IceCubesApp/Packages/Status/Sources/Status/Editor/StatusEditorViewModel.swift

import SwiftUI
import DesignSystem
import Models
import Network
import PhotosUI

@MainActor
class StatusEditorViewModel: ObservableObject {
  @Published var statusText = NSAttributedString(string: "") {
    didSet {
      guard !internalUpdate else { return }
      highlightMeta()
    }
  }
  
  @Published var isPosting: Bool = false
  @Published var selectedMedias: [PhotosPickerItem] = [] {
    didSet {
      inflateSelectedMedias()
    }
  }
  @Published var mediasImages: [ImageContainer] = []
  
  struct ImageContainer: Identifiable {
    let id = UUID().uuidString
    let image: UIImage
  }
  
  var client: Client?
  private var internalUpdate: Bool = false
  private var inReplyTo: Status?
  
  let generator = UINotificationFeedbackGenerator()
  
  init(inReplyTo: Status?) {
    self.inReplyTo = inReplyTo
  }
  
  func postStatus() async -> Status? {
    guard let client else { return nil }
    do {
      isPosting = true
      let status: Status = try await client.post(endpoint: Statuses.postStatus(status: statusText.string,
                                                                               inReplyTo: inReplyTo?.id,
                                                                               mediaIds: nil,
                                                                               spoilerText: nil))
      generator.notificationOccurred(.success)
      isPosting = false
      return status
    } catch {
      isPosting = false
      generator.notificationOccurred(.error)
      return nil
    }
  }
  
  func insertReplyTo() {
    if let inReplyTo {
      statusText = .init(string: "@\(inReplyTo.account.acct) ")
    }
  }
  
  func highlightMeta() {
    let mutableString = NSMutableAttributedString(string: statusText.string)
    mutableString.addAttributes([.foregroundColor: UIColor(Color.label)],
                                range: NSMakeRange(0, mutableString.string.utf16.count))
    let hashtagPattern = "(#+[a-zA-Z0-9(_)]{1,})"
    let mentionPattern = "(@+[a-zA-Z0-9(_).]{1,})"
    var ranges: [NSRange] = [NSRange]()

    do {
      let hashtagRegex = try NSRegularExpression(pattern: hashtagPattern, options: [])
      let mentionRegex = try NSRegularExpression(pattern: mentionPattern, options: [])
      
      ranges = hashtagRegex.matches(in: mutableString.string,
                                    options: [],
                                    range: NSMakeRange(0, mutableString.string.utf16.count)).map { $0.range }
      ranges.append(contentsOf: mentionRegex.matches(in: mutableString.string,
                                                     options: [],
                                                     range: NSMakeRange(0, mutableString.string.utf16.count)).map {$0.range})

      for range in ranges {
        mutableString.addAttributes([.foregroundColor: UIColor(Color.brand)],
                                   range: NSRange(location: range.location, length: range.length))
      }
      internalUpdate = true
      statusText = mutableString
      internalUpdate = false
    } catch {
      
    }
  }
  
  func inflateSelectedMedias() {
    for media in selectedMedias {
      media.loadTransferable(type: Data.self) { [weak self] result in
        switch result {
        case .success(let data?):
          if let image = UIImage(data: data) {
            DispatchQueue.main.async {
              self?.mediasImages.append(.init(image: image))
            }
          }
        default:
          break
        }
      }
    }
  }
   
}