Vorrania/ios/Sources/AssignScanView.swift

import SwiftUI

/// Zuordnen per Scan: erst ein Einzelstück (…/i/<UID>) scannen, dann einen
/// Lagerort (…/l/<ID>) – das Stück wird dem Ort zugewiesen. Danach gleich das
/// nächste Stück, ohne Tippen.
struct AssignScanView: View {
    @Environment(\.dismiss) private var dismiss

    @State private var paused = false
    @State private var torchOn = false
    @State private var torchLocked = false
    @State private var pending: Item?          // gescanntes Stück, wartet auf Ort
    @State private var status: String?
    @State private var error: String?

    var body: some View {
        ScrollView {
            VStack(spacing: 14) {
                ScannerView(onCode: { code in Task { await handle(code) } },
                            isPaused: $paused, torchOn: $torchOn, torchLocked: $torchLocked)
                    .aspectRatio(4.0 / 3.0, contentMode: .fit)
                    .clipShape(RoundedRectangle(cornerRadius: 16))
                    .padding(.horizontal)

                if let pending {
                    VStack(spacing: 4) {
                        Text("Einzelstück \(pending.uid)").font(.headline)
                        Text("Jetzt den Lagerort-QR scannen")
                            .font(.caption).foregroundStyle(.secondary)
                        Button("Abbrechen") { self.pending = nil }
                            .font(.caption).padding(.top, 2)
                    }
                    .padding().frame(maxWidth: .infinity)
                    .background(Color.accentColor.opacity(0.15))
                    .clipShape(RoundedRectangle(cornerRadius: 12)).padding(.horizontal)
                } else {
                    Text("Schritt 1: Einzelstück-QR scannen")
                        .font(.caption).foregroundStyle(.secondary)
                }

                if let status {
                    Text(status).font(.callout).foregroundStyle(.green)
                        .frame(maxWidth: .infinity, alignment: .leading).padding(.horizontal)
                }
                if let error {
                    Text(error).font(.callout).foregroundStyle(.red)
                        .frame(maxWidth: .infinity, alignment: .leading).padding(.horizontal)
                }
            }
            .padding(.vertical)
        }
        .navigationTitle("Ort zuordnen")
        .navigationBarTitleDisplayMode(.inline)
        .toolbar {
            ToolbarItem(placement: .topBarLeading) { Button("Fertig") { dismiss() } }
            ToolbarItem(placement: .topBarTrailing) { TorchButton(isOn: $torchOn, locked: $torchLocked) }
        }
    }

    private func handle(_ code: String) async {
        // Lagerort-QR (…/l/<ID>)?
        if let r = code.range(of: "/l/") {
            let idStr = String(code[r.upperBound...])
                .trimmingCharacters(in: CharacterSet(charactersIn: "/ "))
            if let locId = Int(idStr) {
                guard let it = pending else {
                    error = "Erst ein Einzelstück scannen."; status = nil; return
                }
                do {
                    _ = try await APIClient.shared.updateItem(id: it.id, ItemUpdateRequest(
                        locationId: locId, shopId: it.shopId,
                        acquiredOn: it.acquiredOn, warrantyUntil: it.warrantyUntil, note: it.note))
                    status = "\(it.uid) zugeordnet. Nächstes Stück scannen."
                    error = nil
                    pending = nil
                } catch { self.error = error.localizedDescription }
                return
            }
        }
        // Einzelstück-QR (…/i/<UID>)?
        if let r = code.range(of: "/i/") {
            let uid = String(code[r.upperBound...])
                .trimmingCharacters(in: CharacterSet(charactersIn: "/ ")).uppercased()
            if !uid.isEmpty, let it = try? await APIClient.shared.itemByUid(uid: uid) {
                pending = it; status = nil; error = nil
                return
            }
        }
        error = "Unbekannter Code – bitte einen Einzelstück- oder Lagerort-QR scannen."
    }
}