//
//  ShareViewController.swift
//  TimeSafariShareExtension
//
//  Created by Aardimus on 11/24/25.
//

import UIKit
import UniformTypeIdentifiers

class ShareViewController: UIViewController {
    
    private let appGroupIdentifier = "group.app.timesafari"
    private let sharedPhotoBase64Key = "sharedPhotoBase64"
    private let sharedPhotoFileNameKey = "sharedPhotoFileName"
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Set a minimal background (transparent or loading indicator)
        view.backgroundColor = .systemBackground
        
        // Process image immediately without showing UI
        processAndOpenApp()
    }
    
    private func processAndOpenApp() {
        // extensionContext is automatically available on UIViewController when used as extension principal class
        guard let context = extensionContext,
              let inputItems = context.inputItems as? [NSExtensionItem] else {
            extensionContext?.completeRequest(returningItems: [], completionHandler: nil)
            return
        }
        
        processSharedImage(from: inputItems) { [weak self] success in
            guard let self = self, let context = self.extensionContext else {
                return
            }
            
            if success {
                // Set flag that shared photo is ready
                self.setSharedPhotoReadyFlag()
                // Open the main app (using minimal URL - app will detect shared data on activation)
                self.openMainApp()
            }
            
            // Complete immediately - no UI shown
            context.completeRequest(returningItems: [], completionHandler: nil)
        }
    }
    
    private func setSharedPhotoReadyFlag() {
        guard let userDefaults = UserDefaults(suiteName: appGroupIdentifier) else {
            return
        }
        userDefaults.set(true, forKey: "sharedPhotoReady")
        userDefaults.synchronize()
    }
    
    private func processSharedImage(from items: [NSExtensionItem], completion: @escaping (Bool) -> Void) {
        // Find the first image attachment
        for item in items {
            guard let attachments = item.attachments else {
                continue
            }
            
            for attachment in attachments {
                if attachment.hasItemConformingToTypeIdentifier(UTType.image.identifier) {
                    attachment.loadItem(forTypeIdentifier: UTType.image.identifier, options: nil) { [weak self] (data, error) in
                        guard let self = self else {
                            completion(false)
                            return
                        }
                        
                        if let error = error {
                            completion(false)
                            return
                        }
                        
                        // Handle different image data types
                        var imageData: Data?
                        var fileName: String = "shared-image.jpg"
                        
                        if let url = data as? URL {
                            // Image provided as file URL
                            imageData = try? Data(contentsOf: url)
                            fileName = url.lastPathComponent
                        } else if let image = data as? UIImage {
                            // Image provided as UIImage
                            imageData = image.jpegData(compressionQuality: 0.9)
                            fileName = "shared-image.jpg"
                        } else if let data = data as? Data {
                            // Image provided as raw Data
                            imageData = data
                            fileName = "shared-image.jpg"
                        }
                        
                        guard let finalImageData = imageData else {
                            completion(false)
                            return
                        }
                        
                        // Convert to base64
                        let base64String = finalImageData.base64EncodedString()
                        
                        // Store in App Group UserDefaults
                        guard let userDefaults = UserDefaults(suiteName: self.appGroupIdentifier) else {
                            completion(false)
                            return
                        }
                        
                        userDefaults.set(base64String, forKey: self.sharedPhotoBase64Key)
                        userDefaults.set(fileName, forKey: self.sharedPhotoFileNameKey)
                        userDefaults.synchronize()
                        
                        completion(true)
                    }
                    return // Process only the first image
                }
            }
        }
        
        // No image found
        completion(false)
    }
    
    private func openMainApp() {
        // Open the main app with minimal URL - app will detect shared data on activation
        guard let url = URL(string: "timesafari://") else {
            return
        }
        
        var responder: UIResponder? = self
        while responder != nil {
            if let application = responder as? UIApplication {
                application.open(url, options: [:], completionHandler: nil)
                return
            }
            responder = responder?.next
        }
        
        // Fallback: use extension context
        extensionContext?.open(url, completionHandler: nil)
    }

}