import SwiftUI
import UIKit

struct SharingFilesPickerView: View {
    @EnvironmentObject var store: AppStore

    var body: some View {
        DocumentPicker(
            completion: { dataArray, extensionsArray in
                store.dispatch(.sharingAction(.showSharing(false)))
                store.dispatch(.sharingAction(.shareDocuments(dataArray, extensionsArray)))
            },
            cancel: {
                store.dispatch(.sharingAction(.showSharing(false)))
            }
        )
    }
}

struct DocumentPicker: UIViewControllerRepresentable {
    let completion: ([Data], [String]) -> Void
    let cancel: () -> Void

    func makeUIViewController(context: UIViewControllerRepresentableContext<DocumentPicker>) -> UIDocumentPickerViewController {
        let picker: UIDocumentPickerViewController
        picker = UIDocumentPickerViewController(forOpeningContentTypes: [.item], asCopy: true)
        picker.delegate = context.coordinator
        picker.allowsMultipleSelection = true
        return picker
    }

    func updateUIViewController(_: UIDocumentPickerViewController, context _: UIViewControllerRepresentableContext<DocumentPicker>) {}

    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }

    class Coordinator: NSObject, UIDocumentPickerDelegate {
        var parent: DocumentPicker

        init(_ parent: DocumentPicker) {
            self.parent = parent
        }

        func documentPicker(_: UIDocumentPickerViewController, didPickDocumentsAt: [URL]) {
            var dataArray = [Data]()
            var extensionArray = [String]()
            for url in didPickDocumentsAt {
                do {
                    let data = try Data(contentsOf: url)
                    dataArray.append(data)
                    extensionArray.append(url.pathExtension)
                } catch {
                    print("Unable to load data from \(url): \(error)")
                }
            }
            parent.completion(dataArray, extensionArray)
        }

        func documentPickerWasCancelled(_: UIDocumentPickerViewController) {
            parent.cancel()
        }
    }
}