import SwiftUI

struct GoalsView: View {
    @EnvironmentObject private var accountStore: AccountStore
    @StateObject private var viewModel = GoalsViewModel()
    @State private var showingAddGoal = false
    @State private var editingGoal: Goal?

    var body: some View {
        NavigationStack {
            ZStack {
                AppBackground()

                List {
                    if viewModel.goals.isEmpty {
                        emptyState
                    } else {
                        Section {
                            ForEach(viewModel.goals) { goal in
                                GoalRowView(
                                    goal: goal,
                                    progress: viewModel.progress(for: goal),
                                    totalValue: viewModel.totalValue(for: goal),
                                    paceStatus: viewModel.paceStatus(for: goal)
                                )
                                .contentShape(Rectangle())
                                .onTapGesture {
                                    editingGoal = goal
                                }
                                .swipeActions(edge: .trailing, allowsFullSwipe: true) {
                                    Button(role: .destructive) {
                                        viewModel.deleteGoal(goal)
                                    } label: {
                                        Label("Delete", systemImage: "trash")
                                    }
                                }
                                .swipeActions(edge: .leading, allowsFullSwipe: false) {
                                    Button {
                                        editingGoal = goal
                                    } label: {
                                        Label("Edit", systemImage: "pencil")
                                    }
                                    .tint(.appSecondary)
                                }
                            }
                        }
                    }
                }
                .scrollContentBackground(.hidden)
            }
            .navigationTitle("Goals")
            .toolbar {
                ToolbarItem(placement: .navigationBarTrailing) {
                    Button {
                        showingAddGoal = true
                    } label: {
                        Image(systemName: "plus")
                    }
                }
            }
            .sheet(isPresented: $showingAddGoal) {
                GoalEditorView(account: accountStore.showAllAccounts ? nil : accountStore.selectedAccount)
            }
            .sheet(item: $editingGoal) { goal in
                GoalEditorView(account: goal.account, goal: goal)
            }
            .onAppear {
                viewModel.selectedAccount = accountStore.selectedAccount
                viewModel.showAllAccounts = accountStore.showAllAccounts
                viewModel.refresh()
            }
            .onReceive(accountStore.$selectedAccount) { account in
                viewModel.selectedAccount = account
                viewModel.refresh()
            }
            .onReceive(accountStore.$showAllAccounts) { showAll in
                viewModel.showAllAccounts = showAll
                viewModel.refresh()
            }
        }
    }

    private var emptyState: some View {
        VStack(spacing: 16) {
            Image(systemName: "target")
                .font(.system(size: 48))
                .foregroundColor(.secondary)
            Text("Set your first goal")
                .font(.headline)
            Text("Track progress toward milestones like \(AppSettings.getOrCreate(in: CoreDataStack.shared.viewContext).currencySymbol)1M and share your wins.")
                .font(.subheadline)
                .foregroundColor(.secondary)
                .multilineTextAlignment(.center)
        }
        .frame(maxWidth: .infinity)
        .padding(.vertical, 32)
    }
}

struct GoalRowView: View {
    let goal: Goal
    let progress: Double
    let totalValue: Decimal
    let paceStatus: GoalPaceStatus?

    var body: some View {
        VStack(alignment: .leading, spacing: 12) {
            HStack {
                Text(goal.name)
                    .font(.headline)
                Spacer()
                Button {
                    GoalShareService.shared.shareGoal(
                        name: goal.name,
                        progress: progress,
                        currentValue: totalValue,
                        targetValue: goal.targetDecimal
                    )
                } label: {
                    Image(systemName: "square.and.arrow.up")
                        .foregroundColor(.appPrimary)
                }
            }

            GoalProgressBar(progress: progress, tint: .appSecondary, iconColor: .appSecondary)

            HStack {
                Text(totalValue.currencyString)
                    .font(.subheadline.weight(.semibold))
                Spacer()
                Text("of \(goal.targetDecimal.currencyString)")
                    .font(.subheadline)
                    .foregroundColor(.secondary)
            }

            if let targetDate = goal.targetDate {
                Text("Target date: \(targetDate.mediumDateString)")
                    .font(.caption)
                    .foregroundColor(.secondary)
            }

            if let paceStatus {
                Text(paceStatus.statusText)
                    .font(.caption.weight(.semibold))
                    .foregroundColor(paceStatus.isBehind ? .negativeRed : .positiveGreen)
            }
        }
        .padding(.vertical, 8)
    }
}

#Preview {
    GoalsView()
        .environmentObject(AccountStore(iapService: IAPService()))
}