import Foundation
import SwiftUI

/**
 A localized page contains the page content of a single language,
 including the title, url path and required resources

 */
final class LocalizedPage: ObservableObject {

    /**
     The string to use when creating the url for the page.

     Defaults to ``id`` if unset.
     */
    @Published
    var urlString: String

    /**
     The headline to use when showing the entry on it's own page
     */
    @Published
    var title: String

    @Published
    var lastModified: Date?

    /**
     The url used on the old version of the website.

     Needed to redirect links to their new locations.
     */
    let originalUrl: String?

    /**
     All files which occur in the content and are stored.
     - Note: This property defaults to an empty set.
     */
    @Published
    var files: Set<String> = []

    /**
     All files which may occur in the content but are stored externally.

     Missing files which would otherwise produce a warning are ignored when included here.
     - Note: This property defaults to an empty set.
     */
    @Published
    var externalFiles: Set<String> = []

    /**
     Specifies additional files which should be copied to the destination when generating the content.
     - Note: This property defaults to an empty set.
     */
    @Published
    var requiredFiles: Set<String> = []

    @Published
    var linkPreviewImage: String?

    @Published
    var linkPreviewTitle: String?

    @Published
    var linkPreviewDescription: String?

    init(urlString: String,
         title: String,
         lastModified: Date? = nil,
         originalUrl: String? = nil,
         files: Set<String> = [],
         externalFiles: Set<String> = [],
         requiredFiles: Set<String> = [],
         linkPreviewImage: String? = nil,
         linkPreviewTitle: String? = nil,
         linkPreviewDescription: String? = nil) {
        self.urlString = urlString
        self.title = title
        self.lastModified = lastModified
        self.originalUrl = originalUrl
        self.files = files
        self.externalFiles = externalFiles
        self.requiredFiles = requiredFiles
        self.linkPreviewImage = linkPreviewImage
        self.linkPreviewTitle = linkPreviewTitle
        self.linkPreviewDescription = linkPreviewDescription
    }

    @MainActor
    func editableTitle() -> Binding<String> {
        Binding(
            get: {
                self.title
            },
            set: { newValue in
                self.title = newValue
            }
        )
    }
}