroImage: some View {
#if os(Android)
        Image(colorScheme == .dark ? "pin_image_app_dark" : "pin_image_app", bundle: .module)
            .resizable()
#else
        SwiftUI.Image("pin_image_app")
            .resizable()
#endif
    }

    var body: some View {
        GeometryReader { geo in
            let heroHeight = max(360, geo.size.height * 0.44)

            ZStack(alignment: .top) {
                (colorScheme == .dark ? Color.black : AppColors.backgroundLight)
                    .ignoresSafeArea()

                pinHeroImage
                    .scaledToFill()
                    .frame(height: heroHeight + 80)
                    .offset(y: -60)
                    .mask(
                        LinearGradient(
                            colors: [.black, .black, .black.opacity(0.0)],
                            startPoint: .top,
                            endPoint: .bottom
                        )
                    )

                VStack(spacing: 18) {
                    Spacer().frame(height: heroHeight - 100)

                    logoImage
                        .scaledToFit()
                        .frame(height: 180)

                    Text("Descubra lorem ipsum ba bla")
                        .font(AppTypography.heading1)
                        .foregroundStyle(colorScheme == .dark ? AppColors.textInverse : AppColors.textPrimary)
                        .multilineTextAlignment(.leading)
                        .frame(maxWidth: .infinity, alignment: .leading)
                        .padding(.horizontal, 28)
                    
                    Spacer().frame(height: 40)

                    Button {
                        navigate(.loginEmail)
                    } label: {
                        PrimaryButtonLabel(title: "ENTRAR")
                    }
                    .padding(.horizontal, 28)
                    .tint(AppColors.tertiary)

                    HStack(spacing: 6) {
                        Text("Não tem conta ainda?")
                            .foregroundStyle(colorScheme == .dark ? AppColors.textInverse.opacity(0.9) : AppColors.textPrimary)
                        Button("Criar conta") {
                            navigate(.registration)
                        }
                        .foregroundStyle(AppColors.primary)
                    }
                    .font(AppTypography.body)

                    Spacer().frame(height: 12)
                }
            }
            .ignoresSafeArea()
        }
    }
}

struct RegistrationView: View {
    @Binding var root: RootFlow
    @Binding var selectedTab: MainTab
    let tokenStore: TokenStore
    @Binding var appState: AppState
    @State var name = ""
    @State var email = ""
    @State var phone = ""
    @State var acceptedTerms = false
    @Environment(\.dismiss) var dismiss
    @Environment(\.colorScheme) var colorScheme
    let navigate: (Route) -> Void
    
    private var isFormValid: Bool { !name.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty && !email.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty && !phone.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty && acceptedTerms }

    @ViewBuilder private var logoImage: some View {
#if os(Android)
        Image(colorScheme == .dark ? "pedifoods_dark" : "pedifoods", bundle: .module)
            .resizable()
#else
        SwiftUI.Image("pedifoods")
            .resizable()
#endif
    }

    var body: some View {
        ZStack {
            (colorScheme == .dark ? Color.black : AppColors.backgroundLight).ignoresSafeArea()

            ScrollView {
                VStack(spacing: 0) {
                    logoImage
                        .scaledToFit()
                        .frame(width: 120, height: 120)

                    Text("Crie sua conta")
                        .font(AppTypography.heading1)
                        .foregroundStyle(colorScheme == .dark ? Color.white : AppColors.textPrimary)

                    Text("Preencha os dados abaixo para começar.")
                        .font(AppTypography.body)
                        .foregroundStyle(colorScheme == .dark ? Color.white : AppColors.textPrimary)
                        .padding(.top, 8)
                        .padding(.bottom, 20)

                    VStack(spacing: 16) {
                        VStack(alignment: .leading, spacing: 16) {
                            LoginField(icon: "person", placeholder: "Ex: Maria Silva", text: $name)
                            LoginField(icon: "envelope", placeholder: "seu@email.com", text: $email)
                            LoginField(icon: "phone", placeholder: "(00) 00000-0000", text: $phone)
                        }
                    }
                    .padding(.horizontal, 24)

                    HStack(alignment: .top, spacing: 12) {
                        
                        Toggle("", isOn: $acceptedTerms)
                            .labelsHidden()
                            .toggleStyle(SwitchToggleStyle(tint: AppColors.primary))
                        
                        Group {
                            Text("Ao se cadastrar, você concorda com nossos [Termos de Uso](app://terms) e [Política de Privacidade](app://policy)")
                                .foregroundStyle(colorScheme == .dark ? Color.white : AppColors.textPrimary)
                                .tint(AppColors.primary)
                                .environment(\.openURL, OpenURLAction { url in
                                    guard url.scheme == "app" else { return .handled }
                                    
                                    switch url.host {
                                    case "terms":
                                        navigate(.terms)
                                        return .handled
                                    case "policy":
                                        navigate(.policy)
                                        return .handled
                                    default:
                                        return .handled
                                    }
                                })
                        }
                        .multilineTextAlignment(.leading)
                    }
                    .padding(.horizontal, 24)
                    .padding(.top, 16)
                    .padding(.bottom, 16)

                    PrimaryButton(title: "Cadastrar e Receber Código", image: Image(systemName: "arrow.right")) {
                        // TODO: integrar com ApiService e OTP
                        tokenStore.jwt = "demo-token"
                        appState.session.isAuthenticated = true
                        appState.session.jwt = "demo-token"
                        appState.profile.email = email
                        selectedTab = .home
                        root = .main
                    }
                    .padding(.horizontal, 24)
                    .padding(.top, 6)
                    .disabled(!isFormValid)
                    .opacity(isFormValid ? 1.0 : 0.5)
                    .tint(AppColors.tertiary)

                    HStack(spacing: 6) {
                        Text("Já tem uma conta?")
                            .foregroundStyle(colorScheme == .dark ? Color.white.opacity(0.8) : AppColors.secondary)
                        NavigationLink("Entrar") {
                            LoginEmailView(root: $root, selectedTab: $selectedTab, tokenStore: tokenStore, appState: $appState)
                        }
                        .foregroundStyle(AppColors.primary)
                    }
                    .font(AppTypography.body)
                    .padding(.top, 16)

                    Spacer().frame(height: 12)
                }
            }
            .padding(.top, -40)
        }
    }
}

struct LoginEmailView: View {
    @Binding var root: RootFlow
    @Binding var selectedTab: MainTab
    let tokenStore: TokenStore
    @Binding var appState: AppState
    @State var email = ""
    @State var phone = ""
    @Environment(\.dismiss) var dismiss
    @Environment(\.colorScheme) var colorScheme

    @ViewBuilder private var logoImage: some View {
#if os(Android)
        Image(colorScheme == .dark ? "pedifoods_dark" : "pedifoods", bundle: .module)
            .resizable()
#else
        SwiftUI.Image("pedifoods")
            .resizable()
#endif
    }

    var body: some View {
        ZStack {
            (colorScheme == .dark ? Color.black : AppColors.backgroundLight).ignoresSafeArea()

            VStack(spacing: 0) {

                logoImage
                    .scaledToFit()
                    .frame(width: 120, height: 120)

                Text("Boas-vindas!")
                    .font(AppTypography.heading1)
                    .foregroundStyle(colorScheme == .dark ? Color.white : AppColors.textPrimary)
                    .padding(Edge.Set.top, 8)
                    .padding(.bottom, 16)

                VStack(spacing: 16) {
                    VStack(alignment: .leading, spacing: 16) {
                        
                        LoginField(icon: "envelope", placeholder: "seu@email.com", text: $email)
                        
                        LoginField(icon: "phone", placeholder: "(00) 00000-0000", text: $phone)
                    }
                }
                .padding(.horizontal, 24)
                .padding(.bottom, 16)
                
                PrimaryButton(title: "Receber Código", image: Image(systemName: "arrow.right")) {
                    // TODO: integrar com ApiService e OTP
                    tokenStore.jwt = "demo-token"
                    appState.session.isAuthenticated = true
                    appState.session.jwt = "demo-token"
                    appState.profile.email = email
                    selectedTab = .home
                    root = .main
                }
                .padding(.horizontal, 24)
                .tint(AppColors.tertiary)
                
                Text("Enviaremos um código de verificação por SMS \nou E-mail para confirmar seu acesso.")
                    .font(.caption)
                    .foregroundStyle(Color.gray)
                    .multilineTextAlignment(.center)
                    .padding(.horizontal, 40)
                    .padding([.top, .bottom], 16)

                HStack(spacing: 6) {
                    Text("Novo por aqui?")
                        .foregroundStyle(colorScheme == .dark ? Color.white.opacity(0.8) : Color.gray)
                    Text("Crie sua conta")
                        .foregroundStyle(AppColors.primary)
                        .onTapGesture {
                            dismiss()
                        }
                }
                .font(AppTypography.body)
                .padding(.top, 8)

                Spacer()
            }
        }
    }
}

struct LoginField: View {
    let icon: String
    let placeholder: String
    @Binding var text: String

    var body: some View {
        HStack(spacing: 12) {
            Image(systemName: icon)
                .foregroundStyle(Color.gray)
                .frame(width: 28)
            TextField(text: $text, prompt: Text(placeholder).foregroundColor(Color.gray)) { }
                .textInputAutocapitalization(.never)
                .autocorrectionDisabled()
                .foregroundColor(.black)
        }
        .padding(.horizontal, 16)
        .frame(height: 52)
        .background(Color.white)
        .clipShape(RoundedRectangle(cornerRadius: 16, style: .continuous))
        .overlay(
            RoundedRectangle(cornerRadius: 16, style: .continuous)
                .stroke(Color.black.opacity(0.06), lineWidth: 1)
        )
    }
}

struct OtpView: View {
    let email: String

    var body: some View {
        VStack(spacing: 16) {
            Text("OTP")
                .font(AppTypography.heading1)
                .foregroundStyle(Color.white)

            Text("Enviado para \(email)")
                .font(.caption)
                .foregroundStyle(Color.white.opacity(0.8))
        }
        .padding(24)
        .background(AppColors.backgroundLight)
        .ignoresSafeArea()
    }
}
struct TermsOfUseView: View {
    var body: some View {
        ScrollView {
            VStack(alignment: .leading, spacing: 16) {
                Text("Termos de Uso")
                    .font(AppTypography.heading1)
                    .foregroundStyle(AppColors.textPrimary)
                Text("Conteúdo dos termos de uso...")
                    .font(AppTypography.body)
                    .foregroundStyle(AppColors.textPrimary)
            }
            .padding(24)
        }
        .background((Color(UIColor { trait in trait.userInterfaceStyle == .dark ? .black : UIColor(AppColors.backgroundLight) })).ignoresSafeArea())
        .navigationTitle("Termos de Uso")
        .navigationBarTitleDisplayMode(.inline)
    }
}

struct PrivacyPolicyView: View {
    var body: some View {
        ScrollView {
            VStack(alignment: .leading, spacing: 16) {
                Text("Política de Privacidade")
                    .font(AppTypography.heading1)
                    .foregroundStyle(AppColors.textPrimary)
                Text("Conteúdo da política de privacidade...")
                    .font(AppTypography.body)
                    .foregroundStyle(AppColors.textPrimary)
            }
            .padding(24)
        }
        .background((Color(UIColor { trait in trait.userInterfaceStyle == .dark ? .black : UIColor(AppColors.backgroundLight) })).ignoresSafeArea())
        .navigationTitle("Privacidade")
        .navigationBarTitleDisplayMode(.inline)
    }
}