//Made by Lumaa

import Foundation
import SwiftUI
import UIKit
import PhotosUI

public actor Compressor {
    public init() { }
    
    enum CompressorError: Error {
        case noData
    }
    
    public func compressImageFrom(url: URL) async -> Data? {
        await withCheckedContinuation { continuation in
            let sourceOptions = [kCGImageSourceShouldCache: false] as CFDictionary
            guard let source = CGImageSourceCreateWithURL(url as CFURL, sourceOptions) else {
                continuation.resume(returning: nil)
                return
            }
            
            let maxPixelSize: Int = if Bundle.main.bundlePath.hasSuffix(".appex") {
                1536
            } else {
                4096
            }
            
            let downsampleOptions = [
                kCGImageSourceCreateThumbnailFromImageAlways: true,
                kCGImageSourceCreateThumbnailWithTransform: true,
                kCGImageSourceThumbnailMaxPixelSize: maxPixelSize,
            ] as [CFString: Any] as CFDictionary
            
            guard let cgImage = CGImageSourceCreateThumbnailAtIndex(source, 0, downsampleOptions) else {
                continuation.resume(returning: nil)
                return
            }
            
            let data = NSMutableData()
            guard let imageDestination = CGImageDestinationCreateWithData(data, UTType.jpeg.identifier as CFString, 1, nil) else {
                continuation.resume(returning: nil)
                return
            }
            
            let isPNG: Bool = {
                guard let utType = cgImage.utType else { return false }
                return (utType as String) == UTType.png.identifier
            }()
            
            let destinationProperties = [
                kCGImageDestinationLossyCompressionQuality: isPNG ? 1.0 : 0.75,
            ] as CFDictionary
            
            CGImageDestinationAddImage(imageDestination, cgImage, destinationProperties)
            CGImageDestinationFinalize(imageDestination)
            
            continuation.resume(returning: data as Data)
        }
    }
    
    public func compressImageForUpload(_ image: UIImage) async throws -> Data {
        var image = image
        if image.size.height > 5000 || image.size.width > 5000 {
            image = image.resized(to: .init(width: image.size.width / 4,
                                            height: image.size.height / 4))
        }
        
        guard var imageData = image.jpegData(compressionQuality: 0.8) else {
            throw CompressorError.noData
        }
        
        let maxSize = 10 * 1024 * 1024
        
        if imageData.count > maxSize {
            while imageData.count > maxSize {
                guard let compressedImage = UIImage(data: imageData),
                      let compressedData = compressedImage.jpegData(compressionQuality: 0.8)
                else {
                    throw CompressorError.noData
                }
                imageData = compressedData
            }
        }
        
        return imageData
    }
    
    func compressVideo(_ url: URL) async -> URL? {
        await withCheckedContinuation { continuation in
            let urlAsset = AVURLAsset(url: url, options: nil)
            let presetName: String = if Bundle.main.bundlePath.hasSuffix(".appex") {
                AVAssetExportPreset1280x720
            } else {
                AVAssetExportPreset1920x1080
            }
            guard let exportSession = AVAssetExportSession(asset: urlAsset, presetName: presetName) else {
                continuation.resume(returning: nil)
                return
            }
            let outputURL = URL.temporaryDirectory.appending(path: "\(UUID().uuidString).\(url.pathExtension)")
            exportSession.outputURL = outputURL
            exportSession.outputFileType = .mp4
            exportSession.shouldOptimizeForNetworkUse = true
            exportSession.exportAsynchronously { () in
                continuation.resume(returning: outputURL)
            }
        }
    }
    }