import SwiftUI

/// A single anonymous encounter in the feed.
///
/// Until mutual consent, the other person is a **silhouette** — a shape, not
/// a profile. This visual language is the privacy promise made visible: you
/// know a human was here, but you don't know who until they choose to be seen.
struct SilhouetteRow: View {
    let encounter: Encounter
    /// Called when the user taps "Wave" on a silhouette.
    var onWave: () -> Void

    var body: some View {
        HStack(spacing: 16) {
            // Silhouette avatar — deliberately anonymous.
            ZStack {
                Circle()
                    .fill(Color.gray.opacity(0.25))
                    .frame(width: 48, height: 48)
                Image(systemName: "person.fill")
                    .foregroundColor(.gray)
            }

            VStack(alignment: .leading, spacing: 4) {
                Text(title)
                    .font(.headline)
                Text(subtitle)
                    .font(.caption)
                    .foregroundColor(.secondary)
            }

            Spacer()

            // Action depends on status.
            switch encounter.status {
            case .silhouette:
                Button("Wave", action: onWave)
                    .buttonStyle(.borderedProminent)
                    .tint(.green)
            case .waved:
                Text("Waved ✓")
                    .font(.caption)
                    .foregroundColor(.green)
            case .mutual:
                Image(systemName: "checkmark.circle.fill")
                    .foregroundColor(.green)
            case .declined:
                Image(systemName: "xmark.circle.fill")
                    .foregroundColor(.red)
            }
        }
        .padding()
        .background(
            RoundedRectangle(cornerRadius: 16)
                .fill(Color(.secondarySystemBackground))
        )
    }

    private var title: String {
        switch encounter.status {
        case .mutual:
            return "Connected"
        default:
            return "Someone nearby"
        }
    }

    private var subtitle: String {
        var parts: [String] = [encounter.tier.title]
        if let place = encounter.placeHint { parts.append(place) }
        parts.append(encounter.timestamp.formatted(.relative(presentation: .named)))
        return parts.joined(separator: " · ")
    }
}