import SwiftUI
import SwiftData

struct ContentView: View {
    let startupStorageError: String?
    @EnvironmentObject private var automation: BackgroundSyncCoordinator
    @Environment(\.openWindow) private var openWindow
    @State private var selectedJob: SyncJob?
    @State private var section: AppSection = .jobs
    @State private var showingNewJob = false
    @State private var showingSplash = true
    @State private var showingStorageAlert = false

    init(startupStorageError: String? = nil) {
        self.startupStorageError = startupStorageError
    }

    var body: some View {
        ZStack {
            mainContent
                .opacity(showingSplash ? 0 : 1)

            if showingSplash {
                SplashView()
                    .transition(.opacity.combined(with: .scale(scale: 1.01)))
                    .zIndex(10)
            }
        }
        .sheet(isPresented: $showingNewJob) { JobEditorView() }
        .alert("Storage Recovery Mode", isPresented: $showingStorageAlert) {
            Button("OK", role: .cancel) {}
        } message: {
            Text(startupStorageError ?? "Rsync Studio is using temporary storage.")
        }
        .onAppear { showingStorageAlert = startupStorageError != nil }
        .task {
            guard showingSplash else { return }
            try? await Task.sleep(for: .seconds(1.0))
            withAnimation(.easeOut(duration: 0.28)) { showingSplash = false }
        }
    }

    private var mainContent: some View {
        VStack(spacing: 0) {
            sectionHeader
            Divider()

            switch section {
            case .jobs:
                HSplitView {
                    JobListView(selection: $selectedJob, showingNewJob: $showingNewJob)
                        .frame(minWidth: 320, idealWidth: 360, maxWidth: 390)

                    Group {
                        if let selectedJob {
                            JobDetailView(job: selectedJob)
                        } else {
                            emptyJobsView
                        }
                    }
                    .frame(minWidth: 620, maxWidth: .infinity, maxHeight: .infinity)
                }
                .frame(maxWidth: .infinity, maxHeight: .infinity)

            case .calendar:
                ScheduleCalendarView()

            case .history:
                RunHistoryView(onBack: { section = .jobs })
            }
        }
        .background(Color(nsColor: .windowBackgroundColor))
    }

    private var emptyJobsView: some View {
        VStack(spacing: 20) {
            ZStack {
                RoundedRectangle(cornerRadius: 24, style: .continuous)
                    .fill(Color.accentColor.opacity(0.10))
                    .frame(width: 92, height: 92)
                Image(systemName: "arrow.triangle.2.circlepath")
                    .font(.system(size: 42, weight: .medium))
                    .foregroundStyle(Color.accentColor)
            }

            VStack(spacing: 7) {
                Text("Select a Sync Job")
                    .font(.title2.bold())
                Text("Choose a job from the list to review its paths, automation and recent status.")
                    .foregroundStyle(.secondary)
                    .multilineTextAlignment(.center)
                    .frame(maxWidth: 430)
            }

            Button {
                showingNewJob = true
            } label: {
                Label("New Sync Job", systemImage: "plus")
                    .frame(minWidth: 120)
            }
            .buttonStyle(.borderedProminent)
            .controlSize(.large)
        }
        .frame(maxWidth: .infinity, maxHeight: .infinity)
        .padding(40)
    }

    private var sectionHeader: some View {
        HStack(spacing: 18) {
            HStack(spacing: 11) {
                Image(systemName: "arrow.triangle.2.circlepath.circle.fill")
                    .font(.system(size: 27, weight: .medium))
                    .symbolRenderingMode(.hierarchical)
                    .foregroundStyle(Color.accentColor)

                VStack(alignment: .leading, spacing: 1) {
                    Text("Rsync Studio")
                        .font(.headline)
                    Text(section.subtitle)
                        .font(.caption)
                        .foregroundStyle(.secondary)
                }
            }

            Spacer()

            if automation.activity != .idle {
                HStack(spacing: 7) {
                    AnimatedSyncIndicator(size: 18, lineWidth: 2.6)
                    Text(automation.activityDisplayTitle)
                        .font(.caption.weight(.medium))
                        .lineLimit(1)
                }
                .padding(.horizontal, 10)
                .padding(.vertical, 6)
                .background(.thinMaterial, in: Capsule())
            }

            if let serviceError = automation.lastError {
                Image(systemName: "exclamationmark.triangle.fill")
                    .foregroundStyle(Color.orange)
                    .help(serviceError)
                    .accessibilityLabel("Background service error")
            }

            Picker("Section", selection: $section) {
                Label("Jobs", systemImage: "rectangle.stack").tag(AppSection.jobs)
                Label("Calendar", systemImage: "calendar").tag(AppSection.calendar)
                Label("History", systemImage: "clock.arrow.circlepath").tag(AppSection.history)
            }
            .pickerStyle(.segmented)
            .labelsHidden()
            .frame(width: 390)

            Button {
                openWindow(id: "help")
            } label: {
                Label("Help", systemImage: "questionmark.circle")
            }
            .buttonStyle(.bordered)
            .help("Open Rsync Studio Help")
        }
        .padding(.horizontal, 18)
        .frame(height: 70)
        .background(.bar)
    }
}

enum AppSection: Hashable {
    case jobs, calendar, history

    var subtitle: String {
        switch self {
        case .jobs: return "Jobs & Automation"
        case .calendar: return "Schedule Calendar"
        case .history: return "Run History"
        }
    }
}


struct AnimatedSyncIndicator: View {
    let size: CGFloat
    var lineWidth: CGFloat = 7

    @State private var rotation = 0.0
    @State private var pulse = false

    var body: some View {
        ZStack {
            Circle()
                .stroke(Color.accentColor.opacity(0.10), lineWidth: lineWidth)

            Circle()
                .trim(from: 0.05, to: 0.76)
                .stroke(
                    AngularGradient(
                        colors: [
                            Color.accentColor.opacity(0.18),
                            Color.accentColor,
                            Color.accentColor.opacity(0.40)
                        ],
                        center: .center
                    ),
                    style: StrokeStyle(lineWidth: lineWidth, lineCap: .round)
                )
                .rotationEffect(.degrees(rotation))

            Circle()
                .fill(Color.accentColor)
                .frame(width: max(4, lineWidth * 1.05), height: max(4, lineWidth * 1.05))
                .offset(y: -(size / 2))
                .rotationEffect(.degrees(rotation + 18))

            Image(systemName: "arrow.triangle.2.circlepath")
                .font(.system(size: size * 0.31, weight: .semibold))
                .foregroundStyle(Color.accentColor)
                .scaleEffect(pulse ? 1.04 : 0.94)
                .opacity(pulse ? 1 : 0.72)
        }
        .frame(width: size, height: size)
        .onAppear {
            rotation = 0
            pulse = false
            withAnimation(.linear(duration: 1.15).repeatForever(autoreverses: false)) {
                rotation = 360
            }
            withAnimation(.easeInOut(duration: 0.9).repeatForever(autoreverses: true)) {
                pulse = true
            }
        }
    }
}