//
//  NCViewerImageCommon.swift
//  Nextcloud
//
//  Created by Marino Faggiana on 04/03/2020.
//  Copyright © 2020 Marino Faggiana. All rights reserved.
//
//  Author Marino Faggiana <marino.faggiana@nextcloud.com>
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
//

import Foundation
import SVGKit

class NCViewerImageCommon: NSObject {
    @objc static let shared: NCViewerImageCommon = {
        let instance = NCViewerImageCommon()
        return instance
    }()
    
    private let appDelegate = UIApplication.shared.delegate as! AppDelegate

    static var offOutlineAudio: UIImage?
    static var offOutlineVideo: UIImage?
    static var offOutlineImage: UIImage?

    override init() {
        NCViewerImageCommon.offOutlineAudio = CCGraphics.changeThemingColorImage(UIImage.init(named: "offOutlineAudio"), width: UIScreen.main.bounds.size.width, height: UIScreen.main.bounds.size.width, color: NCBrandColor.sharedInstance.brandElement)
        NCViewerImageCommon.offOutlineVideo = CCGraphics.changeThemingColorImage(UIImage.init(named: "offOutlineVideo"), width: UIScreen.main.bounds.size.width, height: UIScreen.main.bounds.size.width, color: NCBrandColor.sharedInstance.brandElement)
        NCViewerImageCommon.offOutlineImage = CCGraphics.changeThemingColorImage(UIImage.init(named: "offOutlineImage"), width: UIScreen.main.bounds.size.width, height: UIScreen.main.bounds.size.width, color: NCBrandColor.sharedInstance.brandElement)
    }
    
    func getMetadatasDatasource(metadata: tableMetadata?, mediaDatasorce: Bool, layoutKey: String, completion: @escaping (_ metadatas: [tableMetadata]?) -> Void) {
        guard let metadata = metadata else {
            completion(nil)
            return
        }
        if mediaDatasorce {
            appDelegate.activeMedia.reloadDataSourceWithCompletion { (metadatas) in
                completion(metadatas)
            }
        } else {
            let metadatas = NCManageDatabase.sharedInstance.getMetadatasViewer(predicate: NSPredicate(format: "account == %@ AND serverUrl == %@ AND (typeFile == %@ || typeFile == %@ || typeFile == %@)", metadata.account, metadata.serverUrl, k_metadataTypeFile_image, k_metadataTypeFile_video, k_metadataTypeFile_audio), sorted: NCUtility.shared.getSortedForView(key: layoutKey, serverUrl: metadata.serverUrl), ascending: NCUtility.shared.getAscendingForView(key: layoutKey, serverUrl: metadata.serverUrl))
            completion(metadatas)
        }
    }
    
    func getThumbnailImage(metadata: tableMetadata) -> UIImage? {
        
        if CCUtility.fileProviderStoragePreviewIconExists(metadata.ocId, etag: metadata.etag) {
            let imagePath = CCUtility.getDirectoryProviderStoragePreviewOcId(metadata.ocId, etag: metadata.etag)!
            return UIImage.init(contentsOfFile: imagePath)
        }
        
        return nil
    }
    
    func getImage(metadata: tableMetadata) -> UIImage? {
        
        let ext = CCUtility.getExtension(metadata.fileNameView)
        var image: UIImage?
        
        if CCUtility.fileProviderStorageSize(metadata.ocId, fileNameView: metadata.fileNameView) > 0 && metadata.typeFile == k_metadataTypeFile_image {
           
            let previewPath = CCUtility.getDirectoryProviderStoragePreviewOcId(metadata.ocId, etag: metadata.etag)!
            let imagePath = CCUtility.getDirectoryProviderStorageOcId(metadata.ocId, fileNameView: metadata.fileNameView)!
            
            if ext == "GIF" {
                if !FileManager().fileExists(atPath: previewPath) {
                    CCGraphics.createNewImage(from: metadata.fileNameView, ocId: metadata.ocId, etag: metadata.etag, typeFile: metadata.typeFile)
                }
                image = UIImage.animatedImage(withAnimatedGIFURL: URL(fileURLWithPath: imagePath))
            } else if ext == "SVG" {
                if let svgImage = SVGKImage(contentsOfFile: imagePath) {
                    let scale = svgImage.size.height / svgImage.size.width
                    svgImage.size = CGSize(width: CGFloat(k_sizePreview), height: (CGFloat(k_sizePreview) * scale))
                    if let image = svgImage.uiImage {
                        if !FileManager().fileExists(atPath: previewPath) {
                            do {
                                try image.pngData()?.write(to: URL(fileURLWithPath: previewPath), options: .atomic)
                            } catch { }
                        }
                        return image
                    } else {
                        return nil
                    }
                } else {
                    return nil
                }
            } else {
                if !FileManager().fileExists(atPath: previewPath) {
                    CCGraphics.createNewImage(from: metadata.fileNameView, ocId: metadata.ocId, etag: metadata.etag, typeFile: metadata.typeFile)
                }
                image = UIImage.init(contentsOfFile: imagePath)
            }
            
        } else {
            
            // AUTOMATIC DOWNLOAD FOR GIF
            
            if (ext == "GIF" || ext == "SVG")  && metadata.session == "" {
                NotificationCenter.default.postOnMainThread(name: k_notificationCenter_menuDownloadImage, userInfo: ["metadata": metadata])
            }
        }
        
        return image
    }
    
    func imageChangeSizeView(viewerImageViewController: NCViewerImageViewController?, size: CGSize, metadata: tableMetadata?) {
        guard let viewerImageViewController = viewerImageViewController else { return }
        
        var image: UIImage?
        var contentViewSaved : NCViewerImageContentView?
        for contentView in viewerImageViewController.contentViews {
            if contentView.position == 0 && contentView.isLoading == false {
                image = contentView.image
                contentViewSaved = contentView
                if metadata != nil , let thumbnailImage = self.getThumbnailImage(metadata: metadata!) {
                    contentView.image = thumbnailImage
                } else {
                    contentView.image = nil
                }
            }
        }
        
        DispatchQueue.main.async {
            viewerImageViewController.changeInViewSize(to: size)
            if image != nil {
                contentViewSaved?.image = image
            }
        }
    }

    func getImageOffOutline(frame: CGRect, type: String) -> UIImage {
        
        if type == k_metadataTypeFile_video {
            return NCViewerImageCommon.offOutlineVideo!
        }
        
        if type == k_metadataTypeFile_audio {
            return NCViewerImageCommon.offOutlineAudio!
        }
        
        return NCViewerImageCommon.offOutlineImage!
    }
}