import Foundation
import VisionKit // Don't forget to import VisionKit

@objc(DataScannerModule)
class DataScannerModule: NSObject, DataScannerViewControllerDelegate {

    private var scannerViewController: DataScannerViewController?
    private var reactPromiseResolver: RCTPromiseResolveBlock?
    private var reactPromiseRejecter: RCTPromiseRejectBlock?

    @objc
    func presentDataScanner(_ resolve: @escaping RCTPromiseResolveBlock, rejecter reject: @escaping RCTPromiseRejectBlock) {
        DispatchQueue.main.async {
            guard DataScannerViewController.isSupported else {
                reject("UNSUPPORTED", "DataScanner is not supported on this device.", nil)
                return
            }

            self.reactPromiseResolver = resolve
            self.reactPromiseRejecter = reject

            self.scannerViewController = DataScannerViewController(
                recognizedDataTypes: [.text(), .barcode(symbologies: [.aztec, .qr])],
                qualityLevel: .fast,
                recognizesMultipleItems: true,
                isPinchToZoomEnabled: true,
                isGuidanceEnabled: true,
                isHighlightingEnabled: true
            )

            self.scannerViewController?.delegate = self

            if let rootViewController = UIApplication.shared.windows.first?.rootViewController {
                rootViewController.present(self.scannerViewController!, animated: true, completion: nil)
            } else {
                reject("NO_ROOT_VC", "Could not find root view controller.", nil)
            }
        }
    }

    @objc
    func dismissDataScanner(_ resolve: @escaping RCTPromiseResolveBlock, rejecter reject: @escaping RCTPromiseRejectBlock) {
        DispatchQueue.main.async {
            self.scannerViewController?.dismiss(animated: true, completion: {
                self.scannerViewController = nil
                resolve("Dismissed")
            })
        }
    }

    // MARK: - DataScannerViewControllerDelegate

    func dataScanner(_ dataScanner: DataScannerViewController, didAdd addedItems: [DataScannerViewController.RecognizedItem], allItems: [DataScannerViewController.RecognizedItem]) {
        // Process recognized items and send them back to React Native
        var results: [[String: Any]] = []
        for item in addedItems {
            switch item {
            case .text(let text):
                results.append(["type": "text", "value": text.transcript])
            case .barcode(let barcode):
                results.append(["type": "barcode", "value": barcode.payloadStringValue ?? ""])
            @unknown default:
                break
            }
        }
        // You'd likely send updates more frequently, or send all items when the scanner is dismissed.
        // For simplicity, this example just sends added items.
        // You'd use self.reactPromiseResolver to send the data back.
        // Example: self.reactPromiseResolver?(results)
        // Or use RCTEventEmitter for continuous updates.
    }

    func dataScanner(_ dataScanner: DataScannerViewController, didTapOn item: DataScannerViewController.RecognizedItem) {
        // Handle tap if needed
    }

    func dataScanner(_ dataScanner: DataScannerViewController, didRemove removedItems: [DataScannerViewController.RecognizedItem], allItems: [DataScannerViewController.RecognizedItem]) {
        // Handle removal if needed
    }

    func dataScanner(_ dataScanner: DataScannerViewController, didUpdate updatedItems: [DataScannerViewController.RecognizedItem], allItems: [DataScannerViewController.RecognizedItem]) {
        // Handle updates if needed
    }

    func dataScanner(_ dataScanner: DataScannerViewController, didTerminateWithError error: Error) {
        self.reactPromiseRejecter?("SCANNER_ERROR", error.localizedDescription, error)
        self.scannerViewController?.dismiss(animated: true, completion: nil)
        self.scannerViewController = nil
    }
}