//
// Copyright 2025 Element Creations Ltd.
// Copyright 2022-2025 New Vector Ltd.
//
// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
// Please see LICENSE files in the repository root for full details.
//

import Compound
import SwiftUI

struct FileRoomTimelineView: View {
    @Environment(\.timelineContext) private var context
    let timelineItem: FileRoomTimelineItem
    
    var body: some View {
        TimelineStyler(timelineItem: timelineItem) {
            MediaFileRoomTimelineContent(filename: timelineItem.content.filename,
                                         fileSize: timelineItem.content.fileSize,
                                         caption: timelineItem.content.caption,
                                         formattedCaption: timelineItem.content.formattedCaption,
                                         trailingReservedSize: timelineItem.trailingReservedSize,
                                         shouldBoost: timelineItem.shouldBoost,
                                         contentScannerService: context?.contentScannerService,
                                         mediaSource: timelineItem.content.source) {
                context?.send(viewAction: .mediaTapped(itemID: timelineItem.id))
            }
            .accessibilityLabel(L10n.commonFile)
        }
    }
}

// MARK: Content

struct MediaFileRoomTimelineContent: View {
    let filename: String
    let fileSize: UInt?
    let caption: String?
    let formattedCaption: AttributedString?
    var trailingReservedSize: CGSize = .zero
    var shouldBoost = false
    var isAudioFile = false
    var contentScannerService: ContentScannerServiceProtocol?
    var mediaSource: MediaSourceProxy?
    
    private var fileDescription: String {
        var fileDescription = "\(filename.validatedFileExtension.uppercased())"
        if let fileSize {
            fileDescription += " (\(fileSize.formatted(.byteCount(style: .file))))"
        }
        return fileDescription
    }
    
    var onMediaTap: (() -> Void)?
    
    private var icon: KeyPath<CompoundIcons, Image> {
        isAudioFile ? \.audio : \.attachment
    }
    
    var body: some View {
        VStack(alignment: .leading, spacing: 8) {
            ContentScanningView(contentScannerService: contentScannerService,
                                mediaSource: mediaSource) {
                if let onMediaTap {
                    filePreview(isScanning: false)
                        .onTapGesture(perform: onMediaTap)
                } else {
                    filePreview(isScanning: false)
                }
            } scanningContent: {
                filePreview(isScanning: true)
            } unsafeContent: { failure in
                ContentScanningFailureView(failure: failure)
            }
            
            if let formattedCaption {
                FormattedBodyText(attributedString: formattedCaption,
                                  trailingReservedSize: trailingReservedSize,
                                  boostFontSize: shouldBoost)
            } else if let caption {
                FormattedBodyText(text: caption,
                                  trailingReservedSize: trailingReservedSize,
                                  boostFontSize: shouldBoost)
            }
        }
    }
    
    func filePreview(isScanning: Bool) -> some View {
        Label {
            VStack(alignment: .leading, spacing: 0) {
                Text(filename)
                    .foregroundStyle(.compound.textPrimary)
                    .font(.compound.bodyLG)
                Text(fileDescription)
                    .font(.compound.bodySM)
                    .foregroundStyle(.compound.textSecondary)
            }
            .font(.compound.bodyLG)
            .foregroundStyle(.compound.textPrimary)
            .lineLimit(2)
        } icon: {
            Group {
                if isScanning {
                    ProgressView()
                        .scaledFrame(size: CompoundIcon.Size.medium.value, relativeTo: .body)
                } else {
                    CompoundIcon(icon, size: .medium, relativeTo: .body)
                        .foregroundColor(.compound.iconPrimary)
                }
            }
            .scaledPadding(6)
            .background(.compound.iconOnSolidPrimary,
                        in: RoundedRectangle(cornerRadius: 4, style: .continuous))
        }
        .labelStyle(.custom(spacing: 8, alignment: .center))
        .padding(.horizontal, 4) // Add to the styler's padding of 8, as we use the default insets for the caption.
    }
}

// MARK: - Previews

struct FileRoomTimelineView_Previews: PreviewProvider, TestablePreview {
    static let viewModel = TimelineViewModel.mock
    static let scanningViewModel = TimelineViewModel.mock(contentScannerService: ContentScannerServiceMock(.init(scanResult: nil)))
    static let unsafeViewModel = TimelineViewModel.mock(contentScannerService: ContentScannerServiceMock(.init(scanResult: false)))
    
    static var previews: some View {
        VStack(spacing: 20.0) {
            FileRoomTimelineView(timelineItem: makeItem(filename: "document.pdf"))
            
            FileRoomTimelineView(timelineItem: makeItem(filename: "document.pdf",
                                                        fileSize: 3 * 1024 * 1024))
            
            FileRoomTimelineView(timelineItem: makeItem(filename: "very very very very long named document.pdf",
                                                        fileSize: 3 * 1024 * 1024))
            
            FileRoomTimelineView(timelineItem: makeItem(filename: "spreadsheet.xlsx",
                                                        fileSize: 17 * 1024,
                                                        caption: "The important figures you asked me to send over."))
            
            FileRoomTimelineView(timelineItem: makeItem(filename: "document.txt",
                                                        fileSize: 456,
                                                        caption: "Plain caption",
                                                        formattedCaption: "Formatted caption"))
        }
        .environmentObject(viewModel.context)
        
        VStack(spacing: 20.0) {
            FileRoomTimelineView(timelineItem: makeItem(filename: "scanning.pdf",
                                                        fileSize: 3 * 1024 * 1024,
                                                        caption: "The file is being scanned."))
                .environmentObject(scanningViewModel.context)
                .environment(\.timelineContext, scanningViewModel.context)
            
            FileRoomTimelineView(timelineItem: makeItem(filename: "unsafe.pdf",
                                                        fileSize: 3 * 1024 * 1024,
                                                        caption: "The file is not safe."))
                .environmentObject(unsafeViewModel.context)
                .environment(\.timelineContext, unsafeViewModel.context)
        }
        .previewDisplayName("Content Scanner")
    }
    
    static func makeItem(filename: String,
                         fileSize: UInt? = nil,
                         caption: String? = nil,
                         formattedCaption: AttributedString? = nil) -> FileRoomTimelineItem {
        .init(id: .randomEvent,
              timestamp: .mock,
              isOutgoing: false,
              isEditable: false,
              canBeRepliedTo: true,
              sender: .init(id: "Bob"),
              content: .init(filename: filename,
                             caption: caption,
                             formattedCaption: formattedCaption,
                             source: try? MediaSourceProxy(url: .mockMXCFile, mimeType: nil),
                             fileSize: fileSize,
                             thumbnailSource: nil,
                             contentType: nil))
    }
}