fuelboard/FuelBoard/StationDetailView.swift

import SwiftUI
import MapKit
import UIKit

/// DEBUG-only explanation of the Best Value numbers for one station. It carries
/// no precise user coordinates and is never persisted.
struct FuelSavingsJourneyDiagnostics {
    let rows: [(label: String, value: String)]
}

/// Detail sheet for a tapped station (when Settings → Tap station = More info).
/// Shows a small map preview, the address, distance from the current location,
/// and a Directions button that opens Apple Maps — the same destination a direct
/// tap would have opened. The station name lives in the sheet header, not in a
/// row.
struct StationDetailView: View {
    let station: FuelStation
    let location: Coordinate?
    let distanceUnit: DistanceUnit
    var fuelSavings: FuelSavingsAvailability? = nil
    var fuelSavingsAmount: FuelSavingsFillAmount = FuelSavingsSettings.defaultPreferredAmount
    var savingsBaselineStationName: String? = nil
    var journeyDiagnostics: FuelSavingsJourneyDiagnostics? = nil
    /// Whether this station is starred for the fuel currently being viewed, and
    /// the toggle that flips it. Passed from the list that opened the sheet, so
    /// the star here and the star on the row are the same fuel-scoped
    /// favourite and cannot drift apart.
    var isFavourite: Bool = false
    var onToggleFavourite: (() -> Void)? = nil
    @Environment(\.dismiss) private var dismiss
    @State private var showingReportIssueConfirmation = false

    private let reportIssueURL = URL(string: "https://www.gov.uk/guidance/report-an-error-in-fuel-prices-or-forecourt-details")!

    private var stationCoordinate: CLLocationCoordinate2D {
        CLLocationCoordinate2D(latitude: station.lat, longitude: station.lng)
    }

    var body: some View {
        NavigationStack {
            List {
                Section {
                    Map(position: .constant(.region(MKCoordinateRegion(
                        center: stationCoordinate,
                        span: MKCoordinateSpan(latitudeDelta: 0.02, longitudeDelta: 0.02)
                    )))) {
                        Marker(station.name, coordinate: stationCoordinate)
                            .tint(.red)
                    }
                    .frame(height: 180)
                    .clipShape(RoundedRectangle(cornerRadius: 12))
                    .allowsHitTesting(false)
                    .listRowInsets(EdgeInsets())
                }
                Section {
                    // The station name is NOT repeated here: the sheet header
                    // (navigationTitle, inline) already shows it, and the address
                    // line below has any leading repeat of the name stripped, so
                    // a "Name" row only said it twice.
                    LabeledContent("Address", value: StationAddressLine.display(address: station.address,
                                                                             postcode: station.postcode,
                                                                             name: station.name))
                    if let location {
                        let km = FuelStore.displayDistanceKM(
                            station: station, userLat: location.lat, userLng: location.lng
                        )
                        LabeledContent("Distance", value: distanceUnit.format(km))
                            .monospacedDigit()
                    }
                    ForEach(StationNotice.notices(for: station)) { notice in
                        Label(notice.title, systemImage: notice.symbolName)
                            .font(.subheadline.weight(.semibold))
                            .foregroundStyle(.orange)
                            .padding(.horizontal, 10)
                            .padding(.vertical, 6)
                            .background(Capsule().fill(Color.orange.opacity(0.14)))
                    }
                }
                // Only shown while Fuel Savings backs it. `fuelSavings` is nil
                // when the feature is off — `savingsLookup` returns nil when it
                // is not configured — so the heading cannot be left dangling
                // over an empty section.
                if let fuelSavings {
                    Section {
                        FuelSavingsSummaryView(
                            availability: fuelSavings,
                            amount: fuelSavingsAmount,
                            baselineStationName: savingsBaselineStationName,
                            distanceUnit: distanceUnit
                        )
                    } header: {
                        Text("Best Value")
                    }
                }

#if DEBUG
                if let journeyDiagnostics {
                    Section("Best Value Diagnostics") {
                        ForEach(journeyDiagnostics.rows, id: \.label) { row in
                            LabeledContent(row.label, value: row.value)
                                .font(.caption)
                                .monospacedDigit()
                        }
                    }
                }
#endif

                Section {
                    Button {
                        if let url = station.mapsDirectionsURL {
                            UIApplication.shared.open(url)
                        }
                    } label: {
                        Label("Directions", systemImage: "arrow.triangle.turn.up.right.diamond.fill")
                    }
                    Button(role: .destructive) {
                        showingReportIssueConfirmation = true
                    } label: {
                        Label("Report issue", systemImage: "exclamationmark.bubble.fill")
                    }
                }
            }
            .navigationTitle(station.name)
            .navigationBarTitleDisplayMode(.inline)
            .alert("Report an error?", isPresented: $showingReportIssueConfirmation) {
                Button("Cancel", role: .cancel) { }
                Button("Report") {
                    UIApplication.shared.open(reportIssueURL)
                }
            } message: {
                Text("Are you sure you want to report an error in fuel prices or forecourt details? This will open in your chosen browser.")
            }
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("Done") { dismiss() }
                }
                ToolbarItem(placement: .confirmationAction) {
                    Button {
                        onToggleFavourite?()
                    } label: {
                        Image(systemName: isFavourite ? "star.fill" : "star")
                    }
                    .tint(isFavourite ? Color.yellow : nil)
                    .disabled(onToggleFavourite == nil)
                    .accessibilityLabel(
                        isFavourite
                            ? String(localized: "Remove from favourites", comment: "Unstar a station from the More info sheet")
                            : String(localized: "Add to favourites", comment: "Star a station from the More info sheet")
                    )
                }
            }
        }
    }
}