//
//  MP_DownloadManager.swift
//  MusicPlayer
//
//  Created by 忆海16 on 2024/5/14.
//

import Foundation
import Foundation
import Tiercel
class DownloadManager: NSObject {
    static let shared = DownloadManager()

    var session: SessionManager!
    var progressHandlers: [URL: (CGFloat) -> Void] = [:]
    var completionHandlers: [URL: (Result<MPPositive_SongItemModel, Error>) -> Void] = [:]
    var downloadTasks: [URL: URLSessionDownloadTask] = [:]
    var progressStorage: [URL: CGFloat] = [:] // 新增进度存储
    var songHandlers:[URL: MPPositive_SongItemModel] = [:]
    private override init() {
        super.init()
        var configuration = SessionConfiguration()
        configuration.timeoutIntervalForRequest = 60
        configuration.maxConcurrentTasksLimit = 6
        configuration.allowsCellularAccess = true
        session = SessionManager("com.yourApp.backgroundDownload", configuration: configuration)
    }
    func downloadVideo(from url: URL, song:MPPositive_SongItemModel, progressHandler: @escaping (CGFloat) -> Void, completion: @escaping (Result<MPPositive_SongItemModel, Error>) -> Void) {
        progressHandlers[url] = progressHandler
        completionHandlers[url] = completion
        songHandlers[url] = song
        let downloadTask = session.download(url, headers: ["Accept-Encoding": "gzip, deflate"])
        //配置进度条
        downloadTask?.progress(handler: { [weak self] (task) in
            guard let self = self else {return}
            progressHandlers[task.url]?(task.progress.fractionCompleted)
            progressStorage[task.url] = task.progress.fractionCompleted
        })
        //配置任务完成事件
        downloadTask?.success(handler: { [weak self] (task) in
            guard let self = self else {return}
            //任务下载成功,进行文件转移
            let originalURL = task.url
            //任务下载地址
            let filePathUrl:URL = URL(fileURLWithPath: task.filePath)
            print("任务下载地址:\(filePathUrl)")
            let downloadsURL = DocumentsURL.appendingPathComponent("Downloads")
            if !FileManager.default.fileExists(atPath: downloadsURL.path) {
                do {
                    try FileManager.default.createDirectory(at: downloadsURL, withIntermediateDirectories: true, attributes: nil)
                } catch {
                    completionHandlers[originalURL]?(.failure(error))
                    return
                }
            }

            let fileURL = downloadsURL.appendingPathComponent("\(MP_PlayerManager.shared.loadPlayer.currentVideo.song.videoId ?? "").mp4")
            do {
                try FileManager.default.moveItem(at: filePathUrl, to: fileURL)
                //回调VideoID
                completionHandlers[originalURL]?(.success(songHandlers[originalURL]!))
                progressStorage[originalURL] = nil // 清除已完成任务的进度记录
            } catch {
                completionHandlers[originalURL]?(.failure(error))
            }
        }).failure(handler: {  [weak self] (task) in
            guard let self = self else {return}
            //任务下载失败
            let originalURL = task.url
            if let error = task.error {
                completionHandlers[originalURL]?(.failure(error))
            }
        })
    }
    func getProgress(for url: URL) -> CGFloat? {
        return progressStorage[url]
    }
    func cancelAllTasksIfNeeded() {
        // 根据需求，取消所有任务，或者根据任务状态进行过滤
        for key in progressStorage.keys {
            session.cancel(key)
        }
    }
    //删除下载文件
    func deleteFileDocuments(_ videoId:String, completion:@escaping((String) -> Void)) {
        let downloadsURL = DocumentsURL.appendingPathComponent("Downloads")
        let fileURL = downloadsURL.appendingPathComponent("\(videoId).mp4")
        if FileManager.default.fileExists(atPath: fileURL.absoluteString) {
            do{
                try FileManager.default.removeItem(at: fileURL)
                //文件删除成功
                completion(videoId)
            }catch{
                print("删除文件时发生错误：\(error)")
            }
        }else {
            print("文件不存在")
        }
    }
}




//class DownloadManager {
//
//    static let shared = DownloadManager()
//
//    private init() {}
//
//    func downloadVideo(from url: URL, videoId: String, progressView: CircularProgressView, completion: @escaping (Result<URL, Error>) -> Void) {
//        let destination: DownloadRequest.Destination = { _, _ in
//            let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
//            let downloadsURL = documentsURL.appendingPathComponent("Downloads")
//
//            // 检查并创建 Downloads 文件夹
//            if !FileManager.default.fileExists(atPath: downloadsURL.path) {
//                do {
//                    try FileManager.default.createDirectory(at: downloadsURL, withIntermediateDirectories: true, attributes: nil)
//                } catch {
//                    completion(.failure(error))
//                    return (downloadsURL, [.removePreviousFile, .createIntermediateDirectories])
//                }
//            }
//
//            let fileURL = downloadsURL.appendingPathComponent("\(videoId).mp4")
//            return (fileURL, [.removePreviousFile, .createIntermediateDirectories])
//        }
//
//        AF.download(url, to: destination).downloadProgress { progress in
//            progressView.setProgress(to: CGFloat(progress.fractionCompleted))
//        }.response { response in
//            if let error = response.error {
//                completion(.failure(error))
//            } else if let filePath = response.fileURL {
//                completion(.success(filePath))
//            }
//        }
//    }
//}