import SwiftUI

struct HomeView: View {
    @Environment(AuthManager.self) private var authManager
    @State private var viewModel = HomeViewModel()

    var body: some View {
        NavigationStack {
            ScrollView {
                VStack(spacing: 20) {
                    if viewModel.isLoading {
                        LoadingView(message: "Loading dashboard...")
                            .frame(height: 300)
                    } else {
                        // Quick Stats Card
                        caloriesSummaryCard

                        // Macros Card
                        macrosCard

                        // Quick Actions
                        quickActionsCard
                    }

                    if let error = viewModel.errorMessage {
                        ErrorBanner(message: error) {
                            Task { await viewModel.load() }
                        }
                    }
                }
                .padding(16)
            }
            .background(Color.canvas)
            .navigationTitle("Dashboard")
            .toolbar {
                ToolbarItem(placement: .topBarTrailing) {
                    Menu {
                        Button(role: .destructive) {
                            authManager.logout()
                        } label: {
                            Label("Sign Out", systemImage: "rectangle.portrait.and.arrow.right")
                        }
                    } label: {
                        Image(systemName: "person.circle.fill")
                            .font(.title3)
                            .foregroundStyle(Color.accentWarm)
                    }
                }
            }
            .refreshable {
                await viewModel.load()
            }
            .task {
                await viewModel.load()
            }
        }
    }

    private var caloriesSummaryCard: some View {
        VStack(spacing: 16) {
            HStack {
                VStack(alignment: .leading, spacing: 4) {
                    Text("Today")
                        .font(.headline)
                        .foregroundStyle(Color.text1)
                    Text(Date().displayString)
                        .font(.subheadline)
                        .foregroundStyle(Color.text3)
                }
                Spacer()
                Text("\(viewModel.entryCount) entries")
                    .font(.caption)
                    .foregroundStyle(Color.text4)
                    .padding(.horizontal, 10)
                    .padding(.vertical, 4)
                    .background(Color.surfaceSecondary)
                    .clipShape(Capsule())
            }

            MacroRingLarge(
                current: viewModel.totalCalories,
                goal: viewModel.goal.calories,
                color: .caloriesColor,
                size: 140,
                lineWidth: 12
            )

            HStack(spacing: 0) {
                macroStat("Eaten", value: Int(viewModel.totalCalories), unit: "kcal")
                Spacer()
                macroStat("Remaining", value: Int(max(viewModel.goal.calories - viewModel.totalCalories, 0)), unit: "kcal")
                Spacer()
                macroStat("Goal", value: Int(viewModel.goal.calories), unit: "kcal")
            }
        }
        .padding(20)
        .background(Color.surface)
        .clipShape(RoundedRectangle(cornerRadius: 16))
        .shadow(color: .black.opacity(0.04), radius: 8, y: 4)
    }

    private var macrosCard: some View {
        VStack(spacing: 14) {
            Text("Macros")
                .font(.headline)
                .foregroundStyle(Color.text1)
                .frame(maxWidth: .infinity, alignment: .leading)

            HStack(spacing: 20) {
                MacroRing(
                    current: viewModel.totalProtein,
                    goal: viewModel.goal.protein,
                    color: .proteinColor,
                    label: "Protein",
                    unit: "g",
                    size: 68
                )
                MacroRing(
                    current: viewModel.totalCarbs,
                    goal: viewModel.goal.carbs,
                    color: .carbsColor,
                    label: "Carbs",
                    unit: "g",
                    size: 68
                )
                MacroRing(
                    current: viewModel.totalFat,
                    goal: viewModel.goal.fat,
                    color: .fatColor,
                    label: "Fat",
                    unit: "g",
                    size: 68
                )
            }
            .frame(maxWidth: .infinity)
        }
        .padding(20)
        .background(Color.surface)
        .clipShape(RoundedRectangle(cornerRadius: 16))
        .shadow(color: .black.opacity(0.04), radius: 8, y: 4)
    }

    private var quickActionsCard: some View {
        VStack(spacing: 12) {
            Text("Quick Actions")
                .font(.headline)
                .foregroundStyle(Color.text1)
                .frame(maxWidth: .infinity, alignment: .leading)

            HStack(spacing: 12) {
                quickActionButton(icon: "plus.circle.fill", label: "Log Food", color: .accentEmerald)
                quickActionButton(icon: "doc.text.fill", label: "Templates", color: .carbsColor)
                quickActionButton(icon: "clock.fill", label: "History", color: .accentWarm)
            }
        }
        .padding(20)
        .background(Color.surface)
        .clipShape(RoundedRectangle(cornerRadius: 16))
        .shadow(color: .black.opacity(0.04), radius: 8, y: 4)
    }

    private func macroStat(_ label: String, value: Int, unit: String) -> some View {
        VStack(spacing: 2) {
            Text("\(value)")
                .font(.system(.title3, design: .rounded, weight: .bold))
                .foregroundStyle(Color.text1)
            Text("\(label)")
                .font(.caption2)
                .foregroundStyle(Color.text4)
        }
    }

    private func quickActionButton(icon: String, label: String, color: Color) -> some View {
        VStack(spacing: 8) {
            Image(systemName: icon)
                .font(.title2)
                .foregroundStyle(color)
            Text(label)
                .font(.caption)
                .fontWeight(.medium)
                .foregroundStyle(Color.text2)
        }
        .frame(maxWidth: .infinity)
        .padding(.vertical, 16)
        .background(color.opacity(0.06))
        .clipShape(RoundedRectangle(cornerRadius: 12))
    }
}