import SwiftUI

struct ProfileScreen: View {
    @EnvironmentObject var appState: AppState
    @Environment(\.dismiss) private var dismiss
    @State private var appearAnimation = false
    @State private var avatarURLLoaded: URL?

    // Profile data from API
    @State private var profile: APIService.UserProfile?
    @State private var isLoadingProfile = true
    @State private var profileError: String?

    // Edit mode
    @State private var isEditing = false
    @State private var editFirstName = ""
    @State private var editLastName = ""
    @State private var isSaving = false
    @State private var saveError: String?

    private var displayName: String {
        if let p = profile {
            return [p.firstName, p.lastName].filter { !$0.isEmpty }.joined(separator: " ")
        }
        return appState.userName ?? "Worker"
    }

    private var avatarURL: URL? {
        if let loaded = avatarURLLoaded { return loaded }
        guard let urlString = appState.userPhotoUrl, !urlString.isEmpty else { return nil }
        return URL(string: urlString)
    }

    var body: some View {
        ScrollView {
            VStack(spacing: 20) {
                // Avatar section
                VStack(spacing: 8) {
                    if let url = avatarURL {
                        AsyncImage(url: url) { phase in
                            switch phase {
                            case .success(let image):
                                image
                                    .resizable()
                                    .scaledToFill()
                            case .failure:
                                placeholderAvatar
                            default:
                                ProgressView()
                                    .frame(width: 80, height: 80)
                            }
                        }
                        .frame(width: 80, height: 80)
                        .clipShape(Circle())
                        .overlay(Circle().stroke(Color.payfritGreen.opacity(0.3), lineWidth: 2))
                        .shadow(color: .black.opacity(0.1), radius: 6, y: 3)
                    } else {
                        placeholderAvatar
                    }

                    Text(displayName)
                        .font(.title3)
                        .fontWeight(.bold)
                        .foregroundColor(.primary)

                    Text(appState.roleName)
                        .font(.caption)
                        .foregroundColor(.secondary)
                }
                .frame(maxWidth: .infinity)
                .padding(.top, 16)
                .scaleEffect(appearAnimation ? 1 : 0.9)
                .opacity(appearAnimation ? 1 : 0)

                // Content
                if isLoadingProfile {
                    LoadingView(message: "Loading profile...")
                        .frame(height: 120)
                } else if let error = profileError {
                    ErrorView(message: error) { loadProfile() }
                } else if isEditing {
                    editSection
                        .transition(.opacity.combined(with: .move(edge: .bottom)))
                } else {
                    infoSection
                        .opacity(appearAnimation ? 1 : 0)
                        .offset(y: appearAnimation ? 0 : 15)
                }

                Spacer()
                    .frame(height: 20)
            }
        }
        .background(Color(.systemGroupedBackground).ignoresSafeArea())
        .navigationTitle("Profile")
        .navigationBarTitleDisplayMode(.inline)
        .toolbar {
            if !isEditing && !isLoadingProfile && profileError == nil {
                ToolbarItem(placement: .navigationBarTrailing) {
                    Button("Edit") { startEditing() }
                        .foregroundColor(.payfritGreen)
                }
            }
        }
        .task {
            await loadAvatarAndProfile()
        }
        .onAppear {
            withAnimation(.spring(response: 0.5, dampingFraction: 0.8)) {
                appearAnimation = true
            }
        }
    }

    // MARK: - Info Section (Read-Only)

    private var infoSection: some View {
        VStack(alignment: .leading, spacing: 12) {
            Text("Account Information")
                .font(.subheadline)
                .fontWeight(.semibold)
                .foregroundColor(.payfritGreen)
                .padding(.horizontal, 16)

            VStack(spacing: 0) {
                if let p = profile {
                    infoRow(icon: "person.fill", label: "First Name", value: p.firstName.isEmpty ? "-" : p.firstName)
                    Divider().padding(.leading, 54)
                    infoRow(icon: "person.fill", label: "Last Name", value: p.lastName.isEmpty ? "-" : p.lastName)
                    Divider().padding(.leading, 54)
                }
                infoRow(icon: "briefcase.fill", label: "Role", value: appState.roleName)
            }
            .background(Color(.secondarySystemGroupedBackground))
            .clipShape(RoundedRectangle(cornerRadius: 10, style: .continuous))
            .padding(.horizontal, 16)
        }
    }

    // MARK: - Edit Section

    private var editSection: some View {
        VStack(alignment: .leading, spacing: 12) {
            Text("Edit Profile")
                .font(.subheadline)
                .fontWeight(.semibold)
                .foregroundColor(.payfritGreen)
                .padding(.horizontal, 16)

            VStack(spacing: 0) {
                editRow(icon: "person.fill", label: "First Name", text: $editFirstName)
                Divider().padding(.leading, 54)
                editRow(icon: "person.fill", label: "Last Name", text: $editLastName)
            }
            .background(Color(.secondarySystemGroupedBackground))
            .clipShape(RoundedRectangle(cornerRadius: 10, style: .continuous))
            .padding(.horizontal, 16)

            if let error = saveError {
                Text(error)
                    .font(.caption)
                    .foregroundColor(.red)
                    .padding(.horizontal, 16)
            }

            HStack(spacing: 12) {
                Button {
                    withAnimation { isEditing = false }
                    saveError = nil
                } label: {
                    Text("Cancel")
                        .frame(maxWidth: .infinity)
                }
                .buttonStyle(.bordered)
                .disabled(isSaving)

                Button { saveProfile() } label: {
                    if isSaving {
                        ProgressView()
                            .progressViewStyle(CircularProgressViewStyle(tint: .white))
                            .frame(maxWidth: .infinity, minHeight: 20)
                    } else {
                        Text("Save")
                            .frame(maxWidth: .infinity)
                    }
                }
                .buttonStyle(.borderedProminent)
                .tint(.payfritGreen)
                .disabled(isSaving)
            }
            .padding(.horizontal, 16)
            .padding(.top, 4)
        }
    }

    // MARK: - Subviews

    private var placeholderAvatar: some View {
        Image(systemName: "person.circle.fill")
            .resizable()
            .foregroundStyle(.linearGradient(
                colors: [Color.payfritGreen.opacity(0.6), Color.payfritGreen.opacity(0.3)],
                startPoint: .top,
                endPoint: .bottom
            ))
            .frame(width: 80, height: 80)
            .shadow(color: .black.opacity(0.1), radius: 6, y: 3)
    }

    private func infoRow(icon: String, label: String, value: String) -> some View {
        HStack(spacing: 14) {
            Image(systemName: icon)
                .font(.subheadline)
                .foregroundColor(.payfritGreen)
                .frame(width: 24)

            VStack(alignment: .leading, spacing: 2) {
                Text(label)
                    .font(.caption)
                    .foregroundColor(.secondary)
                Text(value)
                    .font(.subheadline)
                    .foregroundColor(.primary)
            }

            Spacer()
        }
        .padding(.horizontal, 16)
        .padding(.vertical, 12)
    }

    private func editRow(icon: String, label: String, text: Binding<String>) -> some View {
        HStack(spacing: 14) {
            Image(systemName: icon)
                .font(.subheadline)
                .foregroundColor(.payfritGreen)
                .frame(width: 24)

            VStack(alignment: .leading, spacing: 2) {
                Text(label)
                    .font(.caption)
                    .foregroundColor(.secondary)
                TextField(label, text: text)
                    .font(.subheadline)
                    .textContentType(label == "First Name" ? .givenName : .familyName)
                    .autocorrectionDisabled()
            }

            Spacer()
        }
        .padding(.horizontal, 16)
        .padding(.vertical, 12)
    }

    // MARK: - Actions

    private func loadAvatarAndProfile() async {
        // Load avatar
        do {
            if let urlString = try await APIService.shared.getAvatarUrl(),
               let url = URL(string: urlString) {
                avatarURLLoaded = url
            }
        } catch {
            // Avatar load failed, continue
        }

        // Load profile
        loadProfile()
    }

    private func loadProfile() {
        isLoadingProfile = true
        profileError = nil
        Task {
            do {
                let p = try await APIService.shared.getProfile()
                profile = p
                isLoadingProfile = false
            } catch {
                profileError = error.localizedDescription
                isLoadingProfile = false
            }
        }
    }

    private func startEditing() {
        editFirstName = profile?.firstName ?? ""
        editLastName = profile?.lastName ?? ""
        saveError = nil
        withAnimation { isEditing = true }
    }

    private func saveProfile() {
        isSaving = true
        saveError = nil
        Task {
            do {
                try await APIService.shared.updateProfile(
                    firstName: editFirstName,
                    lastName: editLastName
                )
                // Refresh profile data
                let p = try await APIService.shared.getProfile()
                profile = p

                // Update appState display name
                let newName = [p.firstName, p.lastName]
                    .filter { !$0.isEmpty }
                    .joined(separator: " ")
                appState.userName = newName.isEmpty ? nil : newName

                isSaving = false
                withAnimation { isEditing = false }
            } catch {
                saveError = error.localizedDescription
                isSaving = false
            }
        }
    }
}

#Preview {
    NavigationStack {
        ProfileScreen()
            .environmentObject(AppState())
    }
}