Kordophone/kordophone2/Transcript/TranscriptDisplayItems.swift

//
//  TranscriptDisplayItems.swift
//  kordophone2
//
//  Created by James Magahern on 8/24/25.
//

import Foundation
import SwiftUI

extension TranscriptView.ViewModel
{
    internal func rebuildDisplayItems(animated: Bool = false) {
        var displayItems: [DisplayItem] = []
        var lastDate: Date = .distantPast
        
        let client = XPCClient()
        let dateAnnotationTimeInterval: TimeInterval = 60 * 60 * 30 // 30m
        for message in messages {
            if message.date.timeIntervalSince(lastDate) > dateAnnotationTimeInterval {
                lastDate = message.date
                displayItems.append(.date(message.date))
            }
            
            for attachment in message.attachments {
                displayItems.append(.attachment(attachment))
                
                if !attachment.isPreviewDownloaded {
                    Task.detached {
                        try await client.downloadAttachment(attachmentId: attachment.id, preview: true)
                    }
                }
            }
            
            displayItems.append(.message(message))
        }
        
        let animation: Animation? = animated ? .default : nil
        withAnimation(animation) {
            self.displayItems = displayItems
        }
    }
}

enum DisplayItem: Identifiable
{
    case message(Display.Message)
    case attachment(Display.ImageAttachment)
    case date(Date)
    
    var id: String {
        switch self {
        case .message(let message):
            message.id
        case .attachment(let attachment):
            attachment.id
        case .date(let date):
            date.description
        }
    }
}