//
//  TripDetailView.swift
//  SportsTime
//

import SwiftUI
import SwiftData
import MapKit

struct TripDetailView: View {
    @Environment(\.modelContext) private var modelContext

    let trip: Trip
    let games: [UUID: RichGame]

    @State private var selectedDay: ItineraryDay?
    @State private var showExportSheet = false
    @State private var showShareSheet = false
    @State private var exportURL: URL?
    @State private var shareURL: URL?
    @State private var mapCameraPosition: MapCameraPosition = .automatic
    @State private var isSaved = false
    @State private var showSaveConfirmation = false
    @State private var routePolylines: [MKPolyline] = []
    @State private var isLoadingRoutes = false

    private let exportService = ExportService()
    private let dataProvider = AppDataProvider.shared

    var body: some View {
        ScrollView {
            VStack(spacing: 20) {
                // Header
                tripHeader

                // Score Card
                if let score = trip.score {
                    scoreCard(score)
                }

                // Stats
                statsGrid

                // Map Preview
                mapPreview

                // Day-by-Day Itinerary
                itinerarySection
            }
            .padding()
        }
        .navigationTitle(trip.name)
        .navigationBarTitleDisplayMode(.inline)
        .toolbar {
            ToolbarItemGroup(placement: .primaryAction) {
                Button {
                    Task {
                        await shareTrip()
                    }
                } label: {
                    Image(systemName: "square.and.arrow.up")
                }

                Menu {
                    Button {
                        Task {
                            await exportPDF()
                        }
                    } label: {
                        Label("Export PDF", systemImage: "doc.fill")
                    }

                    Button {
                        saveTrip()
                    } label: {
                        Label(isSaved ? "Saved" : "Save Trip", systemImage: isSaved ? "bookmark.fill" : "bookmark")
                    }
                    .disabled(isSaved)
                } label: {
                    Image(systemName: "ellipsis.circle")
                }
            }
        }
        .sheet(isPresented: $showExportSheet) {
            if let url = exportURL {
                ShareSheet(items: [url])
            }
        }
        .sheet(isPresented: $showShareSheet) {
            if let url = shareURL {
                ShareSheet(items: [url])
            } else {
                ShareSheet(items: [trip.name, trip.formattedDateRange])
            }
        }
        .alert("Trip Saved", isPresented: $showSaveConfirmation) {
            Button("OK", role: .cancel) { }
        } message: {
            Text("Your trip has been saved and can be accessed from My Trips.")
        }
        .onAppear {
            checkIfSaved()
        }
    }

    // MARK: - Header

    private var tripHeader: some View {
        VStack(alignment: .leading, spacing: 8) {
            Text(trip.formattedDateRange)
                .font(.subheadline)
                .foregroundStyle(.secondary)

            HStack(spacing: 16) {
                ForEach(Array(trip.uniqueSports), id: \.self) { sport in
                    Label(sport.rawValue, systemImage: sport.iconName)
                        .font(.caption)
                        .padding(.horizontal, 10)
                        .padding(.vertical, 5)
                        .background(Color.blue.opacity(0.1))
                        .clipShape(Capsule())
                }
            }
        }
        .frame(maxWidth: .infinity, alignment: .leading)
    }

    // MARK: - Score Card

    private func scoreCard(_ score: TripScore) -> some View {
        VStack(spacing: 12) {
            HStack {
                Text("Trip Score")
                    .font(.headline)
                Spacer()
                Text(score.scoreGrade)
                    .font(.largeTitle)
                    .fontWeight(.bold)
                    .foregroundStyle(.green)
            }

            HStack(spacing: 20) {
                scoreItem(label: "Games", value: score.gameQualityScore)
                scoreItem(label: "Route", value: score.routeEfficiencyScore)
                scoreItem(label: "Balance", value: score.leisureBalanceScore)
                scoreItem(label: "Prefs", value: score.preferenceAlignmentScore)
            }
        }
        .padding()
        .background(Color(.secondarySystemBackground))
        .clipShape(RoundedRectangle(cornerRadius: 12))
    }

    private func scoreItem(label: String, value: Double) -> some View {
        VStack(spacing: 4) {
            Text(String(format: "%.0f", value))
                .font(.headline)
            Text(label)
                .font(.caption2)
                .foregroundStyle(.secondary)
        }
    }

    // MARK: - Stats Grid

    private var statsGrid: some View {
        LazyVGrid(columns: [
            GridItem(.flexible()),
            GridItem(.flexible()),
            GridItem(.flexible())
        ], spacing: 16) {
            statCell(value: "\(trip.tripDuration)", label: "Days", icon: "calendar")
            statCell(value: "\(trip.stops.count)", label: "Cities", icon: "mappin.circle")
            statCell(value: "\(trip.totalGames)", label: "Games", icon: "sportscourt")
            statCell(value: trip.formattedTotalDistance, label: "Distance", icon: "road.lanes")
            statCell(value: trip.formattedTotalDriving, label: "Driving", icon: "car")
            statCell(value: String(format: "%.1fh", trip.averageDrivingHoursPerDay), label: "Avg/Day", icon: "gauge.medium")
        }
    }

    private func statCell(value: String, label: String, icon: String) -> some View {
        VStack(spacing: 6) {
            Image(systemName: icon)
                .font(.title2)
                .foregroundStyle(.blue)
            Text(value)
                .font(.headline)
            Text(label)
                .font(.caption)
                .foregroundStyle(.secondary)
        }
        .frame(maxWidth: .infinity)
        .padding(.vertical, 12)
        .background(Color(.secondarySystemBackground))
        .clipShape(RoundedRectangle(cornerRadius: 10))
    }

    // MARK: - Map Preview

    private var mapPreview: some View {
        VStack(alignment: .leading, spacing: 8) {
            HStack {
                Text("Route")
                    .font(.headline)
                Spacer()
                if isLoadingRoutes {
                    ProgressView()
                        .scaleEffect(0.7)
                }
            }

            Map(position: $mapCameraPosition) {
                // Add markers for each stop
                ForEach(stopCoordinates.indices, id: \.self) { index in
                    let stop = stopCoordinates[index]
                    Marker(stop.name, coordinate: stop.coordinate)
                        .tint(.blue)
                }

                // Add actual driving route polylines
                ForEach(routePolylines.indices, id: \.self) { index in
                    MapPolyline(routePolylines[index])
                        .stroke(.blue, lineWidth: 3)
                }
            }
            .frame(height: 200)
            .clipShape(RoundedRectangle(cornerRadius: 12))
            .task {
                updateMapRegion()
                await fetchDrivingRoutes()
            }
        }
    }

    /// Fetch actual driving routes using MKDirections
    private func fetchDrivingRoutes() async {
        let stops = stopCoordinates
        guard stops.count >= 2 else { return }

        isLoadingRoutes = true
        var polylines: [MKPolyline] = []

        for i in 0..<(stops.count - 1) {
            let source = stops[i]
            let destination = stops[i + 1]

            let request = MKDirections.Request()
            request.source = MKMapItem(placemark: MKPlacemark(coordinate: source.coordinate))
            request.destination = MKMapItem(placemark: MKPlacemark(coordinate: destination.coordinate))
            request.transportType = .automobile

            let directions = MKDirections(request: request)

            do {
                let response = try await directions.calculate()
                if let route = response.routes.first {
                    polylines.append(route.polyline)
                }
            } catch {
                // Fallback to straight line if directions fail
                print("Failed to get directions from \(source.name) to \(destination.name): \(error)")
                let straightLine = MKPolyline(coordinates: [source.coordinate, destination.coordinate], count: 2)
                polylines.append(straightLine)
            }
        }

        routePolylines = polylines
        isLoadingRoutes = false
    }

    /// Get coordinates for all stops (from stop coordinate or stadium)
    private var stopCoordinates: [(name: String, coordinate: CLLocationCoordinate2D)] {
        trip.stops.compactMap { stop -> (String, CLLocationCoordinate2D)? in
            // First try to use the stop's stored coordinate
            if let coord = stop.coordinate {
                return (stop.city, coord)
            }
            // Fall back to stadium coordinate if available
            if let stadiumId = stop.stadium,
               let stadium = dataProvider.stadium(for: stadiumId) {
                return (stadium.name, stadium.coordinate)
            }
            return nil
        }
    }

    /// Resolved stadiums from trip stops (for markers)
    private var tripStadiums: [Stadium] {
        trip.stops.compactMap { stop in
            guard let stadiumId = stop.stadium else { return nil }
            return dataProvider.stadium(for: stadiumId)
        }
    }

    private func updateMapRegion() {
        guard !stopCoordinates.isEmpty else { return }

        let coordinates = stopCoordinates.map(\.coordinate)
        let lats = coordinates.map(\.latitude)
        let lons = coordinates.map(\.longitude)

        guard let minLat = lats.min(),
              let maxLat = lats.max(),
              let minLon = lons.min(),
              let maxLon = lons.max() else { return }

        let center = CLLocationCoordinate2D(
            latitude: (minLat + maxLat) / 2,
            longitude: (minLon + maxLon) / 2
        )

        // Add padding to the span
        let latSpan = (maxLat - minLat) * 1.3 + 0.5
        let lonSpan = (maxLon - minLon) * 1.3 + 0.5

        mapCameraPosition = .region(MKCoordinateRegion(
            center: center,
            span: MKCoordinateSpan(latitudeDelta: max(latSpan, 1), longitudeDelta: max(lonSpan, 1))
        ))
    }

    // MARK: - Itinerary

    private var itinerarySection: some View {
        VStack(alignment: .leading, spacing: 12) {
            Text("Itinerary")
                .font(.headline)

            ForEach(tripDays, id: \.self) { dayDate in
                SimpleDayCard(
                    dayNumber: dayNumber(for: dayDate),
                    date: dayDate,
                    gamesOnDay: gamesOn(date: dayDate),
                    travelOnDay: travelOn(date: dayDate)
                )
            }
        }
    }

    /// All calendar days in the trip
    private var tripDays: [Date] {
        let calendar = Calendar.current
        guard let startDate = trip.stops.first?.arrivalDate,
              let endDate = trip.stops.last?.departureDate else { return [] }

        var days: [Date] = []
        var current = calendar.startOfDay(for: startDate)
        let end = calendar.startOfDay(for: endDate)

        while current <= end {
            days.append(current)
            current = calendar.date(byAdding: .day, value: 1, to: current)!
        }
        return days
    }

    /// Day number for a given date
    private func dayNumber(for date: Date) -> Int {
        guard let firstDay = tripDays.first else { return 1 }
        let calendar = Calendar.current
        let days = calendar.dateComponents([.day], from: firstDay, to: date).day ?? 0
        return days + 1
    }

    /// Games scheduled on a specific date
    private func gamesOn(date: Date) -> [RichGame] {
        let calendar = Calendar.current
        let dayStart = calendar.startOfDay(for: date)

        // Get all game IDs from all stops
        let allGameIds = trip.stops.flatMap { $0.games }

        return allGameIds.compactMap { games[$0] }.filter { richGame in
            calendar.startOfDay(for: richGame.game.dateTime) == dayStart
        }
    }

    /// Travel segments departing on a specific date
    private func travelOn(date: Date) -> [TravelSegment] {
        let calendar = Calendar.current
        let dayStart = calendar.startOfDay(for: date)

        return trip.travelSegments.filter { segment in
            calendar.startOfDay(for: segment.departureTime) == dayStart
        }
    }

    // MARK: - Actions

    private func exportPDF() async {
        do {
            let url = try await exportService.exportToPDF(trip: trip, games: games)
            exportURL = url
            showExportSheet = true
        } catch {
            print("Failed to export PDF: \(error)")
        }
    }

    private func shareTrip() async {
        shareURL = await exportService.shareTrip(trip)
        showShareSheet = true
    }

    private func saveTrip() {
        guard let savedTrip = SavedTrip.from(trip, status: .planned) else {
            print("Failed to create SavedTrip")
            return
        }

        modelContext.insert(savedTrip)

        do {
            try modelContext.save()
            isSaved = true
            showSaveConfirmation = true
        } catch {
            print("Failed to save trip: \(error)")
        }
    }

    private func checkIfSaved() {
        let tripId = trip.id
        let descriptor = FetchDescriptor<SavedTrip>(
            predicate: #Predicate { $0.id == tripId }
        )

        if let count = try? modelContext.fetchCount(descriptor), count > 0 {
            isSaved = true
        }
    }
}

// MARK: - Simple Day Card (queries games and travel separately by date)

struct SimpleDayCard: View {
    let dayNumber: Int
    let date: Date
    let gamesOnDay: [RichGame]
    let travelOnDay: [TravelSegment]

    private var formattedDate: String {
        let formatter = DateFormatter()
        formatter.dateFormat = "EEEE, MMM d"
        return formatter.string(from: date)
    }

    private var isRestDay: Bool {
        gamesOnDay.isEmpty && travelOnDay.isEmpty
    }

    /// City where games are (from stadium)
    private var gameCity: String? {
        gamesOnDay.first?.stadium.city
    }

    var body: some View {
        VStack(alignment: .leading, spacing: 12) {
            // Day header
            HStack {
                Text("Day \(dayNumber)")
                    .font(.subheadline)
                    .fontWeight(.semibold)
                    .foregroundStyle(.blue)

                Text(formattedDate)
                    .font(.subheadline)
                    .foregroundStyle(.secondary)

                Spacer()

                if isRestDay {
                    Text("Rest Day")
                        .font(.caption)
                        .padding(.horizontal, 8)
                        .padding(.vertical, 3)
                        .background(Color.green.opacity(0.2))
                        .clipShape(Capsule())
                }
            }

            // Games (each as its own row)
            if !gamesOnDay.isEmpty {
                VStack(alignment: .leading, spacing: 6) {
                    // City label
                    if let city = gameCity {
                        Label(city, systemImage: "mappin")
                            .font(.caption)
                            .foregroundStyle(.secondary)
                    }

                    ForEach(gamesOnDay, id: \.game.id) { richGame in
                        HStack {
                            Image(systemName: richGame.game.sport.iconName)
                                .foregroundStyle(.blue)
                                .frame(width: 20)
                            Text(richGame.matchupDescription)
                                .font(.subheadline)
                            Spacer()
                            Text(richGame.game.gameTime)
                                .font(.caption)
                                .foregroundStyle(.secondary)
                        }
                        .padding(.vertical, 6)
                        .padding(.horizontal, 10)
                        .background(Color(.secondarySystemBackground))
                        .clipShape(RoundedRectangle(cornerRadius: 8))
                    }
                }
            }

            // Travel segments (each as its own row, separate from games)
            ForEach(travelOnDay) { segment in
                HStack(spacing: 8) {
                    Image(systemName: segment.travelMode.iconName)
                        .foregroundStyle(.orange)
                        .frame(width: 20)

                    VStack(alignment: .leading, spacing: 2) {
                        Text("Drive to \(segment.toLocation.name)")
                            .font(.subheadline)
                            .fontWeight(.medium)

                        Text("\(segment.formattedDistance) • \(segment.formattedDuration)")
                            .font(.caption)
                            .foregroundStyle(.secondary)
                    }

                    Spacer()
                }
                .padding(.vertical, 8)
                .padding(.horizontal, 10)
                .background(Color.orange.opacity(0.1))
                .clipShape(RoundedRectangle(cornerRadius: 8))
                .overlay(
                    RoundedRectangle(cornerRadius: 8)
                        .stroke(Color.orange.opacity(0.3), lineWidth: 1)
                )
            }
        }
        .padding()
        .background(Color(.secondarySystemBackground))
        .clipShape(RoundedRectangle(cornerRadius: 12))
    }
}

// MARK: - Share Sheet

struct ShareSheet: UIViewControllerRepresentable {
    let items: [Any]

    func makeUIViewController(context: Context) -> UIActivityViewController {
        UIActivityViewController(activityItems: items, applicationActivities: nil)
    }

    func updateUIViewController(_ uiViewController: UIActivityViewController, context: Context) {}
}

#Preview {
    NavigationStack {
        TripDetailView(
            trip: Trip(
                name: "MLB Road Trip",
                preferences: TripPreferences(
                    startLocation: LocationInput(name: "New York"),
                    endLocation: LocationInput(name: "Chicago")
                )
            ),
            games: [:]
        )
    }
}