//
//  CandidatesView.swift
//  iris
//
//  Created by Codex.
//

import SwiftUI

struct CandidatesView: View {
    @StateObject private var model = CandidatesViewModel()

    var body: some View {
        NavigationStack {
            List {
                Section("Source") {
                    LabeledContent("Location") {
                        Text("London (demo)")
                    }
                    if let updated = model.lastUpdatedAt {
                        LabeledContent("Last update") { Text(timeOnly(from: updated)) }
                    } else {
                        LabeledContent("Last update") { Text("Never") }
                    }
                    if let error = model.lastError {
                        Text(error)
                            .font(.footnote)
                            .foregroundStyle(.secondary)
                    }
                }

                if !model.diagnostics.isEmpty {
                    Section("Diagnostics") {
                        ForEach(model.diagnostics.keys.sorted(), id: \.self) { key in
                            LabeledContent(key) {
                                Text(model.diagnostics[key] ?? "")
                                    .font(.caption)
                                    .foregroundStyle(.secondary)
                                    .textSelection(.enabled)
                            }
                        }
                    }
                }

                Section("Candidates (\(model.candidates.count))") {
                    if model.candidates.isEmpty {
                        Text(model.isLoading ? "Loading…" : "No candidates")
                            .foregroundStyle(.secondary)
                    } else {
                        ForEach(model.candidates, id: \.id) { candidate in
                            CandidateRow(candidate: candidate)
                        }
                    }
                }
            }
            .navigationTitle("Candidates")
            .toolbar {
                ToolbarItem(placement: .topBarTrailing) {
                    Button(model.isLoading ? "Refreshing…" : "Refresh") {
                        model.refresh()
                    }
                    .disabled(model.isLoading)
                }
            }
            .onAppear { model.refresh() }
        }
    }

    private func timeOnly(from date: Date) -> String {
        let formatter = DateFormatter()
        formatter.dateStyle = .none
        formatter.timeStyle = .medium
        return formatter.string(from: date)
    }
}

private struct CandidateRow: View {
    let candidate: Candidate

    var body: some View {
        VStack(alignment: .leading, spacing: 6) {
            HStack(alignment: .firstTextBaseline) {
                Text(candidate.title)
                    .font(.headline)
                    .lineLimit(1)
                Spacer()
                Text(candidate.type.rawValue)
                    .font(.caption)
                    .foregroundStyle(.secondary)
            }
            Text(candidate.subtitle)
                .font(.subheadline)
                .foregroundStyle(.secondary)
                .lineLimit(1)

            HStack(spacing: 12) {
                Text(String(format: "conf %.2f", candidate.confidence))
                Text("ttl \(candidate.ttlSec)s")
                Text(expiresText(now: Int(Date().timeIntervalSince1970)))
            }
            .font(.caption)
            .foregroundStyle(.secondary)
        }
        .padding(.vertical, 4)
    }

    private func expiresText(now: Int) -> String {
        let expiresAt = candidate.createdAt + candidate.ttlSec
        let remaining = expiresAt - now
        if remaining <= 0 { return "expired" }
        if remaining < 60 { return "in \(remaining)s" }
        return "in \(remaining / 60)m"
    }
}

struct CandidatesView_Previews: PreviewProvider {
    static var previews: some View {
        CandidatesView()
    }
}