Impressia/Vernissage/Views/StatusView.swift

//
//  https://mczachurski.dev
//  Copyright © 2022 Marcin Czachurski and the repository contributors.
//  Licensed under the MIT License.
//

import SwiftUI
import MastodonKit
import AVFoundation

struct StatusView: View {
    @EnvironmentObject var applicationState: ApplicationState
    @EnvironmentObject var routerPath: RouterPath

    @Environment(\.dismiss) private var dismiss

    @State var statusId: String
    @State var imageBlurhash: String?
    @State var highestImageUrl: URL?
    @State var imageWidth: Int32?
    @State var imageHeight: Int32?

    @State private var showImageViewer = false
    @State private var firstLoadFinished = false
    
    @State private var statusViewModel: StatusModel?
    
    @State private var selectedAttachmentId: String?
    @State private var exifCamera: String?
    @State private var exifExposure: String?
    @State private var exifCreatedDate: String?
    @State private var exifLens: String?
        
    var body: some View {
        ScrollView {
            if let statusViewModel = self.statusViewModel {
                VStack (alignment: .leading) {
                    ImagesCarousel(attachments: statusViewModel.mediaAttachments,
                                   selectedAttachmentId: $selectedAttachmentId,
                                   exifCamera: $exifCamera,
                                   exifExposure: $exifExposure,
                                   exifCreatedDate: $exifCreatedDate,
                                   exifLens: $exifLens)
                    .onTapGesture {
                        withoutAnimation {
                            self.showImageViewer.toggle()
                        }
                    }
                    
                    VStack(alignment: .leading) {
                        self.reblogInformation()

                        UsernameRow(accountId: statusViewModel.account.id,
                                    accountAvatar: statusViewModel.account.avatar,
                                    accountDisplayName: statusViewModel.account.displayNameWithoutEmojis,
                                    accountUsername: statusViewModel.account.acct)
                        .onTapGesture {
                            self.routerPath.navigate(to: .userProfile(accountId: statusViewModel.account.id,
                                                                      accountDisplayName: statusViewModel.account.displayNameWithoutEmojis,
                                                                      accountUserName: statusViewModel.account.acct))
                        }
                        
                        MarkdownFormattedText(statusViewModel.content.asMarkdown)
                            .environment(\.openURL, OpenURLAction { url in
                                routerPath.handle(url: url, account: self.applicationState.account)
                            })

                        VStack (alignment: .leading) {
                            if let name = statusViewModel.place?.name, let country = statusViewModel.place?.country {
                                LabelIcon(iconName: "mappin.and.ellipse", value: "\(name), \(country)")
                            }
                            
                            LabelIcon(iconName: "camera", value: self.exifCamera)
                            LabelIcon(iconName: "camera.aperture", value: self.exifLens)
                            LabelIcon(iconName: "timelapse", value: self.exifExposure)
                            LabelIcon(iconName: "calendar", value: self.exifCreatedDate?.toDate(.isoDateTimeSec)?.formatted())
                        }
                        .padding(.bottom, 2)
                        .foregroundColor(.lightGrayColor)
                        
                        HStack {
                            Text("Uploaded")
                            Text(statusViewModel.createdAt.toRelative(.isoDateTimeMilliSec))
                                .padding(.horizontal, -4)
                            if let applicationName = statusViewModel.application?.name {
                                Text("via \(applicationName)")
                            }
                        }
                        .foregroundColor(.lightGrayColor)
                        .font(.footnote)
                        
                        InteractionRow(statusViewModel: statusViewModel)
                            .foregroundColor(.accentColor)
                            .padding(8)
                    }
                    .padding(8)
                                        
                    CommentsSection(statusId: statusViewModel.id)
                }
            } else {
                StatusPlaceholder(imageHeight: self.getImageHeight(), imageBlurhash: self.imageBlurhash)
            }
        }
        .navigationBarTitle("Details")
        .fullScreenCover(isPresented: $showImageViewer, content: {
            if let statusViewModel = self.statusViewModel {
                ImagesViewer(statusViewModel: statusViewModel, selectedAttachmentId: selectedAttachmentId ?? String.empty())
            }
        })
        .task {
            do {
                guard firstLoadFinished == false else {
                    return
                }
                
                // Get status from API.
                if let status = try await StatusService.shared.status(withId: self.statusId, for: self.applicationState.account) {
                    let statusViewModel = StatusModel(status: status)
                                        
                    self.statusViewModel = statusViewModel
                    self.selectedAttachmentId = statusViewModel.mediaAttachments.first?.id ?? String.empty()
                    self.firstLoadFinished = true
                    
                    // If we have status in database then we can update data.
                    if let accountData = self.applicationState.account,
                       let statusDataFromDatabase = StatusDataHandler.shared.getStatusData(accountId: accountData.id, statusId: self.statusId) {
                        _ = try await HomeTimelineService.shared.update(status: statusDataFromDatabase, basedOn: status, for: accountData)
                    }
                }
            } catch NetworkError.notSuccessResponse(let response) {
                if response.statusCode() == HTTPStatusCode.notFound, let accountId = self.applicationState.account?.id {
                    StatusDataHandler.shared.remove(accountId: accountId, statusId: self.statusId)
                    ErrorService.shared.handle(NetworkError.notSuccessResponse(response), message: "Status not existing anymore.", showToastr: true)
                    dismiss()
                }
            }
            catch {
                ErrorService.shared.handle(error, message: "Error during download status from server.", showToastr: !Task.isCancelled)
            }
        }
    }
    
    @ViewBuilder func reblogInformation() -> some View {
        if let reblogStatus = self.statusViewModel?.reblogStatus {
            HStack(alignment: .center, spacing: 4) {
                UserAvatar(accountAvatar: reblogStatus.account.avatar, size: .mini)
                Text(reblogStatus.account.displayNameWithoutEmojis)
                Image(systemName: "paperplane")
                    .padding(.trailing, 8)
            }
            .font(.footnote)
            .foregroundColor(Color.mainTextColor.opacity(0.4))
            .background(Color.mainTextColor.opacity(0.1))
            .clipShape(Capsule())
        }
    }
    
    private func setAttachment(_ attachmentData: AttachmentData) {
        exifCamera = attachmentData.exifCamera
        exifExposure = attachmentData.exifExposure
        exifCreatedDate = attachmentData.exifCreatedDate
        exifLens = attachmentData.exifLens
    }
    
    private func getImageHeight() -> Double {
        if let highestImageUrl = self.highestImageUrl, let imageSize = ImageSizeService.shared.get(for: highestImageUrl) {
            return imageSize.height
        }
        
        if let imageHeight = self.imageHeight, let imageWidth = self.imageWidth, imageHeight > 0 && imageWidth > 0 {
            return self.calculateHeight(width: Double(imageWidth), height: Double(imageHeight))
        }
        
        // If we don't have image height and width in metadata, we have to use some constant height.
        return UIScreen.main.bounds.width * 0.75
    }
    
    private func calculateHeight(width: Double, height: Double) -> CGFloat {
        let divider = width / UIScreen.main.bounds.size.width
        return height / divider
    }
}