//
//  CameraView.swift
//  AIGrammar
//
//  Created by oscar on 2024/4/3.
//

import SwiftUI
import UIKit
import Vision

func performOCR(on uiImage: UIImage, completion: @escaping (String) -> Void) {
    guard let cgImage = uiImage.cgImage else { return }
    
    let handler = VNImageRequestHandler(cgImage: cgImage, options: [:])
    let request = VNRecognizeTextRequest { (request, error) in
        guard let observations = request.results as? [VNRecognizedTextObservation] else { return }
        let recognizedStrings = observations.compactMap { $0.topCandidates(1).first?.string }
        completion(recognizedStrings.joined(separator: "\n"))
    }
    request.recognitionLanguages = ["en-US", "zh-Hans"] // 根据需要设置支持的语言
    request.usesLanguageCorrection = true

    do {
        try handler.perform([request])
    } catch {
        print("OCR失败: \(error)")
    }
}



struct CameraView: UIViewControllerRepresentable {
    @Binding var textInput: String
    @Environment(\.presentationMode) var presentationMode
    
    func makeUIViewController(context: Context) -> UIImagePickerController {
        let picker = UIImagePickerController()
        picker.delegate = context.coordinator
        picker.sourceType = .camera
        picker.allowsEditing = true // 启用编辑模式
        return picker
    }
    
    func updateUIViewController(_ uiViewController: UIImagePickerController, context: Context) {}

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

    class Coordinator: NSObject, UINavigationControllerDelegate, UIImagePickerControllerDelegate {
        var parent: CameraView

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

        func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
            // 尝试获取裁剪后的图片
            if let editedImage = info[.editedImage] as? UIImage {
                // 使用裁剪后的图片进行OCR
                performOCR(on: editedImage) { recognizedText in
                    // 更新文本输入
                    self.parent.textInput = recognizedText
                    self.parent.presentationMode.wrappedValue.dismiss()
                }
            } else if let originalImage = info[.originalImage] as? UIImage {
                // 如果用户没有裁剪图片，回退到使用原始图片
                performOCR(on: originalImage) { recognizedText in
                    self.parent.textInput = recognizedText
                    self.parent.presentationMode.wrappedValue.dismiss()
                }
            } else {
                // 如果获取图片失败，直接关闭相机视图
                self.parent.presentationMode.wrappedValue.dismiss()
            }
        }
        
        func imagePickerController2(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
            if let uiImage = info[.originalImage] as? UIImage {
                // 调用OCR处理函数
                performOCR(on: uiImage) { recognizedText in
                    // 更新父视图的文本输入
                    self.parent.textInput = recognizedText
                }
            }
            parent.presentationMode.wrappedValue.dismiss()
        }
    }
}